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Geary WL, Tulloch AIT, Ritchie EG, Doherty TS, Nimmo DG, Maxwell MA, Wayne AF. Identifying historical and future global change drivers that place species recovery at risk. Glob Chang Biol 2023; 29:2953-2967. [PMID: 36864646 DOI: 10.1111/gcb.16661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 11/28/2022] [Indexed: 05/03/2023]
Abstract
Ecosystem management in the face of global change requires understanding how co-occurring threats affect species and communities. Such an understanding allows for effective management strategies to be identified and implemented. An important component of this is differentiating between factors that are within (e.g. invasive predators) or outside (e.g. drought, large wildfires) of a local manager's control. In the global biodiversity hotspot of south-western Australia, small- and medium-sized mammal species are severely affected by anthropogenic threats and environmental disturbances, including invasive predators, fire, and declining rainfall. However, the relative importance of different drivers has not been quantified. We used data from a long-term monitoring program to fit Bayesian state-space models that estimated spatial and temporal changes in the relative abundance of four threatened mammal species: the woylie (Bettongia penicillata), chuditch (Dasyurus geoffroii), koomal (Trichosurus vulpecula) and quenda (Isoodon fusciventor). We then use Bayesian structural equation modelling to identify the direct and indirect drivers of population changes, and scenario analysis to forecast population responses to future environmental change. We found that habitat loss or conversion and reduced primary productivity (caused by rainfall declines) had greater effects on species' spatial and temporal population change than the range of fire and invasive predator (the red fox Vulpes vulpes) management actions observed in the study area. Scenario analysis revealed that a greater extent of severe fire and further rainfall declines predicted under climate change, operating in concert are likely to further reduce the abundance of these species, but may be mitigated partially by invasive predator control. Considering both historical and future drivers of population change is necessary to identify the factors that risk species recovery. Given that both anthropogenic pressures and environmental disturbances can undermine conservation efforts, managers must consider how the relative benefit of conservation actions will be shaped by ongoing global change.
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Affiliation(s)
- William L Geary
- School of Life and Environmental Sciences (Burwood Campus), Centre for Integrative Ecology, Deakin University, Geelong, Victoria, Australia
- Biodiversity Division, Department of Environment, Land, Water and Planning, East Melbourne, Victoria, Australia
| | - Ayesha I T Tulloch
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
- School of Biology and Environmental Science, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Euan G Ritchie
- School of Life and Environmental Sciences (Burwood Campus), Centre for Integrative Ecology, Deakin University, Geelong, Victoria, Australia
| | - Tim S Doherty
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Dale G Nimmo
- Gulbali Institute, School of Agricultural, Environmental and Veterinary Sciences, Charles Sturt University, New South Wales, Albury, Australia
| | - Marika A Maxwell
- Department of Biodiversity, Conservation and Attractions, Manjimup, Western Australia, Australia
| | - Adrian F Wayne
- Department of Biodiversity, Conservation and Attractions, Manjimup, Western Australia, Australia
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Geary WL, Wayne AF, Tulloch AIT, Ritchie EG, Maxwell MA, Doherty TS. Fox and cat responses to fox baiting intensity, rainfall and prey abundance in the Upper Warren, Western Australia. Wildl Res 2022. [DOI: 10.1071/wr21184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Harrison ND, Frick CH, Wayne AF. Repeatable measure of cage trap behaviour to quantify boldness and agitation in a macropod. Aust Mammalogy 2022. [DOI: 10.1071/am22007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Seidlitz A, Bryant KA, Armstrong NJ, Calver MC, Wayne AF. Sign surveys can be more efficient and cost effective than driven transects and camera trapping: a comparison of detection methods for a small elusive mammal, the numbat (Myrmecobius fasciatus). Wildl Res 2021. [DOI: 10.1071/wr20020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Abstract
ContextDetermining the most efficient detection method for a target species is key for successful wildlife monitoring and management. Driven transects and sign surveys are commonly used to monitor populations of the endangered numbat (Myrmecobius fasciatus). Camera trapping is being explored as a new method. These methods were unevaluated for efficacy and cost for numbat detection.
AimsTo compare efficacy and costing of driven transects, sign surveys and camera trapping for detecting numbats in the Upper Warren region, Western Australia.
MethodsSeven repeat sign surveys and driven transects, as well as 4 months of camera trapping, were conducted concurrently at 50 sites along three transects. Numbat detection rates and costing of the three techniques were compared, and detection probabilities were compared between sign surveys and camera trapping.
Key resultsNumbat signs were detected during 88 surveys at 39 sites, exceeding camera trapping (26 detections at 13 sites) and driven transects (seven detections near five sites). The estimated probability for detecting a numbat or a sign thereof (at a site where numbats were present) ranged from 0.21 to 0.35 for a sign survey, and 0.02 to 0.06 for 7 days of camera trapping. Total survey costs were lowest for driven transects, followed by camera trapping and sign surveys. When expressed as cost per numbat detection, sign surveys were cheapest.
ConclusionsComparative studies of survey methods are essential for optimal, cost-effective wildlife monitoring. Sign surveys were more successful and cost effective than camera trapping or driven transects for detecting numbats in the Upper Warren region. Together with occupancy modelling, sign surveys are appropriate to investigate changes in occupancy rates over time, which could serve as a metric for long-term numbat monitoring.
