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Reinke BA, Cayuela H, Janzen FJ, Lemaître JF, Gaillard JM, Lawing AM, Iverson JB, Christiansen DG, Martínez-Solano I, Sánchez-Montes G, Gutiérrez-Rodríguez J, Rose FL, Nelson N, Keall S, Crivelli AJ, Nazirides T, Grimm-Seyfarth A, Henle K, Mori E, Guiller G, Homan R, Olivier A, Muths E, Hossack BR, Bonnet X, Pilliod DS, Lettink M, Whitaker T, Schmidt BR, Gardner MG, Cheylan M, Poitevin F, Golubović A, Tomović L, Arsovski D, Griffiths RA, Arntzen JW, Baron JP, Le Galliard JF, Tully T, Luiselli L, Capula M, Rugiero L, McCaffery R, Eby LA, Briggs-Gonzalez V, Mazzotti F, Pearson D, Lambert BA, Green DM, Jreidini N, Angelini C, Pyke G, Thirion JM, Joly P, Léna JP, Tucker AD, Limpus C, Priol P, Besnard A, Bernard P, Stanford K, King R, Garwood J, Bosch J, Souza FL, Bertoluci J, Famelli S, Grossenbacher K, Lenzi O, Matthews K, Boitaud S, Olson DH, Jessop TS, Gillespie GR, Clobert J, Richard M, Valenzuela-Sánchez A, Fellers GM, Kleeman PM, Halstead BJ, Grant EHC, Byrne PG, Frétey T, Le Garff B, Levionnois P, Maerz JC, Pichenot J, Olgun K, Üzüm N, Avcı A, Miaud C, Elmberg J, Brown GP, Shine R, Bendik NF, O'Donnell L, Davis CL, Lannoo MJ, Stiles RM, Cox RM, Reedy AM, Warner DA, Bonnaire E, Grayson K, Ramos-Targarona R, Baskale E, Muñoz D, Measey J, de Villiers FA, Selman W, Ronget V, Bronikowski AM, Miller DAW. Diverse aging rates in ectothermic tetrapods provide insights for the evolution of aging and longevity. Science 2022; 376:1459-1466. [PMID: 35737773 DOI: 10.1126/science.abm0151] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Comparative studies of mortality in the wild are necessary to understand the evolution of aging; yet, ectothermic tetrapods are underrepresented in this comparative landscape, despite their suitability for testing evolutionary hypotheses. We present a study of aging rates and longevity across wild tetrapod ectotherms, using data from 107 populations (77 species) of nonavian reptiles and amphibians. We test hypotheses of how thermoregulatory mode, environmental temperature, protective phenotypes, and pace of life history contribute to demographic aging. Controlling for phylogeny and body size, ectotherms display a higher diversity of aging rates compared with endotherms and include phylogenetically widespread evidence of negligible aging. Protective phenotypes and life-history strategies further explain macroevolutionary patterns of aging. Analyzing ectothermic tetrapods in a comparative context enhances our understanding of the evolution of aging.
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Affiliation(s)
- Beth A Reinke
- Department of Biology, Northeastern Illinois University, Chicago, IL, USA
- Department of Ecosystem Science and Management, Pennsylvania State University, State College, PA, USA
| | - Hugo Cayuela
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Fredric J Janzen
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, USA
| | | | - Jean-Michel Gaillard
- Université Lyon 1, Laboratoire de Biométrie et Biologie Evolutive, Villeurbanne, France
| | - A Michelle Lawing
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX, USA
| | - John B Iverson
- Department of Biology, Earlham College, Richmond, IN, USA
| | - Ditte G Christiansen
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland
| | - Iñigo Martínez-Solano
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain
| | - Gregorio Sánchez-Montes
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain
| | - Jorge Gutiérrez-Rodríguez
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain
- Department of Integrative Ecology, Estación Biológica de Doñana (EBD-CSIC), Seville, Spain
| | - Francis L Rose
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA
| | - Nicola Nelson
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Susan Keall
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Alain J Crivelli
- Research Institute for the Conservation of Mediterranean Wetlands, Tour du Valat, Arles, France
| | | | - Annegret Grimm-Seyfarth
- Department Conservation Biology and Social-Ecological Systems, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Klaus Henle
- Department Conservation Biology and Social-Ecological Systems, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Emiliano Mori
- Consiglio Nazionale delle Ricerche, Istituto di Ricerca sugli Ecosistemi Terrestri, Sesto Fiorentino, Italy
| | | | - Rebecca Homan
- Biology Department, Denison University, Granville, OH, USA
| | - Anthony Olivier
- Research Institute for the Conservation of Mediterranean Wetlands, Tour du Valat, Arles, France
| | - Erin Muths
- US Geological Survey, Fort Collins Science Center, Fort Collins, CO, USA
| | - Blake R Hossack
- US Geological Survey, Northern Rocky Mountain Science Center, Wildlife Biology Program, University of Montana, Missoula, MT, USA
| | - Xavier Bonnet
- Centre d'Etudes Biologiques de Chizé, CNRS UMR 7372 - Université de La Rochelle, Villiers-en-Bois, France
| | - David S Pilliod
- US Geological Survey, Forest and Rangeland Ecosystem Science Center, Boise, ID, USA
| | | | | | - Benedikt R Schmidt
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland
- Info Fauna Karch, Neuchâtel, Switzerland
| | - Michael G Gardner
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
- Evolutionary Biology Unit, South Australian Museum, Adelaide, SA, Australia
| | - Marc Cheylan
- PSL Research University, Université de Montpellier, Université Paul-Valéry, Montpellier, France
| | - Françoise Poitevin
- PSL Research University, Université de Montpellier, Université Paul-Valéry, Montpellier, France
| | - Ana Golubović
- Institute of Zoology, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Ljiljana Tomović
- Institute of Zoology, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | | | - Richard A Griffiths
- Durrell Institute of Conservation and Ecology, School of Anthropology and Conservation, University of Kent, Canterbury, Kent, UK
| | | | - Jean-Pierre Baron
- Ecole normale supérieure, PSL University, Département de biologie, CNRS, UMS 3194, Centre de recherche en écologie expérimentale et prédictive (CEREEP-Ecotron IleDeFrance), Saint-Pierre-lès-Nemours, France
| | - Jean-François Le Galliard
- Ecole normale supérieure, PSL University, Département de biologie, CNRS, UMS 3194, Centre de recherche en écologie expérimentale et prédictive (CEREEP-Ecotron IleDeFrance), Saint-Pierre-lès-Nemours, France
- Sorbonne Université, CNRS, INRA, UPEC, IRD, Institute of Ecology and Environmental Sciences, iEES-Paris, Paris, France
| | - Thomas Tully
- Sorbonne Université, CNRS, INRA, UPEC, IRD, Institute of Ecology and Environmental Sciences, iEES-Paris, Paris, France
| | - Luca Luiselli
- Institute for Development, Ecology, Conservation and Cooperation, Rome, Italy
- Department of Animal and Applied Biology, Rivers State University of Science and Technology, Port Harcourt, Nigeria
- Department of Zoology, University of Lomé, Lomé, Togo
| | | | - Lorenzo Rugiero
- Institute for Development, Ecology, Conservation and Cooperation, Rome, Italy
| | - Rebecca McCaffery
- US Geological Survey, Forest and Rangeland Ecosystem Science Center, Port Angeles, WA, USA
| | - Lisa A Eby
- Wildlife Biology Program, University of Montana, Missoula, MT, USA
| | - Venetia Briggs-Gonzalez
- Department of Wildlife Ecology and Conservation, Fort Lauderdale Research and Education Center, University of Florida, Fort Lauderdale, FL, USA
| | - Frank Mazzotti
- Department of Wildlife Ecology and Conservation, Fort Lauderdale Research and Education Center, University of Florida, Fort Lauderdale, FL, USA
| | - David Pearson
- Department of Biodiversity, Conservation and Attractions, Wanneroo, WA, Australia
| | - Brad A Lambert
- Colorado Natural Heritage Program, Colorado State University, Fort Collins, CO, USA
| | - David M Green
- Redpath Museum, McGill University, Montreal, QC, Canada
| | | | | | - Graham Pyke
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, CN, Kunming, PR China
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | | | - Pierre Joly
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, Villeurbanne, France
| | - Jean-Paul Léna
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, Villeurbanne, France
| | - Anton D Tucker
- Department of Biodiversity, Conservation and Attractions, Parks and Wildlife Service-Marine Science Program, Kensington, WA, Australia
| | - Col Limpus
- Threatened Species Operations, Queensland Department of Environment and Science, Ecosciences Precinct, Dutton Park, QLD, Australia
| | | | - Aurélien Besnard
- CNRS, EPHE, UM, SupAgro, IRD, INRA, UMR 5175 CEFE, PSL Research University, Montpelier, France
| | - Pauline Bernard
- Conservatoire d'espaces naturels d'Occitanie, Montpellier, France
| | - Kristin Stanford
- Ohio Sea Grant and Stone Laboratory, The Ohio State University, Put-In-Bay, OH, USA
| | - Richard King
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL, USA
| | - Justin Garwood
- California Department of Fish and Wildlife, Arcata, CA, USA
| | - Jaime Bosch
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain
- IMIB-Biodiversity Research Unit, University of Oviedo-Principality of Asturias, Mieres, Spain
- Centro de Investigación, Seguimiento y Evaluación, Sierra de Guadarrama National Park, Rascafría, Spain
| | - Franco L Souza
- Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | - Jaime Bertoluci
- Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, São Paulo, Brazil
| | - Shirley Famelli
- School of Science, RMIT University, Melbourne, VIC, Australia
- Environmental Research Institute, North Highland College, University of the Highlands and Islands, Thurso, Scotland, UK
| | | | - Omar Lenzi
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland
| | - Kathleen Matthews
- USDA Forest Service (Retired), Pacific Southwest Research Station, Albany, CA, USA
| | - Sylvain Boitaud
- Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés, Villeurbanne, France
| | - Deanna H Olson
- USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR, USA
| | - Tim S Jessop
- Centre for Integrative Ecology, Deakin University, Waurn Ponds, Geelong, VIC, Australia
| | - Graeme R Gillespie
- Department of Environment and Natural Resources, Palmerston, NT, Australia
| | - Jean Clobert
- Station d'Ecologie Théorique et Expérimentale de Moulis, CNRS-UMR532, Saint Girons, France
| | - Murielle Richard
- Station d'Ecologie Théorique et Expérimentale de Moulis, CNRS-UMR532, Saint Girons, France
| | - Andrés Valenzuela-Sánchez
- Instituto de Conservación, Biodiversidad y Territorio, Facultad de Ciencias Forestales y Recursos Naturales, Universidad Austral de Chile, Valdivia, Chile
- ONG Ranita de Darwin, Valdivia, Chile
| | - Gary M Fellers
- US Geological Survey, Western Ecological Research Center, Point Reyes National Seashore, Point Reyes, CA, USA
| | - Patrick M Kleeman
- US Geological Survey, Western Ecological Research Center, Point Reyes National Seashore, Point Reyes, CA, USA
| | - Brian J Halstead
- US Geological Survey, Western Ecological Research Center, Dixon Field Station, Dixon, CA, USA
| | - Evan H Campbell Grant
- US Geological Survey Eastern Ecological Research Center (formerly Patuxent Wildlife Research Center), S.O. Conte Anadromous Fish Research Center, Turners Falls, MA, USA
| | - Phillip G Byrne
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, Australia
| | | | | | | | - John C Maerz
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA
| | - Julian Pichenot
- Université de Reims Champagne-Ardenne, Centre de Recherche et de Formation en Eco-éthologie, URCA-CERFE, Boult-aux-Bois, France
| | - Kurtuluş Olgun
- Department of Biology, Faculty of Science and Arts, Aydın Adnan Menderes University, Aydın, Turkey
| | - Nazan Üzüm
- Department of Biology, Faculty of Science and Arts, Aydın Adnan Menderes University, Aydın, Turkey
| | - Aziz Avcı
- Department of Biology, Faculty of Science and Arts, Aydın Adnan Menderes University, Aydın, Turkey
| | - Claude Miaud
- PSL Research University, Université de Montpellier, Université Paul-Valéry, Montpellier, France
| | - Johan Elmberg
- Department of Environmental Science and Bioscience, Kristianstad University, Kristianstad, Sweden
| | - Gregory P Brown
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Richard Shine
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Nathan F Bendik
- Watershed Protection Department, City of Austin, Austin, TX, USA
| | - Lisa O'Donnell
- Balcones Canyonlands Preserve, City of Austin, Austin, TX, USA
| | | | | | | | - Robert M Cox
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Aaron M Reedy
- Department of Biology, University of Virginia, Charlottesville, VA, USA
- Department of Biological Sciences, Auburn University, Auburn, AL, USA
| | - Daniel A Warner
- Department of Biological Sciences, Auburn University, Auburn, AL, USA
| | - Eric Bonnaire
- Office National des Forêts, Agence de Meurthe-et-Moselle, Nancy, France
| | - Kristine Grayson
- Department of Biology, University of Richmond, Richmond, VA, USA
| | | | - Eyup Baskale
- Department of Biology, Faculty of Science and Arts, Pamukkale University, Denizli, Turkey
| | - David Muñoz
- Department of Ecosystem Science and Management, Pennsylvania State University, State College, PA, USA
| | - John Measey
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Stellenbosch, South Africa
| | - F Andre de Villiers
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Stellenbosch, South Africa
| | - Will Selman
- Department of Biology, Millsaps College, Jackson, MS, USA
| | - Victor Ronget
- Unité Eco-anthropologie (EA), Muséum National d'Histoire Naturelle, CNRS, Université Paris Diderot, Paris, France
| | - Anne M Bronikowski
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, USA
| | - David A W Miller
- Department of Ecosystem Science and Management, Pennsylvania State University, State College, PA, USA
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Jessop TS, Gillespie GR. Monitoring methods influence native predator detectability and inferred occupancy responses to introduced carnivore management. Wildl Res 2022. [DOI: 10.1071/wr22012] [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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Purwandana D, Ariefiandy A, Azmi M, Nasu SA, Sahudin, Dos AA, Jessop TS. Turning ghosts into dragons: improving camera monitoring outcomes for a cryptic low-density Komodo dragon population in eastern Indonesia. Wildl Res 2021. [DOI: 10.1071/wr21057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Abstract Context Detection probability is a key attribute influencing population-level wildlife estimates necessary for conservation inference. Increasingly, camera traps are used to monitor threatened reptile populations and communities. Komodo dragon (Varanus komodoensis) populations have been previously monitored using camera traps; however, considerations for improving detection probability estimates for very low-density populations have not been well investigated. Aims Here we compare the effects of baited versus non-baited camera monitoring protocols to influence Komodo dragon detection and occupancy estimates alongside monitoring survey design and cost considerations for ongoing population monitoring within the Wae Wuul Nature Reserve on Flores Island, Indonesia. Methods Twenty-six camera monitoring stations (CMS) were deployed throughout the study area with a minimum of 400 m among CMS to achieve independent sampling units. Each CMS was randomly assigned as a baited or non-baited camera monitoring station and deployed for 6 or 30 daily sampling events. Key results Baited camera monitoring produced higher site occupancy estimates with reduced variance. Komodo dragon detection probability estimates were 0.15 ± 0.092–0.22 (95% CI), 0.01 ± 0.001–0.03, and 0.03 ± 0.01–0.04 for baited (6 daily survey sampling events), unbaited (6 daily survey sampling events) and long-unbaited (30 daily survey sampling events) sampling durations respectively. Additionally, the provision of baited lures at cameras had additional benefits for Komodo detection, survey design and sampling effort costs. Conclusions Our study indicated that baited cameras provide the most effective monitoring method to survey low-density Komodo dragon populations in protected areas on Flores. Implications We believe our monitoring approach now lends itself to evaluating population responses to ecological and anthropogenic factors, hence informing conservation efforts in this nature reserve.
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Iannucci A, Benazzo A, Natali C, Arida EA, Zein MSA, Jessop TS, Bertorelle G, Ciofi C. Population structure, genomic diversity and demographic history of Komodo dragons inferred from whole-genome sequencing. Mol Ecol 2021; 30:6309-6324. [PMID: 34390519 PMCID: PMC9292392 DOI: 10.1111/mec.16121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 12/31/2020] [Revised: 07/28/2021] [Accepted: 08/03/2021] [Indexed: 02/07/2023]
Abstract
Population and conservation genetics studies have greatly benefited from the development of new techniques and bioinformatic tools associated with next-generation sequencing. Analysis of extensive data sets from whole-genome sequencing of even a few individuals allows the detection of patterns of fine-scale population structure and detailed reconstruction of demographic dynamics through time. In this study, we investigated the population structure, genomic diversity and demographic history of the Komodo dragon (Varanus komodoensis), the world's largest lizard, by sequencing the whole genomes of 24 individuals from the five main Indonesian islands comprising the entire range of the species. Three main genomic groups were observed. The populations of the Island of Komodo and the northern coast of Flores, in particular, were identified as two distinct conservation units. Degrees of genomic divergence among island populations were interpreted as a result of changes in sea level affecting connectivity across islands. Demographic inference suggested that Komodo dragons probably experienced a relatively steep population decline over the last million years, reaching a relatively stable Ne during the Saalian glacial cycle (400-150 thousand years ago) followed by a rapid Ne decrease. Genomic diversity of Komodo dragons was similar to that found in endangered or already extinct reptile species. Overall, this study provides an example of how whole-genome analysis of a few individuals per population can help define population structure and intraspecific demographic dynamics. This is particularly important when applying population genomics data to conservation of rare or elusive endangered species.
