Bad news for bobtails: understanding predatory behaviour of a resource-subsidised corvid towards an island endemic reptile
W. Oversby A , S. M. Ferguson A , R. A. Davis B and P. W. Bateman
A C
+ Author Affiliations
- Author Affiliations
A School of Molecular and Life Sciences, Curtin University, Bentley, Perth, WA 6845, Australia.
B School of Science, Edith Cowan University, Joondalup, Perth, WA 6027, Australia.
C Corresponding author. Email: bill.bateman@curtin.edu.au
Wildlife Research 45(7) 595-601 https://doi.org/10.1071/WR18051
Submitted: 31 March 2018 Accepted: 31 August 2018 Published: 18 October 2018
Abstract
Context: Resource subsidisation as a result of urbanisation and other human activity can have positive impacts for some opportunistic predators. Many species of corvid have benefitted from the expansion of human-dominated habitats; however, their impacts on co-occurring prey fauna are generally poorly understood.
Aims: We aimed to test the hypothesis that urbanisation associated with tourism impacts the predator–prey relationship between Australian ravens, or wardongs (Corvus coronoides), a ubiquitous corvid of southern Australia, and Rottnest Island bobtails (Tiliqua rugosa konowi), a subspecies of bobtail lizard isolated to a small (19 km2) island off the coast of Western Australia.
Methods: Using clay model lizards and camera traps, we assessed the wardongs’ attack rates by distance from the settlement and by whether the model was in closed or open habitat.
Key Results: We found that while wardongs preyed upon Rottnest Island bobtails, predation was not affected by proximity to human settlement despite the highest number of wardongs being found there. Models in closed vegetation were attacked by wardong significantly more than were those in open vegetation.
Implications: Increased predation rates in closed vegetation suggests that current revegetation efforts on the island may be increasing the availability of preferred hunting habitat for the wardong. This finding may influence decisions by management on whether to control the large population of wardongs on the island.
References
Abbott, I (2009). Aboriginal names of bird species in south-west Western Australia, with suggestions for their adoption into common usage. Conservation Science Western Australia 7, 213–278.Alacs, E., and Georges, A. (2008). Wildlife across our borders: a review of the illegal trade in Australia. The Australian Journal of Forensic Sciences 40, 147–160.
| Wildlife across our borders: a review of the illegal trade in Australia.Crossref | GoogleScholarGoogle Scholar |
Bateman, P. W., and Fleming, P. A. (2012). Big city life: carnivores in urban environments. Journal of Zoology 287, 1–23.
| Big city life: carnivores in urban environments.Crossref | GoogleScholarGoogle Scholar |
Bateman, P. W., Fleming, P. A., and Rolek, B. (2014). Bite me: blue tails as a ‘risky-decoy’ defense tactic for lizards. Current Zoology 60, 333–337.
| Bite me: blue tails as a ‘risky-decoy’ defense tactic for lizards.Crossref | GoogleScholarGoogle Scholar |
Bateman, P. W., Fleming, P. A., and Wolfe, A. K. (2017). A different kind of ecological modelling: the use of clay model organisms to explore predator–prey interactions in vertebrates. Journal of Zoology 301, 251–262.
| A different kind of ecological modelling: the use of clay model organisms to explore predator–prey interactions in vertebrates.Crossref | GoogleScholarGoogle Scholar |
Bates, D., Maechler, M., Bolker, B., and Walker, S. (2015). Fitting linear mixed-effects models using lme4. Journal of Statistical Software 67, 1–48.
| Fitting linear mixed-effects models using lme4.Crossref | GoogleScholarGoogle Scholar |
Bird, D. M., Varland, D. E., and Negro, J. J. (Eds) (1996). ‘Raptors in Human Landscapes: Adaptation to Built and Cultivated Environments.’ (Academic Press: London.)
Boarman, W. I. (2003). Managing a subsidized predator population: reducing common raven predation on desert tortoises. Environmental Management 32, 205–217.
| Managing a subsidized predator population: reducing common raven predation on desert tortoises.Crossref | GoogleScholarGoogle Scholar |
Brodie, E. D. (1993). Differential avoidance of coral snake banded patterns by free‐ranging avian predators in Costa Rica. Evolution 47, 227–235.
| Differential avoidance of coral snake banded patterns by free‐ranging avian predators in Costa Rica.Crossref | GoogleScholarGoogle Scholar |
Castilla, A. M., Gosá, A., Galán, P., and Pérez-Mellado, V. (1999). Green tails in lizards of the genus Podarcis: do they influence the intensity of predation? Herpetologica 55, 530–537.
Cogger, H. (2014). ‘Reptiles and Amphibians of Australia.’ (CSIRO Publishing: Melbourne.)
Cooper, S. M., and Ginnett, T. F. (2000). Potential effects of supplemental feeding of deer on nest predation. Wildlife Society Bulletin 28, 660–666.
Fleming, P. A., and Bateman, P. W. (2018). Novel predation opportunities in anthropogenic landscapes. Animal Behaviour , .
| Novel predation opportunities in anthropogenic landscapes.Crossref | GoogleScholarGoogle Scholar |
Fox, J., and Weisberg, S. (2011). ‘An {R} Companion to Applied Regression’, 2nd edn. (Sage: Thousand Oaks, CA.)