ImplicationsThere is no ‘best’ method for wildlife surveys. Case-specific comparison of animal detection methods is recommended to ensure optimal methods. For the numbat population in the Upper Warren region, further studies are needed to improve numbat detection rates from camera trapping, and to test sign surveys in autumn (March to May), when surviving juvenile numbats have established their own territory and assumptions regarding population closure are less likely to be violated.
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Seidlitz A, Bryant KA, Armstrong NJ, Calver M, Wayne AF. Optimising camera trap height and model increases detection and individual identification rates for a small mammal, the numbat (Myrmecobius fasciatus). Aust Mammalogy 2021. [DOI: 10.1071/am20020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Camera traps are widely used to collect data for wildlife management, but species-specific testing is crucial. We conducted three trials to optimise camera traps for detecting numbats (Myrmecobius fasciatus), a 500–700-g mammal. We compared detection rates from (1) Reconyx PC900 camera traps installed at heights ranging from 10–45cm, and (2) Reconyx PC900, Swift 3C standard and wide-angle camera traps with differing detection zone widths. Finally, we compared elevated, downward-angled time-lapse cameras installed at heights ranging from 1–2m to obtain dorsal images for individual numbat identification. Camera traps set at 25cm had the highest detection rates but missed 40% of known events. During model comparison, Swift 3C wide-angle camera traps recorded 89%, Swift 3C standard 51%, and Reconyx PC900 37% of known events. The number of suitable images from elevated, downward-angled cameras, depicting dorsal fur patterns, increased with increasing camera height. The use of well regarded camera trap brands and generic recommendations for set-up techniques cannot replace rigorous, species-specific testing. For numbat detection, we recommend the Swift 3C wide-angle model installed at 25-cm height. For individual numbat identification, elevated, downward-angled time-lapse cameras were useful; however, more research is needed to optimise this technique.
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Northover AS, Thompson RCA, Lymbery AJ, Wayne AF, Keatley S, Ash A, Elliot AD, Morris K, Godfrey SS. Altered parasite community structure in an endangered marsupial following translocation. Int J Parasitol Parasites Wildl 2019; 10:13-22. [PMID: 31334028 PMCID: PMC6617222 DOI: 10.1016/j.ijppaw.2019.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/27/2019] [Accepted: 07/02/2019] [Indexed: 12/12/2022]
Abstract
Fauna translocations play an integral role in the management of threatened wildlife, though we are limited by our understanding of how the host-parasite community changes during translocation. During this longitudinal field-based study, we monitored gastrointestinal, blood-borne and ectoparasite taxa infecting woylies (Bettongia penicillata) for up to 12 months following two fauna translocations to supplement existing wild woylie populations in three different sites (Dryandra, Walcott and Warrup East) within the south-west of Western Australia. We aimed to (a) identify changes in parasite community structure of both translocated and resident woylies following translocation; and (b) evaluate the efficacy of ivermectin treatment in translocated hosts. Destination site and time since translocation had the strongest effects on parasite prevalence and mean faecal egg counts following translocation. Ivermectin treatment did not significantly reduce parasite prevalence or mean faecal egg counts in treated hosts. Prior to translocation, parasite community composition differed significantly between woylies selected for translocation and resident woylies within each release site. Following translocation, the parasite communities of translocated and resident hosts converged to become more similar over time, with loss of parasite taxa and novel host-parasite associations emerging. This is the first study to examine changes to the broader parasite community in translocated and resident animals following translocation. The dominant site-specific response of parasites following translocation reinforces the importance of incorporating parasite studies to enhance our fundamental understanding of perturbations in host-parasite systems during translocation, in particular the site-level drivers of parasite dynamics. Perturbations to host-parasite systems during translocation are poorly understood. Parasite dynamics were strongly impacted by site and time since translocation. The parasite communities of translocated and resident hosts converged over time. Ivermectin treatment had no significant impact on target parasites. Translocation protocols should consider the intrinsic biodiversity value of parasites.
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Affiliation(s)
- Amy S Northover
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - R C Andrew Thompson
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Alan J Lymbery
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Adrian F Wayne
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Brain Street, Manjimup, Western Australia, 6258, Australia
| | - Sarah Keatley
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Amanda Ash
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Aileen D Elliot
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Keith Morris
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Wildlife Place, Woodvale, Western Australia, 6946, Australia
| | - Stephanie S Godfrey
- Department of Zoology, University of Otago, 362 Leith Street, Dunedin, 9016, New Zealand
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Northover AS, Keatley S, Elliot AD, Hobbs RP, Yang R, Lymbery AJ, Godfrey SS, Wayne AF, Thompson RCA. Identification of a novel species of Eimeria Schneider, 1875 from the woylie, Bettongia penicillata Gray (Diprotodontia: Potoroidae) and the genetic characterisation of three Eimeria spp. from other potoroid marsupials. Syst Parasitol 2019; 96:553-563. [PMID: 31332672 DOI: 10.1007/s11230-019-09870-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 06/15/2019] [Indexed: 12/28/2022]
Abstract
Faecal samples (n = 1,093) collected from the woylie Bettongia penicillata Gray, in south-western Australia were examined for the presence of coccidian parasites. Eimeria sp. oöcysts were detected in 15.2% of samples. Faecal samples obtained from the eastern bettong Bettongia gaimardi (Desmarest) (n = 4) and long-nosed potoroo Potorous tridactylus (Kerr) (n = 12) in Tasmania, were also screened for the presence of Eimeria spp. (prevalence 50% and 41.7%, respectively). Morphological and genetic comparison with other known species of Eimeria indicates that the material identified in woylies is novel. This study aimed to (i) morphologically describe and genetically characterise Eimeria woyliei n. sp. found in woylies; and (ii) genetically characterise Eimeria gaimardi Barker, O'Callaghan & Beveridge, 1988, Eimeria potoroi Barker, O'Callaghan & Beveridge, 1988, and Eimeria mundayi Barker, O'Callaghan & Beveridge, 1988, from other potoroid marsupials. Molecular phylogenetic analyses conducted at the 18S rDNA and mitochondrial cytochrome c oxidase subunit 1 (cox1) loci revealed that E. woyliei n. sp. was most closely related to Eimeria setonicis Barker, O'Callaghan & Beveridge, 1988, at the 18S rDNA locus, and Eimeria trichosuri O'Callaghan & O'Donoghue, 2001, at the cox1 locus. Eimeria woyliei n. sp. is the sixth species of Eimeria to be formally described from potoroid marsupials.