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Affiliation(s)
| | - Andrea Benazzo
- Department of Life Sciences and BiotechnologyUniversity of FerraraFerraraItaly
| | - Chiara Natali
- Department of BiologyUniversity of FlorenceFirenzeItaly
| | - Evy Ayu Arida
- Research Center for BiologyThe Indonesian Institute of Sciences (LIPI)Cibinong Science CenterCibinongIndonesia
| | - Moch Samsul Arifin Zein
- Research Center for BiologyThe Indonesian Institute of Sciences (LIPI)Cibinong Science CenterCibinongIndonesia
| | - Tim S. Jessop
- School of Life and Environmental SciencesDeakin UniversityGeelongVic.Australia
| | - Giorgio Bertorelle
- Department of Life Sciences and BiotechnologyUniversity of FerraraFerraraItaly
| | - Claudio Ciofi
- Department of BiologyUniversity of FlorenceFirenzeItaly
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Jessop TS, Holmes B, Sendjojo A, Thorpe MO, Ritchie EG. Assessing the benefits of integrated introduced predator management for recovery of native predators. Restor Ecol 2021. [DOI: 10.1111/rec.13419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tim S. Jessop
- Centre for Integrative Ecology, School of Life and Environmental Sciences Deakin University Geelong Victoria 3216 Australia
| | - Ben Holmes
- Wimmera Catchment Management Authority Horsham Victoria 3400 Australia
| | - Arvel Sendjojo
- Centre for Integrative Ecology, School of Life and Environmental Sciences Deakin University Geelong Victoria 3216 Australia
| | - Mary O. Thorpe
- Centre for Integrative Ecology, School of Life and Environmental Sciences Deakin University Geelong Victoria 3216 Australia
| | - Euan G. Ritchie
- Centre for Integrative Ecology, School of Life and Environmental Sciences Deakin University Geelong Victoria 3216 Australia
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Ariefiandy A, Purwandana D, Azmi M, Panggur MR, Mardani J, Parra DP, Jessop TS. Invasive water buffalo population trends and competition-related consequences for native rusa deer in eastern Indonesian protected areas. Mamm Biol 2021. [DOI: 10.1007/s42991-021-00161-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Purwandana D, Imansyah MJ, Ariefiandy A, Rudiharto H, Ciofi C, Jessop TS. Insights into the Nesting Ecology and Annual Hatchling Production of the Komodo Dragon. COPEIA 2020. [DOI: 10.1643/ch-19-337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
| | | | | | - Heru Rudiharto
- Komodo National Park, Labuan Bajo 86711, Flores, Indonesia
| | - Claudio Ciofi
- Department of Biology, University of Florence, Via Madonna del Piano 6–50019 Sesto Fiorentino (FI), Italy
| | - Tim S. Jessop
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds 3220, Australia; t.jessop@ deakin.edu.au. Send reprint requests to this address
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Jones AR, Jessop TS, Ariefiandy A, Brook BW, Brown SC, Ciofi C, Benu YJ, Purwandana D, Sitorus T, Wigley TML, Fordham DA. Identifying island safe havens to prevent the extinction of the World's largest lizard from global warming. Ecol Evol 2020; 10:10492-10507. [PMID: 33072275 PMCID: PMC7548163 DOI: 10.1002/ece3.6705] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [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: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 11/10/2022] Open
Abstract
The Komodo dragon (Varanus komodoensis) is an endangered, island‐endemic species with a naturally restricted distribution. Despite this, no previous studies have attempted to predict the effects of climate change on this iconic species. We used extensive Komodo dragon monitoring data, climate, and sea‐level change projections to build spatially explicit demographic models for the Komodo dragon. These models project the species’ future range and abundance under multiple climate change scenarios. We ran over one million model simulations with varying model parameters, enabling us to incorporate uncertainty introduced from three main sources: (a) structure of global climate models, (b) choice of greenhouse gas emission trajectories, and (c) estimates of Komodo dragon demographic parameters. Our models predict a reduction in range‐wide Komodo dragon habitat of 8%–87% by 2050, leading to a decrease in habitat patch occupancy of 25%–97% and declines of 27%–99% in abundance across the species' range. We show that the risk of extirpation on the two largest protected islands in Komodo National Park (Rinca and Komodo) was lower than other island populations, providing important safe havens for Komodo dragons under global warming. Given the severity and rate of the predicted changes to Komodo dragon habitat patch occupancy (a proxy for area of occupancy) and abundance, urgent conservation actions are required to avoid risk of extinction. These should, as a priority, be focused on managing habitat on the islands of Komodo and Rinca, reflecting these islands’ status as important refuges for the species in a warming world. Variability in our model projections highlights the importance of accounting for uncertainties in demographic and environmental parameters, structural assumptions of global climate models, and greenhouse gas emission scenarios when simulating species metapopulation dynamics under climate change.
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Affiliation(s)
- Alice R Jones
- The Environment Institute and School of Biological Sciences The University of Adelaide Adelaide SA Australia.,Department for Environment and Water Adelaide SA Australia
| | - Tim S Jessop
- Centre for Integrative Ecology School of Life and Environmental Sciences Deakin University Waurn Ponds Vic. Australia.,Komodo Survival Program Bali Indonesia
| | | | - Barry W Brook
- School of Natural Sciences University of Tasmania Hobart Tas Australia
| | - Stuart C Brown
- The Environment Institute and School of Biological Sciences The University of Adelaide Adelaide SA Australia
| | - Claudio Ciofi
- Komodo Survival Program Bali Indonesia.,Department of Biology University of Florence Sesto Fiorentino Italy
| | | | | | - Tamen Sitorus
- Balai Besar Konservasi Sumber Daya Alam Kupang Indonesia
| | - Tom M L Wigley
- The Environment Institute and School of Biological Sciences The University of Adelaide Adelaide SA Australia.,Climate and Global Dynamics Laboratory National Center for Atmospheric Research Boulder CO USA
| | - Damien A Fordham
- The Environment Institute and School of Biological Sciences The University of Adelaide Adelaide SA Australia
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Feit B, Dempster T, Jessop TS, Webb JK, Letnic M. A trophic cascade initiated by an invasive vertebrate alters the structure of native reptile communities. Glob Chang Biol 2020; 26:2829-2840. [PMID: 32034982 DOI: 10.1111/gcb.15032] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 12/16/2019] [Accepted: 02/04/2020] [Indexed: 06/10/2023]
Abstract
Invasive vertebrates are frequently reported to have catastrophic effects on the populations of species which they directly impact. It follows then, that if invaders exert strong suppressive effects on some species then other species will indirectly benefit due to ecological release from interactions with directly impacted species. However, evidence that invasive vertebrates trigger such trophic cascades and alter community structure in terrestrial ecosystems remains rare. Here, we ask how the cane toad, a vertebrate invader that is toxic to many of Australia's vertebrate predators, influences lizard assemblages in a semi-arid rangeland. In our study area, the density of cane toads is influenced by the availability of water accessible to toads. We compared an index of the abundance of sand goannas, a large predatory lizard that is susceptible to poisoning by cane toads and the abundances of four lizard families preyed upon by goannas (skinks, pygopods, agamid lizards and geckos) in areas where cane toads were common or rare. Consistent with the idea that suppression of sand goannas by cane toads initiates a trophic cascade, goanna activity was lower and small lizards were more abundant where toads were common. The hypothesis that suppression of sand goannas by cane toads triggers a trophic cascade was further supported by our findings that small terrestrial lizards that are frequently preyed upon by goannas were more affected by toad abundance than arboreal geckos, which are rarely consumed by goannas. Furthermore, the abundance of at least one genus of terrestrial skinks benefitted from allogenic ecosystem engineering by goannas where toads were rare. Overall, our study provides evidence that the invasion of ecosystems by non-native species can have important effects on the structure and integrity of native communities extending beyond their often most obvious and frequently documented direct ecological effects.
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Affiliation(s)
- Benjamin Feit
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Tim Dempster
- School of Biosciences, University of Melbourne, Melbourne, Vic., Australia
| | - Tim S Jessop
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, Vic., Australia
| | - Jonathan K Webb
- School of Life Sciences, University of Technology Sydney, Broadway, NSW, Australia
| | - Mike Letnic
- Centre for Ecosystem Science, School of BEES, University of New South Wales, Sydney, NSW, Australia
- Evolution and Ecology Research Centre, School of BEES, University of New South Wales, Sydney, NSW, Australia
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Jessop TS, Ariefiandy A, Forsyth DM, Purwandana D, White CR, Benu YJ, Madsen T, Harlow HJ, Letnic M. Komodo dragons are not ecological analogs of apex mammalian predators. Ecology 2020; 101:e02970. [DOI: 10.1002/ecy.2970] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 10/03/2019] [Accepted: 12/04/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Tim S. Jessop
- School of Life and Environmental Sciences Centre for Integrative Ecology Deakin University Waurn Ponds Victoria 3220 Australia
| | | | - David M. Forsyth
- New South Wales Department of Primary Industries Vertebrate Pest Research Unit Orange New South Wales 2800 Australia
| | | | - Craig R. White
- School of Biological Sciences Monash University Clayton Victoria 3800 Australia
| | | | - Thomas Madsen
- School of Life and Environmental Sciences Centre for Integrative Ecology Deakin University Waurn Ponds Victoria 3220 Australia
| | - Henry J. Harlow
- Department of Physiology and Zoology University of Wyoming Laramie Wyoming 82071 USA
| | - Mike Letnic
- School of Biological, Earth and Environmental Sciences Centre for Ecosystem Science University of New South Wales Kensington New South Wales 2033 Australia
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12
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Hu Y, Doherty TS, Jessop TS. How influential are squamate reptile traits in explaining population responses to environmental disturbances? Wildl Res 2020. [DOI: 10.1071/wr19064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Abstract Context Understanding how organismal attributes influence sensitivity to environmental perturbations is a central theme in ecology and conservation. Certain traits, such as body size, habitat use, dietary preference and reproductive output are considered important determinants of animal species’ responses to the impacts of ecological disturbances. However, the general relationships between functional traits and post-disturbance responses by animals are not fully understood. AimsOur primary aim was to use a meta-analysis to evaluate the influence of species traits on variation in population abundances of squamate reptiles (i.e. lizards and snakes). MethodsWe extracted data from 107 original published studies, from which 1027 mean effect sizes of post-disturbance responses by 298 species were estimated. We examined short-term responses only (i.e. within 3 years since the most recent disturbance). A comprehensive range of disturbances was examined, such as habitat destruction, fragmentation, fire, and exotic-species invasions. We used Bayesian linear mixed-effect modelling (BLMM), utilising the Markov-chain Monte Carlo algorithm (MCMC) for the meta-regression. Specifically, we tested the influence of eight species traits (body size, diet, temporal activity pattern, sociality, reproductive mode, clutch size, habitat selection, and mean body temperature), along with disturbance type, in explaining variation in species-specific abundance responses of squamate reptiles post-disturbance. Key resultsPost-disturbance abundance responses of squamate species were significantly influenced by two parameters, namely, mean body temperature and clutch size. In general, significant positive responses post-disturbance were observed for species with higher mean body temperatures and a greater clutch size. The type of disturbance had no detectable influence on squamate abundances. The influence of random effects (heterogeneity among studies and species, and broad taxonomic identity) accounted for more of the model variation than did the fixed effects (species traits and disturbance type). ConclusionsCertain species traits exerted some influence on the sensitivities of lizards and snakes to ecological disturbances, although the influence of random effects was very strong. Our findings are likely to be a result of the complexity and idiosyncratic nature of natural abundance patterns among animal species, in addition to the potential confounding effect of methodological differences among studies. ImplicationsThe present study is the first major quantitative synthesis of how species traits influence population-level responses of squamate reptiles to ecological disturbances. The findings can be used to guide conservation efforts and ecological management, such as by prioritising the efforts of mitigation on species that reproduce more slowly, and those with lower body temperatures.
