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Behrendorff L, King R, Allen BL. Trouble in paradise: When two species of conservation and cultural value clash, causing a management conundrum. Ecol Evol 2023; 13:e10726. [PMID: 38020708 PMCID: PMC10653987 DOI: 10.1002/ece3.10726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 10/12/2023] [Accepted: 10/20/2023] [Indexed: 12/01/2023] Open
Abstract
Threatened species throughout the world are in decline due to various causes. In some cases, predators of conservation or cultural value are causing the decline of threatened prey, presenting a conservation conundrum for managers. We surveyed marine turtle nests on K'gari (formally known as Fraser Island), Australia, to investigate dingo predation of green and loggerhead turtle nests, where each of these species is of conservation value. Our monitoring revealed that 84% of nests were predated by dingoes. Only 16% of nests were not consumed by dingoes, and only 5.7% of nests were confirmed to have successfully hatched. Up to 94% of nests were consumed in some areas, and predation rates were similar across different dingo packs. Information on the available numbers of nests and dingoes in the area indicated that turtle nests alone are sufficient to support extant dingoes over the summer. These results indicate that marine turtle eggs represent a previously unquantified but important food source for dingoes on K'gari, and that turtle nests at this rookery site are under serious threat from dingoes. This research should highlight the importance of prioritising the protection of turtle nests from dingoes or risk losing the entire rookery forever in the near future.
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Affiliation(s)
- Linda Behrendorff
- School of Agriculture and Food SciencesUniversity of QueenslandGattonQueenslandAustralia
- Queensland Government Department of Environment and ScienceQueensland Parks and Wildlife ServiceK'gariQueenslandAustralia
| | - Rachel King
- School of Mathematics, Physics and ComputingUniversity of Southern QueenslandToowoombaQueenslandAustralia
| | - Benjamin L. Allen
- Institute for Life Sciences and the EnvironmentUniversity of Southern QueenslandToowoombaQueenslandAustralia
- Centre for African Conservation EcologyNelson Mandela UniversityPort ElizabethSouth Africa
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2
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Dogs suppress a pivotal function in the food webs of sandy beaches. Sci Rep 2022; 12:14069. [PMID: 35982210 PMCID: PMC9388640 DOI: 10.1038/s41598-022-18194-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 08/08/2022] [Indexed: 12/04/2022] Open
Abstract
Domestic dogs are the most abundant carnivore globally and have demonstrable negative impacts to wildlife; yet, little evidence regarding their functional roles in natural food webs exists. Adding dogs to food webs may result in a net loss (via suppression of naturally occurring species), net gain (via mesopredator release), or no change (via functional replacement) to ecosystem function. Scavenging is a pivotal function in ecosystems, particularly those that are energetically supported by carrion. Dogs also scavenge on animal carcasses, but whether scavenging by dogs influences the structural and functional properties of food webs remains unclear. Here we used camera traps baited with carrion to test the effect of dogs on the composition and diversity of the vertebrate scavenger guild, as well as carrion detection and consumption rates. We conducted this work in sandy beach ecosystems, which rely on the import of marine organic matter (i.e. stranding of dead marine animals). Diversity of the scavenger community was similar on beaches without dogs. Dogs increased the time it took for carcasses to be detected and decreased the proportion of carrion consumed. This ‘dog suppression effect’ on scavenging was stronger for nocturnal mammalian scavengers, presumably being driven by indirect trait-mediated effects, which raises further questions about the broader ecological consequences of domestic dogs in natural systems.
