Exploring the use of a fragmented landscape by a large arboreal marsupial using incidental sighting records from community members

Abstract

Effective conservation of large mammalian species within a human-modified landscape depends on the knowledge of their ability to utilise available suitable habitat within a matrix of unsuitable habitat. We use incidental sightings of Lumholtz’s tree-kangaroo (Dendrolagus lumholtzi) in north-eastern Australia that were recorded by community members in a non-standardised way to assess the functional connectivity of the highly fragmented landscape of the Atherton Tablelands for this species. By applying spatial analytical tools to available mapped information on landscape attributes and the reported sightings it was found that the species shows a low matrix resistance. Since most sightings within the matrix were found within 150 m of a patch with suitable habitat and the average distance between these patches was 77 m it can be concluded that Lumholtz’s tree-kangaroos are able to reach most fragmented suitable habitat given certain limitations of the accuracy of the used maps and sighting locations. Based on distances between suitable habitat patches and their predominant size of up to 2 ha we expect that the species can include several fragments into its home range. More sightings of Lumholtz’s tree-kangaroos than expected by chance within the matrix during dry seasons combined with shorter than expected distances into the matrix suggests the existence of seasonal resource-driven movements of this species. Due to the non-standardised nature of the data the derived conclusions need to be tested in rigorous scientific projects before they can be integrated into the development of conservation strategies for Lumholtz’s tree-kangaroos on the Atherton Tablelands.