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Affiliation(s)
- Amy S Northover
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia.
| | - Sarah Keatley
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
| | - Aileen D Elliot
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
| | - Russell P Hobbs
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
| | - Rongchang Yang
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
| | - Alan J Lymbery
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
| | - Stephanie S Godfrey
- Department of Zoology, University of Otago, 362 Leith Street, Dunedin, 9016, New Zealand
| | - Adrian F Wayne
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Brain Street, Manjimup, WA, 6258, Australia
| | - R C Andrew Thompson
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
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Northover AS, Godfrey SS, Keatley S, Lymbery AJ, Wayne AF, Cooper C, Pallant L, Morris K, Thompson RCA. Increased Trypanosoma spp. richness and prevalence of haemoparasite co-infection following translocation. Parasit Vectors 2019; 12:126. [PMID: 30898141 PMCID: PMC6427866 DOI: 10.1186/s13071-019-3370-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 03/01/2019] [Indexed: 01/20/2023] Open
Abstract
Background Understanding how fauna translocation and antiparasitic drug treatment impact parasite community structure within a host is vital for optimising translocation outcomes. Trypanosoma spp. and piroplasms (Babesia and Theileria spp.) are known to infect Australian marsupials, including the woylie (Bettongia penicillata). However relatively little is known about these haemoparasites, or how they respond to management practices such as translocation. We monitored haemoparasites infecting woylies for up to 12 months during two fauna translocations to supplement existing woylie populations in three different sites (Dryandra, Walcott and Warrup East) within south-western Australia between 2014 and 2016, with the aim of investigating (i) how haemoparasite prevalence, Trypanosoma spp. richness and Trypanosoma spp. community composition varied over time and between different sites following translocation; and (ii) whether ivermectin treatment indirectly impacts haemoparasite prevalence. Using molecular methods, 1211 blood samples were screened for the presence of trypanosomes, and a subset of these samples (n = 264) were also tested for piroplasms. Results Trypanosomes and piroplasms were identified in 55% and 94% of blood samples, respectively. We identified five Trypanosoma species, two Theileria species, a single species of Babesia and a novel Bodo species. Trypanosoma spp. richness and the prevalence of haemoparasite co-infection increased after translocation. Prior to translocation, Trypanosoma spp. community composition differed significantly between translocated and resident woylies within Walcott and Warrup East, but not Dryandra. Six months later, there was a significant difference between translocated and resident woylies within Dryandra, but not Walcott or Warrup East. The response of haemoparasites to translocation was highly site-specific, with predominant changes to the haemoparasite community in translocated woylies occurring within the first few months following translocation. Ivermectin treatment had no significant effect on haemoparasite prevalence. Conclusions This study contributes to our understanding of haemoparasite dynamics in woylies following translocation. The highly site-specific and rapid response of haemoparasites to translocation highlights the need to better understand what drives these effects. Given that haemoparasite prevalence and composition of translocated and resident animals changed significantly following translocation, we propose that parasite monitoring should form an essential component of translocation protocols, and such protocols should endeavour to monitor translocated hosts and cohabiting species. Electronic supplementary material The online version of this article (10.1186/s13071-019-3370-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Amy S Northover
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia.