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3
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Somaweera R, Nifong J, Rosenblatt A, Brien ML, Combrink X, Elsey RM, Grigg G, Magnusson WE, Mazzotti FJ, Pearcy A, Platt SG, Shirley MH, Tellez M, Ploeg J, Webb G, Whitaker R, Webber BL. The ecological importance of crocodylians: towards evidence‐based justification for their conservation. Biol Rev Camb Philos Soc 2020; 95:936-959. [DOI: 10.1111/brv.12594] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 02/20/2020] [Accepted: 02/25/2020] [Indexed: 12/27/2022]
Affiliation(s)
- Ruchira Somaweera
- CSIRO Health and Biosecurity Floreat WA 6014 Australia
- School of Biological Sciences, University of Western Australia Crawley WA 6009 Australia
| | - James Nifong
- IFAS‐Fort Lauderdale Research & Education Center, University of Florida Fort Lauderdale FL 33314 USA
| | - Adam Rosenblatt
- University of North Florida 1 UNF Drive, Jacksonville FL 32224 USA
| | - Mathew L. Brien
- Queensland Parks and WildlifeDepartment of Environment and Science Cairns QLD 4870 Australia
| | - Xander Combrink
- Department of Nature ConservationTshwane University of Technology Pretoria South Africa
| | - Ruth M. Elsey
- Louisiana Department of Wildlife and Fisheries Rockefeller Wildlife Refuge Grand Chenier LA 70643 USA
| | - Gordon Grigg
- School of Biological SciencesUniversity of Queensland St Lucia QLD 4072 Australia
| | - William E. Magnusson
- Coordenação da Biodiversidade, Instituto Nacional da Pesquisas da Amazônia Manaus 69067 Brazil
| | - Frank J. Mazzotti
- Department of Wildlife Ecology and ConservationEverglades Research and Education Center, University of Florida Gainesville FL 32603 USA
| | - Ashley Pearcy
- Section for Ecoinformatics and Biodiversity, Department of BioScienceAarhus University Aarhus Denmark
| | - Steven G. Platt
- Wildlife Conservation Society ‐ Myanmar Program Yangon Myanmar
| | - Matthew H. Shirley
- Tropical Conservation InstituteFlorida International University Miami FL 33181 USA
| | | | - Jan Ploeg
- Australian National Centre for Ocean Resources and Security, Innovation Campus, University of Wollongong Wollongong NSW 2522 Australia
| | - Grahame Webb
- Wildlife Management International Karama NT 0812 Australia
- Research Institute for the Environment and Livelihoods, Charles Darwin University Casuarina NT 0810 Australia
| | - Rom Whitaker
- The Madras Crocodile Bank Trust & Centre for Herpetology Mahabalipuram 603104 India
| | - Bruce L. Webber
- CSIRO Health and Biosecurity Floreat WA 6014 Australia
- School of Biological Sciences, University of Western Australia Crawley WA 6009 Australia
- Western Australian Biodiversity Science Institute Perth WA 6000 Australia
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4
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Drumheller SK, Nestler JH, Hackett Farris CE, Farris SC, Mazzotti FJ. Crocodylus acutus (American crocodile) bite marks on a nest data logger. PeerJ 2020; 8:e8577. [PMID: 32110490 PMCID: PMC7032054 DOI: 10.7717/peerj.8577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/16/2020] [Indexed: 11/30/2022] Open
Abstract
Several data loggers deployed to monitor temperature and humidity of Crocodylus acutus (American crocodile) nests in South Florida could not be located after hatching. One badly damaged data logger was retrieved, providing insight into the possible fate of the others. Using a taphonomic approach, we identified numerous indentations, consistent with crocodylian bite marks, and inconsistent with potential mammalian or squamate bites. It seems most likely that the data logger was damaged by the nesting C. acutus rather than during attempted nest predation. Estimated bite forces for reproductive age, female C. acutus exceed the predicted material properties of the data logger’s housing, suggesting that the bites were exploratory in nature. We suggest that data loggers be removed prior to hatching or permit remote data storage.