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13
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Ariefiandy A, Purwandana D, Benu YJ, Letnic M, Jessop TS. Knee deep in trouble: rusa deer use an aquatic escape behaviour to delay attack by Komodo dragons. Aust Mammalogy 2020. [DOI: 10.1071/am18052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We document six observations of an aquatic behaviour used by rusa deer (Rusa timorensis) to delay an imminent attack from Komodo dragons (Varanus komodoensis). This unusual behaviour arose after rusa deer fled into the nearby seawater following an attack from a solitary Komodo dragon. Once in the sea, rusa deer remained relatively stationary by standing in shallow water (<1 m deep) for up to 4 h. This behaviour generally allowed rusa deer to avoid an in-water attack from Komodo dragons. However, if rusa did not die from injuries, they moved back onto land and were subsequently killed by Komodo dragons. The aquatic behaviour delays subsequent attacks on rusa deer by Komodo dragons, but this appears only to postpone, rather than prevent, the deer’s death.
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Lind AL, Lai YYY, Mostovoy Y, Holloway AK, Iannucci A, Mak ACY, Fondi M, Orlandini V, Eckalbar WL, Milan M, Rovatsos M, Kichigin IG, Makunin AI, Johnson Pokorná M, Altmanová M, Trifonov VA, Schijlen E, Kratochvíl L, Fani R, Velenský P, Rehák I, Patarnello T, Jessop TS, Hicks JW, Ryder OA, Mendelson JR, Ciofi C, Kwok PY, Pollard KS, Bruneau BG. Genome of the Komodo dragon reveals adaptations in the cardiovascular and chemosensory systems of monitor lizards. Nat Ecol Evol 2019; 3:1241-1252. [PMID: 31358948 PMCID: PMC6668926 DOI: 10.1038/s41559-019-0945-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 06/13/2019] [Indexed: 01/24/2023]
Abstract
Monitor lizards are unique among ectothermic reptiles in that they have high aerobic capacity and distinctive cardiovascular physiology resembling that of endothermic mammals. Here, we sequence the genome of the Komodo dragon Varanus komodoensis, the largest extant monitor lizard, and generate a high-resolution de novo chromosome-assigned genome assembly for V. komodoensis using a hybrid approach of long-range sequencing and single-molecule optical mapping. Comparing the genome of V. komodoensis with those of related species, we find evidence of positive selection in pathways related to energy metabolism, cardiovascular homoeostasis, and haemostasis. We also show species-specific expansions of a chemoreceptor gene family related to pheromone and kairomone sensing in V. komodoensis and other lizard lineages. Together, these evolutionary signatures of adaptation reveal the genetic underpinnings of the unique Komodo dragon sensory and cardiovascular systems, and suggest that selective pressure altered haemostasis genes to help Komodo dragons evade the anticoagulant effects of their own saliva. The Komodo dragon genome is an important resource for understanding the biology of monitor lizards and reptiles worldwide.
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Affiliation(s)
| | - Yvonne Y Y Lai
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Yulia Mostovoy
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | | | - Alessio Iannucci
- Department of Biology, University of Florence, Sesto Fiorentino, Italy
| | - Angel C Y Mak
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Marco Fondi
- Department of Biology, University of Florence, Sesto Fiorentino, Italy
| | - Valerio Orlandini
- Department of Biology, University of Florence, Sesto Fiorentino, Italy
| | - Walter L Eckalbar
- Institute for Human Genetics, University of California, San Francisco, CA, USA
| | - Massimo Milan
- Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro, Italy
| | - Michail Rovatsos
- Department of Ecology, Charles University, Prague, Czech Republic
- Institute of Animal Physiology and Genetics, The Czech Academy of Sciences, Liběchov, Czech Republic
| | - Ilya G Kichigin
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, Russia
| | - Alex I Makunin
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, Russia
| | - Martina Johnson Pokorná
- Department of Ecology, Charles University, Prague, Czech Republic
- Institute of Animal Physiology and Genetics, The Czech Academy of Sciences, Liběchov, Czech Republic
| | - Marie Altmanová
- Department of Ecology, Charles University, Prague, Czech Republic
- Institute of Animal Physiology and Genetics, The Czech Academy of Sciences, Liběchov, Czech Republic
| | | | - Elio Schijlen
- B.U. Bioscience, Wageningen University, Wageningen, The Netherlands
| | - Lukáš Kratochvíl
- Department of Ecology, Charles University, Prague, Czech Republic
| | - Renato Fani
- Department of Biology, University of Florence, Sesto Fiorentino, Italy
| | | | - Ivan Rehák
- Prague Zoological Garden, Prague, Czech Republic
| | - Tomaso Patarnello
- Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro, Italy
| | - Tim S Jessop
- Centre for Integrative Ecology, Deakin University, Waurn Ponds, Victoria, Australia
| | - James W Hicks
- Department of Ecology and Evolutionary Biology, School of Biological Sciences, University of California, Irvine, CA, USA
| | - Oliver A Ryder
- Institute for Conservation Research, San Diego Zoo, Escondido, CA, USA
| | - Joseph R Mendelson
- Zoo Atlanta, Atlanta, GA, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Claudio Ciofi
- Department of Biology, University of Florence, Sesto Fiorentino, Italy
| | - Pui-Yan Kwok
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
- Institute for Human Genetics, University of California, San Francisco, CA, USA
- Department of Dermatology, University of California, San Francisco, CA, USA
| | - Katherine S Pollard
- Gladstone Institutes, San Francisco, CA, USA.
- Institute for Human Genetics, University of California, San Francisco, CA, USA.
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA.
- Institute for Computational Health Sciences, University of California, San Francisco, CA, USA.
- Chan-Zuckerberg BioHub, San Francisco, CA, USA.
| | - Benoit G Bruneau
- Gladstone Institutes, San Francisco, CA, USA.
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA.
- Department of Pediatrics, University of California, San Francisco, CA, USA.
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15
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Jessop TS, Ariefiandy A, Purwandana D, Benu YJ, Hyatt M, Letnic M. Little to fear: largest lizard predator induces weak defense responses in ungulate prey. Behav Ecol 2019. [DOI: 10.1093/beheco/ary200] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Tim S Jessop
- Centre for Integrative Ecology, School of Life and Environmental Science, Deakin University, Waurn Ponds, Victoria, Australia
- Komodo Survival Program, Denpasar, Bali, Indonesia
| | | | | | | | - Matthew Hyatt
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, New South Wales, Australia
| | - Mike Letnic
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, New South Wales, Australia
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Eyck HJ, Buchanan KL, Crino OL, Jessop TS. Effects of developmental stress on animal phenotype and performance: a quantitative review. Biol Rev Camb Philos Soc 2019; 94:1143-1160. [DOI: 10.1111/brv.12496] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 12/08/2018] [Accepted: 12/13/2018] [Indexed: 12/26/2022]
Affiliation(s)
- Harrison J.F. Eyck
- Centre for Integrative Ecology, Deakin University, School of Life and Environmental Sciences, 75 Pigdons rd; Geelong VIC 3216 Australia
| | - Katherine L. Buchanan
- Centre for Integrative Ecology, Deakin University, School of Life and Environmental Sciences, 75 Pigdons rd; Geelong VIC 3216 Australia
| | - Ondi L. Crino
- Centre for Integrative Ecology, Deakin University, School of Life and Environmental Sciences, 75 Pigdons rd; Geelong VIC 3216 Australia
| | - Tim S. Jessop
- Centre for Integrative Ecology, Deakin University, School of Life and Environmental Sciences, 75 Pigdons rd; Geelong VIC 3216 Australia
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Abstract
Context Australia harbours an immense diversity of reptiles, which are generally expected to have frequent and diverse trophic interactions with introduced mammalian carnivores. Nevertheless, the potential for predatory or competitive interactions is likely to be contingent on multiple processes, including the importance of reptiles in the diet of introduced predators, alongside overlaps in their body sizes and ecological niches that would influence the strength of their interactions. In Australia’s temperate and relatively productive mesic environments there is little understanding of how introduced mammalian predators affect reptile assemblages. Aims The aim was to investigate the effects that a European red fox (Vulpes vulpes; 5–7kg) suppression program had on the abundance and species richness of a reptile community, with species ranging in size from the largest local ectothermic predator, the lace monitor (Varanus varius; 4–7kg), to small terrestrial reptiles (mostly 10–150g). Methods We utilised two sampling designs (baited camera monitoring stations and pitfall trapping) to evaluate the effects of fox suppression and other site-level ecological covariates (fire regime and habitat vegetation characteristics) on the lace monitor and small terrestrial reptiles. Reptile abundance and richness at site level were estimated from count-related abundance models. Key results For lace monitors, significantly higher abundances occurred in poison-baited areas relative to control areas. This suggests that fox suppression can affect the populations of the lace monitor via mesopredator release arising from reduced competition and, possibly, predation. For small terrestrial reptiles, neither abundance nor species richness were influenced by fox suppression. Individual abundances of the three most common small reptile species matched the overall pattern, as only responses to structural parameters of the habitat were detected. Conclusions Fox suppression can have different impacts for different reptile taxa, pending their ecological niche, as only the largest species was affected. Implications Increase in lace monitor abundance may change food web dynamics in fox-suppressed sites, such as by increasing predation pressure on arboreal marsupials.
