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Knutie SA, Webster CN, Vaziri GJ, Albert L, Harvey JA, LaRue M, Verrett TB, Soldo A, Koop JAH, Chaves JA, Wegrzyn JL. Urban living can rescue Darwin's finches from the lethal effects of invasive vampire flies. GLOBAL CHANGE BIOLOGY 2024; 30:e17145. [PMID: 38273516 DOI: 10.1111/gcb.17145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 12/15/2023] [Accepted: 12/21/2023] [Indexed: 01/27/2024]
Abstract
Human activity changes multiple factors in the environment, which can have positive or negative synergistic effects on organisms. However, few studies have explored the causal effects of multiple anthropogenic factors, such as urbanization and invasive species, on animals and the mechanisms that mediate these interactions. This study examines the influence of urbanization on the detrimental effect of invasive avian vampire flies (Philornis downsi) on endemic Darwin's finches in the Galápagos Islands. We experimentally manipulated nest fly abundance in urban and non-urban locations and then characterized nestling health, fledging success, diet, and gene expression patterns related to host defense. Fledging success of non-parasitized nestlings from urban (79%) and non-urban (75%) nests did not differ significantly. However, parasitized, non-urban nestlings lost more blood, and fewer nestlings survived (8%) compared to urban nestlings (50%). Stable isotopic values (δ15 N) from urban nestling feces were higher than those from non-urban nestlings, suggesting that urban nestlings are consuming more protein. δ15 N values correlated negatively with parasite abundance, which suggests that diet might influence host defenses (e.g., tolerance and resistance). Parasitized, urban nestlings differentially expressed genes within pathways associated with red blood cell production (tolerance) and pro-inflammatory response (innate immunological resistance), compared to parasitized, non-urban nestlings. In contrast, parasitized non-urban nestlings differentially expressed genes within pathways associated with immunoglobulin production (adaptive immunological resistance). Our results suggest that urban nestlings are investing more in pro-inflammatory responses to resist parasites but also recovering more blood cells to tolerate blood loss. Although non-urban nestlings are mounting an adaptive immune response, it is likely a last effort by the immune system rather than an effective defense against avian vampire flies since few nestlings survived.
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Affiliation(s)
- Sarah A Knutie
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, USA
- Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, USA
| | - Cynthia N Webster
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Grace J Vaziri
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Lauren Albert
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Johanna A Harvey
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, USA
- Department of Science and Technology, University of Maryland, College Park, Maryland, USA
| | - Michelle LaRue
- School of Earth and Environment, University of Canterbury, Christchurch, New Zealand
| | - Taylor B Verrett
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Alexandria Soldo
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Jennifer A H Koop
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Jaime A Chaves
- Department of Biology, San Francisco State University, San Francisco, California, USA
- Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador
| | - Jill L Wegrzyn
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, USA
- Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, USA
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2
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Solomon G, Love AC, Vaziri GJ, Harvey J, Verrett T, Chernicky K, Simons S, Albert L, Chaves JA, Knutie SA. Effect of urbanization and parasitism on the gut microbiota of Darwin's finch nestlings. Mol Ecol 2023; 32:6059-6069. [PMID: 37837269 DOI: 10.1111/mec.17164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 09/20/2023] [Accepted: 10/02/2023] [Indexed: 10/15/2023]
Abstract
Host-associated microbiota can be affected by factors related to environmental change, such as urbanization and invasive species. For example, urban areas often affect food availability for animals, which can change their gut microbiota. Invasive parasites can also influence microbiota through competition or indirectly through a change in the host immune response. These interacting factors can have complex effects on host fitness, but few studies have disentangled the relationship between urbanization and parasitism on an organism's gut microbiota. To address this gap in knowledge, we investigated the effects of urbanization and parasitism by the invasive avian vampire fly (Philornis downsi) on the gut microbiota of nestling small ground finches (Geospiza fuliginosa) on San Cristóbal Island, Galápagos. We conducted a factorial study in which we experimentally manipulated parasite presence in an urban and nonurban area. Faeces were then collected from nestlings to characterize the gut microbiota (i.e. bacterial diversity and community composition). Although we did not find an interactive effect of urbanization and parasitism on the microbiota, we did find main effects of each variable. We found that urban nestlings had lower bacterial diversity and different relative abundances of taxa compared to nonurban nestlings, which could be mediated by introduction of the microbiota of the food items or changes in host physiology. Additionally, parasitized nestlings had lower bacterial richness than nonparasitized nestlings, which could be mediated by a change in the immune system. Overall, this study advances our understanding of the complex effects of anthropogenic stressors on the gut microbiota of birds.
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Affiliation(s)
- Gabrielle Solomon
- Department of Ecology and Evolutionary Biology, University of Connecticut, Connecticut, Storrs, USA
| | - Ashley C Love
- Department of Ecology and Evolutionary Biology, University of Connecticut, Connecticut, Storrs, USA
| | - Grace J Vaziri
- Department of Ecology and Evolutionary Biology, University of Connecticut, Connecticut, Storrs, USA
| | - Johanna Harvey
- Department of Ecology and Evolutionary Biology, University of Connecticut, Connecticut, Storrs, USA
| | - Taylor Verrett
- Department of Ecology and Evolutionary Biology, University of Connecticut, Connecticut, Storrs, USA
| | - Kiley Chernicky
- Department of Ecology and Evolutionary Biology, University of Connecticut, Connecticut, Storrs, USA
| | - Shelby Simons
- Department of Ecology and Evolutionary Biology, University of Connecticut, Connecticut, Storrs, USA
| | - Lauren Albert
- Department of Ecology and Evolutionary Biology, University of Connecticut, Connecticut, Storrs, USA
| | - Jaime A Chaves
- Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador
- Galapagos Science Center, Puerto Baquerizo Moreno, Galapagos, Ecuador
- Department of Biology, San Francisco State University, California, San Francisco, USA
| | - Sarah A Knutie
- Department of Ecology and Evolutionary Biology, University of Connecticut, Connecticut, Storrs, USA
- Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador
- Institute for Systems Genomics, University of Connecticut, Connecticut, Storrs, USA
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3
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Sinclair BJ. An annotated checklist of the Diptera of the Galápagos Archipelago (Ecuador). Zootaxa 2023; 5283:1-102. [PMID: 37518751 DOI: 10.11646/zootaxa.5283.1.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Indexed: 08/01/2023]
Abstract
The Diptera fauna of the Galápagos Archipelago is updated and an annotated checklist is presented. Currently 50 families, 207 genera, and a minimum of 324 species are recorded from the islands. Approximately 107 species are considered to have arrived on the Galápagos Islands through human introductions, an estimated 101 species are considered endemic, 42 species have naturally colonized the islands from mainland Americas, 21 species are either introduced or arrived naturally and 53 species remain unidentified. The following new combination is proposed: Chrysanthrax primitivus (Walker) is moved to Hemipenthes Loew as H. primitivus (Walker) comb. nov. All references to the Galápagos taxonomic literature are included, known island species distributions listed and general remarks on the biology of many species are provided.
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Affiliation(s)
- Bradley J Sinclair
- Canadian Food Inspection Agency; K.W. Neatby Bldg.; C.E.F.; 960 Carling Ave.; Ottawa; ON; Canada K1A 0C6; Canadian National Collection of Insects; Arachnids and Nematodes; Agriculture and Agri-Food Canada; K.W. Neatby Bldg.; C.E.F.; 960 Carling Ave.; Ottawa; ON; Canada K1A 0C6.
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Li X, Cai X, Ding S, Wang L, Li W, Liu X, Zhang C, Yang D. Phylogeny and Evolutionary Timescale of Muscidae (Diptera: Calyptratae) Inferred from Mitochondrial Genomes. INSECTS 2023; 14:286. [PMID: 36975971 PMCID: PMC10059281 DOI: 10.3390/insects14030286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/10/2023] [Accepted: 03/12/2023] [Indexed: 06/18/2023]
Abstract
House flies (Muscidae) comprise the most species-rich family of the muscoid grade with over 5000 described species worldwide, and they are abundant in various terrestrial and aquatic ecosystems. The high number of species, varied appearances, complex feeding habits, and wide distributions have hindered researchers from understanding their phylogeny and evolutionary history. Here, we newly sequenced fifteen mitochondrial genomes and reconstructed the phylogenetic relationships and divergence time among eight subfamilies of Muscidae (Diptera). The best phylogenetic tree, which was inferred by IQ-Tree, recovered the monophyly for seven out of eight subfamilies (except for Mydaeinae). Based on phylogenetic analyses and morphological characteristics, we prefer the subfamily status of Azeliinae and Reinwardtiinae, and separate Stomoxyinae from Muscinae. Genus Helina Robineau-Desvoidy, 1830 was synonymized with Phaonia Robineau-Desvoidy, 1830. The divergence time estimation indicated Muscidae originated at 51.59 Ma (early Eocene). Most subfamilies had originated around 41 Ma. We provided a mtgenomic viewpoint on the phylogenetic relationships and divergence time estimation of Muscidae.
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Affiliation(s)
- Xin Li
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Xiaodong Cai
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Shuangmei Ding
- The Institute of Scientific and Technical Research on Archives, National Archives Administration of China, Beijing 100050, China
| | - Liang Wang
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Wenliang Li
- College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang 471023, China
| | - Xiaoyan Liu
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Chuntian Zhang
- College of Life Science, Shenyang Normal University, Shenyang 110034, China
| | - Ding Yang
- College of Plant Protection, China Agricultural University, Beijing 100193, China
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Pike CL, Kofler B, Richner H, Tebbich S. Parental food provisioning and nestling growth under Philornis downsi parasitism in the Galapagos Green Warbler-Finch, classified as 'vulnerable' by the IUCN. JOURNAL OF ORNITHOLOGY 2023; 164:669-676. [PMID: 37205902 PMCID: PMC10188583 DOI: 10.1007/s10336-023-02049-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 01/31/2023] [Accepted: 02/04/2023] [Indexed: 05/21/2023]
Abstract
In the Galapagos Islands, many endemic landbird populations are declining due to habitat degradation, food availability, introduced species and other factors. Given nestlings typically lack efficient defense mechanisms against parasites, hematophagous ectoparasites such as the larvae of the introduced Avian Vampire Fly, Philornis downsi, can impose high brood mortality and cause threatening population declines in Darwin finches and other landbirds. Here, we assess whether the food compensation hypothesis (i.e., the parents' potential to compensate for deleterious parasite effects via increased food provisioning) applies to the Green Warbler-Finch. We differentiated nests with low or high infestation levels by P. downsi and quantified food provisioning rates of male and female parents, time females spent brooding nestlings, and nestling growth. Male provisioning rates, total provisioning rates and female brooding time did not significantly vary in relation to infestation levels, nor by the number of nestlings. Opposed to the predictions of the food compensation hypothesis, females showed significantly reduced provisioning rates at high infestation levels. Nestling body mass was significantly lower and there was a reduction of skeletal growth, although not significantly, in highly infested nests. The females' response to high infestation may be due to parasites directly attacking and weakening brooding females, or else that females actively reduce current reproductive effort in favor of future reproduction. This life-history trade-off may be typical for Darwin finches and many tropical birds with long lifespans and therefore high residual reproductive value. Conservation strategies may not build on the potential for parental food compensation by this species.