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Affiliation(s)
- Stephanie K Drumheller
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, United States of America
| | - Jennifer H Nestler
- Department of Wildlife Ecology and Conservation, Fort Lauderdale Research and Education Center, University of Florida, Fort Lauderdale, FL, United States of America
| | - Caitlin E Hackett Farris
- Department of Wildlife Ecology and Conservation, Fort Lauderdale Research and Education Center, University of Florida, Fort Lauderdale, FL, United States of America
| | - Seth C Farris
- Department of Wildlife Ecology and Conservation, Fort Lauderdale Research and Education Center, University of Florida, Fort Lauderdale, FL, United States of America
| | - Frank J Mazzotti
- Department of Wildlife Ecology and Conservation, Fort Lauderdale Research and Education Center, University of Florida, Fort Lauderdale, FL, United States of America
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5
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Genetic structure and diversity of Australian freshwater crocodiles (Crocodylus johnstoni) from the Kimberley, Western Australia. CONSERV GENET 2020. [DOI: 10.1007/s10592-020-01259-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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6
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Somaweera R, Brien ML, Sonneman T, Didham RK, Webber BL. Absence of evidence is not evidence of absence: Knowledge shortfalls threaten the effective conservation of freshwater crocodiles. Glob Ecol Conserv 2019. [DOI: 10.1016/j.gecco.2019.e00773] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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7
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Tatler J, Prowse TAA, Roshier DA, Allen BL, Cassey P. Resource pulses affect prey selection and reduce dietary diversity of dingoes in arid Australia. Mamm Rev 2019. [DOI: 10.1111/mam.12157] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jack Tatler
- School of Biological SciencesUniversity of Adelaide Adelaide SA 5005 Australia
| | - Thomas A. A. Prowse
- School of Mathematical SciencesUniversity of Adelaide Adelaide SA 5005 Australia
| | - David A. Roshier
- Australian Wildlife Conservancy PO Box 8070 Subiaco East WA 6008 Australia
- Australia Centre for Ecosystem ScienceUniversity of New South Wales Sydney NSW 2052 Australia
| | - Benjamin L. Allen
- Institute for Life Sciences and the EnvironmentUniversity of Southern Queensland Toowoomba Queensland 4350 Australia
| | - Phillip Cassey
- School of Biological SciencesUniversity of Adelaide Adelaide SA 5005 Australia
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Cedillo-Leal C, Simoncini MS, Leiva PML, Larriera A, Lang JW, Piña CI. Eggshell structure in Caiman latirostris eggs improves embryo survival during nest inundation. Proc Biol Sci 2018; 284:rspb.2016.2675. [PMID: 28469027 DOI: 10.1098/rspb.2016.2675] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Accepted: 04/05/2017] [Indexed: 11/12/2022] Open
Abstract
Egg inundation often results in poor hatching success in crocodylians. However, how tolerant eggs are to submergence, and/or how eggshell ultrastructure may affect embryo survival when inundated, are not well understood. In this study, our objective was to determine if embryo survival in Caiman latirostris is affected by eggshell surface roughness, when eggs are submerged under water. Tolerance to inundation was tested early (day 30) versus late (day 60) in development, using eight clutches (four per time treatments), subdivided into four groups: (N = 9 per clutch per treatment; 9 × 4 = 36 eggs per group). 'Rough' eggshell represented the natural, unmodified eggshell surface structure. 'Smooth' eggshell surface structure was created by mechanically sanding the natural rough surface to remove surface columnar elements and secondary layer features, e.g. irregularities that result in 'roughness'. When inundated by submerging eggs under water for 10 h at day 30, 'smooth' eggshell structure resulted in more than twice as many dead embryos (16 versus 6, smooth versus rough; N = 36), and fewer than half as many healthy embryos (6 versus 13, smooth versus rough, respectively; N = 36). By contrast, at day 60, inundation resulted in very low hatching success, regardless of eggshell surface structure. Only two hatchlings survived the inundation, notably in the untreated group with intact, rough eggshells. Inundation produced a high rate of malformations (58% at day 30), but did not affect hatchling size. Our results indicate that eggshell roughness enhances embryo survival when eggs are inundated early in development, but not late in development. Apparently, the natural surface 'roughness' entraps air bubbles at the eggshell surface during inundation, thereby facilitating gas exchange through the eggshell even when the egg is submerged under water.
