Introduction
Three feral horse aerial surveys were funded by the Australian Alps Liaison Committee (AALC) covering the Australian Alps National Parks in 2001, 2003 and 2009 following the methods established by Walter and Hone (2003) with the aim of monitoring horse population trends over time. A sharp drop in population size was observed between 2001 and 2003 which was attributed to broad-scale intense fires across the Australian Alps in the summer of 2002 – 03. The wild horse population in the Australian Alps National Parks had increased back to pre-fire levels by 2009.
In 2014 the aerial survey methods were changed to increase the scale and intensity of the survey. The primary aims of the new survey were to establish accurate and precise estimates of the Australian Alps feral horse populations (including outside of national parks), and to have sufficient sampling intensity to provide separate estimates of horse abundances in northern Kosciuszko National Park (KNP), southern KNP and the Alpine National Park in Victoria. The survey area was expanded beyond the national park boundaries to encompass the entire known distribution of feral horses in the Australian Alps with the exception of a few small isolated populations. Areas of very steep terrain, some of which were included in the previous surveys, were excluded from the 2014 survey area because the required constant height and aircraft speed for a helicopter survey could not be maintained. Additional changes necessitated by Occupational Health and Safety (OH &S) requirements for helicopter operations included the placement of an air safety observer in the front of the aircraft, which resulted in an altered seating and sighting configuration for the two horse observers.
The population in the 2014 survey area was estimated to be 9,520 horses (95% CI 7,529 – 11,814). Recognising that modifications to the 2014 survey design and method make analysis of population trends from previous surveys difficult the next survey (planned for autumn 2019) will follow the 2014 model as closely as possible.