Habitat-dependent population regulation in an irrupting population of long-nosed bandicoots (Perameles nasuta)

Abstract

We used isodars to analyse habitat-dependent population regulation by long-nosed bandicoots Perameles nasuta during an irruption and subsequent population crash in three habitats (heath, woodland and forest) at Booderee National Park, south-eastern Australia. Specifically, we aimed to see whether patterns of habitatdependent population regulation matched a priori estimates of quantitative and qualitative differences between habitats. We also tested if habitat preference changed between the increasing and decreasing phase of the irruption as predicted by the reciprocating dispersal theory. Quantitative differences in habitat quality were indexed by the relative abundance of the main food of long-nosed bandicoots (terrestrial invertebrates), while qualitative differences were indexed by the availability of refuge from predation (vegetation understorey density). One index of fitness, body weight, was highest in forest, and lowest in heath, suggesting an ideal despotic model of habitat selection. Over the entire course of the irruption, there was density-dependent habitat selection with forest and woodland both quantitatively superior to heath. This reflected the overall abundance of invertebrates with highest abundance in woodland and forest and less in heath. Isodar analysis also revealed that although forest was quantitatively better than heath and equivalent to woodland it was qualitatively poorer than either habitat. Heath had a higher density of understorey than woodland and woodland having a higher density of understorey than forest giving crossover population regulation. When the increasing and declining phase of the irruption were analysed separately, no habitat was quantitatively superior to any other during either phase. The lack of switching in preference between habitats from the increasing to the declining phase of the irruption and the virtual absence of any dispersal by adults, does not support the reciprocating dispersal hypothesis.

Unintended Consequences of Invasive Predator Control in an Australian Forest: Overabundant Wallabies and Vegetation Change

“…Since 1999, Booderee National Park (BNP) on the south-east coast of Australia, has maintained an intensive fox control program that has resulted in the increase in abundance of a number of native mammal species [31], [32]. There has been an increase in the abundance of macropods of approximately 10 fold between 2003 and 2009.…”

Booderee National Park Management: Connecting science and management

“…Indeed, these managers have lead-authored or coauthored a number of scientific articles based, in part, on the monitoring data gathered at BNP (e.g. Lindenmayer et al 2008aLindenmayer et al , 2009Dexter et al 2011Dexter et al , 2012MacGregor et al 2013). Moreover, Park staff are on the supervisory panel of several postgraduate students working on key projects within BNP to ensure these studies are relevant to management (sensu Russell-Smith et al 2003) as well as scientifically robust.…”

“…Lindenmayer et al 2008a), although, the latter species has exhibited major interannual fluctuations in abundance(Dexter et al 2011; C. MacGregor, D. Lindenmayer and J. Wood, unpublished data).…”

Bandicoots return to Booderee: initial survival, dispersal, home range and habitat preferences of reintroduced southern brown bandicoots (eastern sub species; Isoodon obesulus obesulus)

“…A.2). In addition, Dexter et al (2011) used vegetation structure data 425 collected by Lindenmayer et al (2008) at BNP to provide an index of the relative protection from 426 predation afforded by each habitat for the long nosed bandicoot (a species with comparable dietary 427 requirements and predation vulnerability as the southern brown bandicoot). They found that heath 428 provided the densest understorey and thus the best protection from predators, followed by 429 woodland then forest.…”