1
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Liu J, Tu F, Liu M, Wang J, Zhang Z. Antifertility effects of EP-1 (quinestrol and levonorgestrel) on Pacific rats (Rattus exulans). Integr Zool 2024; 19:127-142. [PMID: 37884475 DOI: 10.1111/1749-4877.12774] [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] [Indexed: 10/28/2023]
Abstract
Pest rodents pose a serious threat to island biodiversity. Fertility control could be an alternative approach to control the impact of rodents on these islands. In this study, we examined the antifertility effects of EP-1 baits containing quinestrol (E) and levonorgestrel (P) using a dose of 50 ppm E and P at three different ratios (E:P ratio = 1:2, 1:1, and 2:1) on Pacific rats (Rattus exulans) in the Xisha Islands, Hainan, China. Compared to the control group, all animals in EP-1 treatment groups showed significantly decreased food intake and body weight. In treated males, there were obvious abnormalities in testis structure and a significant decrease of relative seminal vesicle weight, but no significant effect on relative uterine and ovarian weights (g kg-1 body weight), or ovarian structure in females. Adding 8% sucrose to the original 50-ppm baits (E:P ratio = 1:1) significantly increased bait palatability for males and females. This dose induced uterine edema and abnormalities of ovarian structure in females but had no significant negative effect on the relative testis, epididymis, and seminal vesicle weights (g kg-1 body weight) or sperm density in males. In summary, 50-ppm EP-1 (1:1) baits have the potential to disrupt the fertility of females, and 8% sucrose addition to the EP-1 baits (E:P ratio = 1:1) could improve bait palatability. This dose disrupted the testis structure in males. Future studies are needed to improve bait acceptance and assess the antifertility effects of EP-1 (1:1) on Pacific rats in captive breeding trials and under field conditions.
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Affiliation(s)
- Jing Liu
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, Hainan, China
| | - Feiyun Tu
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, Hainan, China
| | - Ming Liu
- Secretariat Office, International Society of Zoological Science and Society and Journal Office, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Jichao Wang
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, Hainan, China
| | - Zhibin Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
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2
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Holthuijzen WA, Flint EN, Green SJ, Plissner JH, Simberloff D, Sweeney D, Wolf CA, Jones HP. An invasive appetite: Combining molecular and stable isotope analyses to reveal the diet of introduced house mice (Mus musculus) on a small, subtropical island. PLoS One 2023; 18:e0293092. [PMID: 37856477 PMCID: PMC10586637 DOI: 10.1371/journal.pone.0293092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 10/04/2023] [Indexed: 10/21/2023] Open
Abstract
House mice (Mus musculus) pose a conservation threat on islands, where they adversely affect native species' distributions, densities, and persistence. On Sand Island of Kuaihelani, mice recently began to depredate nesting adult mōlī (Laysan Albatross, Phoebastria immutabilis). Efforts are underway to eradicate mice from Sand Island, but knowledge of mouse diet is needed to predict ecosystem response and recovery following mouse removal. We used next-generation sequencing to identify what mice eat on Sand Island, followed by stable isotope analysis to estimate the proportions contributed by taxa to mouse diet. We collected paired fecal and hair samples from 318 mice between April 2018 to May 2019; mice were trapped approximately every eight weeks among four distinct habitat types to provide insight into temporal and spatial variation. Sand Island's mice mainly consume arthropods, with nearly equal (but substantially smaller) contributions of C3 plants, C4 plants, and mōlī. Although seabird tissue is a small portion of mouse diet, mice consume many detrital-feeding arthropods in and around seabird carcasses, such as isopods, flesh flies, ants, and cockroaches. Additionally, most arthropods and plants eaten by mice are non-native. Mouse diet composition differs among habitat types but changes minimally throughout the year, indicating that mice are not necessarily limited by food source availability or accessibility. Eradication of house mice may benefit seabirds on Sand Island (by removing a terrestrial, non-native predator), but it is unclear how arthropod and plant communities may respond and change. Non-native and invasive arthropods and plants previously consumed (and possibly suppressed) by mice may be released post-eradication, which could prevent recovery of native taxa. Comprehensive knowledge of target species' diet is a critical component of eradication planning. Dietary information should be used both to identify and to monitor which taxa may respond most strongly to invasive species removal and to assess if proactive, pre-eradication management activities are warranted.