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Affiliation(s)
- César Cedillo-Leal
- Instituto de Ecología Aplicada, Universidad Autónoma de Tamaulipas, Ciudad Victoria, Mexico
| | - Melina S Simoncini
- Proyecto Yacaré-Laboratorio de Zoología Aplicada: Anexo Vertebrados (FHUC-UNL/MASPyMA), Santa Fe, Argentina .,CICyTTP-UADER-Prov Entre Ríos-CONICET. FCyT, Dr Materi y España, Diamante, Argentina
| | - Pamela M L Leiva
- Proyecto Yacaré-Laboratorio de Zoología Aplicada: Anexo Vertebrados (FHUC-UNL/MASPyMA), Santa Fe, Argentina.,CICyTTP-UADER-Prov Entre Ríos-CONICET. FCyT, Dr Materi y España, Diamante, Argentina
| | - Alejandro Larriera
- Proyecto Yacaré-Laboratorio de Zoología Aplicada: Anexo Vertebrados (FHUC-UNL/MASPyMA), Santa Fe, Argentina
| | - Jeffrey W Lang
- Conservation Biology Program, University of Minnesota, St Paul, MN 55108, Minnesota, USA
| | - Carlos I Piña
- Proyecto Yacaré-Laboratorio de Zoología Aplicada: Anexo Vertebrados (FHUC-UNL/MASPyMA), Santa Fe, Argentina .,CICyTTP-UADER-Prov Entre Ríos-CONICET. FCyT, Dr Materi y España, Diamante, Argentina
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9
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10
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Torralvo K, Botero-Arias R, Magnusson WE. Temporal variation in black-caiman-nest predation in varzea of central Brazilian amazonia. PLoS One 2017; 12:e0183476. [PMID: 28854258 PMCID: PMC5576742 DOI: 10.1371/journal.pone.0183476] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 08/04/2017] [Indexed: 12/03/2022] Open
Abstract
On the Amazon floodplain, the main predators of black caiman (Melanosuchus niger) eggs are jaguars (Panthera onca), tegu lizards (Tupinambis teguixim), capuchin monkeys (Sapajus macrocephalus) and humans (Homo sapiens). In this study, we investigated the relationship between predator attacks on nests and incubation period, and evaluated the influence of initial predation on subsequent predation in the Mamirauá Sustainable Development Reserve. We also evaluated the influence of presence of females near the nests and manipulation of nests on the occurrence of attacks. We compared results from data obtained with camera traps and vestiges left by predators on estimates of rates of predation by different predators. Egg predation was recorded in 32% of the 658 black caiman nests monitored during two years. Our results suggest that the probability of predation on black caiman eggs is relatively constant throughout the incubation period and that predation on eggs was lower when adults, presumably females, were present. Careful opening of nests and handling of eggs did not increase the number of attacks on black caiman nests. Nest opening by a predator appeared to increase the chances of a subsequent attack because most of the attacks on nests occurred soon after a predator first opened the nest. However, attacks by another species of predator do not appear to be necessary to initiate attacks by any other species of predator. Results based on camera traps and vestiges differed, but use of vestiges was adequate for identifying the principal predators on eggs in black caiman nests and, in many circumstances, the vestiges may be better for estimating predation by humans. In this study, opening nests and handling eggs did not increase the number of attacks on black caiman nests.