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Affiliation(s)
- Courtney L. Pike
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Vienna Austria
| | - Barbara Kofler
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Vienna Austria
| | - Heinz Richner
- Department of Biology, University of Bern, Bern, Bern Switzerland
| | - Sabine Tebbich
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Vienna Austria
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6
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Common LK, Kleindorfer S, Colombelli-Négrel D, Dudaniec RY. Genetics reveals shifts in reproductive behaviour of the invasive bird parasite Philornis downsi collected from Darwin’s finch nests. Biol Invasions 2022. [DOI: 10.1007/s10530-022-02935-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
AbstractDue to novel or dynamic fluctuations in environmental conditions and resources, host and parasite relationships can be subject to diverse selection pressures that may lead to significant changes during and after invasion of a parasite. Genomic analyses are useful for elucidating evolutionary processes in invasive parasites following their arrival to a new area and host. Philornis downsi (Diptera: Muscidae), the avian vampire fly, was introduced to the Galápagos Islands circa 1964 and has since spread across the archipelago, feeding on the blood of developing nestlings of endemic land birds. Since its discovery, there have been significant changes to the dynamics of P. downsi and its novel hosts, such as shifting mortality rates and changing oviposition behaviour, however no temporal genetic studies have been conducted. We collected P. downsi from nests and traps from a single island population over a 14-year period, and genotyped flies at 469 single nucleotide polymorphisms (SNPs) using restriction-site associated DNA sequencing (RADSeq). Despite significant genetic differentiation (FST) between years, there was no evidence for genetic clustering within or across four sampling years between 2006 and 2020, suggesting a lack of population isolation. Sibship reconstructions from P. downsi collected from 10 Darwin’s finch nests sampled in 2020 showed evidence for shifts in reproductive behaviour compared to a similar genetic analysis conducted in 2004–2006. Compared with this previous study, females mated with fewer males, individual females oviposited fewer offspring per nest, but more unique females oviposited per nest. These findings are important to consider within reproductive control techniques, and have fitness implications for both parasite evolution and host fitness.
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Kleindorfer S, Colombelli‐Négrel D, Common LK, O’Connor JA, Peters KJ, Katsis AC, Dudaniec RY, Sulloway FJ, Adreani NM. Functional traits and foraging behaviour: avian vampire fly larvae change the beak and fitness of their Darwin’s finch hosts. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Sonia Kleindorfer
- College of Science and Engineering Flinders University Adelaide Australia
- Konrad Lorenz Research Center for Behavior and Cognition and Department of Behavioral and Cognitive Biology University of Vienna Vienna Austria
| | | | - Lauren K. Common
- College of Science and Engineering Flinders University Adelaide Australia
| | | | - Katharina J. Peters
- College of Science and Engineering Flinders University Adelaide Australia
- Evolutionary Genetics Group, Department of Anthropology University of Zurich Zurich Switzerland
- School of Earth and Environment Christchurch New Zealand
| | - Andrew C. Katsis
- College of Science and Engineering Flinders University Adelaide Australia
| | | | | | - Nicolas M. Adreani
- Konrad Lorenz Research Center for Behavior and Cognition and Department of Behavioral and Cognitive Biology University of Vienna Vienna Austria
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8
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Martina C, Krenn L, Krupicka L, Yamada H, Hood-Nowotny R, Lahuatte PF, Yar J, Schwemhofer T, Fischer B, Causton CE, Tebbich S. Evaluating Volatile Plant Compounds of Psidium galapageium (Myrtales: Myrtaceae) as Repellents Against Invasive Parasitic Diptera in the Galapagos Islands. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:89-98. [PMID: 34761264 DOI: 10.1093/jme/tjab183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Indexed: 06/13/2023]
Abstract
Plant-based repellents represent a safe, economic, and viable alternative to managing invasive insects that threaten native fauna. Observations of self-medication in animals can provide important cues to the medicinal properties of plants. A recent study in the Galapagos Islands found that Darwin's finches apply the leaves of Psidium galapageium (Hooker 1847) to their feathers, extracts of which were repellent to mosquitoes and the parasitic fly Philornis downsi (Dodge & Aitkens 1968; Diptera: Muscidae). Introduced mosquitoes are suspected vectors of avian pathogens in the Galapagos Islands, whereas the larvae of P. downsi are blood-feeders, causing significant declines of the endemic avifauna. In this study, we investigated the volatile compounds found in P. galapageium, testing each against a model organism, the mosquito Anopheles arabiensis (Patton 1905; Diptera: Culicidae), with the aim of singling out the most effective compound for repelling dipterans. Examinations of an ethanolic extract of P. galapageium, its essential oil and each of their respective fractions, revealed a mixture of monoterpenes and sesquiterpenes, the latter consisting mainly of guaiol, trans-nerolidol, and β-eudesmol. Of these, trans-nerolidol was identified as the most effective repellent to mosquitoes. This was subsequently tested at four different concentrations against P. downsi, but we did not find a repellence response. A tendency to avoid the compound was observed, albeit significance was not achieved in any case. The lack of repellence suggests that flies may respond to a combination of the volatile compounds found in P. galapageium, rather than to a single compound.
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Affiliation(s)
- C Martina
- Department of Behavioral and Cognitive Biology, University of Vienna, 1090 Vienna, Austria
- Insect Pest Control Section, International Atomic Energy Agency, 1400, Vienna, Austria
| | - L Krenn
- Department of Pharmacognosy, University of Vienna, A-1090, Vienna, Austria
| | - L Krupicka
- Department of Pharmacognosy, University of Vienna, A-1090, Vienna, Austria
| | - H Yamada
- Insect Pest Control Section, International Atomic Energy Agency, 1400, Vienna, Austria
| | - R Hood-Nowotny
- Institute of Soil Research, University of Natural Resources and Life Sciences (BOKU), 1180 Vienna, Austria
| | - P F Lahuatte
- Charles Darwin Foundation, Charles Darwin Research Station, Santa Cruz Island, Galapagos Islands, Ecuador
| | - J Yar
- Charles Darwin Foundation, Charles Darwin Research Station, Santa Cruz Island, Galapagos Islands, Ecuador
| | - T Schwemhofer
- Department of Behavioral and Cognitive Biology, University of Vienna, 1090 Vienna, Austria
| | - B Fischer
- Department of Evolutionary Biology, Unit for Theoretical Biology, University of Vienna, A-1090, Vienna, Austria
| | - C E Causton
- Charles Darwin Foundation, Charles Darwin Research Station, Santa Cruz Island, Galapagos Islands, Ecuador
| | - S Tebbich
- Department of Behavioral and Cognitive Biology, University of Vienna, 1090 Vienna, Austria
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9
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Kleindorfer S, Common LK, O'Connor JA, Garcia-Loor J, Katsis AC, Dudaniec RY, Colombelli-Négrel D, Adreani NM. Female in-nest attendance predicts the number of ectoparasites in Darwin's finch species. Proc Biol Sci 2021; 288:20211668. [PMID: 34905711 PMCID: PMC8670954 DOI: 10.1098/rspb.2021.1668] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 11/19/2021] [Indexed: 11/12/2022] Open
Abstract
Selection should act on parental care and favour parental investment decisions that optimize the number of offspring produced. Such predictions have been robustly tested in predation risk contexts, but less is known about alternative functions of parental care under conditions of parasitism. The avian vampire fly (Philornis downsi) is a myasis-causing ectoparasite accidentally introduced to the Galápagos Islands, and one of the major mortality causes in Darwin's finch nests. With an 11-year dataset spanning 21 years, we examine the relationship between parental care behaviours and number of fly larvae and pupae in Darwin's finch nests. We do so across three host species (Camarhynchus parvulus, C. pauper, Geospiza fuliginosa) and one hybrid Camarhynchus group. Nests with longer female brooding duration (minutes per hour spent sitting on hatchlings to provide warmth) had fewer parasites, and this effect depended on male food delivery to chicks. Neither male age nor number of nest provisioning visits were directly associated with number of parasites. While the causal mechanisms remain unknown, we provide the first empirical study showing that female brooding duration is negatively related to the number of ectoparasites in nests. We predict selection for coordinated host male and female behaviour to reduce gaps in nest attendance, especially under conditions of novel and introduced ectoparasites.
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Affiliation(s)
- Sonia Kleindorfer
- College of Science and Engineering, Flinders University, Adelaide 5001, Australia
- Konrad Lorenz Research Center for Behavior and Cognition and Department of Behavioral and Cognitive Biology, University of Vienna, Vienna 1090, Austria
| | - Lauren K. Common
- College of Science and Engineering, Flinders University, Adelaide 5001, Australia
| | | | - Jefferson Garcia-Loor
- Konrad Lorenz Research Center for Behavior and Cognition and Department of Behavioral and Cognitive Biology, University of Vienna, Vienna 1090, Austria
- Charles Darwin Research Station, Galápagos, Ecuador
| | - Andrew C. Katsis
- College of Science and Engineering, Flinders University, Adelaide 5001, Australia
| | - Rachael Y. Dudaniec
- Department of Biological Sciences, Macquarie University, Sydney 2109, Australia
| | | | - Nico M. Adreani
- Konrad Lorenz Research Center for Behavior and Cognition and Department of Behavioral and Cognitive Biology, University of Vienna, Vienna 1090, Austria
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10
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Temporal and spatial variation in sex-specific abundance of the avian vampire fly (Philornis downsi). Parasitol Res 2021; 121:63-74. [PMID: 34799771 PMCID: PMC8748338 DOI: 10.1007/s00436-021-07350-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/12/2021] [Indexed: 10/26/2022]
Abstract
Understanding the range and behaviour of an invasive species is critical to identify key habitat areas to focus control efforts. Patterns of range use in parasites can differ temporally, across life stages and between sexes. The invasive avian vampire fly, Philornis downsi, spends the larval stage of its life within bird nests, feeding on developing nestlings and causing high levels of mortality and deformation. However, little is known of the ecology and behaviour of the non-parasitic adult fly life stage. Here, we document sex-specific temporal and spatial patterns of abundance of adult avian vampire flies during a single Darwin's finch breeding season. We analyse fly trapping data collected across 7 weeks in the highlands (N = 405 flies) and lowlands (N = 12 flies) of Floreana Island (Galápagos). Lowland catches occurred later in the season, which supports the hypothesis that flies may migrate from the food-rich highlands to the food-poor lowlands once host breeding has commenced. Fly abundance was not correlated with host nesting density (oviposition site) but was correlated with distance to the agricultural zone (feeding site). We consistently caught more males closer to the agricultural zone and more females further away from the agricultural zone. These sex differences suggest that males may be defending or lekking at feeding sites in the agricultural zone for mating. This temporal and sex-specific habitat use of the avian vampire fly is relevant for developing targeted control methods and provides insight into the behavioural ecology of this introduced parasite on the Galápagos Archipelago.
