Authors
David Forsyth, Andrew Gormley, Luke Woodford and Tony Fitzgerald
Summary
‘Reduction in biodiversity of native vegetation by Sambar Deer (Cervus unicolor)’ has been listed as a threatening process under the Flora and Fauna Guarantee Act 1988, and there is concern that native vegetation may be vulnerable to impacts of Sambar Deer immediately post-fire. However, little is known about the impacts of fire on the population levels of Sambar Deer, except that deer are sometimes killed. The objective of this project was to evaluate the effects of the Black Saturday fires on occupancy and abundance of Sambar Deer using pre- and post-fire data from burnt and unburnt habitat.
The effects of the Black Saturday fires on Sambar Deer abundances were assessed using repeated annual counts of faecal pellets along 30 150-m transects in part of Kinglake National Park, which was burnt by the high-intensity Kilmore East fire on Black Saturday (7 February 2009), and in part of Mount Buffalo National Park, which was not burnt in the Black Saturday fires and serves as a comparison. Pellets were counted in spring for two years pre-fire (2007, 2008) and two years post-fire (2009, 2010) in both areas. Sambar Deer pellets increased during the four years of counts in the unburnt Mount Buffalo National Park. In Kinglake National Park, pellets increased in the two years prior to Black Saturday, but no pellets were recorded eight months after the Kilmore East fire and very few pellets were counted 20 months after the fire.
We evaluated the effects of the Black Saturday fires on Sambar Deer occupancy at a larger spatial scale by sampling 15 pairs of 4 km2 sites in areas burnt by the Kilmore East, Murrindindi, Bunyip, Dargo, and Beechworth fires. One of each pair had been burnt while the other was not burnt but was located within 15 km of the fire edge. Pre-fire data collected in September 2008–January 2009 were available for five burnt and nine unburnt sites. Sampling was undertaken 16–24 months after the Black Saturday fires using three survey methods: sign searches along a 400-m transect, two remote camera traps set for 21 days and faecal pellet counts along three 150-m transects. We found that Sambar Deer occupancy was only weakly reduced in burnt sites 16–24 months after the Black Saturday fires.
We conclude that Sambar Deer abundances were greatly reduced by the large-scale and high-intensity Black Saturday fires, but that nearly all burnt habitat was occupied 16–24 months later. However, it is expected that Sambar Deer populations in some areas (e.g. part of Kinglake National Park) will take many years to reach pre-fire abundances. Continued annual monitoring of pellet transects at Kinglake National Park will enable the recovery of the Sambar Deer population to be evaluated. A key remaining knowledge gap is the impacts of Sambar Deer on post-fire vegetation dynamics, including those of Victorian Rare or Threatened Species (VROTS).