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Affiliation(s)
- Kelly Torralvo
- Programa de Pós-Graduação em Ecologia, National Institute of Amazonian Research; Manaus, AM, Brazil
- Mamirauá Institute for Sustainable Development, Tefé, AM, Brazil
| | - Robinson Botero-Arias
- Mamirauá Institute for Sustainable Development, Tefé, AM, Brazil
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, United States of America
| | - William E. Magnusson
- Coordenação da Biodiversidade, Instituto Nacional de Pesquisas da Amazônia; Manaus, AM, Brazil
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11
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The metabolic cost of nesting: body condition and blood parameters of Caiman crocodilus and Melanosuchus niger in Central Amazonia. J Comp Physiol B 2017. [PMID: 28631010 PMCID: PMC5756262 DOI: 10.1007/s00360-017-1103-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Although nesting ecology is well studied in several crocodilian species, it is not known how nest attendance influences physiology and body condition of nesting females. In this study, we describe body condition and serum biochemical values of nesting female, non-nesting female and male spectacled caiman (Caiman crocodilus) and black caiman (Melanosuchus niger) in two areas of Central Amazonia. We also evaluated the effect of nest age and nest distance to water on body condition and blood parameters of nesting females. Body condition and plasmatic concentrations of glucose, triglycerides, lactate and uric acid of nesting females were significantly different from those of non-nesting females and males in C. crocodilus, but not in M. niger. Our study also demonstrated that nest age and distance to water had a negative effect on female body condition in C. crocodilus, but not in M. niger. Female C. crocodilus attending older nests or nests built further away from permanent water bodies tended to have lower body condition. Our results demonstrate that the nesting strategy of C. crocodilus has a metabolic cost associated with nest attendance for nesting females, which appear to depend on accumulated energetic reserves during nest attendance. In contrast, nest attendance had little effect on the physiology of female M. niger.
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12
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The Past and Present Nesting Ecology of Nile Crocodiles in Ndumo Game Reserve, South Africa: Reason for Concern? J HERPETOL 2017. [DOI: 10.1670/13-200] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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13
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Combrink X, Warner JK, Downs CT. Nest predation and maternal care in the Nile crocodile (Crocodylus niloticus) at Lake St Lucia, South Africa. Behav Processes 2016; 133:31-36. [PMID: 27816524 DOI: 10.1016/j.beproc.2016.10.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 09/06/2016] [Accepted: 10/31/2016] [Indexed: 11/19/2022]
Abstract
Information regarding nest predation, nest abandonment, and maternal care in the Nile crocodile (Crocodylus niloticus) is largely restricted to anecdotal observations, and has not been studied quantitatively. Consequently, we investigated their nesting biology using camera-traps over four years at Lake St Lucia, South Africa. We obtained 4305 photographs (daylight captures=90.1%, nocturnal=9.9%) of 19 nest-guarding females. Of 19 monitored nests, 37% were raided by predators (mean=12.1±6.2days subsequent to camera placement). All females returned to their nests following first predation, and on average returned three times between predator raids before nest abandonment. Water monitors (Varanus niloticus) and marsh mongoose (Atilax paludinosus) were the main egg predators. Nesting raids lasted 5.9±1.6days. Diurnally females were seldom on the nest, except during cool/cloudy weather or rain, preferring to guard from nearby shade. Females defended nests aggressively against non-human intruders. Five Nile crocodile females were observed liberating their hatchlings from nests. A detailed sequence of a mother excavating and transporting hatchlings revealed 13 excursions between nest and water over 32.5h. This, after months of continual nest attendance and defence, is illustrative of the high level of maternal care in Nile crocodiles. Camera-trapping is an effective, non-invasive method for further crocodile nesting behaviour research.
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Affiliation(s)
- Xander Combrink
- School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa.
| | - Jonathan K Warner
- School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa.
| | - Colleen T Downs
- School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa.
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14
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Behrendorff L, Leung LKP, McKinnon A, Hanger J, Belonje G, Tapply J, Jones D, Allen BL. Insects for breakfast and whales for dinner: the diet and body condition of dingoes on Fraser Island (K'gari). Sci Rep 2016; 6:23469. [PMID: 27009879 PMCID: PMC4806299 DOI: 10.1038/srep23469] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 03/08/2016] [Indexed: 11/24/2022] Open
Abstract
Top-predators play stabilising roles in island food webs, including Fraser Island, Australia. Subsidising generalist predators with human-sourced food could disrupt this balance, but has been proposed to improve the overall health of the island’s dingo (Canis lupus dingo) population, which is allegedly ‘starving’ or in ‘poor condition’. We assess this hypothesis by describing the diet and health of dingoes on Fraser Island from datasets collected between 2001 and 2015. Medium-sized mammals (such as bandicoots) and fish were the most common food items detected in dingo scat records. Stomach contents records revealed additional information on diet, such as the occurrence of human-sourced foods. Trail camera records highlighted dingo utilisation of stranded marine fauna, particularly turtles and whales. Mean adult body weights were higher than the national average, body condition scores and abundant-excessive fat reserves indicated a generally ideal-heavy physical condition, and parasite loads were low and comparable to other dingo populations. These data do not support hypotheses that Fraser Island dingoes have restricted diets or are in poor physical condition. Rather, they indicate that dingoes on Fraser Island are capable of exploiting a diverse array of food sources which contributes to the vast majority of dingoes being of good-excellent physical condition.