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11
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Pike CL, Ramirez IE, Anchundia DJ, Fessl B, Heimpel GE, Causton CE. Behavior of the Avian Parasite Philornis downsi (Diptera: Muscidae) in and Near Host Nests in the Galapagos Islands. JOURNAL OF INSECT BEHAVIOR 2021; 34:296-311. [PMID: 35153376 PMCID: PMC8813692 DOI: 10.1007/s10905-021-09789-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 10/22/2021] [Accepted: 10/29/2021] [Indexed: 06/14/2023]
Abstract
UNLABELLED The Avian Vampire Fly, Philornis downsi, has invaded the Galapagos Islands, where it causes high mortality of endemic and native landbird species, including most species of Darwin's finches. Control methods are under development, but key information is missing about the reproductive biology of P. downsi and the behavior of flies in and near nests of their hosts. We used external and internal nest cameras to record the behavior of P. downsi adults within and outside nests of the Galapagos Flycatcher, Myiarchus magnirostris, throughout all stages of the nesting cycle. These recordings showed that P. downsi visited flycatcher nests throughout the day with higher fly activity during the nestling phase during vespertine hours. The observations also revealed that multiple P. downsi individuals can visit nests concurrently, and that there are some interactions among these flies within the nest. Fly visitation to nests occurred significantly more often while parent birds were away from the nest than in the nest, and this timing appears to be a strategy to avoid predation by parent birds. We report fly mating behavior outside the nest but not in the nest cavity. We discuss the relevance of these findings for the adaptive forces shaping P. downsi life history strategies as well as rearing and control measures. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s10905-021-09789-7.
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Affiliation(s)
- Courtney L. Pike
- Charles Darwin Research Station, Charles Darwin Foundation, Puerto Ayora, Santa Cruz Ecuador
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Vienna Austria
| | | | - David J. Anchundia
- Charles Darwin Research Station, Charles Darwin Foundation, Puerto Ayora, Santa Cruz Ecuador
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Vienna Austria
| | - Birgit Fessl
- Charles Darwin Research Station, Charles Darwin Foundation, Puerto Ayora, Santa Cruz Ecuador
| | | | - Charlotte E. Causton
- Charles Darwin Research Station, Charles Darwin Foundation, Puerto Ayora, Santa Cruz Ecuador
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12
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Wemer L, Hegemann A, Isaksson C, Nebel C, Kleindorfer S, Gamauf A, Adrion M, Sumasgutner P. Reduced ectoparasite load, body mass and blood haemolysis in Eurasian kestrels (Falco tinnunculus) along an urban-rural gradient. Naturwissenschaften 2021; 108:42. [PMID: 34491450 PMCID: PMC8423637 DOI: 10.1007/s00114-021-01745-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 07/22/2021] [Accepted: 08/09/2021] [Indexed: 12/21/2022]
Abstract
Urbanisation is proceeding at an alarming rate which forces wildlife to either retreat from urban areas or cope with novel stressors linked to human presence and activities. For example, urban stressors like anthropogenic noise, artificial light at night and chemical pollution can have severe impacts on the physiology of wildlife (and humans), in particular the immune system and antioxidant defences. These physiological systems are important to combat and reduce the severity of parasitic infections, which are common among wild animals. One question that then arises is whether urban-dwelling animals, whose immune and antioxidant system are already challenged by the urban stressors, are more susceptible to parasitic infections. To assess this, we studied nestlings of Eurasian kestrels (Falco tinnunculus) in Vienna, Austria, during 2015 and 2017. We measured biomarkers of innate immune function, oxidative stress and body mass index and ectoparasite infection intensity in 143 nestlings (from 56 nests) along an urban gradient. Nestlings in more urbanised areas had overall fewer ectoparasites, lower haemolysis (complement activity) and lower body mass index compared to nestlings in less urbanised areas. None of the other immune or oxidative stress markers were associated with the urban gradient. Despite some non-significant results, our data still suggest that kestrel nestlings experience some level of reduced physiological health, perhaps as a consequence of exposure to more urban stressors or altered prey availability in inner-city districts even though they had an overall lower ectoparasite burden in these heavily urbanised areas.
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Affiliation(s)
- Laura Wemer
- Department of Integrative Zoology, University of Vienna, Vienna, Austria.,Natural History Museum Vienna, Vienna, Austria
| | - Arne Hegemann
- Department of Biology, Lund University, Lund, Sweden
| | | | - Carina Nebel
- FitzPatrick Institute of African Ornithology, DSI-NRF Centre of Excellence, University of Cape Town, Cape Town, South Africa.,Department of Biology, University of Turku, Turku, Finland
| | - Sonia Kleindorfer
- Konrad Lorenz Research Centre, Core Facility for Behaviour and Cognition, Department of Behavioral & Cognitive Biology, University of Vienna, Vienna, Austria.,College of Science and Engineering, Flinders University, Bedford Park, SA, 5001, Australia
| | | | - Marius Adrion
- Department of Integrative Zoology, University of Vienna, Vienna, Austria.,Natural History Museum Vienna, Vienna, Austria.,NABU E.V, Head office, Berlin, Germany
| | - Petra Sumasgutner
- Natural History Museum Vienna, Vienna, Austria. .,FitzPatrick Institute of African Ornithology, DSI-NRF Centre of Excellence, University of Cape Town, Cape Town, South Africa. .,Konrad Lorenz Research Centre, Core Facility for Behaviour and Cognition, Department of Behavioral & Cognitive Biology, University of Vienna, Vienna, Austria.
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13
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Bueno I, Singer RS, Yoe C, Parrish R, Travis DA, Ponder JB. Optimizing Risk Management Strategies for the Control of Philornis downsi—A Threat to Birds in the Galápagos Islands. FRONTIERS IN CONSERVATION SCIENCE 2021. [DOI: 10.3389/fcosc.2021.721892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
One of the most concerning threats to Galápagos bird populations, including some critically endangered species, is the invasive parasitic fly Philornis downsi. While long-term sustained solutions are under study, immediate actions are needed to reduce the impacts of this fly. Application of permethrin to birds's nests has been successfully done, but there might be potential long-term reproductive effects to birds. Cyromazine, an insect growth regulator, has been proposed as an alternative, but its risks and effectiveness are unknown. The goal of this study was to assist managers to determine which combination of chemical (permethrin or cyromazine) and mode of application (injection, spray, and self-fumigation) was likely to be most effective to control P. downsi while minimizing toxicity to small land birds in Galápagos, given data available and high levels of uncertainty in some cases. This study is presented as a semi-quantitative risk assessment employing the use of a multi-criteria decision analysis (MCDA) model. For the six potential alternatives resulting from the combination of chemical and mode of application, the criteria were given a score from 1 to 6 supported by available evidence from the literature and from expert opinion. In addition, three different scenarios with different sets of weights for each criterion were assessed with stakeholder's input. Considering the scenario with higher weight to effectiveness of the method against P. downsi while also weighing heavily to minimize the toxicity to birds, cyromazine spray followed by permethrin injection were the preferred strategies. Self-fumigation was the mode of application with highest uncertainty but with much potential to be further explored for its feasibility. The approach taken here to evaluate mitigation strategies against an important threat for avian species in Galápagos can also be used in other conservation programs when making real time decisions under uncertainty.
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14
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Common LK, Sumasgutner P, Dudaniec RY, Colombelli-Négrel D, Kleindorfer S. Avian vampire fly (Philornis downsi) mortality differs across Darwin's finch host species. Sci Rep 2021; 11:15832. [PMID: 34349147 PMCID: PMC8338931 DOI: 10.1038/s41598-021-94996-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 07/19/2021] [Indexed: 12/03/2022] Open
Abstract
In invasive parasites, generalism is considered advantageous during the initial phase of introduction. Thereafter, fitness costs to parasites, such as host-specific mortality, can drive parasites towards specialism to avoid costly hosts. It is important to determine changes in host specificity of invasive populations to understand host-parasite dynamics and their effects on vulnerable host populations. We examined changes in mortality in the introduced avian vampire fly (Philornis downsi) (Diptera: Muscidae), a generalist myasis-causing ectoparasite, between 2004 and 2020 on Floreana Island (Galápagos). Mortality was measured as the proportion of immature larvae found upon host nest termination. Over the time period, the avian vampire fly was most abundant and had low mortality in nests of the critically endangered medium tree finch (Camarhynchus pauper) and had the highest mortality in nests of hybrid tree finches (Camarhynchus spp.). Low larval mortality was also found in small tree (Camarhynchus parvulus) and small ground finch (Geospiza fuliginosa) nests. Selection could favour avian vampire flies that select medium tree finch nests and/or avoid hybrid nests. Overall, the finding of differences in avian vampire fly survival across host species is parsimonious with the idea that the introduced fly may be evolving towards host specialisation.
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Affiliation(s)
- Lauren K Common
- College of Science and Engineering, Flinders University, Bedford Park, SA, 5001, Australia
| | - Petra Sumasgutner
- Department of Behavioral and Cognitive Biology, Konrad Lorenz Research Center, Core Facility for Behavior and Cognition, University of Vienna, Vienna, Austria
| | - Rachael Y Dudaniec
- Department of Biological Sciences, Macquarie University, Sydney, NSW , 2109, Australia
| | | | - Sonia Kleindorfer
- College of Science and Engineering, Flinders University, Bedford Park, SA, 5001, Australia. .,Department of Behavioral and Cognitive Biology, Konrad Lorenz Research Center, Core Facility for Behavior and Cognition, University of Vienna, Vienna, Austria.
