Suitability of Passive Integrated Transponder Tags for Marking Live Animals for Trade.

Abstract

Passive Integrated Transponder (PIT) tags were subject to a series of experimental manipulations designed to simulate conditions operating during the course of trade in animals. Experiments were designed to determine the effects of tag-wand angle of orientation, various barriers between tags and wands and different wand-readers on the distance at which a reading could be made. The distances at which readings can be made are subject to influences by all three variables. The effect of tag-wand angle of orientation is likely to be trivial under most circumstances. Of more importance to the utility of PIT tags for animal trade is environmental interference, particularly that due to metallic barriers (plate or mesh). Different wand-readers produce idiosyncratic results in relation to orientation of the tag and wand and type of barrier. Implantation of tags in cane toads (Bufo marinus) indicates that tags are long lived and reliable. Loss of tags from the toads was relatively rare and probably due to error during the insertion of tags. PIT tags proved resistant to preservation in formalin or ethanol, and to the decomposition of animals in which they had been inserted. Tags inserted into 14 species of Australian mammal provided reliable identification of individuals, and were lost only from species that fly (bats) or are arboreal and glide (a petaurid marsupial). PIT tags are outstandingly reliable and provide for rapid identification of individual animals. Limitations to the use of PIT tags in trade in animals are the inability to conduct readings from a distance (>50mm), and their vulnerability to environmental interference. Technological improvements in taglscannerlreader design may improve the distance from which readings may be made, and cages could possibly be designed in ways that minimise environmental interference. Until these developments have occurred, the PIT tag does not provide cost-effective improvements in the ability to identify animals used in trade.