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18
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Jessop TS, Webb J, Dempster T, Feit B, Letnic M. Interactions between corticosterone phenotype, environmental stressor pervasiveness and irruptive movement-related survival in the cane toad. J Exp Biol 2018; 221:jeb.187930. [PMID: 30352824 DOI: 10.1242/jeb.187930] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Accepted: 10/19/2018] [Indexed: 11/20/2022]
Abstract
Animals use irruptive movement to avoid exposure to stochastic and pervasive environmental stressors that impact fitness. Beneficial irruptive movements transfer individuals from high-stress areas (conferring low fitness) to alternative localities that may improve survival or reproduction. However, being stochastic, environmental stressors can limit an animal's preparatory capacity to enhance irruptive movement performance. Thus individuals must rely on pre-existing, or rapidly induced, physiological and behavioural responses. Rapid elevation of glucocorticoid hormones in response to environmental stressors are widely implicated in adjusting physiological and behaviour processes that could influence irruptive movement capacity. However, there remains little direct evidence demonstrating that corticosterone-regulated movement performance or interaction with pervasiveness of environmental stress, confers adaptive movement outcomes. Here, we compared how movement-related survival of cane toads (Rhinella marina) varied with three different experimental corticosterone phenotypes across four increments of increasing environmental stressor pervasiveness (i.e. distance from water in a semi-arid landscape). Our results indicated that toads with phenotypically increased corticosterone levels attained higher movement-related survival compared with individuals with control or lowered corticosterone phenotypes. However, the effects of corticosterone phenotypes on movement-related survival to some extent co-varied with stressor pervasiveness. Thus, our study demonstrates how the interplay between an individual's corticosterone phenotype and movement capacity alongside the arising costs of movement and the pervasiveness of the environmental stressor can affect survival outcomes.
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Affiliation(s)
- Tim S Jessop
- Centre for Integrative Ecology, Deakin University, Victoria, 3220, Australia
| | - Jonathan Webb
- School of the Environment, University of Technology Sydney, NSW 2007, Australia
| | - Tim Dempster
- School of Biosciences, University of Melbourne, Victoria, 3010, Australia
| | - Benjamin Feit
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.,School of Biological, Earth and Environmental Sciences, University of New South Wales, NSW 2052, Australia
| | - Mike Letnic
- School of Biological, Earth and Environmental Sciences, University of New South Wales, NSW 2052, Australia
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Jessop TS, Ariefiandy A, Purwandana D, Ciofi C, Imansyah J, Benu YJ, Fordham DA, Forsyth DM, Mulder RA, Phillips BL. Exploring mechanisms and origins of reduced dispersal in island Komodo dragons. Proc Biol Sci 2018; 285:rspb.2018.1829. [PMID: 30429305 DOI: 10.1098/rspb.2018.1829] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 10/22/2018] [Indexed: 11/12/2022] Open
Abstract
Loss of dispersal typifies island biotas, but the selective processes driving this phenomenon remain contentious. This is because selection via, both indirect (e.g. relaxed selection or island syndromes) and direct (e.g. natural selection or spatial sorting) processes may be involved, and no study has yet convincingly distinguished between these alternatives. Here, we combined observational and experimental analyses of an island lizard, the Komodo dragon (Varanus komodoensis, the world's largest lizard), to provide evidence for the actions of multiple processes that could contribute to island dispersal loss. In the Komodo dragon, concordant results from telemetry, simulations, experimental translocations, mark-recapture, and gene flow studies indicated that despite impressive physical and sensory capabilities for long-distance movement, Komodo dragons exhibited near complete dispersal restriction: individuals rarely moved beyond the valleys they were born/captured in. Importantly, lizard site-fidelity was insensitive to common agents of dispersal evolution (i.e. indices of risk for inbreeding, kin and intraspecific competition, and low habitat quality) that consequently reduced survival of resident individuals. We suggest that direct selection restricts movement capacity (e.g. via benefits of spatial philopatry and increased costs of dispersal) alongside use of dispersal-compensating traits (e.g. intraspecific niche partitioning) to constrain dispersal in island species.
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Affiliation(s)
- Tim S Jessop
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds 3220, Australia
| | | | | | - Claudio Ciofi
- Department of Animal Biology and Genetics, University of Florence, Florence 50125, Italy
| | - Jeri Imansyah
- Komodo Survival Program, Denpasar 80223, Bali, Indonesia
| | | | - Damien A Fordham
- The Environment Institute and School of Earth and Environmental Science, The University of Adelaide, Adelaide, South Australia 5005, Australia.,Center for Macroecology, Evolution, and Climate, National Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - David M Forsyth
- Vertebrate Pest Research Unit, New South Wales Department of Primary Industries, Orange, New South Wales 2800, Australia
| | - Raoul A Mulder
- School of Biosciences, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Benjamin L Phillips
- School of Biosciences, University of Melbourne, Parkville, Victoria 3010, Australia
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Jessop TS, Lane M, Wilson RS, Narayan EJ. Testing for Short- and Long-Term Thermal Plasticity in Corticosterone Responses of an Ectothermic Vertebrate. Physiol Biochem Zool 2018; 91:967-975. [PMID: 29863953 DOI: 10.1086/698664] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Phenotypic plasticity, broadly defined as the capacity of one genotype to produce more than one phenotype, is a key mechanism for how animals adapt to environmental (including thermal) variation. Vertebrate glucocorticoid hormones exert broad-scale regulation of physiological, behavioral, and morphological traits that influence fitness under many life-history or environmental contexts. Yet the capacity for vertebrates to demonstrate different types of thermal plasticity, including rapid compensation or longer acclimation in glucocorticoid hormone function, when subject to different environmental temperature regimes remains poorly addressed. Here, we explore whether patterns of urinary corticosterone metabolites respond (i.e., evidence of acclimation) to repeated short-term and sustained long-term temperature exposures in an amphibian, the cane toad (Rhinella marina). In response to three repeated short (30-min) high-temperature (37°C) exposures (at 10-d intervals), toads produced urinary corticosterone metabolite responses of sequentially greater magnitude, relative to controls. However, toads subjected to 4 wk of acclimation to either cool (18°C)- or warm (30°C)-temperature environments did not differ significantly in their urinary corticosterone metabolite responses during exposure to a thermal ramp (18°-36°C). Together, these results indicate that adult toads had different, including limited, capacities for their glucocorticoid responses to demonstrate plasticity to different regimes of environmental temperature variation. We advocate further research as necessary to identify plasticity, or lack thereof, in glucocorticoid physiology, to better understand how vertebrates can regulate organismal responses to environmental variation.
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Affiliation(s)
- Tim S Jessop
- 1 Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Geelong, Victoria 3220, Australia
| | - Meagan Lane
- 2 School of Biosciences, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Robbie S Wilson
- 3 School of Biological Sciences, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Edward J Narayan
- 4 School of Science and Health, Hawkesbury campus, Western Sydney University, Locked Bag 1797, Penrith, New South Wales 2751, Australia
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Feit B, Gordon CE, Webb JK, Jessop TS, Laffan SW, Dempster T, Letnic M. Invasive cane toads might initiate cascades of direct and indirect effects in a terrestrial ecosystem. Biol Invasions 2018. [DOI: 10.1007/s10530-018-1665-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/24/2023]
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Sorby KL, Green MP, Dempster TD, Jessop TS. Can physiological engineering/programming increase multi-generational thermal tolerance to extreme temperature events? J Exp Biol 2018; 221:jeb.174672. [DOI: 10.1242/jeb.174672] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 05/22/2018] [Indexed: 02/02/2023]
Abstract
Organisms increasingly encounter higher frequencies of extreme weather events as a consequence of global climate change. Currently, few strategies are available to mitigate climate change effects on animals arising from acute extreme high temperature events. We tested the capacity of physiological engineering to influence the intra- and multi-generational upper thermal tolerance capacity of a model organism Artemia, subjected to extreme high temperatures. Enhancement of specific physiological regulators during development could affect thermal tolerances or life-history attributes affecting subsequent fitness. Using experimental Artemia populations we exposed F0 individuals to one of four treatments; heat hardening (28°C to 36°C, 1°C per 10 minutes), heat hardening plus serotonin (0.056 µg ml−1), heat hardening plus methionine (0.79 mg ml−1), and a control treatment. Regulator concentrations were based on previous literature. Serotonin may promote thermotolerance, acting upon metabolism and life-history. Methionine acts as a methylation agent across generations. For all groups, measurements were collected for three performance traits of individual thermal tolerance (upper sublethal thermal limit, lethal limit, and dysregulation range) over two generations. Results showed no treatment increased upper thermal limit during acute thermal stress, although serotonin-treated and methionine-treated individuals outperformed controls across multiple thermal performance traits. Additionally, some effects were evident across generations. Together these results suggest phenotypic engineering provides complex outcomes; and if implemented with heat hardening can further influence performance in multiple thermal tolerance traits, within and across generations. Potentially, such techniques could be up-scaled to provide resilience and stability in populations susceptible to extreme temperature events.
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Affiliation(s)
- Kris L. Sorby
- School of BioSciences, University of Melbourne, Parkville 3010, Australia
| | - Mark P. Green
- School of BioSciences, University of Melbourne, Parkville 3010, Australia
| | - Tim D. Dempster
- School of BioSciences, University of Melbourne, Parkville 3010, Australia
| | - Tim S. Jessop
- School of BioSciences, University of Melbourne, Parkville 3010, Australia
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Yewers MSC, Jessop TS, Stuart-Fox D. Endocrine differences among colour morphs in a lizard with alternative behavioural strategies. Horm Behav 2017; 93:118-127. [PMID: 28478216 DOI: 10.1016/j.yhbeh.2017.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Revised: 03/18/2017] [Accepted: 05/02/2017] [Indexed: 11/16/2022]
Abstract
Alternative behavioural strategies of colour morphs are expected to associate with endocrine differences and to correspond to differences in physical performance (e.g. movement speed, bite force in lizards); yet the nature of correlated physiological and performance traits in colour polymorphic species varies widely. Colour morphs of male tawny dragon lizards Ctenophorus decresii have previously been found to differ in aggressive and anti-predator behaviours. We tested whether known behavioural differences correspond to differences in circulating baseline and post-capture stress levels of androgen and corticosterone, as well as bite force (an indicator of aggressive performance) and field body temperature. Immediately after capture, the aggressive orange morph had higher circulating androgen than the grey morph or the yellow morph. Furthermore, the orange morph maintained high androgen following acute stress (30min of capture); whereas androgen increased in the grey and yellow morphs. This may reflect the previously defined behavioural differences among morphs as the aggressive response of the yellow morph is conditional on the colour of the competitor and the grey morph shows consistently low aggression. In contrast, all morphs showed an increase in corticosterone concentration after capture stress and morphs did not differ in levels of corticosterone stress magnitude (CSM). Morphs did not differ in size- and temperature-corrected bite force but did in body temperature at capture. Differences in circulating androgen and body temperature are consistent with morph-specific behavioural strategies in C. decresii but our results indicate a complex relationship between hormones, behaviour, temperature and bite force within and between colour morphs.
