Global PositioningSystem (GPS) satellite navigation receivers are increasingly being used in ecologicaland behavioural studies to track the movements of animals in relation to theenvironments in which they live and forage. Concurrent recording of the animal'sforaging behaviour (e.g. from jaw movement recording) allows foraging locationsto be determined. By combining the animal GPS movement and foraging data withhabitat and vegetation maps using a Geographical Information System (GIS) itis possible to relate animal movement and foraging location to landscape andhabitat features and vegetation types. This powerful approach is opening upnew opportunities to study the spatial aspects of animal behaviour, especiallyforaging behaviour, with far greater precision and objectivity than before.
Advances in GPS technology now mean that sub-metre precision systems can beused to track animals, extending the range of application of this technologyfrom landscape and habitat scale to paddock and patch scale studies. As wellas allowing ecological hypotheses to be empirically tested at the patch scale,the improvements in precision are also leading to the approach being increasingextended from large scale ecological studies to smaller (paddock) scale agriculturalstudies.
The use of sub-metre systems brings both new scientific opportunities and newtechnological challenges. For example, fitting all of the animals in a groupwith sub-metre precision GPS receivers allows their relative inter-individualdistances to be precisely calculated, and their relative orientations can bederived from data from a digital compass fitted to each receiver. These data,analyzed using GIS, could give new insights into the social behaviour of animals.However, the improvements in precision with which the animals are being trackedalso needs equivalent improvements in the precision with which habitat and vegetationare mapped. This needs some degree of automation, as vegetation mapping at afine spatial scale using the traditional manual approach is far too time consuming.This paper explores these issues, discussing new applications as well as approachesto overcoming some of the associated problems.
