1,2NSW Agriculture, 161 Kite Street (Locked Bag 21), Orange NSW 2800
2Northern New England Rural Lands Protection Board,
PO Box 108 Glen Innes NSW 2370
1Corresponding author – Phone: 02-63913606, Fax: 02-63913767
Several types of pest animal cause agricultural losses within the area overseen by the Northern New England Rural Lands Protection Board (NNE RLPB). The wild dog causes significant losses in the sheep, goat and cattle industries. In the past predation and sightings have been largely under reported. To gain an accurate picture of the problem, NNE RLPB ratepayers were surveyed about the vertebrate pest activity on their land. This survey has enabled predation, sightings and baiting to be plotted on a property by property basis using cadastral links in a Geographic Information System (GIS). Flight paths for aerial baiting are mapped at the time of application while ground based strategic and reactive baiting by groups and individuals is plotted through 1080 records and linked to relevant properties.
RLPBs and land holders need to become more accountable for their wild dog control progammes, especially their use of aerial baiting. Documenting the spatial distribution of wild dog sightings, predation and baiting is vital for the development of effective wild dog management plans, for targeting pest control officers’ activities to areas of high pest density, and for pest control orders where areas of high conservation value for pure dingoes have been identified. This mapping will become increasingly valuable over time to monitor changes in wild dog activity and the effectiveness of control programmes.
The core functions of RLPBs are to protect the NSW community from the dangers of exotic and endemic animal disease and to control pest animals. The NNE RLPB covers 1,919,000ha of prime beef and fine wool country in northern NSW. One of the greatest threats facing graziers, particularly along the eastern side of the RLPB, is wild dog predation of sheep, goats and calves. This pest causes enormous loss and disruption to livestock enterprises, especially those running sheep and goats. Between July 1999 and June 2000, wild dogs were responsible for killing 3 large animals (cattle and horses), 139 calves, 2229 sheep and 97 goats, whilst mauling 60 large animals, 127 calves, 1479 sheep and 41 goats.
The NNE RLPB has a very high exposure to public lands containing wild dogs. The NNE RLPB contains, (or is within 10km of) significant areas of both National Park (319,000ha) and State Forest (189,000ha). These areas contain large numbers of wild dogs but also some pockets of dingoes, which may have some conservation value. It is important for both political and societal reasons to identify and conserve pure dingo populations whilst supporting the control of wild dogs in surrounding agricultural enterprises.
The NSW Threatened Species Conservation (TSC) Act protects endangered, vulnerable or rare species and provides measures to remove threatening processes through Threat Abatement Plans and assist recovery by putting Recovery Plans in place. In the context of wild dog control, the NSW Rural Lands Protection (RLP) Act serves to provide regulatory control of wild dogs to minimise predation of livestock and native fauna. These two acts provide potential for conflict as the RLP Act pest animal orders to control wild dogs may be detrimental to the conservation objectives of TSC Act (Davis and Leys, 2001).
Wild dogs impact across most areas of the State. However, damage is particularly noticeable in areas adjoining public land. It is well known that wild dogs emanate from the security of National Parks and State Forests (RLPB Annual Report, 1999). RLPBs remain concerned about wild dogs with further restrictions to aerial baiting on publicly managed lands and additions to the existing areas of National Parks and Reserves.
In autumn 2000, the New England, Hunter and Coastal Aerial Wild Dog Baiting Program dropped 4,122 kgs of 1080 meat baits. A total of 144 wild dogs were reported killed (poisoned, trapped, shot) while 831 were sighted. Vertebrate pest control programs are coming under increasing scrutiny by the public and the need for implementing each program must be soundly justified (Fleming et al, 2001). To date, baiting has occurred based upon a history of predation and local knowledge. Land holders, RLPBs and Wild dog control Associations are now held considerably more accountable than previously, particularly in relation to aerial baiting. The future of wild dog control, and thus the sustainability of grazing enterprises in tableland areas, is reliant upon the maintenance of sound records of wild dog activity by way of sightings, predation and other indicators (RLPB Annual Report, 1999). Aerial baiting programs involving the National Parks and Wildlife Service (NPWS) estate will no longer take place unless there are statistics relating to the occurrence of wild dogs in the area. To assess the effectiveness of programs to manage wild dogs, it is essential to monitor the impacts of wild dogs on livestock production (Fleming et al, 2001). NSW Agriculture will no longer subsidise baiting programmes unless RLPBs provide wild dog predation data.
This study offers potential to improve both wild dog control and conservation outcomes by targeting wild dog control resources where they are most effective. The main objectives of strategic baiting around large conservation areas are; to prevent dingoes moving out from the fringes of conservation areas and causing agricultural losses; and to prevent feral domestic dogs entering these areas and diluting the gene pool of pure dingoes.
NSW Agriculture and the NNE RLPB have begun a preliminary study to spatially enable the NNE RLPB Wild Dog Database. NNE RLPB maintains records of wild dog predation, wild dog sightings and 1080 distribution by individual land holders. Preliminary investigations of these data in a Geographic Information System (GIS), has identified patterns previously undetected adding weight to a case for continued funding of wild dog control programmes.