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Affiliation(s)
| | - Tim S Jessop
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Australia
| | - Devi Stuart-Fox
- School of BioSciences, The University of Melbourne, Australia
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Lyndon-Gee F, Sumner J, Hu Y, Ciofi C, Jessop TS. Abundance and genetic diversity responses of a lizard (Eulamprus heatwolei) to logging disturbance. AUST J ZOOL 2017. [DOI: 10.1071/zo17051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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
Rotational logging practices are used with the goal of reducing forest disturbance impacts on biodiversity. However, it is poorly understood whether such forest management practices conserve the demographic and genetic composition of animal populations across logged landscapes. Here we investigated whether rotational logging practices alter patterns of landscape-scale population abundance and genetic diversity of a forest-dwelling lizard (Eulamprus heatwolei) in south-eastern Australia. We sampled lizards (n = 407) at up to 48 sites across a chronosequence of logging disturbance intervals (<10 to >60 years after logging) to assess site-specific population changes and genetic diversity parameters. Lizard abundances exhibited a significant curvilinear response to time since logging, with decreased numbers following logging (<10 years), increased abundance as the forest regenerated (10–20 years), before decreasing again in older regenerated forest sites (>30 years). Lizard genetic diversity parameters were not significantly influenced by logging disturbance. These results suggest that logging practices, whilst inducing short-term changes to population abundance, had no measurable effects on the landscape-scale genetic diversity of E. heatwolei. These results are important as they demonstrate the value of monitoring for evaluating forest management efficacy, and the use of different population-level markers to make stronger inference about the potential impacts of logging activities.
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Jessop TS, Lane ML, Teasdale L, Stuart-Fox D, Wilson RS, Careau V, Moore IT. Multiscale Evaluation of Thermal Dependence in the Glucocorticoid Response of Vertebrates. Am Nat 2016; 188:342-56. [DOI: 10.1086/687588] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Ariefiandy A, Forsyth DM, Purwandana D, Imansyah J, Ciofi C, Rudiharto H, Seno A, Jessop TS. Temporal and spatial dynamics of insular Rusa deer and wild pig populations in Komodo National Park. J Mammal 2016. [DOI: 10.1093/jmammal/gyw131] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Slade B, Parrott ML, Paproth A, Magrath MJL, Gillespie GR, Jessop TS. Assortative mating among animals of captive and wild origin following experimental conservation releases. Biol Lett 2015; 10:20140656. [PMID: 25411380 DOI: 10.1098/rsbl.2014.0656] [Citation(s) in RCA: 20] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Captive breeding is a high profile management tool used for conserving threatened species. However, the inevitable consequence of generations in captivity is broad scale and often-rapid phenotypic divergence between captive and wild individuals, through environmental differences and genetic processes. Although poorly understood, mate choice preference is one of the changes that may occur in captivity that could have important implications for the reintroduction success of captive-bred animals. We bred wild-caught house mice for three generations to examine mating patterns and reproductive outcomes when these animals were simultaneously released into multiple outdoor enclosures with wild conspecifics. At release, there were significant differences in phenotypic (e.g. body mass) and genetic measures (e.g. Gst and F) between captive-bred and wild adult mice. Furthermore, 83% of offspring produced post-release were of same source parentage, inferring pronounced assortative mating. Our findings suggest that captive breeding may affect mating preferences, with potentially adverse implications for the success of threatened species reintroduction programmes.
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Affiliation(s)
- Brendan Slade
- Department of Zoology, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Marissa L Parrott
- Wildlife Conservation and Science, Zoos Victoria, Parkville, Victoria 3056, Australia
| | - Aleisha Paproth
- Department of Zoology, University of Melbourne, Parkville, Victoria 3010, Australia Wildlife Conservation and Science, Zoos Victoria, Parkville, Victoria 3056, Australia
| | - Michael J L Magrath
- Wildlife Conservation and Science, Zoos Victoria, Parkville, Victoria 3056, Australia
| | - Graeme R Gillespie
- Department of Zoology, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Tim S Jessop
- Department of Zoology, University of Melbourne, Parkville, Victoria 3010, Australia
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McCurry MR, Mahony M, Clausen PD, Quayle MR, Walmsley CW, Jessop TS, Wroe S, Richards H, McHenry CR. The relationship between cranial structure, biomechanical performance and ecological diversity in varanoid lizards. PLoS One 2015; 10:e0130625. [PMID: 26106889 PMCID: PMC4479569 DOI: 10.1371/journal.pone.0130625] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [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: 03/09/2015] [Accepted: 05/21/2015] [Indexed: 11/18/2022] Open
Abstract
Skull structure is intimately associated with feeding ability in vertebrates, both in terms of specific performance measures and general ecological characteristics. This study quantitatively assessed variation in the shape of the cranium and mandible in varanoid lizards, and its relationship to structural performance (von Mises strain) and interspecific differences in feeding ecology. Geometric morphometric and linear morphometric analyses were used to evaluate morphological differences, and finite element analysis was used to quantify variation in structural performance (strain during simulated biting, shaking and pulling). This data was then integrated with ecological classes compiled from relevant scientific literature on each species in order to establish structure-function relationships. Finite element modelling results showed that variation in cranial morphology resulted in large differences in the magnitudes and locations of strain in biting, shaking and pulling load cases. Gracile species such as Varanus salvadorii displayed high strain levels during shaking, especially in the areas between the orbits. All models exhibit less strain during pull back loading compared to shake loading, even though a larger force was applied (pull =30N, shake = 20N). Relationships were identified between the morphology, performance, and ecology. Species that did not feed on hard prey clustered in the gracile region of cranial morphospace and exhibited significantly higher levels of strain during biting (P = 0.0106). Species that fed on large prey clustered in the elongate area of mandible morphospace. This relationship differs from those that have been identified in other taxonomic groups such as crocodiles and mammals. This difference may be due to a combination of the open 'space-frame' structure of the varanoid lizard skull, and the 'pull back' behaviour that some species use for processing large prey.
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Affiliation(s)
- Matthew R. McCurry
- Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
- School of Environmental and Life Science, University of Newcastle, Newcastle, Australia
- Geosciences, Museum Victoria, Melbourne, Australia
| | - Michael Mahony
- School of Environmental and Life Science, University of Newcastle, Newcastle, Australia
| | | | - Michelle R. Quayle
- Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | | | - Tim S. Jessop
- Department of Zoology, University of Melbourne, Melbourne, Australia
| | - Stephen Wroe
- School of Engineering, University of Newcastle, Newcastle, Australia
- The Function, Evolution & Anatomy Research Lab, Zoology Division, School of Environmental and Rural Sciences, University of New England, Armidale, Australia
| | - Heather Richards
- School of Engineering, University of Newcastle, Newcastle, Australia
| | - Colin R. McHenry
- Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
- School of Engineering, University of Newcastle, Newcastle, Australia
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Jessop TS, Anson JR, Narayan E, Lockwood T. An Introduced Competitor Elevates Corticosterone Responses of a Native Lizard (Varanus varius). Physiol Biochem Zool 2015; 88:237-45. [DOI: 10.1086/680689] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Narayan EJ, Jessop TS, Hero J. Invasive cane toad triggers chronic physiological stress and decreased reproductive success in an island endemic. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12446] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Edward J. Narayan
- School of Animal and Veterinary Sciences Charles Sturt University Wagga Wagga NSW 2678Australia
- Environmental Futures Research Institute School of Environment Griffith University Griffith QLD 4222Australia
| | - Tim S. Jessop
- School of BioSciences University of Melbourne Melbourne Vic 3010Australia
- Centre for Integrative Ecology School of Life and Environmental Science Deakin University Waurn Ponds Vic 3220Australia
| | - Jean‐Marc Hero
- Environmental Futures Research Institute School of Environment Griffith University Griffith QLD 4222Australia
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Affiliation(s)
- Mike Letnic
- School of Biological, Earth and Environmental Sciences; University of New South Wales; Sydney NSW 2052 Australia
- Centre for Ecosystem Science; University of New South Wales; Sydney NSW 2052 Australia
- School of Biological Sciences; University of Sydney; Sydney NSW 2006 Australia
| | - Jonathan K. Webb
- School of Biological Sciences; University of Sydney; Sydney NSW 2006 Australia
- School of the Environment; University of Technology Sydney; Sydney NSW 2007 Australia
| | - Tim S. Jessop
- Department of Zoology; University of Melbourne; Melbourne Vic. 3010 Australia
| | - Tim Dempster
- Department of Zoology; University of Melbourne; Melbourne Vic. 3010 Australia
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Cavallo C, Dempster T, Kearney MR, Kelly E, Booth D, Hadden KM, Jessop TS. Predicting climate warming effects on green turtle hatchling viability and dispersal performance. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12389] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Catherine Cavallo
- Department of Zoology University of Melbourne Parkville Victoria3010 Australia
| | - Tim Dempster
- Department of Zoology University of Melbourne Parkville Victoria3010 Australia
| | - Michael R. Kearney
- Department of Zoology University of Melbourne Parkville Victoria3010 Australia
| | - Ella Kelly
- Department of Zoology University of Melbourne Parkville Victoria3010 Australia
| | - David Booth
- School of Biological Sciences University of Queensland St. Lucia Queensland4067 Australia
| | - Kate M. Hadden
- Tiwi Land Council PO Box 38545 Winnellie Northern Territory0821 Australia
| | - Tim S. Jessop
- Department of Zoology University of Melbourne Parkville Victoria3010 Australia
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Jessop TS, Dempster T, Letnic M, Webb JK. Interplay among nocturnal activity, melatonin, corticosterone and performance in the invasive cane toad (Rhinella marinus). Gen Comp Endocrinol 2014; 206:43-50. [PMID: 25063397 DOI: 10.1016/j.ygcen.2014.07.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 06/26/2014] [Accepted: 07/14/2014] [Indexed: 10/25/2022]
Abstract
Most animals conduct daily activities exclusively either during the day or at night. Here, hormones such as melatonin and corticosterone, greatly influence the synchronization or regulation of physiological and behavioral cycles needed for daily activity. How then do species that exhibit more flexible daily activity patterns, responses to ecological, environmental or life-history processes, regulate daily hormone profiles important to daily performance? This study examined the consequences of (1) nocturnal activity on diel profiles of melatonin and corticosterone and (2) the effects of experimentally increased acute melatonin levels on physiological and metabolic performance in the cane toad (Rhinella marinus). Unlike inactive captive toads that had a distinct nocturnal melatonin profile, nocturnally active toads sampled under field and captive conditions, exhibited decreased nocturnal melatonin profiles with no evidence for any phase shift. Nocturnal corticosterone levels were significantly higher in field active toads than captive toads. In toads with experimentally increased melatonin levels, plasma lactate and glucose responses following recovery post exercise were significantly different from control toads. However, exogenously increased melatonin did not affect resting metabolism in toads. These results suggest that toads could adjust daily hormone profiles to match nocturnal activity requirements, thereby avoiding performance costs induced by high nocturnal melatonin levels. The ability of toads to exhibit plasticity in daily hormone cycles, could have broad implications for how they and other animals utilize behavioral flexibility to optimize daily activities in response to natural and increasingly human mediated environmental variation.