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15
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Katsis AC, Colombelli-Négrel D, Common LK, O’connor JA, Dudaniec RY, García-Loor J, Kleindorfer S. Nestling behaviour predicts naris deformation in Darwin’s finches parasitized by the avian vampire fly. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Although in-nest parasitism can reduce the fitness of avian hosts, the severity of these effects may vary with host physiology and behaviour. If certain nestling behaviours are beneficial for resisting parasitism, then selection may favour some behavioural phenotypes over others. Here, we tested whether differences in nestling behaviour mediate the negative effects of parasitism, using small ground finches (Geospiza fuliginosa), on Floreana Island, that had been parasitized by the invasive avian vampire fly (Philornis downsi). We first established, using 4 years of breeding data (2005, 2006, 2010 and 2020), that nestlings exposed to more parasites had larger nares and, among older nestlings only, lower body mass. We then examined, using data from the 2020 season, whether each nestling’s behaviour (specifically, its response to human handling) predicted the severity of its naris deformation. When faced with high-intensity parasitism, more responsive nestlings (i.e. those that struggled more during handling) had larger nares compared to more docile nestlings. This suggests that more responsive nestlings suffer greater fitness costs due to parasitism, although we also discuss alternative explanations. Future work should consider the stability and heritability of these nestling behavioural differences and whether parasite-induced selection shapes behavioural variation at the population level.
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Affiliation(s)
- Andrew C Katsis
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Diane Colombelli-Négrel
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Lauren K Common
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Jody A O’connor
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
- Department for Environment and Water, Government of South Australia, Adelaide, South Australia, Australia
| | - Rachael Y Dudaniec
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
| | | | - Sonia Kleindorfer
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
- Konrad Lorenz Research Centre for Behaviour and Cognition and Department of Behavioural and Cognitive Biology, University of Vienna, Vienna, Austria
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16
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Tebbich S, Schwemhofer T, Fischer B, Pike C. Darwin’s finches habitually anoint their feathers with leaves of the endemic tree
Psidium galapageium
during the non‐breeding season. Ethology 2021. [DOI: 10.1111/eth.13153] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Sabine Tebbich
- Department of Behavioural and Cognitive Biology University of Vienna Vienna Austria
| | - Timo Schwemhofer
- Department of Behavioural and Cognitive Biology University of Vienna Vienna Austria
| | - Barbara Fischer
- Department of Evolutionary Biology Unit for Theoretical Biology University of Vienna Vienna Austria
| | - Courtney Pike
- Department of Behavioural and Cognitive Biology University of Vienna Vienna Austria
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17
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Jose PA, Ben-Yosef M, Lahuatte P, Causton CE, Heimpel GE, Jurkevitch E, Yuval B. Shifting microbiomes complement life stage transitions and diet of the bird parasite Philornis downsi from the Galapagos Islands. Environ Microbiol 2021; 23:5014-5029. [PMID: 33587780 DOI: 10.1111/1462-2920.15435] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 02/12/2021] [Indexed: 01/04/2023]
Abstract
Domestication disconnects an animal from its natural environment and diet, imposing changes in the attendant microbial community. We examine these changes in Philornis downsi (Muscidae), an invasive parasitic fly of land birds in the Galapagos Islands. Using a 16S rDNA profiling approach we studied the microbiome of larvae and adults of wild and laboratory-reared populations. These populations diverged in their microbiomes, significantly more so in larval than in adult flies. In field-collected second-instar larvae, Klebsiella (70.3%) was the most abundant taxon, while in the laboratory Ignatzschineria and Providencia made up 89.2% of the community. In adults, Gilliamella and Dysgonomonas were key members of the core microbiome of field-derived females and males but had no or very low representation in the laboratory. Adult flies harbour sex-specific microbial consortia in their gut, as male core microbiomes were significantly dominated by Klebsiella. Thus, P. downsi microbiomes are dynamic and shift correspondingly with life cycle and diet. Sex-specific foraging behaviour of adult flies and nest conditions, which are absent in the laboratory, may contribute to shaping distinct larval, and adult male and female microbiomes. We discuss these findings in the context of microbe-host co-evolution and the implications for control measures.
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Affiliation(s)
- Polpass Arul Jose
- Faculty of Agriculture Food and Environment, The Hebrew University of Jerusalem, Rehovot, 7612001, Israel
| | - Michael Ben-Yosef
- Department of Entomology, Agricultural Research Organization, Gilat Center, M. P. Negev, 85280, Israel
| | - Paola Lahuatte
- Charles Darwin Research Station, Charles Darwin Foundation, Puerto Ayora, Galapagos, 200350, Ecuador
| | - Charlotte E Causton
- Charles Darwin Research Station, Charles Darwin Foundation, Puerto Ayora, Galapagos, 200350, Ecuador
| | - George E Heimpel
- Department of Entomology, University of Minnesota, 1980 Folwell Avenue, MN, 55108, USA
| | - Edouard Jurkevitch
- Faculty of Agriculture Food and Environment, The Hebrew University of Jerusalem, Rehovot, 7612001, Israel
| | - Boaz Yuval
- Faculty of Agriculture Food and Environment, The Hebrew University of Jerusalem, Rehovot, 7612001, Israel
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18
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Heyer E, Cimadom A, Wappl C, Tebbich S. Parental care in the Small Tree Finch Camarhynchus parvulus in relation to parasitism and environmental factors. THE IBIS 2021; 163:137-149. [PMID: 33362293 PMCID: PMC7754105 DOI: 10.1111/ibi.12845] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 04/28/2020] [Indexed: 05/30/2023]
Abstract
The parental food compensation hypothesis suggests that parents may compensate for the negative effects of parasites on chicks by increased food provisioning. However, this ability differs widely among host species and may also depend on ecological factors such as adverse weather conditions and habitat quality. Although weed management can improve habitat quality, management measures can bring about a temporary decrease in food availability and thus may reduce parents' ability to provide their nestlings with enough energy. In our study we investigated the interaction of parasitism and weed management, and the influence of climate on feeding rates in a Darwin's tree finch species, which is negatively impacted by two invasive species. The larvae of the invasive parasitic fly Philornis downsi ingest the blood and body tissues of tree finch nestlings, and the invasive Blackberry Rubus niveus affects one of the main habitats of Darwin's tree finches. We compared parental food provisioning of the Small Tree Finch Camarhynchus parvulus in parasitized and parasite-free nests in three different areas, which differed in invasive weed management (no management, short-term and long-term management). In a parasite reduction experiment, we investigated whether the Small Tree Finch increases food provisioning rates to nestlings when parasitized and whether this ability depends on weed management conditions and precipitation. Our results provide no evidence that Small Tree Finches can compensate with additional food provisioning when parasitized with P. downsi. However, we found an increase in male effort in the short-term management area, which might indicate that males compensate for lower food quality with increased provisioning effort. Furthermore, parental food provisioning was lower during rainfall, which provides an explanation for the negative influence of rain on breeding success found in earlier studies. Like other Darwin's finches, the Small Tree Finch seems to lack the ability to compensate for the negative effects of P. downsi parasitism, which is one explanation for why this invasive parasite has such a devastating effect on this host species.
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Affiliation(s)
- Eileen Heyer
- Department of Behavioural BiologyUniversity of ViennaAlthanstraße 141090ViennaAustria
| | - Arno Cimadom
- Department of Behavioural BiologyUniversity of ViennaAlthanstraße 141090ViennaAustria
| | - Christian Wappl
- Department of Behavioural BiologyUniversity of ViennaAlthanstraße 141090ViennaAustria
| | - Sabine Tebbich
- Department of Behavioural BiologyUniversity of ViennaAlthanstraße 141090ViennaAustria
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19
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Timing of infestation influences virulence and parasite success in a dynamic multi-host-parasite interaction between the invasive parasite, Philornis downsi, and Darwin's finches. Oecologia 2020; 195:249-259. [PMID: 33258992 PMCID: PMC7882474 DOI: 10.1007/s00442-020-04807-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 11/16/2020] [Indexed: 12/30/2022]
Abstract
Recently commenced host–parasite interactions provide an excellent opportunity to study co-evolutionary processes. Multi-host systems are especially informative because variation in virulence between hosts and temporal changes provides insight into evolutionary dynamics. However, empirical data under natural conditions are scarce. In the present study, we investigated the interaction between Darwin’s finches and the invasive fly Philornis downsi whose larvae feed on the blood of nestlings. Recently, however, the fly has changed its behavior and now also attacks incubating females. Two sympatric hosts are affected differently by the parasite and parasite load has changed over time. Our study observed a reversal of trends described two decades ago: while, currently, small tree finches (Camarhynchus parvulus) experience significantly higher parasite load than warbler finches (Certhidea olivacea), this was the opposite two decades ago. Currently, fledging success is higher in warbler finches compared to small tree finches. Our data indicate that not only intensity but also timing of infestation influences hosts’ reproductive success and parasite fitness. During incubation, prevalence was higher in warbler finches, but once chicks had hatched, prevalence was 100% in both species and parasite load was higher in small tree finches. Furthermore, our results suggest faster development and higher reproductive success of P. downsi in small tree finch nests. A change in host preference driven by larvae competition could have led to the reversal in parasite load.
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20
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Population structure of a nest parasite of Darwin’s finches within its native and invasive ranges. CONSERV GENET 2020. [DOI: 10.1007/s10592-020-01315-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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21
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Common LK, O'Connor JA, Dudaniec RY, Peters KJ, Kleindorfer S. Evidence for rapid downward fecundity selection in an ectoparasite (Philornis downsi) with earlier host mortality in Darwin's finches. J Evol Biol 2020; 33:524-533. [PMID: 31961983 PMCID: PMC7217188 DOI: 10.1111/jeb.13588] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 01/09/2020] [Accepted: 01/15/2020] [Indexed: 01/05/2023]
Abstract
Fecundity selection is a critical component of fitness and a major driver of adaptive evolution. Trade‐offs between parasite mortality and host resources are likely to impose a selection pressure on parasite fecundity, but this is little studied in natural systems. The ‘fecundity advantage hypothesis’ predicts female‐biased sexual size dimorphism whereby larger females produce more offspring. Parasitic insects are useful for exploring the interplay between host resource availability and parasite fecundity, because female body size is a reliable proxy for fecundity in insects. Here we explore temporal changes in body size in the myiasis‐causing parasite Philornis downsi (Diptera: Muscidae) on the Galápagos Islands under conditions of earlier in‐nest host mortality. We aim to investigate the effects of decreasing host resources on parasite body size and fecundity. Across a 12‐year period, we observed a mean of c. 17% P. downsi mortality in host nests with 55 ± 6.2% host mortality and a trend of c. 66% higher host mortality throughout the study period. Using specimens from 116 Darwin's finch nests (Passeriformes: Thraupidae) and 114 traps, we found that over time, P. downsi pupae mass decreased by c. 32%, and male (c. 6%) and female adult size (c. 11%) decreased. Notably, females had c. 26% smaller abdomens in later years, and female abdomen size was correlated with number of eggs. Our findings imply natural selection for faster P. downsi pupation and consequently smaller body size and lower parasite fecundity in this newly evolving host–parasite system.
