Macropod Management, Maria Island National Park: Annual Report and Recommendations June 2018

The recommendation for 2018 is for a maximum of 350 Bennetts wallaby (Macropus rufogriseus rufogriseus) and a maximum of 200 Tasmanian pademelon (Thylogale billardierii) to be culled on Maria Island. This recommendation is the result of careful consideration of the results from this year’s Integrated Monitoring Strategy (2010); below average rainfall for eight out of the past twelve months; and the proposed reduction in Tasmanian devil (Sarcophilus harrisii) numbers from an estimated 130 in 2016 to ∼65 this year as advised by the Save the Tasmanian Devil Program (STDP). Population monitoring results indicate increasing trend estimates for Forester kangaroo (M. giganteus), Bennetts wallaby and Tasmanian pademelon since last year. However, Forester kangaroo population trend estimates are the lowest of all marsupial herbivores on Maria Island and as such should not be culled. The results of biological monitoring indicate fatty liver change (a key indicator of nutritional stress), anaemia and high numbers of intestinal parasites in sampled Bennetts wallaby and Tasmanian pademelon. High numbers of intestinal parasites are an indication of intense grazing pressure on already contaminated pasture, lack of dispersal and reduced pasture growth from an extended period of low rainfall. Fecundity (the number of females with pouch young) is high for all three macropod species due to one month of high rainfall while the kidney fat index (KFI) is lower than the past two years.

As endorsed by the Maria Island National Park and Ile Des Phoques Nature Reserve Management Plan, 1998 and the Maria Island Macropod Management Program (MMMP) Directions Statement (2011), culling to reducing grazing pressure on Maria Island aims to improve animal welfare during the upcoming winter period. The current levels of nutritional stress and limited food resources would result in adverse animal welfare outcomes if a cull does not occur. This decision has been made in consultation with an experienced veterinarian and following discussions between all agencies involved in the MMMP. In particular, the number of devils on Maria Island has been significantly reduced following the removal of 33 adults and 38 imps in May 2017 with a further 30 devils to be trapped and removed in June this year (STDP 2018). The lower density of devils is expected to have limited impacts on macropod populations, due to alternative prey species being available on Maria Island. Climate forecasts from the Bureau of Meteorology also indicate only a moderate chance of exceeding median rainfall this winter, with the long term weather outlook indicating reduced impacts from a neutral El Niño Southern Oscillation (ENSO) cycle (i.e. average conditions) further limiting the potential for pasture growth in early spring.