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Affiliation(s)
- Tim S Jessop
- Department of Zoology, University of Melbourne, Victoria 3010, Australia.
| | - Tim Dempster
- Department of Zoology, University of Melbourne, Victoria 3010, Australia
| | - Mike Letnic
- School of Biological, Earth and Environmental Sciences, The University of New South Wales, NSW 2052, Australia
| | - Jonathan K Webb
- School of the Environment, University of Technology, Broadway, NSW 2007, Australia
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Letnic M, Webb JK, Jessop TS, Florance D, Dempster T. Artificial water points facilitate the spread of an invasive vertebrate in arid Australia. J Appl Ecol 2014. [DOI: 10.1111/1365-2664.12232] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Mike Letnic
- Centre for Ecosystem Science; School of Biological; Earth and Environmental Sciences; University of New South Wales; Sydney NSW 2052 Australia
| | - Jonathan K. Webb
- School of the Environment; University of Technology Sydney; Sydney NSW 2007 Australia
| | - Tim S. Jessop
- Department of Zoology; University of Melbourne; Melbourne Vic. 3010 Australia
| | - Daniel Florance
- School of Biological Sciences; University of Sydney; Sydney NSW 2006 Australia
| | - Tim Dempster
- Department of Zoology; University of Melbourne; Melbourne Vic. 3010 Australia
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Abstract
Plasticity or evolution in behavioural responses are key attributes of successful animal invasions. In northern Australia, the invasive cane toad (Rhinella marina) recently invaded semi-arid regions. Here, cane toads endure repeated daily bouts of severe desiccation and thermal stress during the long dry season (April-October). We investigated whether cane toads have shifted their ancestral nocturnal rehydration behaviour to one that exploits water resources during the day. Such a shift in hydration behaviour could increase the fitness of individual toads by reducing exposure to desiccation and thermal stress suffered during the day even within terrestrial shelters. We used a novel method (acoustic tags) to monitor the daily hydration behaviour of 20 toads at two artificial reservoirs on Camfield station, Northern Territory. Remarkably, cane toads visited reservoirs to rehydrate during daylight hours, with peaks in activity between 9.00 and 17.00. This diurnal pattern of rehydration activity contrasts with nocturnal rehydration behaviour exhibited by adult toads in their native geographical range and more mesic parts of Australia. Our results demonstrate that cane toads phase shift a key behaviour to survive in a harsh semi-arid landscape. Behavioural phase shifts have rarely been reported in invasive species but could facilitate ongoing invasion success.
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Affiliation(s)
- Jonathan K Webb
- School of the Environment, University of Technology Sydney, , Broadway, New South Wales 2007, Australia
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Jessop TS, Letnic M, Webb JK, Dempster T. Adrenocortical stress responses influence an invasive vertebrate's fitness in an extreme environment. Proc Biol Sci 2013; 280:20131444. [PMID: 23945686 DOI: 10.1098/rspb.2013.1444] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Continued range expansion into physiologically challenging environments requires invasive species to maintain adaptive phenotypic performance. The adrenocortical stress response, governed in part by glucocorticoid hormones, influences physiological and behavioural responses of vertebrates to environmental stressors. However, any adaptive role of this response in invasive populations that are expanding into extreme environments is currently unclear. We experimentally manipulated the adrenocortical stress response of invasive cane toads (Rhinella marina) to investigate its effect on phenotypic performance and fitness at the species' range front in the Tanami Desert, Australia. Here, toads are vulnerable to overheating and dehydration during the annual hot-dry season and display elevated plasma corticosterone levels indicative of severe environmental stress. By comparing unmanipulated control toads with toads whose adrenocortical stress response was manipulated to increase acute physiological stress responsiveness, we found that control toads had significantly reduced daily evaporative water loss and higher survival relative to the experimental animals. The adrenocortical stress response hence appears essential in facilitating complex phenotypic performance and setting fitness trajectories of individuals from invasive species during range expansion.
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Affiliation(s)
- Tim S Jessop
- Department of Zoology, University of Melbourne, Victoria 3010, Australia.
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Ariefiandy A, Purwandana D, Coulson G, Forsyth DM, Jessop TS. Monitoring the ungulate prey of the Komodo dragonVaranus komodoensis: distance sampling or faecal counts? Wildlife Biology 2013. [DOI: 10.2981/11-098] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Anson JR, Dickman CR, Boonstra R, Jessop TS. Stress triangle: do introduced predators exert indirect costs on native predators and prey? PLoS One 2013; 8:e60916. [PMID: 23585861 PMCID: PMC3621665 DOI: 10.1371/journal.pone.0060916] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [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: 07/18/2012] [Accepted: 03/05/2013] [Indexed: 11/23/2022] Open
Abstract
Non-consumptive effects of predators on each other and on prey populations often exceed the effects of direct predation. These effects can arise from fear responses elevating glucocorticoid (GC) hormone levels (predator stress hypothesis) or from increased vigilance that reduces foraging efficiency and body condition (predator sensitive foraging hypothesis); both responses can lead to immunosuppression and increased parasite loads. Non-consumptive effects of invasive predators have been little studied, even though their direct impacts on local species are usually greater than those of their native counterparts. To address this issue, we explored the non-consumptive effects of the invasive red fox Vulpes vulpes on two native species in eastern Australia: a reptilian predator, the lace monitor Varanus varius and a marsupial, the ringtail possum Pseudocheirus peregrinus. In particular, we tested predictions derived from the above two hypotheses by comparing the basal glucocorticoid levels, foraging behaviour, body condition and haemoparasite loads of both native species in areas with and without fox suppression. Lace monitors showed no GC response or differences in haemoparasite loads but were more likely to trade safety for higher food rewards, and had higher body condition, in areas of fox suppression than in areas where foxes remained abundant. In contrast, ringtails showed no physiological or behavioural differences between fox-suppressed and control areas. Predator sensitive foraging is a non-consumptive cost for lace monitors in the presence of the fox and most likely represents a response to competition. The ringtail’s lack of response to the fox potentially represents complete naiveté or strong and rapid selection to the invasive predator. We suggest evolutionary responses are often overlooked in interactions between native and introduced species, but must be incorporated if we are to understand the suite of forces that shape community assembly and function in the wake of biological invasions.
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Affiliation(s)
- Jennifer R Anson
- School of Biological Sciences, University of Sydney, Sydney, New South Wales, Australia.