Gehrt, S. D., Riley, S. P., and Cypher, B. L. (Eds) (2010). ‘Urban Carnivores: Ecology, Conflict, and Conservation.’ (John Hopkins University Press: Baltimore, MD.)
Grémillet, D., Pichegru, L., Kuntz, G., Woakes, A. G., Wilkinson, S., Crawford, R. J., and Ryan, P. G. (2008). A junk-food hypothesis for gannets feeding on fishery waste. Proceedings of the Royal Society of London. Series B, Biological Sciences 275, 1149–1156.
| A junk-food hypothesis for gannets feeding on fishery waste.Crossref | GoogleScholarGoogle Scholar |
Hanna, E., and Cardillo, M. (2014). Island mammal extinctions are determined by interactive effects of life history, island biogeography and mesopredator suppression. Global Ecology and Biogeography 23, 395–404.
| Island mammal extinctions are determined by interactive effects of life history, island biogeography and mesopredator suppression.Crossref | GoogleScholarGoogle Scholar |
Hawlena, D., Saltz, D., Abramsky, Z., and Bouskila, A. (2010). Ecological trap for desert lizards caused by anthropogenic changes in habitat structure that favor predator activity. Conservation Biology 24, 803–809.
| Ecological trap for desert lizards caused by anthropogenic changes in habitat structure that favor predator activity.Crossref | GoogleScholarGoogle Scholar |
Higgins, P. J., Peter, J. M., and Cowling, S. J. (Eds) (2006). ‘Handbook of Australian, New Zealand and Antarctic Birds. Volume 7: Boatbill to Starlings.’ (Oxford University Press: Melbourne.)
Holmes, F. (2018). The value of animal behaviour as a bio-indicator of restoration quality. PhD Thesis, Edith Cowan University, Perth, WA.
Holt, R. D. (1984). Spatial heterogeneity, indirect interactions, and the coexistence of prey species. American Naturalist 124, 377–406.
| Spatial heterogeneity, indirect interactions, and the coexistence of prey species.Crossref | GoogleScholarGoogle Scholar |
Lawson, F. (1905). A visit to Rottnest Island, WA. Emu - Austral Ornithology 4, 129–132.
| A visit to Rottnest Island, WA.Crossref | GoogleScholarGoogle Scholar |
Li, B., Belasen, A., Pafilis, P., Bednekoff, P., and Foufopoulos, J. (2014). Effects of feral cats on the evolution of anti-predator behaviours in island reptiles: insights from an ancient introduction. Proceedings of the Royal Society of London. Series B, Biological Sciences 281, 20140339.
| Effects of feral cats on the evolution of anti-predator behaviours in island reptiles: insights from an ancient introduction.Crossref | GoogleScholarGoogle Scholar |
Marzluff, J. M. (2001). Worldwide urbanization and its effects on birds. In ‘Avian Ecology and Conservation in an Urbanizing World’. (Eds J. Marzluff, R. Bowman and R. Donnelly.) pp. 19–47. (Springer: New York.)
Marzluff, J. M., and Neatherlin, E. (2006). Corvid response to human settlements and campgrounds: causes, consequences, and challenges for conservation. Biological Conservation 130, 301–314.
| Corvid response to human settlements and campgrounds: causes, consequences, and challenges for conservation.Crossref | GoogleScholarGoogle Scholar |
Marzluff, J. M., McGowan, K. J., Donnelly, R., and Knight, R. L. (2001). Causes and consequences of expanding American crow populations. In ‘Avian Ecology and Conservation in an Urbanizing World’. (Eds J. Marzluff, R. Bowman and R. Donnelly.) pp. 331–363. (Springer: New York.)
Mather, S. (2009). The bushbirds of Rottnest Island. Western Australian Bird Notes 132, 1–5.
Mo, M. (2017). Killing of a mobbing crested pigeon Ocyphaps lophotes by an Australian raven Corvus coronoides. Australian Field Ornithology 34, 35–36.
| Killing of a mobbing crested pigeon Ocyphaps lophotes by an Australian raven Corvus coronoides.Crossref | GoogleScholarGoogle Scholar |
Newsome, T. M., Ballard, G. A., Fleming, P. J., van de Ven, R., Story, G. L., and Dickman, C. R. (2014). Human-resource subsidies alter the dietary preferences of a mammalian top predator. Oecologia 175, 139–150.
| Human-resource subsidies alter the dietary preferences of a mammalian top predator.Crossref | GoogleScholarGoogle Scholar |
Newsome, T. M., Dellinger, J. A., Pavey, C. R., Ripple, W. J., Shores, C. R., Wirsing, A. J., and Dickman, C. R. (2015). The ecological effects of providing resource subsidies to predators. Global Ecology and Biogeography 24, 1–11.
| The ecological effects of providing resource subsidies to predators.Crossref | GoogleScholarGoogle Scholar |
O’Brien, R. C., Larcombe, A., Meyer, J., Forbes, S. L., and Dadour, I. (2010). The scavenging behaviour of the Australian raven (Corvus coronoides): patterns and influencing factors. Sylvia (Praha) 46, 133–148.
