Dispersal and the influence of rainfall on a population of the carnivorous marsupial swamp antechinus (Antechinus minimus maritimus)
Rannveig Magnusdottir A B D , Barbara A. Wilson A C and Pall Hersteinsson BA School of Ecology and Environment, Deakin University, Geelong, Vic. 3217, Australia.
B Institute of Biology, University of Iceland, 101 Reykjavík, Iceland.
C Present address: Department of Environment and Conservation, Locked Bag 104, Bentley Delivery Centre, WA 6983, Australia.
D Corresponding author. Email: rannveig@hi.is
Wildlife Research 35(5) 446-454 https://doi.org/10.1071/WR06156
Submitted: 18 November 2006 Accepted: 26 May 2008 Published: 19 August 2008
Abstract
Although there is evidence that recent climatic changes have had significant impacts on a wide range of species in the Northern Hemisphere, the influence of climate change, particularly drought, on Australian native small mammal species is poorly understood. In this study we investigated dispersal patterns and the influence of rainfall on the swamp antechinus (Antechinus minimus maritimus). Peak abundance occurred after the highest total annual rainfall for two decades, in 2001. A year later the population had declined to 10% of the peak. Birth dates appeared to occur three weeks earlier following a year of high rainfall. The dispersal of nine litters of pouch young (n = 62) was assessed following two breeding seasons. Young males remained on the natal site until December–January and dispersed before the breeding season. New males entered the population between January and June. More than 50% of females were residents and remained on the site to breed; the remaining females were trapped only once. After the male die-off the movements of pregnant females increased and they appeared to expand their home ranges. A. minimus exhibits philopatry of females and dispersal of males, as observed in other Antechinus species but dispersal occurs 2–3 months after weaning. This contrasts with juveniles of other Antechinus species that disperse abruptly after weaning. This study provides evidence that precipitation does have a major effect on the abundance of dasyurid species, making them vulnerable to drought and local or regional extinctions, particularly in areas of fragmented habitat and drying climates.
Acknowledgements
We thank John Aberton, Kylie Annett, Rodney Armistead, Kate Hicks, Magnús Jóhannsson, Mandy Lock and Ellen Mitchell for greatly appreciated help in the field and with statistics. The research has been supported by grants from the Australian Research Council and Alcoa World Alumina. It was conducted under a Department of Sustainability and Environmental Scientific Permit and with ethics approvals (A10/99, A12/02 and A16/02) from Deakin University Animal Ethics Committee. Finally, we thank Dr Andrea Taylor and the anonymous reviewers whose comments and suggestions substantially improved this paper.
Aberton, J. , Wilson, B. , and Chenery, K. (1994). Observations on the behaviour of Antechinus minimus maritimus (Marsupialia: Dasyuridae). The Victorian Naturalist 111, 135–138.
Banks, S. , Skerratt, L. , and Taylor, A. (2002). Female dispersal and relatedness structure in common wombats (Vombatus ursinus). Journal of Zoology London 256, 389–399.
| Crossref | GoogleScholarGoogle Scholar |
Lazenby-Cohen, K. (1991). Communal nesting in Antechinus stuartii (Marsupialia: Dasyuridae). Australian Journal of Zoology 39, 273–283.
| Crossref | GoogleScholarGoogle Scholar |
McCarty, J. P. (2001). Ecological consequences of recent climate change. Conservation Biology 15, 320–331.
| Crossref | GoogleScholarGoogle Scholar |
Moore, J. , and Ali, R. (1984). Are dispersal and inbreeding avoidance related? Animal Behaviour 32, 94–112.
| Crossref | GoogleScholarGoogle Scholar |
Wainer, J. (1976). Studies of an island population of Antechinus minimus (Marsupialia, Dasyuridae). Australian Journal of Zoology 19, 1–7.
Wainer, J. , and Gibson, R. (1976). Habitat of the swamp antechinus in Victoria. Distribution and habitat requirements of the mainland swamp antechinus Antechinus minimus maritimus. The Victorian Naturalist 93, 253–255.
Wilson, B. (1986). Reproduction in the female dasyurid Antechinus minimus maritimus (Marsupialia: Dasyuridae). Australian Journal of Zoology 34, 189–197.
| Crossref | GoogleScholarGoogle Scholar |
Woolley, P. A. (1984). Reproduction in Antechinomys laniger (‘spenceri’ Form) (Marsupialia: Dasyuridae): field and laboratory investigations. Australian Wildlife Research 11, 481–489.
| Crossref | GoogleScholarGoogle Scholar |