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Affiliation(s)
- Lauren K Common
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | - Jody A O'Connor
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia.,Department for Environment and Water, Government of South Australia, Adelaide, SA, Australia
| | - Rachael Y Dudaniec
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Katharina J Peters
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | - Sonia Kleindorfer
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia.,Konrad Lorenz Research Center for Behaviour and Cognition and Department of Behavioural and Cognitive Biology, University of Vienna, Vienna, Austria
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22
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Causton CE, Moon RD, Cimadom A, Boulton RA, Cedeño D, Lincango MP, Tebbich S, Ulloa A. Population dynamics of an invasive bird parasite, Philornis downsi (Diptera: Muscidae), in the Galapagos Islands. PLoS One 2019; 14:e0224125. [PMID: 31626686 PMCID: PMC6874344 DOI: 10.1371/journal.pone.0224125] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 10/06/2019] [Indexed: 01/05/2023] Open
Abstract
The invasive parasitic fly, Philornis downsi (Muscidae), is one of the greatest threats to the avifauna of the Galapagos Islands. The larvae of this fly feed on the blood and tissues of developing nestlings of at least 18 endemic and native birds. The aim of the current study was to investigate biotic and abiotic factors that may influence the population dynamics of this invasive parasite. To study the influence of vegetation zone and related climatic factors on fly numbers, a bi-weekly monitoring program using papaya-baited traps was carried out at a dry, lowland site and at a humid, highland site on Santa Cruz Island between 2012-2014. Female flies, a large proportion of which were inseminated and gravid, were collected throughout the year at both sites, indicating females were active during and between the bird breeding seasons. This is the first evidence that female flies are able to persist even when hosts are scarce. On the other hand, catch rates of male flies declined between bird breeding seasons. Overall, catch rates of P. downsi were higher in the drier, lowland habitat, which may be a consequence of host or resource availability. Time was a stronger predictor of adult fly numbers than climate, further suggesting that P. downsi does not appear to be limited by its environment, but rather by host availability. Seasonal catch rates suggested that populations in both habitats were continuous and multivoltine. Numbers of adult female flies appeared to be regulated chiefly by simple direct density dependence, and may be governed by availability of bird nests with nestlings. Nevertheless, confounding factors such as the existence of reservoir hosts that perpetuate fly populations and changes in behavior of P. downsi may increase the vulnerability of bird hosts that are already IUCN red-listed or in decline.
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Affiliation(s)
- Charlotte E. Causton
- Charles Darwin Research Station, Charles Darwin Foundation, Puerto Ayora,
Santa Cruz Island, Galapagos Islands, Ecuador
| | - Roger D. Moon
- Department of Entomology, University of Minnesota, St. Paul, MN, United
States of America
| | - Arno Cimadom
- Department of Behavioural Biology, University of Vienna, Vienna,
Austria
| | - Rebecca A. Boulton
- College of Life and Environmental Sciences, University of Exeter,
Cornwall, United Kingdom
| | - Daniel Cedeño
- Charles Darwin Research Station, Charles Darwin Foundation, Puerto Ayora,
Santa Cruz Island, Galapagos Islands, Ecuador
| | - María Piedad Lincango
- Charles Darwin Research Station, Charles Darwin Foundation, Puerto Ayora,
Santa Cruz Island, Galapagos Islands, Ecuador
- Facultad De Ciencias Agrícolas, Universidad Central Del Ecuador, Quito,
Pichincha, Ecuador
| | - Sabine Tebbich
- Department of Behavioural Biology, University of Vienna, Vienna,
Austria
| | - Angel Ulloa
- Charles Darwin Research Station, Charles Darwin Foundation, Puerto Ayora,
Santa Cruz Island, Galapagos Islands, Ecuador
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23
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Kleindorfer S, Custance G, Peters KJ, Sulloway FJ. Introduced parasite changes host phenotype, mating signal and hybridization risk: Philornis downsi effects on Darwin's finch song. Proc Biol Sci 2019; 286:20190461. [PMID: 31185871 DOI: 10.1098/rspb.2019.0461] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Introduced parasites that alter their host's mating signal can change the evolutionary trajectory of a species through sexual selection. Darwin's Camarhynchus finches are threatened by the introduced fly Philornis downsi that is thought to have accidentally arrived on the Galapagos Islands during the 1960s. The P. downsi larvae feed on the blood and tissue of developing finches, causing on average approximately 55% in-nest mortality and enlarged naris size in survivors. Here we test if enlarged naris size is associated with song characteristics and vocal deviation in the small tree finch ( Camarhynchus parvulus), the critically endangered medium tree finch ( C. pauper) and the recently observed hybrid tree finch group ( Camarhynchus hybrids). Male C. parvulus and C. pauper with enlarged naris size produced song with lower maximum frequency and greater vocal deviation, but there was no significant association in hybrids. Less vocal deviation predicted faster pairing success in both parental species. Finally, C. pauper males with normal naris size produced species-specific song, but male C. pauper with enlarged naris size had song that was indistinguishable from other tree finches. When parasites disrupt host mating signal, they may also facilitate hybridization. Here we show how parasite-induced naris enlargement affects vocal quality, resulting in blurred species mating signals.
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Affiliation(s)
- Sonia Kleindorfer
- 1 College of Science and Engineering, Flinders University , Adelaide 5001 , Australia.,2 Konrad Lorenz Research Station and Department of Behavioural Biology, University of Vienna , Vienna , Austria
| | - Georgina Custance
- 1 College of Science and Engineering, Flinders University , Adelaide 5001 , Australia
| | - Katharina J Peters
- 1 College of Science and Engineering, Flinders University , Adelaide 5001 , Australia
| | - Frank J Sulloway
- 3 Department of Psychology, University of California , 2121 Berkeley Way, Room 3302, 4125 Tolman Hall, Berkeley, CA 94720 , USA
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24
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Peters KJ, Evans C, Aguirre JD, Kleindorfer S. Genetic admixture predicts parasite intensity: evidence for increased hybrid performance in Darwin's tree finches. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181616. [PMID: 31183118 PMCID: PMC6502384 DOI: 10.1098/rsos.181616] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 03/07/2019] [Indexed: 06/09/2023]
Abstract
Hybridization can increase adaptive potential when enhanced genetic diversity or novel genetic combinations confer a fitness advantage, such as in the evolution of anti-parasitic mechanisms. Island systems are especially susceptible to invasive parasites due to the lack of defence mechanisms that usually coevolve in long-standing host-parasite relationships. We test if host genetic admixture affects parasite numbers in a novel host-parasite association on the Galápagos Islands. Specifically, we compare the number of Philornis downsi in nests with offspring sired by Darwin's small tree finch (Camarhynchus parvulus), Darwin's medium tree finch (C. pauper) and hybrids of these two species. The number of P. downsi decreased with an increasing genetic admixture of the attending male, and nests of hybrid males had approximately 50% fewer parasites than C. parvulus nests, and approximately 60% fewer parasites than C. pauper nests. This finding indicates that hybridization in this system could be favoured by selection and reveal a mechanism to combat an invasive parasite.
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Affiliation(s)
- Katharina J. Peters
- College of Science and Engineering, Flinders University, Adelaide, Australia
- School of Natural and Computational Sciences, Massey University, Auckland, New Zealand
| | - Christine Evans
- College of Science and Engineering, Flinders University, Adelaide, Australia
- School of Natural and Computational Sciences, Massey University, Auckland, New Zealand
| | - J. David Aguirre
- School of Natural and Computational Sciences, Massey University, Auckland, New Zealand
| | - Sonia Kleindorfer
- College of Science and Engineering, Flinders University, Adelaide, Australia
- Konrad Lorenz Research Station and Department of Behavioural Biology, University of Vienna, Austria
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25
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McNew SM, Knutie SA, Goodman GB, Theodosopoulos A, Saulsberry A, Yépez R. J, Bush SE, Clayton DH. Annual environmental variation influences host tolerance to parasites. Proc Biol Sci 2019; 286:20190049. [PMID: 30963843 PMCID: PMC6408884 DOI: 10.1098/rspb.2019.0049] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 02/06/2019] [Indexed: 12/16/2022] Open
Abstract
When confronted with a parasite or pathogen, hosts can defend themselves by resisting or tolerating the attack. While resistance can be diminished when resources are limited, it is unclear how robust tolerance is to changes in environmental conditions. Here, we investigate the sensitivity of tolerance in a single host population living in a highly variable environment. We manipulated the abundance of an invasive parasitic fly, Philornis downsi, in nests of Galápagos mockingbirds ( Mimus parvulus) over four field seasons and measured host fitness in response to parasitism. Mockingbird tolerance to P. downsi varied significantly among years and decreased when rainfall was limited. Video observations indicate that parental provisioning of nestlings appears key to tolerance: in drought years, mockingbirds likely do not have sufficient resources to compensate for the effects of P. downsi. These results indicate that host tolerance is a labile trait and suggest that environmental variation plays a major role in mediating the consequences of host-parasite interactions.
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Affiliation(s)
- Sabrina M. McNew
- Department of Biology, University of Utah, Salt Lake City, UT 84112-0840, USA
| | - Sarah A. Knutie
- Department of Biology, University of Utah, Salt Lake City, UT 84112-0840, USA
| | - Graham B. Goodman
- Department of Biology, University of Utah, Salt Lake City, UT 84112-0840, USA
| | | | - Ashley Saulsberry
- Department of Biology, University of Utah, Salt Lake City, UT 84112-0840, USA
| | - Janai Yépez R.
- Charles Darwin Research Station, Santa Cruz Island, Galápagos, Ecuador
| | - Sarah E. Bush
- Department of Biology, University of Utah, Salt Lake City, UT 84112-0840, USA
| | - Dale H. Clayton
- Department of Biology, University of Utah, Salt Lake City, UT 84112-0840, USA
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PREFLEDGING MORTALITY AND THE ABUNDANCE OF MOSQUITOES BITING NESTLING BARN OWLS ( TYTO ALBA) IN FLORIDA, USA. J Wildl Dis 2019; 55:597-607. [PMID: 30702952 DOI: 10.7589/2017-12-307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mosquito-borne diseases can have disastrous effects on avian populations; therefore, most studies of bird and mosquito interactions have focused on the mortality and morbidity associated with the diseases. However, the effect of mosquitoes feeding on birds, independent of disease, has not been well studied. We studied Barn Owls (Tyto alba) nesting in artificial nest boxes in sugarcane (Saccharum officinarum) fields in Florida, US. To reduce mosquito effects on nestlings, we used an insecticide spray in half of the nest boxes. Mosquito suction traps were fixed to the outside of eight nest boxes (four treated and four untreated) to collect mosquitoes over a 24-h period (one trap night) once weekly, from incubation until all nestlings fledged. Collected mosquitoes were counted, sorted into blood-fed and unfed females, and identified to species when possible. The dominant mosquito species captured were Culex nigripalpus, Mansonia dyari, and Mansonia titillans. The highest total number of mosquitoes and blood-fed mosquitoes captured in a suction trap in one trap night was 3,193 and 379, respectively. Overall, significantly fewer mosquitoes were captured from treated nest boxes compared to untreated boxes. Nestling age influenced the total number of mosquitoes captured, with the highest numbers associated with fledglings 22-42 d old. The highest numbers of blood-fed mosquitoes were captured when nestlings were 22-28 d old. Nestlings in insecticide-treated boxes had higher survival rates compared to those in untreated boxes during months with high mosquito numbers. Mosquitoes can impose energetic costs on nestlings by causing stress from irritation, dehydration, and the constant regeneration of blood cells. These costs, in addition to factors such as food shortage, temperature, and overall health of the nestling, can contribute to higher mortality rates during nesting periods with high mosquito numbers.