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Affiliation(s)
- Wieteke A. Holthuijzen
- Department of Ecology & Evolutionary Biology, University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
| | - Elizabeth N. Flint
- Marine National Monuments of the Pacific, U.S. Fish and Wildlife Service, Honolulu, Hawaiʻi, United States of America
| | - Stefan J. Green
- Genomics and Microbiome Core Facility, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Jonathan H. Plissner
- Midway Atoll National Wildlife Refuge, U.S. Fish and Wildlife Service, Waipahu, Hawaiʻi, United States of America
| | - Daniel Simberloff
- Department of Ecology & Evolutionary Biology, University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
| | - Dagmar Sweeney
- Institute for Health Research & Policy, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Coral A. Wolf
- Island Conservation, Santa Cruz, California, United States of America
| | - Holly P. Jones
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, United States of America
- Institute for the Study of the Environment, Sustainability, and Energy, Northern Illinois University, DeKalb, Illinois, United States of America
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3
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Courtois P, Martinez C, Thomas A. Spatial priorities for invasive alien species control in protected areas. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 878:162675. [PMID: 36933722 DOI: 10.1016/j.scitotenv.2023.162675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/31/2023] [Accepted: 03/02/2023] [Indexed: 05/13/2023]
Abstract
Given the limited funds available for the management of invasive alien species (IASs), there is a need to design cost-effective strategies to prioritize their control. In this paper, we propose a cost-benefit optimization framework that incorporates the spatially explicit costs and benefits of invasion control, as well as the spatial invasion dynamics. Our framework offers a simple yet operational priority-setting criterion for the spatially explicit management of IASs under budget constraints. We applied this criterion to the control of the invasion of primrose willow (genus Ludwigia) in a protected area in France. Using a unique geographic information system panel dataset on control costs and invasion levels through space for a 20-year period, we estimated the costs of invasion control and a spatial econometric model of primrose willow invasion dynamics. Next, we used a field choice experiment to estimate the spatially explicit benefits of invasion control. Applying our priority criterion, we show that, unlike the current management strategy that controls the invasion in a spatially homogeneous manner, the criterion recommends targeted control on heavily invaded areas that are highly valued by users. We also show that the returns on investment are high, justifying the need to increase the allocated budgets and to treat the invasion more drastically. We conclude with policy recommendations and possible extensions, including the development of operational cost-benefit decision-support tools to assist local decision-makers in setting management priorities.
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Affiliation(s)
- Pierre Courtois
- CEE-M, Université de Montpellier, CNRS, INRAE, Instit Agro, 34000 Montpellier, France.
| | - César Martinez
- CEE-M, Université de Montpellier, CNRS, INRAE, Instit Agro, 34000 Montpellier, France; INRAE, BioSP, 84914 Avignon, France.
| | - Alban Thomas
- Paris-Saclay Applied Economics, Université Paris-Saclay, INRAE, AgroParisTech, 91120 Palaiseau, France.
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4
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Yarita S, Morgan-Richards M, Trewick SA. Genotypic detection of barriers to rat dispersal: Rattus rattus behind a peninsula predator-proof fence. Biol Invasions 2023; 25:1723-1738. [PMID: 36777104 PMCID: PMC9900205 DOI: 10.1007/s10530-023-03004-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 01/12/2023] [Indexed: 02/09/2023]
Abstract
Clear delimitation of management units is essential for effective management of invasive species. Analysis of population genetic structure of target species can improve identification and interpretation of natural and artificial barriers to dispersal. In Aotearoa New Zealand where the introduced ship rat (Rattus rattus) is a major threat to native biodiversity, effective suppression of pest numbers requires removal and limitation of reinvasion from outside the managed population. We contrasted population genetic structure in rat populations over a wide scale without known barriers, with structure over a fine scale with potential barriers to dispersal. MtDNA D-loop sequences and microsatellite genotypes resolved little genetic structure in southern North Island population samples of ship rat 100 km apart. In contrast, samples from major islands differed significantly for both mtDNA and nuclear markers. We also compared ship rats collected within a small peninsula reserve bounded by sea, suburbs and, more recently, a predator fence with rats in the surrounding forest. Here, mtDNA did not differ but genotypes from 14 nuclear loci were sufficient to distinguish the fenced population. This suggests that natural (sea) and artificial barriers (town, fence) are effectively limiting gene flow among ship rat populations over the short distance (~ 500 m) between the peninsula reserve and surrounding forest. The effectiveness of the fence alone is not clear given it is a recent feature and no historical samples exist; resampling population genetic diversity over time will improve understanding. Nonetheless, the current genetic isolation of the fenced rat population suggests that rat eradication is a sensible management option given that reinvasion appears to be limited and could probably be managed with a biosecurity programme. Supplementary Information The online version contains supplementary material available at 10.1007/s10530-023-03004-8.