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Affiliation(s)
- Linda Behrendorff
- The University of Queensland, School of Agriculture and Food Sciences, Gatton, Queensland 4343, Australia.,Queensland Parks and Wildlife Service, Department of National Parks, Sport and Racing, Fraser Island, Queensland 4581, Australia
| | - Luke K-P Leung
- The University of Queensland, School of Agriculture and Food Sciences, Gatton, Queensland 4343, Australia
| | - Allan McKinnon
- Department of Environmental Heritage Protection, Threatened Species Unit, Moggill, Queensland 4070, Australia
| | - Jon Hanger
- Endeavour Veterinary Ecology, Toorbul, Queensland 4510, Australia
| | - Grant Belonje
- Fraser Coast Veterinary Services, Maryborough, Queensland 4650, Australia
| | - Jenna Tapply
- Queensland Parks and Wildlife Service, Department of National Parks, Sport and Racing, Fraser Island, Queensland 4581, Australia
| | - Darryl Jones
- Griffith University, Environmental Futures Research Institute, Nathan, Queensland 4111, Australia
| | - Benjamin L Allen
- The University of Southern Queensland, Institute for Agriculture and the Environment, Toowoomba, Queensland 4350, Australia
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15
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Newey S, Davidson P, Nazir S, Fairhurst G, Verdicchio F, Irvine RJ, van der Wal R. Limitations of recreational camera traps for wildlife management and conservation research: a practitioner's perspective. AMBIO 2015; 44 Suppl 4:624-635. [PMID: 26508349 PMCID: PMC4623860 DOI: 10.1007/s13280-015-0713-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The availability of affordable 'recreational' camera traps has dramatically increased over the last decade. We present survey results which show that many conservation practitioners use cheaper 'recreational' units for research rather than more expensive 'professional' equipment. We present our perspective of using two popular models of 'recreational' camera trap for ecological field-based studies. The models used (for >2 years) presented us with a range of practical problems at all stages of their use including deployment, operation, and data management, which collectively crippled data collection and limited opportunities for quantification of key issues arising. Our experiences demonstrate that prospective users need to have a sufficient understanding of the limitations camera trap technology poses, dimensions we communicate here. While the merits of different camera traps will be study specific, the performance of more expensive 'professional' models may prove more cost-effective in the long-term when using camera traps for research.
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Affiliation(s)
- Scott Newey
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK.
- Faculty of Applied Ecology, Hedmark University College, Evenstad, 2480, Koppang, Norway.
| | - Paul Davidson
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK.
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 3UU, UK.
| | - Sajid Nazir
- dot.rural, University of Aberdeen, Aberdeen, AB24 5UA, UK.
| | - Gorry Fairhurst
- Electronics Research Group, School of Engineering, University of Aberdeen, Aberdeen, AB24 3UE, UK.
| | - Fabio Verdicchio
- Electronics Research Group, School of Engineering, University of Aberdeen, Aberdeen, AB24 3UE, UK.
| | - R Justin Irvine
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK.
| | - René van der Wal
- Aberdeen Centre for Environmental Sustainability, School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 3UU, UK.