Oksanen, T., Oksanen, L., and Gyllenberg, M. (1992). Exploitation ecosystems in heterogeneous habitat complexes II: impact of small-scale heterogeneity on predator-prey dynamics. Evolutionary Ecology 6, 383–398.
| Exploitation ecosystems in heterogeneous habitat complexes II: impact of small-scale heterogeneity on predator-prey dynamics.Crossref | GoogleScholarGoogle Scholar |
Playford, P. E. (1988). ‘Guidebook to the geology of Rottnest Island.’ (Geological Society of Australia, WA Division and the Geological Survey of Western Australia: Perth).
Pusenius, J., and Ostfeld, R. S. (2002). Mammalian predator scent, vegetation cover and tree seedling predation by meadow voles. Ecography 25, 481–487.
| Mammalian predator scent, vegetation cover and tree seedling predation by meadow voles.Crossref | GoogleScholarGoogle Scholar |
R Core Team (2017). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. Available at http://www.R-project.org/ [Verified September 2018]
Radeloff, V. C., Hammer, R. B., Stewart, S. I., Fried, J. S., Holcomb, S. S., and McKeefry, J. F. (2005). The wildland–urban interface in the United States. Ecological Applications 15, 799–805.
| The wildland–urban interface in the United States.Crossref | GoogleScholarGoogle Scholar |
Rottnest Island Authority (RIA) (2014). Rottnest Island Management Plan 2014–19; a 20-year vision. Available at http://ria.wa.gov.au/policy-and-reports/management-plans-and-legislation (Accessed 26 October 2017).
Rowley, I. (1970). The genus Corvus (Aves: Corvidae) in Australia. Wildlife Research 15, 27–71.
| The genus Corvus (Aves: Corvidae) in Australia.Crossref | GoogleScholarGoogle Scholar |
Saunders, D. A., and De Rebeira, P. (2009). A case study of the conservation value of a small tourist resort island: Birds of Rottnest Island, Western Australia 1905–2007. Pacific Conservation Biology 15, 11–31.
| A case study of the conservation value of a small tourist resort island: Birds of Rottnest Island, Western Australia 1905–2007.Crossref | GoogleScholarGoogle Scholar |
Schneider, M. F. (2001). Habitat loss, fragmentation and predator impact: spatial implications for prey conservation. Journal of Applied Ecology 38, 720–735.
| Habitat loss, fragmentation and predator impact: spatial implications for prey conservation.Crossref | GoogleScholarGoogle Scholar |
Sharpe, P. B., and Van Horne, B. (1998). Influence of habitat on behavior of Townsend’s ground squirrels (Spermophilus townsendii). Journal of Mammalogy 79, 906–918.
| Influence of habitat on behavior of Townsend’s ground squirrels (Spermophilus townsendii).Crossref | GoogleScholarGoogle Scholar |
Skarphéðinsson, K. H. (1990). Breeding biology, movements, and persecution of ravens in Iceland. Acta Naturalia Islandica 33, 1–45.
Stevenson, C. (2011). Ecological impacts of Australian Ravens on bush bird communities on Rottnest Island. PhD Thesis, Murdoch University, Perth. Available from http://researchrepository.murdoch.edu.au/id/eprint/7492/
Stewart, P. J. (1997). Some aspects of the ecology of an urban corvid: the Australian raven (Corvus coronoides) in metropolitan Perth. BSc (Hons) Thesis, Edith Cowan University, Perth. Available from http://ro.ecu.edu.au/theses_hons/295/
Storr, G. M. (1965). The avifauna of Rottnest Island, Western Australia III. Land birds. Emu - Austral Ornithology. 64, 172–180.
| The avifauna of Rottnest Island, Western Australia III. Land birds.Crossref | GoogleScholarGoogle Scholar |
Tchabovsky, A. V., Krasnov, B., Khokhlova, I. S., and Shenbrot, G. I. (2001). The effect of vegetation cover on vigilance and foraging tactics in the fat sand rat Psammomys obesus. Journal of Ethology 19, 105–113.
| The effect of vegetation cover on vigilance and foraging tactics in the fat sand rat Psammomys obesus.Crossref | GoogleScholarGoogle Scholar |
Thorson, J. M., Morgan, R. A., Brown, J. S., and Norman, J. E. (1998). Direct and indirect cues of predatory risk and patch use by fox squirrels and thirteen-lined ground squirrels. Behavioral Ecology 9, 151–157.
| Direct and indirect cues of predatory risk and patch use by fox squirrels and thirteen-lined ground squirrels.Crossref | GoogleScholarGoogle Scholar |
Worrell, T., Admiraal, R., Bateman, P. W., and Fleming, P. A. (2017). Are tourism and conservation compatible for ‘island tame’ species? Animal Conservation 20, 155–163.
| Are tourism and conservation compatible for ‘island tame’ species?Crossref | GoogleScholarGoogle Scholar |