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Affiliation(s)
- Shogo Yarita
- grid.148374.d0000 0001 0696 9806Wildlife and Ecology, School of Natural Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand
| | - Mary Morgan-Richards
- grid.148374.d0000 0001 0696 9806Wildlife and Ecology, School of Natural Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand
| | - Steven A. Trewick
- grid.148374.d0000 0001 0696 9806Wildlife and Ecology, School of Natural Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand
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5
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Do Invasive Mammal Eradications from Islands Support Climate Change Adaptation and Mitigation? CLIMATE 2021. [DOI: 10.3390/cli9120172] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Climate change represents a planetary emergency that is exacerbating the loss of native biodiversity. In response, efforts promoting climate change adaptation strategies that improve ecosystem resilience and/or mitigate climate impacts are paramount. Invasive Alien Species are a key threat to islands globally, where strategies such as preventing establishment (biosecurity), and eradication, especially invasive mammals, have proven effective for reducing native biodiversity loss and can also advance ecosystem resilience and create refugia for native species at risk from climate change. Furthermore, there is growing evidence that successful eradications may also contribute to mitigating climate change. Given the cross-sector potential for eradications to reduce climate impacts alongside native biodiversity conservation, we sought to understand when conservation managers and funders explicitly sought to use or fund the eradication of invasive mammals from islands to achieve positive climate outcomes. To provide context, we first summarized available literature of the synergistic relationship between invasive species and climate change, including case studies where invasive mammal eradications served to meet climate adaptation or mitigation solutions. Second, we conducted a systematic review of the literature and eradication-related conference proceedings to identify when these synergistic effects of climate and invasive species were explicitly addressed through eradication practices. Third, we reviewed projects from four large funding entities known to support climate change solutions and/or native biodiversity conservation efforts and identified when eradications were funded in a climate change context. The combined results of our case study summary paired with systematic reviews found that, although eradicating invasive mammals from islands is an effective climate adaptation strategy, island eradications are poorly represented within the climate change adaptation and mitigation funding framework. We believe this is a lost opportunity and encourage eradication practitioners and funders of climate change adaptation to leverage this extremely effective nature-based tool into positive conservation and climate resilience solutions.
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6
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Abstract
AbstractNumerous island species have gone extinct and many extant, but threatened, island endemics require ongoing monitoring of their conservation status. The small tree Vachellia anegadensis was formerly thought to occur only on the limestone island of Anegada in the British Virgin Islands and was categorized as Critically Endangered. However, in 2008 it was discovered on the volcanic island of Fallen Jerusalem, c. 35 km from Anegada, and in 2018 it was recategorized as Endangered. To inform conservation interventions, we examined the species’ distribution, genetic population structure, dependency on pollinators and preferred habitat, and documented any threats. We found V. anegadensis to be locally widespread on Anegada but uncommon on Fallen Jerusalem and established that geographical location does not predict genetic differentiation amongst populations. Vachellia anegadensis produces the highest number of seed pods when visited by animal pollinators, in particular Lepidoptera. Introduced animals and disturbance by humans appear to be the main threats to V. anegadensis, and in situ conservation is critical for the species’ long-term survival.
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7
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Kurle CM, Zilliacus KM, Sparks J, Curl J, Bock M, Buckelew S, Williams JC, Wolf CA, Holmes ND, Plissner J, Howald GR, Tershy BR, Croll DA. Indirect effects of invasive rat removal result in recovery of island rocky intertidal community structure. Sci Rep 2021; 11:5395. [PMID: 33686134 PMCID: PMC7940711 DOI: 10.1038/s41598-021-84342-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 02/03/2021] [Indexed: 02/07/2023] Open
Abstract
Eleven years after invasive Norway rats (Rattus norvegicus) were eradicated from Hawadax Island, in the Aleutian Islands, Alaska, the predicted three-level trophic cascade in the rocky intertidal, with native shorebirds as the apex predator, returned, leading to a community resembling those on rat-free islands with significant decreases in invertebrate species abundances and increases in fleshy algal cover. Rats had indirectly structured the intertidal community via their role as the apex predator in a four-level trophic cascade. Our results are an excellent example of an achievable and relatively short-term community-level recovery following removal of invasive animals. These conservation successes are especially important for islands as their disproportionately high levels of native biodiversity are excessively threatened by invasive mammals.
