The Wollondilly and Wingecarribee Rivers in the Southern Tablelands are two of the main tributaries of the Warragamba dam which supplies Sydney's drinking water. For many square kilometres around the junction of these two rivers, located about 30 kms west of Moss Vale, the rugged river valleys and adjacent plateaus provide ideal habitat for a significant population of feral goats. The only effective method of feral goat control in this sort of country is shooting from a helicopter.
Land responsibility in the area is vested in mainly private landholders, but also the National Parks and Wildlife Service (NPWS) and the Sydney Catchment Authority (SCA). Overall catchment integrity is the responsibility of the Hawkesbury Nepean Catchment Management Authority (HNCMA), which was the main funding agency for the shoot. The area is located partly within the Tablelands LHPA and partly within the Cumberland LHPA districts.
The rationale for feral goat control varies between landholders and agencies:
Feral goats are classified as a key threatening process due to competition for shelter with endangered rock wallabies (there are rock wallaby colonies located within the Sydney drinking water catchment). Feral goats also damage Aboriginal heritage sites.
The 2009 goat shoot was organised by LHPA Rangers who realised that there would be a lot of dead goats (population estimates from aerial surveys were 1000+ goats) and asked me if there could be any useful animal health information obtained from the carcasses which could be accessed by road on private property.
Taking into account the limited time and manpower available, I considered the following tests would be worthwhile:
Major cost constraints required the faecal samples to be pooled - a maximum of 25 goats per pool for OJD culture. Faecal samples were stored in an esky with ice bricks. Because the headquarters where the team was based (Bangadilly Station) is on the Moss Vale side of the rivers and only an hours drive from EMAI at Camden, it was possible to deliver all faecal samples to the lab within 24 hours of collection.
Lab. costs for this testing were a significant non-budget item which had to be put to the Cumberland Board. The Directors were enthusiastic about the idea of adding animal health value to a pest animal project, and supported the request for funding for laboratory tests.
The shoot was conducted from 2nd - 6th November, 2009 after a major public and agency consultation program. The core shoot team consisted of 3 Rangers from Tablelands and 3 Rangers from Cumberland, plus DV Camden and the helicopter pilot. Occasional navigational assistance was provided by CMA and SCA staff. Shooting was by FAAST accredited LHPA Rangers, using Vietnam vintage SLRs. The ground team, consisting of the DV + 1 Ranger (with others joining in from time to time) could only access carcasses shot on private property on the Cumberland side of the rivers.
As a joint agency exercise, the shoot was well organised and highly successful. Staff of both LHPAs worked together very well, and the experience was enjoyed by all (except the goats).
If the exercise is repeated (and the plan is to do so if funds are available), I would like to repeat the animal health exercise on the Goulburn side of the catchment, where sheep numbers are significant, OJD has been present there at a high prevalence in the past and the hypothesis that feral goats could carry OJD would be more fairly tested.
This would mean finding a base on the Goulburn side of the rivers, and accessing goats shot on sheep properties in the Tablelands LHPA. Once the faeces are collected, other tests such as internal parasites provide bonus information at low cost.