Aerial survey of donkey and horse populations in the Victoria River District 2006
Saalfeld, Keith
E-Publications; PublicationNT; E-Books
0000-00-00
Made available via the Publications (Legal Deposit) Act 2004 (NT).
2001 and 2006 Aerial survey. 2001 survey was published by Parks and Wildlife Commission of the Northern Territory, Palmerston (N.T.) 2006 survey was published by Department of Natural Resources, Environment and The Arts, Palmerston (N.T.)
English
Feral livestock -- Northern Territory -- Victoria River Downs; Donkeys -- Northern Territory -- Victoria River Downs; Horses -- Northern Territory -- Victoria River Downs
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https://hdl.handle.net/10070/230511
https://hdl.handle.net/10070/670949
https://hdl.handle.net/10070/670947
Figure 6: Population estimates of both donkeys and horses in the VRD 1981 to 2001. In relation to the estimates of horse population it should be noted that the current survey attempted to exclude domestic stock from the estimate of feral numbers by excluding any sightings of horses inside a ten kilometre radius of station homesteads from the analysis, on the basis that these would most likely be domestic stock. It is extremely difficult for observers to differentiate between domestic and feral horse stock as in most circumstances they are not aware of their location in the air in relation to the homesteads and brands etc. are not visible from the air. This exclusion was not done in the 1992 and 1996 surveys and it is unknown if it was done in the earlier surveys, hence the current estimate will under-estimate in relation to the earlier surveys. This exclusion of presumed domestic horse stock has been carried out to ensure that estimates of feral stock on a property and the required off-take to achieve control are accurate. Both the current and early surveys (1981, 1984 and 1988) utilised known off-take levels from specific areas to derive environmental corrections. Without environmental correction estimates are relative and any comparison between surveys is of limited value. Of more value is a comparison of changes in relative distributions between surveys. With this said, the very high density of donkeys in 2001 and the significant increase in density from 1996 to 2001 means that consideration of the change in density from 1996 to 2001 on a minimum cell basis will be valuable in identifying where donkey control effort needs to be targeted. While horse numbers and density have shown a slight decline from 1996 to 2001, as for donkeys, consideration of the change in density from 1996 to 2001 on a minimum cell basis will be valuable in identifying where horse control effort needs to be targeted. Figures 7 and 8 show the change in density from 1996 to 2001 for donkeys and horses on a minimum cell basis. Areas covered by the 2001 survey that were not surveyed in 1996 have been excluded. 0 20,000 40,000 60,000 80,000 100,000 120,000 1980 1985 1990 1995 2000 2005 Year Po pu la tio n Es tim at e Donkeys Horses