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Affiliation(s)
- Carolyn M Kurle
- Division of Biological Sciences, Ecology, Behavior, and Evolution Section, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92023, USA.
| | - Kelly M Zilliacus
- Conservation Action Lab, University of California Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA
| | - Jenna Sparks
- Conservation Action Lab, University of California Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA.,Oikonos Ecosystem Knowledge, PO Box 2570, Santa Cruz, CA, 95063, USA
| | - Jen Curl
- Island Conservation, 2100 Delaware Ave, Suite 1, Santa Cruz, CA, 95060, USA.,Alaska Department of Fish and Game, Division of Wildlife Conservation, 1300 College Rd, Fairbanks, AK, 99701, USA
| | - Mila Bock
- Conservation Action Lab, University of California Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA.,Great Basin Institute, 16750 Mt. Rose Highway, Reno, NV, 89511, USA
| | - Stacey Buckelew
- Island Conservation, 2100 Delaware Ave, Suite 1, Santa Cruz, CA, 95060, USA.,Axiom Data Science, 1016 W 6th Ave, Ste. 105, Anchorage, AK, 99501, USA
| | - Jeffrey C Williams
- US Fish and Wildlife Service, Alaska Maritime National Wildlife Refuge, 95 Sterling Highway, Suite 1, Homer, AK, 99603, USA
| | - Coral A Wolf
- Island Conservation, 2100 Delaware Ave, Suite 1, Santa Cruz, CA, 95060, USA
| | - Nick D Holmes
- Island Conservation, 2100 Delaware Ave, Suite 1, Santa Cruz, CA, 95060, USA.,The Nature Conservancy, 201 Mission Street #4, San Francisco, CA, 94105, USA
| | - Jonathan Plissner
- Island Conservation, 2100 Delaware Ave, Suite 1, Santa Cruz, CA, 95060, USA
| | - Gregg R Howald
- Island Conservation, 2100 Delaware Ave, Suite 1, Santa Cruz, CA, 95060, USA.,FreshWater Life, Telluride, CO, USA
| | - Bernie R Tershy
- Conservation Action Lab, University of California Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA
| | - Donald A Croll
- Conservation Action Lab, University of California Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA.
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8
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Ng L, Garcia JE, Dyer AG, Stuart-Fox D. The ecological significance of time sense in animals. Biol Rev Camb Philos Soc 2020; 96:526-540. [PMID: 33164298 DOI: 10.1111/brv.12665] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 10/12/2020] [Accepted: 10/28/2020] [Indexed: 11/29/2022]
Abstract
Time is a fundamental dimension of all biological events and it is often assumed that animals have the capacity to track the duration of experienced events (known as interval timing). Animals can potentially use temporal information as a cue during foraging, communication, predator avoidance, or navigation. Interval timing has been traditionally investigated in controlled laboratory conditions but its ecological relevance in natural environments remains unclear. While animals may time events in artificial and highly controlled conditions, they may not necessarily use temporal information in natural environments where they have access to other cues that may have more relevance than temporal information. Herein we critically evaluate the ecological contexts where interval timing has been suggested to provide adaptive value for animals. We further discuss attributes of interval timing that are rarely considered in controlled laboratory studies. Finally, we encourage consideration of ecological relevance when designing future interval-timing studies and propose future directions for such experiments.