Datasets and Preliminary Analysis
In 1999, the NNE RLPB surveyed its ratepayers about wild dog activity on their properties. The mail survey was posted with the 1999 compulsory Land and Stock Return, a tactic which achieved a very high response rate (1234 respondents or 70%). The survey ascertained the level of vertebrate pest activity for a range of pest species and the types of control measures employed by land holders and groups.
Flight paths for aerial baiting are mapped at the time of application while ground based strategic and reactive baiting by groups and individuals is plotted through 1080 records and linked to relevant properties.
The survey data were entered into the NNE RLPB’s ratepayer database. A subset of this database was exported for use in the NSW Agriculture GIS. The subset contained all vertebrate pest survey data together with the lot and deposited plan numbers (lot/DP) for the parcels of land making up the properties for which vertebrate pest activities were reported. The lot/DP information for the one or more properties a ratepayer owns is stored in a single field in the database. This design feature meant that a substantial effort had to be made to separate out each parcel’s lot/DP identifier so that it could be joined to the corresponding lot/DP fields in the NSW Digital Cadastral Database (DCDB), and hence provide the spatial information enabling mapping of the pest data. The database would be improved if there were separate records for each property a ratepayer owned, and if there were a separate database table made up of separate records of every lot/DP for every property.
This feature of the database (multiple properties combined into a single record for ratepayers owning more than one property) caused a problem. Like the lot/DP data, the pest information for all a ratepayer’s properties is part of the ratepayer’s single record. Hence, pest animal activities and baiting on one property were shown as occurring across all that ratepayer’s properties. For instance, if a land holder had baited rabbits on one property and baited dogs on another, both those locations were shown as having both rabbits and dogs baited. The local knowledge of the NNE RLPB’s staff was necessary to identify these anomalies. They were manually corrected in the GIS following consultation with the Board.
Large format plots (A0) were prepared and distributed to the RLPB for comment. The maps displayed properties where wild dog predation, wild dog sighting and wild dog baiting had been reported. A NPWS and NSW State Forest (NSWSF) boundary overlay was included, together with aerial baiting flight paths and a selection of towns, roads and rivers. The maps make it obvious that the majority of stock predation by wild dogs occurs along the eastern edge of the RLPB. This area coincides with the distribution of National Parks and State Forests.
As mentioned above, National Parks and State Forests are reported to be refuges for wild dogs. The pest information discussed here enables that observation to be more closely examined. Now, after surveying the diurnal and nocturnal activity of wild dogs in the field, Harden (1985) reported that a wild dog travels an average distance of 15 km in 24 hours. With this information in mind, the GIS was used to create a buffer zone 15 km wide around the National Park and State Forest boundaries. The spatial data set representing the properties reporting wild dog predation was “intersected” with the buffer zone, in order to determine the percentage of properties experiencing predation within 15 km of National Parks and State Forests.
Spatial analysis of these combined datasets revealed that almost 100% of reported stock predation had occurred within 15kms of these public lands. Of 4175 predations, 4171 were reported on properties (partly or wholly) within this zone. The remaining four predations were on a single property 20km from the nearest public land, but linked by a significant corridor of timber to the nearest National Park. A small subset of the properties experiencing predation and their relationship to public lands is shown in Figure 1.
Figure 1. Properties Reporting Stock Predation in Relation to Public Lands
This preliminary finding indicates the need for continued wild dog suppression around public lands to reduce agricultural losses. Poisoning with 1080 is the most cost effective means of reducing populations of wild dogs over large areas of remote or inaccessible country (Fleming et al, 2001). A compromise suitable to land holders and environmentalists must be reached. This may involve the identification of pockets where sufficient numbers of dogs with pure dingo genetics exist, then implementing a buffer area within which dogs are controlled. This will have the dual benefit of minimising stock losses whilst preventing dogs from diluting the dingo genepool.
The NNE RLPB intends to continue collecting data on vertebrate pest activity through an annual ratepayer survey. This dataset will become increasingly valuable over time as it will facilitate a quantitative assessment of the changes in vertebrate pest activity and therefore the effectiveness of control programmes. Conservation and control objectives will be better served through targeted control programmes. The distribution of enterprise structure (cattle, sheep, goats, deer) can be plotted through time. These changes will be analysed in relation to baiting and predation by wild dogs.
These data will be essential for developing future management plans likely to be required under the new RLPB legislation, particularly where areas of high conservation value for pure dingoes have been identified.
Only wild dog activity has been examined to date, however rabbit, fox and pig data are also collected during the ratepayer survey. These other data will be analysed in a GIS to determine spatial patterns and assist in targeting control programmes.
Davis, E.O. and Leys, A.R. (2001) Reconciling wild dog control and dingo conservation under New South Wales legislation. In the Proceedings of the 12th Australian Vertebrate Pest Conference, Melbourne, 21-25 May 2001
Fleming, P., Corbett, L., Harden, R. and Thomson, P. (2001) Managing the Impacts of Dingoes and Other Wild Dogs. Bureau of Rural Sciences, Canberra.
Harden, R.H. (1985) The ecology of the dingo in north-eastern New South Wales.
I. Movements and home range. Australian Wildlife Research 12: 25–38.
RLPB Annual Report (1999) Rural Lands Protection Boards’ Association of NSW.