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27
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Funk ER, Burns KJ. Evolutionary distinctiveness and conservation priorities in a large radiation of songbirds. Anim Conserv 2018. [DOI: 10.1111/acv.12462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- E. R. Funk
- Department of Biology San Diego State University San Diego CA USA
| | - K. J. Burns
- Department of Biology San Diego State University San Diego CA USA
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28
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McNew SM, Clayton DH. Alien Invasion: Biology of Philornis Flies Highlighting Philornis downsi, an Introduced Parasite of Galápagos Birds. ANNUAL REVIEW OF ENTOMOLOGY 2018; 63:369-387. [PMID: 29058976 DOI: 10.1146/annurev-ento-020117-043103] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The muscid genus Philornis comprises approximately 50 described species of flies, nearly all of which are obligate parasites of nestling birds. Philornis species are native to the Neotropics and widely distributed from Florida to Argentina. Most research on this group has focused on P. downsi, which was introduced to the Galápagos Islands in the late twentieth century. Although Philornis parasitism kills nestlings in several native host species, nowhere do the effects seem more severe than in P. downsi in the Galápagos. Here, we review studies of native and introduced Philornis in an attempt to identify factors that may influence virulence and consider implications for the conservation of hosts in the Galápagos.
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Affiliation(s)
- Sabrina M McNew
- Department of Biology, University of Utah, Salt Lake City, Utah 84112-0840, USA;
| | - Dale H Clayton
- Department of Biology, University of Utah, Salt Lake City, Utah 84112-0840, USA;
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29
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Filek N, Cimadom A, Schulze CH, Jäger H, Tebbich S. The impact of invasive plant management on the foraging ecology of the Warbler Finch ( Certhidea olivacea) and the Small Tree Finch ( Camarhynchus parvulus) on Galápagos. JOURNAL OF ORNITHOLOGY 2018; 159:129-140. [PMID: 31998596 PMCID: PMC6956869 DOI: 10.1007/s10336-017-1481-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 07/16/2017] [Accepted: 07/18/2017] [Indexed: 05/17/2023]
Abstract
In recent decades, arboreal Darwin's Finches have suffered from a dramatic population decline, which has been attributed to parasitism by the invasive botfly Philornis downsi. However, changes to their primary habitat caused by invasive plant species may have additionally contributed to the observed population decline. The humid cloud forest on Santa Cruz Island is a stronghold of arboreal Darwin's Finches but has been invaded by blackberry (Rubus niveus). In some areas, manual control and herbicide application are used to combat this invasion, both causing a temporary removal of the entire understory. We hypothesized that the removal of the understory reduces the availability of arthropods, which are a main food source during chick rearing. We compared the foraging behaviour of Warbler Finches (Certhidea olivacea) and Small Tree Finches (Camarhynchus parvulus) at three study sites that varied in the degree of R. niveus invasion and the length of time since the last herbicide application. We used prey attack rate and foraging success as an index for food availability and predicted a lower attack rate and foraging success in areas that had recently been sprayed with herbicides. We found that both the invasion and the management of R. niveus influenced microhabitat use, foraging substrate and prey choice in both species. Contrary to our hypothesis, we did not find a lower attack rate or foraging success in the area with recent herbicide application. This may be explained by the finding that both species mainly foraged in the canopy but also used dead plant structures of the understory of the recently controlled area that resulted from the invasive plant management.
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Affiliation(s)
- Nikolaus Filek
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Arno Cimadom
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Christian H. Schulze
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030 Vienna, Austria
| | - Heinke Jäger
- Charles Darwin Foundation, Puerto Ayora, Santa Cruz, Galápagos Ecuador
| | - Sabine Tebbich
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
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30
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Fessl B, Heimpel GE, Causton CE. Invasion of an Avian Nest Parasite, Philornis downsi, to the Galapagos Islands: Colonization History, Adaptations to Novel Ecosystems, and Conservation Challenges. DISEASE ECOLOGY 2018. [DOI: 10.1007/978-3-319-65909-1_9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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31
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Abstract
Colonization comprises the physical arrival of a species in a new area, but also its successful establishment within the local community. Oceanic islands, like the Hawaiian and the Galapagos archipelagos, represent excellent systems to study the mechanisms of colonization because of their historical isolation. In this chapter, we first review some of the major mechanisms by which parasites and vectors could arrive to an oceanic island, both naturally or due to human activities, and the factors that may influence their successful establishment in the insular host community. We then explore examples of natural and anthropogenic colonization of the Galapagos Islands by parasites and vectors, focusing on one or more case studies that best represent the diversity of colonization mechanisms that has shaped parasite distribution in the archipelago. Finally, we discuss future directions for research on parasite and vector colonization in Galapagos Islands.
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Affiliation(s)
- Patricia G. Parker
- Department of Biology, University of Missouri – St. Louis, St. Louis, Missouri USA
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32
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Clark NJ, Clegg SM, Sam K, Goulding W, Koane B, Wells K. Climate, host phylogeny and the connectivity of host communities govern regional parasite assembly. DIVERS DISTRIB 2017. [DOI: 10.1111/ddi.12661] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Nicholas J. Clark
- School of Veterinary Science; University of Queensland; Gatton Qld Australia
| | - Sonya M. Clegg
- Edward Grey Institute of Field Ornithology; Department of Zoology; University of Oxford; Oxford UK
| | - Katerina Sam
- Biology Centre CAS; Faculty of Science; Institute of Entomology and University of South Bohemia; Branisovska Ceske Budejovice Czech Republic
| | - William Goulding
- The Landscape Ecology and Conservation Group; School of Earth and Environmental Science; University of Queensland; St Lucia Qld Australia
- Biodiversity and Geosciences Program; Queensland Museum; South Brisbane Qld Australia
| | - Bonny Koane
- The New Guinea Binatang Research Centre; Madang Papua New Guinea
| | - Konstans Wells
- Environmental Futures Research Institute; School of Environment; Griffith University; Nathan Qld Australia
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33
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Ben-Yosef M, Zaada DSY, Dudaniec RY, Pasternak Z, Jurkevitch E, Smith RJ, Causton CE, Lincango MP, Tobe SS, Mitchell JG, Kleindorfer S, Yuval B. Host-specific associations affect the microbiome ofPhilornis downsi, an introduced parasite to the Galápagos Islands. Mol Ecol 2017; 26:4644-4656. [DOI: 10.1111/mec.14219] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 05/25/2017] [Accepted: 06/13/2017] [Indexed: 01/08/2023]
Affiliation(s)
- Michael Ben-Yosef
- Department of Entomology; Faculty of Agriculture Food and Environment; The Hebrew University of Jerusalem; Rehovot Israel
| | - Doron S. Y. Zaada
- Department of Entomology; Faculty of Agriculture Food and Environment; The Hebrew University of Jerusalem; Rehovot Israel
| | - Rachael Y. Dudaniec
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
| | - Zohar Pasternak
- Department of Microbiology and Plant Pathology; Faculty of Agriculture Food and Environment; The Hebrew University of Jerusalem; Rehovot Israel
| | - Edouard Jurkevitch
- Department of Microbiology and Plant Pathology; Faculty of Agriculture Food and Environment; The Hebrew University of Jerusalem; Rehovot Israel
| | - Renee J. Smith
- School of Biological Sciences; Flinders University; Adelaide SA Australia
| | - Charlotte E. Causton
- Charles Darwin Foundation; Puerto Ayora Santa Cruz Island Galápagos Islands Ecuador
| | - Maria Piedad Lincango
- Charles Darwin Foundation; Puerto Ayora Santa Cruz Island Galápagos Islands Ecuador
- Facultad De Ciencias Agrícolas; Universidad Central Del Ecuador; Quito Pichincha Ecuador
| | - Shanan S. Tobe
- School of Biological Sciences; Flinders University; Adelaide SA Australia
- Department of Chemistry and Physics; Arcadia University; Glenside PA USA
| | - James G. Mitchell
- School of Biological Sciences; Flinders University; Adelaide SA Australia
| | - Sonia Kleindorfer
- School of Biological Sciences; Flinders University; Adelaide SA Australia
| | - Boaz Yuval
- Department of Entomology; Faculty of Agriculture Food and Environment; The Hebrew University of Jerusalem; Rehovot Israel
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34
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Sinha SK, Sinha AK, De P, Bhakat S. Larval infestation in a common Pariah Kite Milvus migrans (Boddaert). J Parasit Dis 2017; 41:199-201. [DOI: 10.1007/s12639-016-0777-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 03/08/2016] [Indexed: 11/28/2022] Open
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35
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Knutie SA, Herman JM, Owen JP, Clayton DH. Tri‐trophic ecology of native parasitic nest flies of birds in
T
obago. Ecosphere 2017. [DOI: 10.1002/ecs2.1670] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Sarah A. Knutie
- Department of Biology University of Utah Salt Lake City Utah 84112 USA
| | - Jordan M. Herman
- Department of Biology University of Utah Salt Lake City Utah 84112 USA
| | - Jeb P. Owen
- Department of Entomology Washington State University Pullman Washington 99164 USA
| | - Dale H. Clayton
- Department of Biology University of Utah Salt Lake City Utah 84112 USA
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36
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Cha DH, Mieles AE, Lahuatte PF, Cahuana A, Lincango MP, Causton CE, Tebbich S, Cimadom A, Teale SA. Identification and Optimization of Microbial Attractants for Philornis downsi, an Invasive Fly Parasitic on Galapagos Birds. J Chem Ecol 2016; 42:1101-1111. [PMID: 27744622 DOI: 10.1007/s10886-016-0780-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 09/07/2016] [Accepted: 09/29/2016] [Indexed: 11/28/2022]
Abstract
We investigated the role of olfactory cues from actively fermenting yeast (Saccharomyces cerevisiae) in attraction of adult Philornis downsi and identified two synergistically attractive yeast volatiles. Larvae of this invasive fly parasitize the hatchlings of passerines and threaten the Galapagos avifauna. Gas chromatography coupled with electroantennographic detection (GC-EAD), coupled gas chromatography-mass spectrometry (GC-MS), and field trapping experiments were used to identify volatile compounds from a yeast-sugar solution. EAD responses were consistently elicited by 14 yeast volatiles. In a series of field trapping experiments, a mixture of the 14 EAD-active compounds was similarly attractive to P. downsi when compared to the yeast-sugar solution, and we found that acetic acid and ethanol were essential for attraction. A mixture of 0.03 % acetic acid and 3 % ethanol was as attractive as the 14-component blend, but was not as attractive as the yeast-sugar solution. Philornis downsi showed positive and negative dose-responses to acetic acid in the ranges of 0.01 ~ 0.3 % and 0.3 ~ 9 %, respectively. Further optimization showed that the mixture of 1 % acetic acid and 3 % ethanol was as attractive as the yeast-sugar solution. Both mixtures of acetic acid and ethanol were more selective than the yeast-sugar solution in terms of non-target moths and Polistes versicolor wasps captured. These results indicate that acetic acid and ethanol produced by yeasts are crucial for P. downsi attraction to fermented materials on which they feed as adults and can be used to manage this invasive fly in Galapagos.