| | - Stephanie S Godfrey
- Department of Zoology, University of Otago, 362 Leith Street, Dunedin, 9016, New Zealand
| | - Sarah Keatley
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Alan J Lymbery
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Adrian F Wayne
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Brain Street, Manjimup, Western Australia, 6258, Australia
| | - Crystal Cooper
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Louise Pallant
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Keith Morris
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Wildlife Place, Woodvale, Western Australia, 6946, Australia
| | - R C Andrew Thompson
- College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
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Robinson NM, Scheele BC, Legge S, Southwell DM, Carter O, Lintermans M, Radford JQ, Skroblin A, Dickman CR, Koleck J, Wayne AF, Kanowski J, Gillespie GR, Lindenmayer DB. How to ensure threatened species monitoring leads to threatened species conservation. Ecol Manag Restor 2018. [DOI: 10.1111/emr.12335] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Northover AS, Elliot AD, Keatley S, Lim Z, Botero A, Ash A, Lymbery AJ, Wayne AF, Godfrey SS, Thompson RCA. Debilitating disease in a polyparasitised woylie ( Bettongia penicillata): A diagnostic investigation. Int J Parasitol Parasites Wildl 2018; 7:274-279. [PMID: 30094176 PMCID: PMC6077177 DOI: 10.1016/j.ijppaw.2018.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 06/01/2018] [Accepted: 07/12/2018] [Indexed: 12/25/2022]
Abstract
During monitoring of critically endangered woylie (Bettongia penicillata) populations within the south-west of Western Australia, an adult female woylie was euthanased after being found in extremely poor body condition with diffuse alopecia, debilitating skin lesions and severe ectoparasite infestation. Trypanosoma copemani G2 and Sarcocystis sp. were detected molecularly within tissue samples collected post-mortem. Potorostrongylus woyliei and Paraustrostrongylus sp. nematodes were present within the stomach and small intestine, respectively. Blood collected ante-mortem revealed the presence of moderate hypomagnesaemia, mild hypokalaemia, mild hyperglobulinaemia and mild hypoalbuminaemia. Diffuse megakaryocytic hypoplasia was evident within the bone marrow. We propose various hypotheses that may explain the presence of severe ectoparasite infection, skin disease and poor body condition in this woylie. Given the potential deleterious effects of parasite infection, the importance of monitoring parasites cannot be over-emphasised. Severe ectoparasite infestation, skin disease and poor body condition in a woylie. Trypanosoma copemani genotype 2 and Sarcocystis sp. identified molecularly in tissues. Clinical signs similar to those observed during the woylie decline.
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Affiliation(s)
- Amy S Northover
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Aileen D Elliot
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Sarah Keatley
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Ziyuan Lim
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Adriana Botero
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Amanda Ash
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Alan J Lymbery
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Adrian F Wayne
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Brain Street, Manjimup, Western Australia, 6258, Australia
| | - Stephanie S Godfrey
- Department of Zoology, University of Otago, 362 Leith Street, Dunedin, 9016, New Zealand
| | - R C Andrew Thompson
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
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Godfrey SS, Keatley S, Botero A, Thompson CK, Wayne AF, Lymbery AJ, Morris K, Thompson RCA. Trypanosome co-infections increase in a declining marsupial population. Int J Parasitol Parasites Wildl 2018; 7:221-227. [PMID: 29942738 PMCID: PMC6010928 DOI: 10.1016/j.ijppaw.2018.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 06/06/2018] [Accepted: 06/12/2018] [Indexed: 11/25/2022]
Abstract
Understanding the impacts of parasites on wildlife is growing in importance as diseases pose a threat to wildlife populations. Woylie (syn. brush-tailed bettong, Bettongia penicillata) populations have undergone enigmatic declines in south-western Western Australia over the past decade. Trypanosomes have been suggested as a possible factor contributing towards these declines because of their high prevalence in the declining population. We asked whether temporal patterns of infection with Trypanosoma spp. were associated with the decline patterns of the host, or if other factors (host sex, body condition, co-infection or rainfall) were more influential in predicting infection patterns. Species-specific nested PCRs were used to detect the two most common trypanosomes (T. copemani and T. vegrandis) from 444 woylie blood samples collected between 2006 and 2012. Time relative to the decline (year) and an interaction with co-infection by the other trypanosome best explained patterns of infection for both trypanosomes. The prevalence of single species infections for both T. copemani and T. vegrandis was lower after the population crash, however, the occurrence of co-infections increased after the crash compared to before the crash. Our results suggest an interaction between the two parasites with the decline of their host, leading to a higher level of co-infection after the decline. We discuss the possible mechanisms that may have led to a higher level of co-infection after the population crash, and highlight the importance of considering co-infection when investigating the role of parasites in species declines. Woylie (bettong) populations have declined by >90% over 10 years. Prevalence of Trypanosoma copemani and T. vegrandis increased during the decline, and reset to a lower level after the crash. Overall prevalence of both Trypanosoma spp. decreased during the decline. The proportion of hosts co-infected with both species of Trypanosoma spp. increased after the population crash. Highlights the need to consider co-infection and the effects of declining host populations on parasite prevalence.
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Affiliation(s)
- Stephanie S Godfrey
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia.,Department of Zoology, University of Otago, Dunedin, New Zealand
| | - Sarah Keatley
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
| | - Adriana Botero
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
| | - Craig K Thompson
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
| | - Adrian F Wayne
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia.,Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Western Australia, Australia
| | - Alan J Lymbery
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
| | - Keith Morris
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Western Australia, Australia
| | - R C Andrew Thompson
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
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Wayne AF, Maxwell MA, Ward CG, Wayne JC, Vellios CV, Wilson IJ. Recoveries and cascading declines of native mammals associated with control of an introduced predator. J Mammal 2017. [DOI: 10.1093/jmammal/gyw237] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Hing S, Northover AS, Narayan EJ, Wayne AF, Jones KL, Keatley S, Thompson RCA, Godfrey SS. Evaluating Stress Physiology and Parasite Infection Parameters in the Translocation of Critically Endangered Woylies (Bettongia penicillata). Ecohealth 2017; 14:128-138. [PMID: 28213652 DOI: 10.1007/s10393-017-1214-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 12/31/2016] [Accepted: 01/19/2017] [Indexed: 05/21/2023]
Abstract
Translocation can be stressful for wildlife. Stress may be important in fauna translocation because it has been suggested that it can exacerbate the impact of infectious disease on translocated wildlife. However, few studies explore this hypothesis by measuring stress physiology and infection indices in parallel during wildlife translocations. We analysed faecal cortisol metabolite (FCM) concentration and endoparasite parameters (nematodes, coccidians and haemoparasites) in a critically endangered marsupial, the woylie (Bettongia penicillata), 1-3 months prior to translocation, at translocation, and 6 months later. FCM for both translocated and resident woylies was significantly higher after translocation compared to before or at translocation. In addition, body condition decreased with increasing FCM after translocation. These patterns in host condition and physiology may be indicative of translocation stress or stress associated with factors independent of the translocation. Parasite factors also influenced FCM in translocated woylies. When haemoparasites were detected, there was a significant negative relationship between strongyle egg count and FCM. This may reflect the influence of glucocorticoids on the immune response to micro- and macro-parasites. Our results indicate that host physiology and infection patterns can change significantly during translocation, but further investigation is required to determine how these patterns influence translocation success.