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16
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Meek PD, Ballard GA, Fleming PJS. The pitfalls of wildlife camera trapping as a survey tool in Australia. AUSTRALIAN MAMMALOGY 2015. [DOI: 10.1071/am14023] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Camera trapping is a relatively new addition to the wildlife survey repertoire in Australia. Its rapid adoption has been unparalleled in ecological science, but objective evaluation of camera traps and their application has not kept pace. With the aim of motivating practitioners to think more about selection and deployment of camera trap models in relation to research goals, we reviewed Australian camera trapping studies to determine how camera traps have been used and how their technological constraints may have affected reported results and conclusions. In the 54 camera trapping articles published between 1991 and 2013, mammals (86%) were studied more than birds (10%) and reptiles (3%), with small to medium-sized mammals being most studied. Australian camera trapping studies, like those elsewhere, have changed from more qualitative to more complex quantitative investigations. However, we found that camera trap constraints and limitations were rarely acknowledged, and we identified eight key issues requiring consideration and further research. These are: camera model, camera detection system, camera placement and orientation, triggering and recovery, camera trap settings, temperature differentials, species identification and behavioural responses of the animals to the cameras. In particular, alterations to animal behaviour by camera traps potentially have enormous influence on data quality, reliability and interpretation. The key issues were not considered in most Australian camera trap papers and require further study to better understand the factors that influence the analysis and interpretation of camera trap data and improve experimental design.
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17
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Meek PD, Ballard GA, Vernes K, Fleming PJS. The history of wildlife camera trapping as a survey tool in Australia. AUSTRALIAN MAMMALOGY 2015. [DOI: 10.1071/am14021] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This paper provides an historical review of the technological evolution of camera trapping as a zoological survey tool in Australia. Camera trapping in Australia began in the 1950s when purpose-built remotely placed cameras were used in attempts to rediscover the thylacine (Thylacinus cynocephalus). However, camera traps did not appear in Australian research papers and Australasian conference proceedings until 1989–91, and usage became common only after 2008, with an exponential increase in usage since 2010. Initially, Australian publications under-reported camera trapping methods, often failing to provide fundamental details about deployment and use. However, rigour in reporting of key methods has increased during the recent widespread adoption of camera trapping. Our analysis also reveals a change in camera trap use in Australia, from simple presence–absence studies, to more theoretical and experimental approaches related to population ecology, behavioural ecology, conservation biology and wildlife management. Practitioners require further research to refine and standardise camera trap methods to ensure that unbiased and scientifically rigorous data are obtained from quantitative research. The recent change in emphasis of camera trapping research use is reflected in the decreasing range of camera trap models being used in Australian research. Practitioners are moving away from less effective models that have slow reaction times between detection and image capture, and inherent bias in detectability of fauna, to more expensive brands that offer faster speeds, greater functionality and more reliability.
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Researcher Disturbance Has Minimal Impact on Natural Predation of Caiman Nests in Central Amazonia. J HERPETOL 2014. [DOI: 10.1670/13-081] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Somaweera R, Brien M, Shine R. The Role of Predation in Shaping Crocodilian Natural History. HERPETOLOGICAL MONOGRAPHS 2013. [DOI: 10.1655/herpmonographs-d-11-00001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Ruchira Somaweera
- School of Biological Sciences, University of Sydney, Sydney, New Sout Wales 2006, Australia
| | - Matthew Brien
- Wildlife Management International Pty. Limited, Karama, Northern Territory 0813, Australia
| | - Richard Shine
- School of Biological Sciences, University of Sydney, Sydney, New Sout Wales 2006, Australia