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Affiliation(s)
- Leslie Ng
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia.,Bio-Inspired Digital Sensing (BIDS) Lab, School of Media and Communication, RMIT University, Melbourne, VIC, 3001, Australia
| | - Jair E Garcia
- Bio-Inspired Digital Sensing (BIDS) Lab, School of Media and Communication, RMIT University, Melbourne, VIC, 3001, Australia
| | - Adrian G Dyer
- Bio-Inspired Digital Sensing (BIDS) Lab, School of Media and Communication, RMIT University, Melbourne, VIC, 3001, Australia.,Department of Physiology, Monash University, Clayton, Melbourne, VIC, 3800, Australia
| | - Devi Stuart-Fox
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia
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9
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Miller‐ter Kuile A, Orr D, Bui A, Dirzo R, Klope M, McCauley D, Motta C, Young H. Impacts of rodent eradication on seed predation and plant community biomass on a tropical atoll. Biotropica 2020. [DOI: 10.1111/btp.12864] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ana Miller‐ter Kuile
- Department of Ecology, Evolution, and Marine Biology University of California, Santa Barbara Santa Barbara CA USA
| | - Devyn Orr
- Department of Ecology, Evolution, and Marine Biology University of California, Santa Barbara Santa Barbara CA USA
| | - An Bui
- Department of Ecology, Evolution, and Marine Biology University of California, Santa Barbara Santa Barbara CA USA
| | - Rodolfo Dirzo
- Department of Biology Stanford University Stanford CA USA
| | - Maggie Klope
- Department of Ecology, Evolution, and Marine Biology University of California, Santa Barbara Santa Barbara CA USA
| | - Douglas McCauley
- Department of Ecology, Evolution, and Marine Biology University of California, Santa Barbara Santa Barbara CA USA
| | - Carina Motta
- Department of Ecology, Evolution, and Marine Biology University of California, Santa Barbara Santa Barbara CA USA
| | - Hillary Young
- Department of Ecology, Evolution, and Marine Biology University of California, Santa Barbara Santa Barbara CA USA
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10
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Carpenter JK, Wilmshurst JM, McConkey KR, Hume JP, Wotton DM, Shiels AB, Burge OR, Drake DR. The forgotten fauna: Native vertebrate seed predators on islands. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13629] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
| | - Janet M. Wilmshurst
- Manaaki Whenua ‐ Landcare Research Lincoln New Zealand
- School of Environment University of Auckland Auckland New Zealand
| | - Kim R. McConkey
- School of Natural Sciences and Engineering National Institute of Advanced StudiesIndian Institute of Science Campus Bangalore India
- School of Geography University of Nottingham Malaysia Campus Selangor Malaysia
| | - Julian P. Hume
- Department of Life Sciences Natural History Museum Herts UK
| | - Debra M. Wotton
- Moa's Ark Research Paraparaumu New Zealand
- Biological Sciences University of Canterbury Christchurch New Zealand
| | - Aaron B. Shiels
- USDAAPHISWSNational Wildlife Research Center Fort Collins CO USA
| | | | - Donald R. Drake
- School of Life Sciences University of Hawaiʻi Honolulu HI USA
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11
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Samaniego A, Griffiths R, Gronwald M, Holmes ND, Oppel S, Stevenson BC, Russell JC. Risks posed by rat reproduction and diet to eradications on tropical islands. Biol Invasions 2020. [DOI: 10.1007/s10530-019-02188-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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12
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Siers SR, Shiels AB, Barnhart PD. Invasive Snake Activity Before and After Automated Aerial Baiting. J Wildl Manage 2019. [DOI: 10.1002/jwmg.21794] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Shane R. Siers
- USDA APHIS Wildlife ServicesNational Wildlife Research Center c/o Wildlife Services Guam State Office, 233 Pangelinan Way Barrigada GU 96913 USA
| | - Aaron B. Shiels
- USDA APHIS Wildlife ServicesNational Wildlife Research Center 4101 LaPorte Avenue Fort Collins CO 80521 USA
| | - Patrick D. Barnhart
- USDA APHIS Wildlife ServicesNational Wildlife Research Center PO Box 10880 Hilo HI 96721 USA
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13
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Baker CM, Plein M, Shaikh R, Bode M. Simultaneous invasive alien predator eradication delivers the best outcomes for protected island species. Biol Invasions 2019. [DOI: 10.1007/s10530-019-02161-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Benkwitt CE, Wilson SK, Graham NAJ. Seabird nutrient subsidies alter patterns of algal abundance and fish biomass on coral reefs following a bleaching event. GLOBAL CHANGE BIOLOGY 2019; 25:2619-2632. [PMID: 31157944 DOI: 10.1111/gcb.14643] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 04/02/2019] [Accepted: 04/02/2019] [Indexed: 06/09/2023]
Abstract
Cross-ecosystem nutrient subsidies play a key role in the structure and dynamics of recipient communities, but human activities are disrupting these links. Because nutrient subsidies may also enhance community stability, the effects of losing these inputs may be exacerbated in the face of increasing climate-related disturbances. Nutrients from seabirds nesting on oceanic islands enhance the productivity and functioning of adjacent coral reefs, but it is unknown whether these subsidies affect the response of coral reefs to mass bleaching events or whether the benefits of these nutrients persist following bleaching. To answer these questions, we surveyed benthic organisms and fishes around islands with seabirds and nearby islands without seabirds due to the presence of invasive rats. Surveys were conducted in the Chagos Archipelago, Indian Ocean, immediately before the 2015-2016 mass bleaching event and, in 2018, two years following the bleaching event. Regardless of the presence of seabirds, relative coral cover declined by 32%. However, there was a post-bleaching shift in benthic community structure around islands with seabirds, which did not occur around islands with invasive rats, characterized by increases in two types of calcareous algae (crustose coralline algae [CCA] and Halimeda spp.). All feeding groups of fishes were positively affected by seabirds, but only herbivores and piscivores were unaffected by the bleaching event and sustained the greatest difference in biomass between islands with seabirds versus those with invasive rats. By contrast, corallivores and planktivores, both of which are coral-dependent, experienced the greatest losses following bleaching. Even though seabird nutrients did not enhance community-wide resistance to bleaching, they may still promote recovery of these reefs through their positive influence on CCA and herbivorous fishes. More broadly, the maintenance of nutrient subsidies, via strategies including eradication of invasive predators, may be important in shaping the response of ecological communities to global climate change.