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Affiliation(s)
- Stephanie Hing
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia.
| | - Amy S Northover
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
| | - Edward J Narayan
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW, 2650, Australia
| | - Adrian F Wayne
- Science and Conservation Division, Department of Parks and Wildlife, Manjimup, WA, 6258, Australia
| | - Krista L Jones
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
| | - Sarah Keatley
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
| | - R C Andrew Thompson
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
| | - Stephanie S Godfrey
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
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Northover AS, Godfrey SS, Lymbery AJ, Morris K, Wayne AF, Thompson RCA. Evaluating the Effects of Ivermectin Treatment on Communities of Gastrointestinal Parasites in Translocated Woylies (Bettongia penicillata). Ecohealth 2017; 14:117-127. [PMID: 26719294 DOI: 10.1007/s10393-015-1088-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 09/23/2015] [Accepted: 11/02/2015] [Indexed: 06/05/2023]
Abstract
Wildlife species are often treated with anti-parasitic drugs prior to translocation, despite the effects of this treatment being relatively unknown. Disruption of normal host-parasite relationships is inevitable during translocation, and targeted anti-parasitic drug treatment may exacerbate this phenomenon with inadvertent impacts on both target and non-target parasite species. Here, we investigate the effects of ivermectin treatment on communities of gastrointestinal parasites in translocated woylies (Bettongia penicillata). Faecal samples were collected at three time points (at the time of translocation, and 1 and 3 months post-translocation) and examined for nematode eggs and coccidian oocysts. Parasite prevalence and (for nematodes) abundance were estimated in both treated and untreated hosts. In our study, a single subcutaneous injection of ivermectin significantly reduced Strongyloides-like egg counts 1 month post-translocation. Strongyle egg counts and coccidia prevalence were not reduced by ivermectin treatment, but were strongly influenced by site. Likewise, month of sampling rather than ivermectin treatment positively influenced body condition in woylies post-translocation. Our results demonstrate the efficacy of ivermectin in temporarily reducing Strongyloides-like nematode abundance in woylies. We also highlight the possibility that translocation-induced changes to host density may influence coinfecting parasite abundance and host body condition post-translocation.
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Affiliation(s)
- Amy S Northover
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia.
| | - Stephanie S Godfrey
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
| | - Alan J Lymbery
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
| | - Keith Morris
- Science and Conservation Division, Western Australian Department of Parks and Wildlife, Woodvale, WA, 6946, Australia
| | - Adrian F Wayne
- Science and Conservation Division, Western Australian Department of Parks and Wildlife, Manjimup, WA, 6258, Australia
| | - R C Andrew Thompson
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
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Zosky KL, Wayne AF, Bryant KA, Calver MC, Scarff FR. Diet of the critically endangered woylie (Bettongia penicillata ogilbyi) in south-western Australia. AUST J ZOOL 2017. [DOI: 10.1071/zo17080] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
To assist the management of the critically endangered woylie (Bettongia penicillata ogilbyi), a quantitative study of its diet was conducted across five of the larger subpopulations in south-western Australia. There was a close match between dietary composition established from foregut contents and faecal pellets. Woylies were predominantly mycophagous in all subpopulations, but consumed a broad diet including invertebrates, seeds and other plant material. Individuals in a high-density, fenced subpopulation ate significantly less fungi than free-ranging animals from lower-density subpopulations. Dietary composition did not vary significantly amongst subpopulations in the Upper Warren region, where a range of population densities was observed. Altogether, 79 fungal spore classes were identified, including at least 15 genera from 14 families. Sampling across one year showed that fungi made up a larger fraction of the diet in autumn or winter, and greater diversities of fungi were consumed at these times than at other times of year. This information is essential to provide valuable ecological context for effective population management of woylies, as well as identification and conservation of important habitats.
