The effect of handling under anaesthetic on the recapture rate of wild ship rats ( Rattus rattus)

Abstract This paper describes a two-part study of small predators in New Zealand forests. First, during 12 days of live-trapping, 31 wild ship rats were captured, tagged and released: 9 were handled while anaesthetised using halothane and 22 were handled while conscious using gloves. There was a sig...

Full description

Bibliographic Details
Published in:Animal Welfare
Main Authors: Prout, DM, King, CM
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 2006
Subjects:
Online Access:http://dx.doi.org/10.1017/s0962728600029961
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0962728600029961
Description
Summary:Abstract This paper describes a two-part study of small predators in New Zealand forests. First, during 12 days of live-trapping, 31 wild ship rats were captured, tagged and released: 9 were handled while anaesthetised using halothane and 22 were handled while conscious using gloves. There was a significant difference between the two groups of ship rats in live-recapture rate: 4 out of 9 rats that had been handled while anaesthetised were recaptured alive, compared with 0 of 22 that were handled while conscious. Second, during 12 days of removal-trapping, 23 ship rats were killed, of which 6 were tagged, including 4 of the 9 that had been previously handled while anaesthetised (2 of which had also been recaptured alive during the live-trapping) and 2 that had previously been handled while conscious. These observations have implications for the statistical estimation of population density from capture-mark-recapture data and for the development of protocols for minimising stress in captured animals, especially nocturnal species released from traps in daylight.