Decline in body condition and high drought mortality limit the spread of wild chital deer in north-east Queensland

Michael Brennan, Tony Pople and colleagues have just published “Decline in body condition and high drought mortality limit the spread of wild chital deer in north-east Queensland” in the Rangeland Journal. Chital deer, originally from South Asia and introduced to the Burdekin district in 1886, have been slow to expand their distribution and increase in abundance in that district.  This district experiences fluctuations in forage due to seasonal rainfall and multi-year droughts suggesting forage shortages may have caused sufficient mortalities to limit deer increase and spread. This study recorded the decline in body condition, measured by two fat indices, over the wet and dry seasons of two successive years in two populations when annual rainfall was about 40% below average. The falls in the fat indices were related to decline in chital populations of about 80%. The extent of the decline implied increased mortalities in all age classes as well as reduced reproductive output. It is likely that chital populations have experienced several such drought mortality events since the 1890s which have contributed to their limited spread.

Watter, K., Baxter, G., Brennan, M., Pople, A. and Murray, P. 2019. Decline in body condition and high drought mortality limit the spread of wild chital deer in north-east Queensland, Australia. Rangeland Journal 41(4): 293-299.