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Yeatman GJ, Wayne AF, Mills HR, Prince J. Temporal Patterns in the Abundance of a Critically Endangered Marsupial Relates to Disturbance by Roads and Agriculture. PLoS One 2016; 11:e0160790. [PMID: 27501320 PMCID: PMC4976897 DOI: 10.1371/journal.pone.0160790] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 07/25/2016] [Indexed: 11/18/2022] Open
Abstract
The aim of this study was to investigate how landscape disturbance associated with roads, agriculture and forestry influenced temporal patterns in woylie (Bettongia penicillata) abundance before, during and after periods of rapid population change. Data were collected from an area of approximately 140,000 ha of forest within the Upper Warren region in south-western Australia. Woylie abundance was measured using cage trapping at 22 grid and five transect locations with varying degrees of landscape disturbance between 1994 and 2012. We found evidence that the distribution and abundance of woylies over time appears to be related to the degree of fragmentation by roads and proximity to agriculture. Sites furthest from agriculture supported a greater abundance of woylies and had slower rates of population decline. Sites with fewer roads had a greater abundance of woylies generally and a greater rate of increase in abundance after the implementation of invasive predator control. The results of this study suggest that landscape disturbance is less important at peak population densities, but during times of environmental and population change, sites less dissected by roads and agriculture better support woylie populations. This may be due to the role these factors play in increasing the vulnerability of woylies to introduced predators, population fragmentation, weed species invasion, mortality from road collisions or a reduction in available habitat. Strategies that reduce the impact of disturbance on woylie populations could include the rationalisation of forest tracks and consolidation of contiguous habitat through the acquisition of private property. Reducing the impact of disturbance in the Upper Warren region could improve the resilience of this critically important woylie population during future environmental change.
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Affiliation(s)
- Georgina J. Yeatman
- School of Animal Biology, Faculty of Science, University of Western Australia, Crawley, Western Australia, Australia
- * E-mail:
| | - Adrian F. Wayne
- Department of Parks and Wildlife, Manjimup, Western Australia, Australia
| | - Harriet R. Mills
- School of Animal Biology, Faculty of Science, University of Western Australia, Crawley, Western Australia, Australia
| | - Jane Prince
- School of Animal Biology, Faculty of Science, University of Western Australia, Crawley, Western Australia, Australia
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Yeatman GJ, Wayne AF, Mills HR, Prince J. It’s not all about the creeks: protection of multiple habitats will improve biodiversity conservation in a eucalypt forest. AUST J ZOOL 2016. [DOI: 10.1071/zo16007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Understanding patterns in the distribution and abundance of wildlife across the landscape can aid in identifying the relative importance of habitats for biodiversity conservation. We aimed to identify whether riparian habitats were more important than other areas in the landscape to small terrestrial vertebrates. The study site was surveyed using 450 pit traps distributed across riparian, midslope and ridge top habitat. Riparian sites had the greatest abundance of small vertebrates of the three habitats. During some months of the year, there was a significant difference in the composition of the faunal assemblage between habitats. Unsurprisingly, riparian habitats were particularly important for frog species and it was these species that accounted for the greater abundance in this habitat. Riparian habitat was less important for other taxonomic groups and the more floristically rich midslope and ridge habitats, which had a greater abundance of leaf litter, fallen logs and rock cover, were favoured by mammal and reptile species. The conservation of riparian sites, without the protection of other habitats, overlooks a substantial proportion of the biodiversity in the landscape. This study may help inform management decisions in the Upper Warren region and other similar forested landscapes, regarding the location and timing of fauna monitoring and the frequency of fuel reduction burns.
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Pacioni C, Hunt H, Allentoft ME, Vaughan TG, Wayne AF, Baynes A, Haouchar D, Dortch J, Bunce M. Genetic diversity loss in a biodiversity hotspot: ancient
DNA
quantifies genetic decline and former connectivity in a critically endangered marsupial. Mol Ecol 2015; 24:5813-28. [DOI: 10.1111/mec.13430] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 10/07/2015] [Accepted: 10/13/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Carlo Pacioni
- Ancient DNA Laboratory School of Veterinary and Life Sciences Murdoch University Murdoch WA 6150 Australia
| | - Helen Hunt
- Ancient DNA Laboratory School of Veterinary and Life Sciences Murdoch University Murdoch WA 6150 Australia
| | - Morten E. Allentoft
- Ancient DNA Laboratory School of Veterinary and Life Sciences Murdoch University Murdoch WA 6150 Australia
- Centre for GeoGenetics Natural History Museum University of Copenhagen Øster Voldgade 5‐7 1350 Copenhagen K Denmark
| | - Timothy G. Vaughan
- Department of Computer Science University of Auckland Private Bag 92019 Auckland 1142 New Zealand
| | | | - Alexander Baynes
- Western Australian Museum Locked Bag 49 Welshpool DC WA 6986 Australia
| | - Dalal Haouchar
- Ancient DNA Laboratory School of Veterinary and Life Sciences Murdoch University Murdoch WA 6150 Australia
| | - Joe Dortch
- Archaeology M257 The University of Western Australia 35 Stirling Highway Nedlands WA 6009 Australia
| | - Michael Bunce
- Ancient DNA Laboratory School of Veterinary and Life Sciences Murdoch University Murdoch WA 6150 Australia
- Department of Environment and Agriculture Trace and Environmental DNA Laboratory Kent Street, Bentley Perth WA 6845 Australia
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Pacioni C, Eden P, Reiss A, Ellis T, Knowles G, Wayne AF. Disease hazard identification and assessment associated with wildlife population declines. Ecol Manag Restor 2015. [DOI: 10.1111/emr.12155] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Thompson CK, Wayne AF, Godfrey SS, Thompson RCA. Survival, age estimation and sexual maturity of pouch young of the brush-tailed bettong (Bettongia penicillata) in captivity. Aust Mammalogy 2015. [DOI: 10.1071/am14025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The brush-tailed bettong or woylie (Bettongia penicillata) is a continuous and rapid breeder. However, research investigating the monthly survival and development of young woylies from parturition to parental independence is incomplete. The reproductive biology of eight female woylies was observed for 22 consecutive months within a purpose-built enclosure. Adult female woylies bred continuously and were observed caring for a dependant young 96% of the time. Pouch life of the young was ~102 days, with sexual maturity of female offspring reached as early as 122 days post partum. Crown–rump measurement was an accurate predictor of age for young restricted to the pouch, while skeletal morphometrics were a better predictor of age for ejected pouch young, young-at-foot and subadults. A four-month period between May and August of each study year accounted for 85% of pouch young mortality and 61% of pouch young births where the neonate went on to survive to subadult age. Here we discuss the possibility that pouch young born during the cooler, wetter months of May to August may have an increased chance of survival in the wild, resulting from an increased maternal investment being directed towards the rearing of ‘fitter’ progeny.