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Affiliation(s)
- Dong H Cha
- College of Environmental Science and Forestry, State University of New York, Syracuse, NY, USA.,USDA-ARS, US Pacific Basin Agricultural Research Laboratory, 64 Nowelo St., Hilo, HI, USA
| | - Alejandro E Mieles
- College of Environmental Science and Forestry, State University of New York, Syracuse, NY, USA
| | - Paola F Lahuatte
- Charles Darwin Foundation for the Galapagos Islands, Puerto Ayora, Santa Cruz Island, Galapagos Islands, Ecuador
| | - Andrea Cahuana
- Charles Darwin Foundation for the Galapagos Islands, Puerto Ayora, Santa Cruz Island, Galapagos Islands, Ecuador
| | - Marie Piedad Lincango
- Charles Darwin Foundation for the Galapagos Islands, Puerto Ayora, Santa Cruz Island, Galapagos Islands, Ecuador.,Facultad de Ciencias Agrícolas, Universidad Central del Ecuador, Quito, Ecuador
| | - Charlotte E Causton
- Charles Darwin Foundation for the Galapagos Islands, Puerto Ayora, Santa Cruz Island, Galapagos Islands, Ecuador
| | - Sabine Tebbich
- Department of Behavioural Biology, University of Vienna, 1090, Vienna, Austria
| | - Arno Cimadom
- Department of Behavioural Biology, University of Vienna, 1090, Vienna, Austria
| | - Stephen A Teale
- College of Environmental Science and Forestry, State University of New York, Syracuse, NY, USA.
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37
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Darwin's finches treat their feathers with a natural repellent. Sci Rep 2016; 6:34559. [PMID: 27721475 PMCID: PMC5056383 DOI: 10.1038/srep34559] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 09/12/2016] [Indexed: 11/08/2022] Open
Abstract
Darwin's finches are highly innovative. Recently we recorded for the first time a behavioural innovation in Darwin's finches outside the foraging context: individuals of four species rubbed leaves of the endemic tree Psidium galapageium on their feathers. We hypothesised that this behaviour serves to repel ectoparasites and tested the repellency of P. galapageium leaf extracts against parasites that negatively affect the fitness of Darwin's finches, namely mosquitoes and the invasive hematophagous fly Philornis downsi. Mosquitoes transmit pathogens which have recently been introduced by humans and the larvae of the fly suck blood from nestlings and incubating females. Our experimental evidence demonstrates that P. galapageium leaf extracts repel both mosquitoes and adult P. downsi and also inhibit the growth of P. downsi larvae. It is therefore possible that finches use this plant to repel ectopoarasites.
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38
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Kleindorfer S, Dudaniec RY. Host-parasite ecology, behavior and genetics: a review of the introduced fly parasite Philornis downsi and its Darwin’s finch hosts. BMC ZOOL 2016. [DOI: 10.1186/s40850-016-0003-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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39
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Lahuatte PF, Lincango MP, Heimpel GE, Causton CE. Rearing Larvae of the Avian Nest Parasite, Philornis downsi (Diptera: Muscidae), on Chicken Blood-Based Diets. JOURNAL OF INSECT SCIENCE (ONLINE) 2016; 16:iew064. [PMID: 27493240 PMCID: PMC4973507 DOI: 10.1093/jisesa/iew064] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 06/27/2016] [Indexed: 06/06/2023]
Abstract
Captive rearing of insect pests is necessary to understand their biology and to develop control methods. The avian nest fly, Philornis downsi Dodge and Aitken, is a blood-sucking parasite during its larval stage and a serious threat to endemic birds in the Galapagos Islands where it is considered invasive. In order to procure large numbers of flies for biological studies, rearing media and diets were trialed for rearing the larval stage of P. downsi under controlled conditions in the absence of its avian host. P. downsi eggs were obtained from field-caught female flies, and once eggs hatched they were reared on chicken blood for the first 3 d. Following this, three diets were tested on second- and third-instar larvae: 1) chicken blood only; 2) chicken blood, hydrolyzed protein and dried milk powder; and 3) chicken blood, hydrolyzed protein and brewer's yeast. Out of 385 P. downsi larvae tested, we were able to rear 50 larvae to the adult stage. The highest level of mortality was found in the first-instar larvae. Survivorship of second- and third-instar larvae was similar irrespective of diet and diet did not significantly influence larval or pupal development times; though larvae fed the diet with brewer's yeast developed marginally faster. Pupal weights were similar to those of larvae that had developed on bird hosts in the field. To our knowledge, this is the first effective protocol for rearing a hematophagous parasitic avian fly from egg to adult in the absence of a living host.
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Affiliation(s)
- Paola F Lahuatte
- Carrera De Ciencias Biológicas Y Ambientales, Sector El Dorado, Quito-Ecuador, Universidad Central Del Ecuador, Iquique N14-121 Y Sodiro-Itchimbía Charles Darwin Foundation, Santa Cruz Island, Galapagos Islands, Ecuador
| | - M P Lincango
- Charles Darwin Foundation, Santa Cruz Island, Galapagos Islands, Ecuador Facultad De Ciencias Agrícolas, Universidad Central Del Ecuador, Quito, Ecuador
| | - G E Heimpel
- Department of Entomology, University of Minnesota, St. Paul MN, USA
| | - C E Causton
- Charles Darwin Foundation, Santa Cruz Island, Galapagos Islands, Ecuador
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40
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Kleindorfer S, Sulloway FJ. Naris deformation in Darwin’s finches: Experimental and historical evidence for a post-1960s arrival of the parasite Philornis downsi. Glob Ecol Conserv 2016. [DOI: 10.1016/j.gecco.2016.05.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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42
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Interactions between the Avian Parasite, Philornis downsi (Diptera: Muscidae) and the Galapagos Flycatcher, Myiarchus magnirostris Gould (Passeriformes: Tyrannidae). J Wildl Dis 2015; 51:907-10. [PMID: 26267462 DOI: 10.7589/2015-01-025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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43
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Cimadom A, Ulloa A, Meidl P, Zöttl M, Zöttl E, Fessl B, Nemeth E, Dvorak M, Cunninghame F, Tebbich S. Invasive parasites, habitat change and heavy rainfall reduce breeding success in Darwin's finches. PLoS One 2014; 9:e107518. [PMID: 25248092 PMCID: PMC4172424 DOI: 10.1371/journal.pone.0107518] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 08/19/2014] [Indexed: 11/18/2022] Open
Abstract
Invasive alien parasites and pathogens are a growing threat to biodiversity worldwide, which can contribute to the extinction of endemic species. On the Galápagos Islands, the invasive parasitic fly Philornis downsi poses a major threat to the endemic avifauna. Here, we investigated the influence of this parasite on the breeding success of two Darwin's finch species, the warbler finch (Certhidea olivacea) and the sympatric small tree finch (Camarhynchus parvulus), on Santa Cruz Island in 2010 and 2012. While the population of the small tree finch appeared to be stable, the warbler finch has experienced a dramatic decline in population size on Santa Cruz Island since 1997. We aimed to identify whether warbler finches are particularly vulnerable during different stages of the breeding cycle. Contrary to our prediction, breeding success was lower in the small tree finch than in the warbler finch. In both species P. downsi had a strong negative impact on breeding success and our data suggest that heavy rain events also lowered the fledging success. On the one hand parents might be less efficient in compensating their chicks' energy loss due to parasitism as they might be less efficient in foraging on days of heavy rain. On the other hand, intense rainfalls might lead to increased humidity and more rapid cooling of the nests. In the case of the warbler finch we found that the control of invasive plant species with herbicides had a significant additive negative impact on the breeding success. It is very likely that the availability of insects (i.e. food abundance)is lower in such controlled areas, as herbicide usage led to the removal of the entire understory. Predation seems to be a minor factor in brood loss.