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Affiliation(s)
| | - Shaun K Wilson
- Department of Biodiversity, Conservation and Attractions, Perth, Western Australia, Australia
- Oceans Institute, University of Western Australia, Crawley, Western Australia, Australia
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15
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Shiels AB, Ramírez de Arellano GE. Habitat use and seed removal by invasive rats (
Rattus rattus
) in disturbed and undisturbed rain forest, Puerto Rico. Biotropica 2019. [DOI: 10.1111/btp.12640] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Aaron B. Shiels
- USDA National Wildlife Research Center Fort Collins Colorado
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16
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Gill NS, Yelenik S, Banko P, Dixon CB, Jaenecke K, Peck R. Invasive rat control is an efficient, yet insufficient, method for recovery of the critically endangered Hawaiian plant hau kuahiwi (Hibiscadelphus giffardianus). PLoS One 2018; 13:e0208106. [PMID: 30485341 PMCID: PMC6261625 DOI: 10.1371/journal.pone.0208106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 11/12/2018] [Indexed: 11/24/2022] Open
Abstract
Biological invasions of rodents and other species have been especially problematic on tropical islands. Invasive Rattus rattus consumption of Hibiscadelphus giffardianus (Malvaceae; common Hawaiian name hau kuahiwi) fruit and seeds has been hypothesized to be the most-limiting factor inhibiting the critically endangered tree, but this has not been experimentally tested, and little is known about other factors affecting seed dispersal, germination, and seedling establishment. Thus, we do not know if rat removal is sufficient to increase hau kuahiwi recruitment. This study aims to evaluate the effect of rat population control on the ability of hau kuahiwi to retain fruit and establish seedlings. We compared hau kuahiwi fruiting and seedling recruitment in a stand treated to reduce rat abundance and a neighbouring control stand. Fruit retention increased following treatment but seedling establishment did not. Although rat control improves the ability of hau kuahiwi to retain fruit, other, presently unknown inhibitors to seed dispersal, germination, and/or seedling development remain. Seed and seedling predation by other species, competition from numerous invasive plant species, unsuitable climate, and/or other factors may be primary inhibitors in the absence of rats, but we emphasize that progressive isolation of these factors at individual hau kuahiwi life stages may be necessary to identify the remaining threats to the conservation of this critically endangered plant.
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Affiliation(s)
- Nathan S. Gill
- U.S. Geological Survey, Pacific Island Ecosystems Research Center, Hawai’i Volcanoes National Park, HI, United States of America
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, United States of America
- * E-mail:
| | - Stephanie Yelenik
- U.S. Geological Survey, Pacific Island Ecosystems Research Center, Hawai’i Volcanoes National Park, HI, United States of America
| | - Paul Banko
- U.S. Geological Survey, Pacific Island Ecosystems Research Center, Hawai’i Volcanoes National Park, HI, United States of America
| | - Christopher B. Dixon
- Department of Statistics, Brigham Young University, Provo, UT, United States of America
| | - Kelly Jaenecke
- Hawai’i Cooperative Studies Unit, University of Hawai’i at Hilo, Hawai’i Volcanoes National Park, HI, United States of America
| | - Robert Peck
- Hawai’i Cooperative Studies Unit, University of Hawai’i at Hilo, Hawai’i Volcanoes National Park, HI, United States of America
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