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Yeatman GJ, Wayne AF. Seasonal home range and habitat use of a critically endangered marsupial (Bettongia penicillata ogilbyi) inside and outside a predator-proof sanctuary. Aust Mammalogy 2015. [DOI: 10.1071/am14022] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
An understanding of the factors that influence the distribution of the woylie (Bettongia penicillata ogilbyi) at local and regional scales has been identified as a key knowledge gap, because such knowledge may assist in the recovery of this endangered species. We aimed to investigate the seasonal home-range size and habitat use of woylies to update current knowledge of the species in the context of a substantial decline. Specifically, we examined the home range and habitat use of woylies reintroduced into a sanctuary free from invasive predators and compared these data to those from an external reference site. Eight woylies inside the sanctuary and seven outside were radio-tracked in autumn 2011. The average home-range size was 65.4 (±8.2, s.e.) ha. There was little evidence to suggest any difference in home-range size between woylies inside and outside the sanctuary. Woylies were more likely to be found in the slope and low-lying valley habitats, which have greater water-holding capacity and sandier soils. These relatively large seasonal home ranges, compared with previously published estimates for the species, may be accounted for by low population density, lower seasonal food availability and clustered food distribution. Monitoring the home-range size of woylies within the sanctuary may assist in identifying the carrying capacity of the sanctuary, which has implications for how this population is managed.
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Thompson CK, Wayne AF, Godfrey SS, Thompson RCA. Temporal and spatial dynamics of trypanosomes infecting the brush-tailed bettong (Bettongia penicillata): a cautionary note of disease-induced population decline. Parasit Vectors 2014; 7:169. [PMID: 24708757 PMCID: PMC3985580 DOI: 10.1186/1756-3305-7-169] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 04/01/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The brush-tailed bettong or woylie (Bettongia penicillata) is on the brink of extinction. Its numbers have declined by 90% since 1999, with their current distribution occupying less than 1% of their former Australian range. Woylies are known to be infected with three different trypanosomes (Trypanosoma vegrandis, Trypanosoma copemani and Trypanosoma sp. H25) and two different strains of T. copemani that vary in virulence. However, the role that these haemoparasites have played during the recent decline of their host is unclear and is part of ongoing investigation. METHODS Woylies were sampled from five locations in southern Western Australia, including two neighbouring indigenous populations, two enclosed (fenced) populations and a captive colony. PCR was used to individually identify the three different trypanosomes from blood and tissues of the host, and to investigate the temporal and spatial dynamics of trypanosome infections. RESULTS The spatial pattern of trypanosome infection varied among the five study sites, with a greater proportion of woylies from the Perup indigenous population being infected with T. copemani than from the neighbouring Kingston indigenous population. For an established infection, T. copemani detection was temporally inconsistent. The more virulent strain of T. copemani appeared to regress at a faster rate than the less virulent strain, with the infection possibly transitioning from the acute to chronic phase. Interspecific competition may also exist between T. copemani and T. vegrandis, where an existing T. vegrandis infection may moderate the sequential establishment of the more virulent T. copemani. CONCLUSION In this study, we provide a possible temporal connection implicating T. copemani as the disease agent linked with the recent decline of the Kingston indigenous woylie population within the Upper Warren region of Western Australia. The chronic association of trypanosomes with the internal organs of its host may be potentially pathogenic and adversely affect their long term fitness and coordination, making the woylie more susceptible to predation.
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Affiliation(s)
- Craig K Thompson
- School of Veterinary and Life Sciences, 90 Murdoch University, South Street, Western Australia 6150, Australia.
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Abstract
Abstract
Translocations are an important conservation strategy for many species. However simply observing demographic growth of a translocated population is not sufficient to infer species recovery. Adequate genetic representation of the source population(s) and their long-term viability should also be considered. The woylie Bettongia penicillata ogilbyi has been subject to more formal translocations for conservation than any other marsupial that, up until recently, has resulted in one of the most successful species recoveries in Australia. We used mitochondrial and nuclear DNA markers to assess the genetic outcomes of translocated woylie populations. These populations have lost genetic variability, differentiated from their source population and the supplementation program on two island populations appears to have failed. We discuss the conservation implications that our results have for managing threatened species, outline some general recommendations for the management of present and future translocations and discuss the appropriate sampling design for the establishment of new populations or captive breeding programs that may mitigate the genetic ‘erosion’ seen in our study species. This research provides some practical outcomes and a pragmatic understanding of translocation biology. The findings are directly applicable to other translocation programs.