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Affiliation(s)
- Arno Cimadom
- Department of Behavioural Biology, University of Vienna, Vienna, Austria
| | - Angel Ulloa
- Charles Darwin Foundation, Puerto Ayora, Santa Cruz Island, Galápagos, Ecuador
| | - Patrick Meidl
- Institute for Science and Technology, Klosterneuburg, Austria
| | - Markus Zöttl
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Elisabet Zöttl
- Department of Behavioural Biology, University of Vienna, Vienna, Austria
| | - Birgit Fessl
- Charles Darwin Foundation, Puerto Ayora, Santa Cruz Island, Galápagos, Ecuador
| | | | | | | | - Sabine Tebbich
- Department of Behavioural Biology, University of Vienna, Vienna, Austria
- * E-mail:
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44
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O'Connor JA, Robertson J, Kleindorfer S. Darwin's Finch Begging Intensity Does Not Honestly Signal Need in Parasitised Nests. Ethology 2013. [DOI: 10.1111/eth.12196] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jody A. O'Connor
- School of Biological Sciences; The Flinders University of South Australia; Adelaide SA Australia
| | - Jeremy Robertson
- School of Biological Sciences; The Flinders University of South Australia; Adelaide SA Australia
| | - Sonia Kleindorfer
- School of Biological Sciences; The Flinders University of South Australia; Adelaide SA Australia
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45
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Knutie SA, Koop JAH, French SS, Clayton DH. Experimental test of the effect of introduced hematophagous flies on corticosterone levels of breeding Darwin's finches. Gen Comp Endocrinol 2013; 193:68-71. [PMID: 23892015 PMCID: PMC4383185 DOI: 10.1016/j.ygcen.2013.07.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 06/12/2013] [Accepted: 07/15/2013] [Indexed: 11/30/2022]
Abstract
Parasites can negatively affect the evolutionary fitness of their hosts by eliciting physiological stress responses. Parasite-induced stress can be monitored by measuring changes in the adrenal steroid hormone corticosterone. We examined the effect of an invasive parasite on the corticosterone concentrations of a common species of Darwin's finch, the medium ground finch (Geospiza fortis). Philornis downsi (Diptera: Muscidae) is a parasitic nest fly recently introduced to the Galapagos Islands, where it feeds on the blood of nestlings and breeding adult female finches. Previous work shows that P. downsi significantly reduces the reproductive success of several species of finches. We predicted that the effect of P. downsi on host reproductive success is mediated by stress responses in breeding female finches. High stress levels could reduce the ability of females to invest in offspring, thus decreasing their reproductive success. To test this hypothesis, we experimentally manipulated the abundance of P. downsi in nests, then measured baseline and acute stress-induced corticosterone levels, body condition, and hematocrit (red blood cell content). Acute stress-induced corticosterone levels increased over baseline levels, but this response did not differ significantly with parasite treatment. There was also no significant difference in the body condition or hematocrit of females from parasitized versus non-parasitized nests. Our results suggest that the lower reproductive success of females from parasitized nests is not mediated by a physiological stress response.
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Affiliation(s)
- Sarah A Knutie
- Department of Biology, University of Utah, 257 South 1400 East, Salt Lake City, UT 84112, USA.
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Kent RJ. Molecular methods for arthropod bloodmeal identification and applications to ecological and vector-borne disease studies. Mol Ecol Resour 2013; 9:4-18. [PMID: 21564560 DOI: 10.1111/j.1755-0998.2008.02469.x] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
DNA-based methods have greatly enhanced the sensitivity and specificity of hematophagous arthropod bloodmeal identification. A variety of methods have been applied to study the blood-feeding behaviour of mosquitoes, ticks, black flies and other blood-feeding arthropods as it relates to host-parasite interactions and pathogen transmission. Overviews of the molecular techniques used for bloodmeal identification, their advantages, disadvantages and applications are presented for DNA sequencing, group-specific polymerase chain reaction primers, restriction fragment length polymorphism, real-time polymerase chain reaction, heteroduplex analysis, reverse line-blot hybridization and DNA profiling. Technical challenges to bloodmeal identification including digestion and analysis of mixed bloodmeals are discussed. Analysis of bloodmeal identification results remains a challenge to the field, particularly with regard to incorporation of vertebrate census and ecology data. Future research directions for molecular analysis of arthropod bloodmeals are proposed.
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Affiliation(s)
- Rebekah J Kent
- Arbovirus Diseases Branch, Division of Vector-borne and Infectious Diseases, Centers for Disease Control and Prevention, 3150 Rampart Road, Fort Collins, CO 80521, USA
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Koop JAH, Owen JP, Knutie SA, Aguilar MA, Clayton DH. Experimental demonstration of a parasite-induced immune response in wild birds: Darwin's finches and introduced nest flies. Ecol Evol 2013; 3:2514-23. [PMID: 24567824 PMCID: PMC3930052 DOI: 10.1002/ece3.651] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 05/10/2013] [Accepted: 05/22/2013] [Indexed: 11/10/2022] Open
Abstract
Ecological immunology aims to explain variation among hosts in the strength and efficacy of immunological defenses. However, a shortcoming has been the failure to link host immune responses to actual parasites under natural conditions. Here, we present one of the first experimental demonstrations of a parasite-induced immune response in a wild bird population. The recently introduced ectoparasitic nest fly Philornis downsi severely impacts the fitness of Darwin's finches and other land birds in the Galápagos Islands. An earlier study showed that female medium ground finches (Geospiza fortis) had P. downsi-binding antibodies correlating with presumed variation in fly exposure over time. In the current study, we experimentally manipulated fly abundance to test whether the fly does, in fact, cause changes in antibody levels. We manipulated P. downsi abundance in nests and quantified P. downsi-binding antibody levels of medium ground finch mothers, fathers, and nestlings. We also quantified host behaviors, such as preening, which can integrate with antibody-mediated defenses against ectoparasites. Philornis downsi-binding antibody levels were significantly higher among mothers at parasitized nests, compared to mothers at (fumigated) nonparasitized nests. Mothers with higher antibody levels tended to have fewer parasites in their nests, suggesting that antibodies play a role in defense against parasites. Mothers showed no behavioral changes that would enhance the effectiveness of the immune response. Neither adult males, nor nestlings, had P. downsi-induced immunological or behavioral responses that would enhance defense against flies. None of the parasitized nests fledged any offspring, despite the immune response by mothers. Thus, this study shows that, while the immune response of mothers appeared to be defensive, it was not sufficient to rescue current reproductive fitness. This study further shows the importance of testing the fitness consequences of immune defenses, rather than assuming that such responses increase host fitness. Host immune responses can protect against the negative fitness consequences of parasitism; however, the strength and effectiveness of these responses vary among hosts. Strong host immune responses are often assumed to correlate with greater host fitness. This study investigates the relationship between host immune response, parasite load, and host fitness using Darwin's finches and an invasive nest parasite. We found that while the immune response of mothers appeared defensive, it did not rescue current reproductive fitness.
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Affiliation(s)
- Jennifer A H Koop
- Department of Biology, University of Utah Salt Lake City, Utah, 84112
| | - Jeb P Owen
- Department of Entomology, Washington State University Pullman, Washington, 99164
| | - Sarah A Knutie
- Department of Biology, University of Utah Salt Lake City, Utah, 84112
| | - Maria A Aguilar
- Department of Biology, University of Utah Salt Lake City, Utah, 84112
| | - Dale H Clayton
- Department of Biology, University of Utah Salt Lake City, Utah, 84112
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Velásquez Y, Ivorra T, Grzywacz A, Martínez-Sánchez A, Magaña C, García-Rojo A, Rojo S. Larval morphology, development and forensic importance of Synthesiomyia nudiseta (Diptera: Muscidae) in Europe: a rare species or just overlooked? BULLETIN OF ENTOMOLOGICAL RESEARCH 2013; 103:98-110. [PMID: 22929039 DOI: 10.1017/s0007485312000491] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The muscid Synthesiomyia nudiseta (van der Wulp, 1883) is a species with forensic importance in tropical and subtropical regions of the world. This fly has recently been introduced into southern Europe and, until now, had not been recorded in forensic cases in this region. Here, morphology of all larval instars of S. nudiseta is documented in detail by using a combination of light and scanning electron microscopy. Literature data concerning larval morphology are revised and characters allowing identification from other forensically important Muscidae are listed. The life cycle of this species was studied at four constant temperatures: 15, 20, 25 and 30 °C. Total development varied between 46.50 ± 0.97 days at 15 °C and 15.39 ± 0.32 days at 30 °C. Moreover, we report this species breeding in human corpses, for the first time in Europe, in forensic cases from autopsies at the Anatomical Forensic Institute of Madrid and the Institute of Legal Medicine of Alicante, Spain.
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Affiliation(s)
- Y Velásquez
- University Research Institute of Biodiversity CIBIO, Department of Environmental Sciences, University of Alicante, Alicante, Spain
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Silvestri L, Antoniazzi LR, Couri MS, Monje LD, Beldomenico PM. First record of the avian ectoparasite Philornis downsi Dodge & Aitken, 1968 (Diptera: Muscidae) in Argentina. Syst Parasitol 2011; 80:137-40. [PMID: 21898202 DOI: 10.1007/s11230-011-9314-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 05/02/2011] [Indexed: 10/17/2022]
Abstract
Species of Philornis Meinert, 1890 (Diptera, Muscidae) are Neotropical dipterans that include species with parasitic larvae which feed on nestling birds. To date, all Philornis species that have been recorded from Argentina have parasitic subcutaneous larvae. Here, for the first time for Argentina, we report the finding of Philornis downsi Dodge & Aitken, 1968, a fly with a nest-dwelling, semi-haematophagous larva. This record, from the humid Chaco ecoregion of Argentina in the nest of a saffron finch Sicalis flaveola pelzelni Sclater, substantially extends the known distribution of this species. We also report the consensus sequences of the internal transcribed spacer 1 (ITS1) and ITS2 regions of three of the specimens for future reference and comparison. Further investigation is needed to determine whether Argentina is part of the historical range of P. downsi or, alternatively, represents a recent expansion of its range, perhaps due to climatic changes or other factors of global environmental variation.
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Affiliation(s)
- L Silvestri
- Laboratorio de Ecología de Enfermedades, Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, RP Kreder 2805, 3080, Esperanza, Santa Fe, Argentina
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Koop JAH, Huber SK, Laverty SM, Clayton DH. Experimental demonstration of the fitness consequences of an introduced parasite of Darwin's finches. PLoS One 2011; 6:e19706. [PMID: 21589659 PMCID: PMC3092749 DOI: 10.1371/journal.pone.0019706] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Accepted: 04/14/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Introduced parasites are a particular threat to small populations of hosts living on islands because extinction can occur before hosts have a chance to evolve effective defenses. An experimental approach in which parasite abundance is manipulated in the field can be the most informative means of assessing a parasite's impact on the host. The parasitic fly Philornis downsi, recently introduced to the Galápagos Islands, feeds on nestling Darwin's finches and other land birds. Several correlational studies, and one experimental study of mixed species over several years, reported that the flies reduce host fitness. Here we report the results of a larger scale experimental study of a single species at a single site over a single breeding season. METHODOLOGY/PRINCIPAL FINDINGS We manipulated the abundance of flies in the nests of medium ground finches (Geospiza fortis) and quantified the impact of the parasites on nestling growth and fledging success. We used nylon nest liners to reduce the number of parasites in 24 nests, leaving another 24 nests as controls. A significant reduction in mean parasite abundance led to a significant increase in the number of nests that successfully fledged young. Nestlings in parasite-reduced nests also tended to be larger prior to fledging. CONCLUSIONS/SIGNIFICANCE Our results confirm that P. downsi has significant negative effects on the fitness of medium ground finches, and they may pose a serious threat to other species of Darwin's finches. These data can help in the design of management plans for controlling P. downsi in Darwin's finch breeding populations.
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Affiliation(s)
- Jennifer A H Koop
- Biology Department, University of Utah, Salt Lake City, Utah, United States of America.
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