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Australian Freshwater Crocodiles (Crocodylus johnstoni) Transport Their Hatchlings to the Water. J HERPETOL 2012. [DOI: 10.1670/11-056] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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SOMAWEERA RUCHIRA, SHINE RICHARD. Nest-site selection by crocodiles at a rocky site in the Australian tropics:Making the best of a bad lot. AUSTRAL ECOL 2012. [DOI: 10.1111/j.1442-9993.2012.02406.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Allen BL, Fleming PJS. Reintroducing the dingo: the risk of dingo predation to threatened vertebrates of western New South Wales. WILDLIFE RESEARCH 2012. [DOI: 10.1071/wr11128] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Context The reintroduction of dingoes into sheep-grazing areas south-east of the dingo barrier fence has been suggested as a mechanism to suppress fox and feral-cat impacts. Using the Western Division of New South Wales as a case study, Dickman et al. (2009) recently assessed the risk of fox and cat predation to extant threatened species and concluded that reintroducing dingoes into the area would have positive effects for most of the threatened vertebrates there, aiding their recovery through trophic cascade effects. However, they did not formally assess the risk of dingo predation to the same threatened species. Aims To assess the risk of dingo predation to the extant and locally extinct threatened vertebrates of western New South Wales using methods amenable to comparison with Dickman et al. (2009). Methods The predation-risk assessment method used in Dickman et al. (2009) for foxes and cats was applied here to dingoes, with minor modification to accommodate the dietary differences of dingoes. This method is based on six independent biological attributes, primarily reflective of potential vulnerability characteristics of the prey. Individual-attribute scores were used to derive an overall risk score. Key results Up to 75 (94%) of the 80 extant species were predicted to be at risk of dingo predation (71% at high risk) regardless of any effect dingoes might have on foxes or cats. Up to 17 of the 21 (81%) locally extinct species were predicted to be at high risk of dingo predation using this approach. The re-establishment of even low-density dingo populations may have negative effects on at least 22% of extant threatened vertebrates. Conclusions The generic risk-assessment method was insensitive, and experienced difficulty in describing the true nature of canid predation risk. Despite this weakness, however, it is clear that several threatened vertebrates are susceptible to dingo predation. Prior to the re-establishment of dingoes, we recommend that dingo predation risks to all vertebrates (threatened or otherwise) be assessed using more sensitive and descriptive techniques, and we strongly caution against the positive management of dingoes under current ecological conditions. Implications The results of this study imply that dingoes present similar levels of direct risk to threatened species as foxes and feral cats, and dingo predation of threatened species should be formally considered in any proposal encouraging dingo populations in western New South Wales.
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Somaweera R, Webb JK, Shine R. Determinants of habitat selection by hatchling Australian freshwater crocodiles. PLoS One 2011; 6:e28533. [PMID: 22163308 PMCID: PMC3233590 DOI: 10.1371/journal.pone.0028533] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 11/09/2011] [Indexed: 11/19/2022] Open
Abstract
Animals almost always use habitats non-randomly, but the costs and benefits of using specific habitat types remain unknown for many types of organisms. In a large lake in northwestern Australia (Lake Argyle), most hatchling (<12-month-old) freshwater crocodiles (Crocodylus johnstoni) are found in floating vegetation mats or grassy banks rather than the more widely available open banks. Mean body sizes of young crocodiles did not differ among the three habitat types. We tested four potential explanations for non-random habitat selection: proximity to nesting sites, thermal conditions, food availability, and exposure to predation. The three alternative habitat types did not differ in proximity to nesting sites, or in thermal conditions. Habitats with higher food availability harboured more hatchlings, and feeding rates (obtained by stomach-flushing of recently-captured crocodiles) were highest in such areas. Predation risk may also differ among habitats: we were twice as likely to capture a crocodile after seeing it in open-bank sites than in the other two habitat types. Thus, habitat selection of hatchling crocodiles in this system may be driven both by prey availability and by predation risk.
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Affiliation(s)
- Ruchira Somaweera
- School of Biological Sciences, University of Sydney, Sydney, New South Wales, Australia.
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Somaweera R, Shine R. The (non) impact of invasive cane toads on freshwater crocodiles at Lake Argyle in tropical Australia. Anim Conserv 2011. [DOI: 10.1111/j.1469-1795.2011.00500.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R. Somaweera
- School of Biological Sciences; The University of Sydney; Sydney; NSW; Australia
| | - R. Shine
- School of Biological Sciences; The University of Sydney; Sydney; NSW; Australia
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