Kangaroo Island dunnart
|Kangaroo Island dunnart|
Kitchener, Stoddart and Henry 1984
|Kangaroo Island Dunnart range|
The Kangaroo Island dunnart (Sminthopsis aitkeni) is a dark sooty-grey coloured dunnart species first described in 1969, with paler underparts of its body. It has an average body length of 170–198 mm, a snout to anus length of 80–93 mm, a tail measurement of 90–105 mm, a hind foot of 17.5 mm, ear length of 18 mm and a weight which varies between 20–25 grams. The thin tail that is also gray, but bi-colored with lighter coloring on the bottom. The length of the tail is longer than the length of the body. Kangaroo Island dunnarts are dimorphic, males are larger than females.
Distribution and habitat
This dasyurid is found only on the western half of Kangaroo Island in South Australia, the island's only endemic mammal. The species inhabits mallee heath on laterite soils. It is believed that Kangaroo Island dunnart originally had a range over the whole island. Today, there are six sites in which Kangaroo Island dunnarts have been found. All sites are either in the Flinders Chase National Park or the Ravine des Casoars Wilderness Protection Area, both located on the western part of the island. Recent attempts to locate Kangaroo Island dunnarts on the eastern portion of the island have failed.
The Kangaroo Island dunnart is nocturnal. Their diet consist of invertebrates. Studies done on Kangaroo Island dunnart feces showed that the major component of the Kangaroo Island dunnarts' diet is ants and spiders. However, scorpions, beetles, and grasshoppers are also eaten.
Social organization and breeding
Little is known of the behavior of the Kangaroo Island dunnart. However, it is believed that the Kangaroo Island dunnart is polyestrous, breeding twice during the year. Based on trapping of juveniles, it is believed Kangaroo Islands dunnarts breed in mid-September to October and again in November to December. Gestation period is approximately 12 days. Little is known about parental care. Also, it is thought that males only live for one mating season while females may live to breed for two seasons.
The Kangaroo Island dunnart is listed as critically endangered by The IUCN Red List of Threatened Species. It is believed that there are fewer than 500 individuals. There are six sites on the western portion of Kangaroo Island were Kangaroo Island dunnart are found. The Kangaroo Island dunnart was believed to have a range of the entire island at one time. There are several causes to which the population decreased is attributed. Habitat loss is believed to be one of the primary caused of the decrease in Kangaroo Island dunnart population. Although, no clear habitat preference has been identified for Kangaroo Island dunnarts, they do seem to be depend on some low vegetation. The eastern portion of Kangaroo Island has been largely converted from the natural habitat for agricultural and grazing purposes. 50% of Kangaroo Islands natural habitat has been cleared. Kangaroo Island dunnarts have not been found in the cleared regions. Also, tree dieback caused by Phytophthora cinnamomi, a water mould, has also affected Kangaroo Island dunnart populations. Feral cats may also be a factor in the decreased population. Kangaroo Island dunnart populations are considered particularly vulnerable: because due to their small range a single event can negatively affect a large portion of the population. Forest fire is a major concern for this reason. Forest fires are believed to have impacted the population previously. The Australian government first developed a recovery plan for the Kangaroo Island dunnart in 2011.
- Menkhorst, P.; Knight, F. (2001). A field Guide to the Mammals of Australia. Oxford Press. p. 68. ISBN 0-19-550870-X.
- Groves, C.P. (2005). Wilson, D.E.; Reeder, D.M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press. p. 34. ISBN 0-801-88221-4. OCLC 62265494.
- Gates, J. (2011). Recovery Plan for Kangaroo Island Dunnart (Sminthopsis aitkeni). Department of Environment and Natural Resources, South Australia. pp. 1–12. ISBN 978-0-9806503-0-3.
- van Weenan, J. (2014). Sminthopsis aitkeni. The IUCN Red List of Threatened Species. Archived from the original on 27 June 2014. Retrieved 1 December 2014.