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Affiliation(s)
- Carlo Pacioni
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, 6150, Western Australia
| | - Adrian F. Wayne
- Department of Environment and Conservation, Science Division, Manjimup, 6258, Western Australia
| | - Peter B. S. Spencer
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, 6150, Western Australia
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Botero A, Thompson CK, Peacock CS, Clode PL, Nicholls PK, Wayne AF, Lymbery AJ, Thompson RCA. Trypanosomes genetic diversity, polyparasitism and the population decline of the critically endangered Australian marsupial, the brush tailed bettong or woylie (Bettongia penicillata). Int J Parasitol Parasites Wildl 2013; 2:77-89. [PMID: 24533319 PMCID: PMC3862532 DOI: 10.1016/j.ijppaw.2013.03.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 03/13/2013] [Accepted: 03/14/2013] [Indexed: 12/14/2022]
Abstract
Trypanosomes in Australian marsupials comprise a heterogeneous community. The woylie was the only species found co-infected with different trypanosomes. Some of the trypanosomes found are able to colonize several tissues in the host. Trypanosoma copemani is able to invade cells in vitro. Association between T.copemani and mixed infections with the decline of the woylie.
While much is known of the impact of trypanosomes on human and livestock health, trypanosomes in wildlife, although ubiquitous, have largely been considered to be non-pathogenic. We describe the genetic diversity, tissue tropism and potential pathogenicity of trypanosomes naturally infecting Western Australian marsupials. Blood samples collected from 554 live-animals and 250 tissue samples extracted from 50 carcasses of sick-euthanized or road-killed animals, belonging to 10 species of marsupials, were screened for the presence of trypanosomes using a PCR of the 18S rDNA gene. PCR results revealed a rate of infection of 67% in blood and 60% in tissues. Inferred phylogenetic trees using 18S rDNA and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) sequences showed the presence of eight genotypes that clustered into three clades: a clade including Trypanosoma copemani, a new clade closely related to Trypanosoma gilletti, and a clade including Trypanosoma H25 from an Australian kangaroo. Trypanosome infections were compared in a declining and in a stable population of the endangered Australian marsupial, the brush tailed bettong or woylie (Bettongia penicillata). This marsupial showed high rates of infection with Clade A genotypes (96%) in the declining population, whereas in the stable population, Clade B genotypes were predominant (89%). Mixed infections were common in woylies from the declining but not from the stable population. Histopathological findings associated with either mixed or single infections involving Clade A genotypes, showed a strong inflammatory process and tissue degeneration predominantly in heart, oesophagus and tongue. Trypanosomes were successfully grown in culture and for the first time we demonstrate that a genotype within Clade A has the capacity to not only colonize different tissues in the host but also to invade cells in vitro. These results provide evidence for the potential role of trypanosomes in the decline of a formerly abundant marsupial that is now critically endangered.
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Affiliation(s)
- Adriana Botero
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia
| | - Craig K Thompson
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia
| | - Christopher S Peacock
- School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, WA 6009, Australia ; Telethon Institute for Child Health Research, 100 Roberts Road, Subiaco, WA 6008, Australia
| | - Peta L Clode
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Stirling HWY, Crawley, WA 6009, Australia
| | - Philip K Nicholls
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia
| | - Adrian F Wayne
- Department of Environment and Conservation, Science Division, Manjimup, WA, Australia
| | - Alan J Lymbery
- Fish Health Unit, School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, WA 6150, Australia
| | - R C Andrew Thompson
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia
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Pacioni C, Johansen CA, Mahony TJ, O'Dea MA, Robertson ID, Wayne AF, Ellis T. A virological investigation into declining woylie populations. AUST J ZOOL 2013. [DOI: 10.1071/zo13077] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The woylie (Bettongia penicillata ogilbyi) is a critically endangered small Australian marsupial that is in a state of accelerated population decline for reasons that are currently unknown. The aim of the present study was to elucidate the involvement of several viral pathogens through strategic serological testing of several wild woylie populations. Testing for antibodies against the Wallal and Warrego serogroup of orbiviruses, Macropod herpesvirus 1 and Encephalomyocarditis virus in woylie sera was undertaken through virus neutralisation tests. Moreover, testing for antibodies against the the alphaviruses Ross River virus and Barmah Forest virus and the flaviviruses Kunjin virus and Murray Valley encephalitis virus was undertaken through virus neutralisation tests and ELISA mainly because of the interest in the epidemiology of these important zoonoses as it was considered unlikely to be the cause of the decline. Between 15 and 86 samples were tested for each of the four sites in south-western Australia (Balban, Keninup, Warrup and Karakamia). Results indicated no exposure to any of the viral pathogens investigated, indicating that all populations are currently naïve and may be at risk if these pathogens were to be introduced.
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Kaewmongkol G, Kaewmongkol S, Burmej H, Bennett MD, Fleming PA, Adams PJ, Wayne AF, Ryan U, Irwin PJ, Fenwick SG. Diversity of Bartonella species detected in arthropod vectors from animals in Australia. Comp Immunol Microbiol Infect Dis 2011; 34:411-7. [DOI: 10.1016/j.cimid.2011.07.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 07/20/2011] [Accepted: 07/21/2011] [Indexed: 10/17/2022]
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Webala PW, Craig MD, Law BS, Armstrong KN, Wayne AF, Bradley JS. Bat habitat use in logged jarrah eucalypt forests of south-western Australia. J Appl Ecol 2010. [DOI: 10.1111/j.1365-2664.2010.01934.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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