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Jessop TS, Kearney MR, Moore JL, Lockwood T, Johnston M. Evaluating and predicting risk to a large reptile (Varanus varius) from feral cat baiting protocols. Biol Invasions 2013. [DOI: 10.1007/s10530-012-0398-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Crespi EJ, Williams TD, Jessop TS, Delehanty B. Life history and the ecology of stress: how do glucocorticoid hormones influence life-history variation in animals? Funct Ecol 2012. [DOI: 10.1111/1365-2435.12009] [Citation(s) in RCA: 269] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Erica J. Crespi
- School of Biological Sciences; Washington State University; Box 644236; Pullman; Washington; USA
| | - Tony D. Williams
- Department of Biological Sciences; Simon Fraser University; Burnaby; British Columbia; V5A 1S6; Canada
| | - Tim S. Jessop
- Department of Zoology; University of Melbourne; Melbourne; Victoria; 3010; Australia
| | - Brendan Delehanty
- Department of Biological Sciences; Centre for the Neurobiology of Stress; University of Toronto Scarborough; Toronto; Ontario; M1C 1A4; Canada
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Affiliation(s)
- Tim S. Jessop
- Department of Zoology; University of Melbourne; Melbourne; Victoria; 3010; Australia
| | - Romy Woodford
- Department of Zoology; University of Melbourne; Melbourne; Victoria; 3010; Australia
| | - Matthew R. E. Symonds
- Centre for Integrative Ecology; School of Life and Environmental Sciences; Deakin University; Burwood; Victoria; 3125; Australia
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Laver RJ, Purwandana D, Ariefiandy A, Imansyah J, Forsyth D, Ciofi C, Jessop TS. Life-history and spatial determinants of somatic growth dynamics in Komodo dragon populations. PLoS One 2012; 7:e45398. [PMID: 23028983 PMCID: PMC3446886 DOI: 10.1371/journal.pone.0045398] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [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: 06/08/2012] [Accepted: 08/22/2012] [Indexed: 11/18/2022] Open
Abstract
Somatic growth patterns represent a major component of organismal fitness and may vary among sexes and populations due to genetic and environmental processes leading to profound differences in life-history and demography. This study considered the ontogenic, sex-specific and spatial dynamics of somatic growth patterns in ten populations of the world's largest lizard the Komodo dragon (Varanus komodoensis). The growth of 400 individual Komodo dragons was measured in a capture-mark-recapture study at ten sites on four islands in eastern Indonesia, from 2002 to 2010. Generalized Additive Mixed Models (GAMMs) and information-theoretic methods were used to examine how growth rates varied with size, age and sex, and across and within islands in relation to site-specific prey availability, lizard population density and inbreeding coefficients. Growth trajectories differed significantly with size and between sexes, indicating different energy allocation tactics and overall costs associated with reproduction. This leads to disparities in maximum body sizes and longevity. Spatial variation in growth was strongly supported by a curvilinear density-dependent growth model with highest growth rates occurring at intermediate population densities. Sex-specific trade-offs in growth underpin key differences in Komodo dragon life-history including evidence for high costs of reproduction in females. Further, inverse density-dependent growth may have profound effects on individual and population level processes that influence the demography of this species.
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Affiliation(s)
- Rebecca J. Laver
- Department of Zoology, University of Melbourne, Melbourne, Victoria, Australia
| | | | | | - Jeri Imansyah
- The Komodo Survival Program, Denpasar, Bali, Indonesia
| | - David Forsyth
- Arthur Rylah Institute for Environmental Research, Department of Sustainability and Environment, Melbourne, Victoria, Australia
| | - Claudio Ciofi
- Department of Animal Biology and Genetics, University of Florence, Florence, Italy
| | - Tim S. Jessop
- Department of Zoology, University of Melbourne, Melbourne, Victoria, Australia
- Department of Wildlife, Conservation and Science, Zoos Victoria, Melbourne, Victoria, Australia
- * E-mail:
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Payne CJ, Jessop TS, Guay PJ, Johnstone M, Feore M, Mulder RA. Population, behavioural and physiological responses of an urban population of black swans to an intense annual noise event. PLoS One 2012; 7:e45014. [PMID: 23024783 PMCID: PMC3443219 DOI: 10.1371/journal.pone.0045014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [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: 02/23/2012] [Accepted: 08/14/2012] [Indexed: 11/18/2022] Open
Abstract
Wild animals in urban environments are exposed to a broad range of human activities that have the potential to disturb their life history and behaviour. Wildlife responses to disturbance can range from emigration to modified behaviour, or elevated stress, but these responses are rarely evaluated in concert. We simultaneously examined population, behavioural and hormonal responses of an urban population of black swans Cygnus atratus before, during and after an annual disturbance event involving large crowds and intense noise, the Australian Formula One Grand Prix. Black swan population numbers were lowest one week before the event and rose gradually over the course of the study, peaking after the event, suggesting that the disturbance does not trigger mass emigration. We also found no difference in the proportion of time spent on key behaviours such as locomotion, foraging, resting or self-maintenance over the course of the study. However, basal and capture stress-induced corticosterone levels showed significant variation, consistent with a modest physiological response. Basal plasma corticosterone levels were highest before the event and decreased over the course of the study. Capture-induced stress levels peaked during the Grand Prix and then also declined over the remainder of the study. Our results suggest that even intensely noisy and apparently disruptive events may have relatively low measurable short-term impact on population numbers, behaviour or physiology in urban populations with apparently high tolerance to anthropogenic disturbance. Nevertheless, the potential long-term impact of such disturbance on reproductive success, individual fitness and population health will need to be carefully evaluated.
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Affiliation(s)
| | - Tim S. Jessop
- Department of Zoology, University of Melbourne, Victoria, Australia
- Wildlife Conservation and Science, Zoos Victoria, Victoria, Australia
| | - Patrick-Jean Guay
- Institute for Sustainability and Innovation, Victoria University, Victoria, Australia
| | | | - Megan Feore
- Department of Zoology, University of Melbourne, Victoria, Australia
| | - Raoul A. Mulder
- Department of Zoology, University of Melbourne, Victoria, Australia
- * E-mail:
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Scheelings TF, Jessop TS. Influence of capture method, habitat quality and individual traits on blood parameters of free-ranging lace monitors (Varanus varius). Aust Vet J 2011; 89:360-5. [DOI: 10.1111/j.1751-0813.2011.00815.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bull JJ, Jessop TS, Whiteley M. Deathly drool: evolutionary and ecological basis of septic bacteria in Komodo dragon mouths. PLoS One 2010; 5:e11097. [PMID: 20574514 PMCID: PMC2888571 DOI: 10.1371/journal.pone.0011097] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Accepted: 05/18/2010] [Indexed: 11/28/2022] Open
Abstract
Komodo dragons, the world's largest lizard, dispatch their large ungulate prey by biting and tearing flesh. If a prey escapes, oral bacteria inoculated into the wound reputedly induce a sepsis that augments later prey capture by the same or other lizards. However, the ecological and evolutionary basis of sepsis in Komodo prey acquisition is controversial. Two models have been proposed. The “bacteria as venom” model postulates that the oral flora directly benefits the lizard in prey capture irrespective of any benefit to the bacteria. The “passive acquisition” model is that the oral flora of lizards reflects the bacteria found in carrion and sick prey, with no relevance to the ability to induce sepsis in subsequent prey. A third model is proposed and analyzed here, the “lizard-lizard epidemic” model. In this model, bacteria are spread indirectly from one lizard mouth to another. Prey escaping an initial attack act as vectors in infecting new lizards. This model requires specific life history characteristics and ways to refute the model based on these characteristics are proposed and tested. Dragon life histories (some details of which are reported here) prove remarkably consistent with the model, especially that multiple, unrelated lizards feed communally on large carcasses and that escaping, wounded prey are ultimately fed on by other lizards. The identities and evolutionary histories of bacteria in the oral flora may yield the most useful additional insights for further testing the epidemic model and can now be obtained with new technologies.
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Affiliation(s)
- J J Bull
- Section of Integrative Biology, University of Texas, Austin, Texas, USA.
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Lancaster P, Jessop TS, Stuart-Fox D. Testing the independent effects of population and shelter density on behavioural and corticosterone responses of tree skinks. AUST J ZOOL 2010. [DOI: 10.1071/zo10056] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [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
In animals, social organisation and behaviour can respond to variation in key ecological factors including population and resource density. As these two factors covary, their relative importance is difficult to estimate using field studies. Consequently, we conducted two manipulative experiments varying levels of either population or shelter density to separate their effects on solitary, affiliative and agonistic behaviour and physiology in the social tree skink, Egernia striolata. We used focal observations and plasma concentrations of the hormone corticosterone to measure behavioural and physiological responses to these manipulations. Aggressive behaviours occurred more frequently at high skink density, with males at high density exhibiting social stress, as indicated by increased levels of corticosterone. Skinks at low densities showed greater affiliative behaviour, spending more time basking as pairs. Changes in shelter density influenced exploratory behaviours, with males at low shelter densities exploring enclosures more than those at high shelter densities. Skinks sheltered as pairs more frequently at low shelter density, even after taking into account differences in frequency of pair sheltering expected by chance alone, suggesting that low shelter availability promotes pair behaviour. Corticosterone levels increased over time at low shelter density, which may have been a result of thermal stress coupled with a lack of microclimate variation in comparison to high shelter density. These results suggest that population and resource density are key factors that can independently influence social behaviour and endocrinology, and consequently social organisation, in different ways.
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Chan R, Stuart-Fox D, Jessop TS. Why are females ornamented? A test of the courtship stimulation and courtship rejection hypotheses. Behav Ecol 2009. [DOI: 10.1093/beheco/arp136] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Jessop TS, Chan R, Stuart-Fox D. Sex steroid correlates of female-specific colouration, behaviour and reproductive state in Lake Eyre dragon lizards, Ctenophorus maculosus. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2009; 195:619-30. [DOI: 10.1007/s00359-009-0437-4] [Citation(s) in RCA: 23] [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: 10/28/2008] [Revised: 03/16/2009] [Accepted: 03/18/2009] [Indexed: 11/30/2022]
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Jessop TS, Madsen T, Sumner J, Rudiharto H, Phillips JA, Ciofi C. Maximum body size among insular Komodo dragon populations covaries with large prey density. OIKOS 2006. [DOI: 10.1111/j.0030-1299.2006.14371.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
We investigated plasma hormone profiles of corticosterone in green turtles (Chelonia mydas) in response to a capture stress protocol. Further, we examined whether age class and sex were covariates associated with variation in both basal corticosterone levels and the adrenocortical stress response of non-breeding green turtles. Green turtles responded to the capture stress protocol by significantly increasing plasma levels of corticosterone over an eight-hour period. Further, there was a significant effect of age class on the capacity for green turtles to produce corticosterone in response to a capture stressor, with juvenile green turtles having higher basal levels of corticosterone and producing significantly more corticosterone in response to capture stress than non-breeding adult turtles. In contrast there was no significant sex difference in the corticosterone stress response of green turtles irrespective of age class. In summary, green turtles exhibited an adrenocortical response to a capture stress protocol. This response was significantly associated with different age classes, perhaps suggesting that the response is increased in juvenile turtles to offset the reduced probability of survival consistent with this more vulnerable age class.
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