Powerlink QLD – Small mammal trapping

In 1999, the QPWS re-established three vegetation linkages across the Powerlink QLD easement, through which the 132kV line runs from Kareeya Power Station to Innisfail.

A very limited range of rain forest species (four) were replanted, in row formation, to facilitate rapid and cost-effective revegetation, and provide a linkage across the easement. The linkages are located within the Palmerston section of Wooroonooran National Park, adjacent to the Palmerston ranger station.

Powerlink maintains a number of assets within easements that traverse environmentally sensitive areas, creating barriers to the movement of animals and some birds across the easement. This linear barrier effect is especially powerful in the tropics where several studies have identified and documented the effect.

The objective of this project is to evaluate the usefulness of restored linkages to mammals crossing the (cleared) easement. Cage traps and Elliot (box) traps were established at six sites to assess the composition of small mammal communities in grassland, linkage and intact forest environments, and to determine the extent to which these linkages are used by rainforest mammals.

All relevant permits were obtained from QPWS and Animal Ethics Approval from James Cook University. Trapping events are conducted every two months beginning in November 2005 for twelve months (six trapping rounds).

Forested sites are typically dominated by forest-dependent species, Bush Rat (Rattus sp. fuscipes/leucopus) and Fawn-footed Melomys (Melomys cervinipes), and to a lesser extent White-tailed Rat (Uromys caudimaculatus). Grass dependent species such as the Canefield Rat (Rattus sordidus), House Mouse (Mus musculus) and Burton’s Climbing Rat (Melomys burtoni) are confined to this habitat.

The largest percentage of animals for which movement was recorded was scrotal males. This ready movement is typically by the Bush Rat, an encouraging indicator of successional change in the corridor. Further movement analysis will commence once the twelve month data set is complete.

This study provides important information of the dynamics of the linear barrier effect of corridors and guidance for restoration strategies across powerline easements.