Estimating badger abundance using faecal DNA
Journal
Journal of Applied
Ecology, Volume 40,Number 4, August 2003, pp. 658-666(9)
Blackwell Publishing
Authors
Wilson G.J.; Frantz A.C.; Pope L.C.; Roper T.J.;
Burke T.A.; Cheeseman C.L.; Delahay R.J.
Abstract
Wildlife management and conservation programmes often require accurate
information on population density, but this can be difficult to obtain,
particularly when the species in question is nocturnal or cryptic. Badger
populations in Britain are of intense management interest because they are a
wildlife reservoir host of bovine tuberculosis (TB). Attempts to manage this
infection in badgers, whether by population control or vaccination, require
reliable methods of estimating population size. In addition, such estimates are
also required to support research into badger ecology and TB epidemiology.
Currently, the most accurate estimates of local badger population size are
obtained from labour-intensive and time-consuming mark–recapture studies.
In recent years, DNA has been successfully extracted from the faeces of
certain mammals, and used to generate a genetic profile of the defecating
individual. Here we report on an application of this technology to estimate
badger abundance.
Faecal samples were collected on 10 consecutive days from every freshly
deposited dropping at latrine sites close to occupied setts in three badger
social groups. Badger DNA was extracted from 89% of samples, and 20 different
individuals were reliably identified. The genotypes derived from the faecal
samples were compared with those obtained from blood or samples from badgers
live trapped at the same setts.
The faecal genotypes from badgers with known trap histories revealed
that latrines were used equally by males and females, and by badgers ranging in
age from cubs (<1year old) to 9 years old. Individual badgers
used the latrines on between one and six different nights. Rarefaction analysis
produced abundance estimates that closely matched those obtained from live
trapping.
Synthesis and applications. Systematic sampling and genetic
typing of fresh faeces from badger latrines can provide data that can be used to
estimate abundance accurately. This approach requires considerably less human
resources than repeated live trapping and mark–recapture. The technique may be
valuable for future badger research and management in relation to bovine TB,
where accurate estimates of abundance at a local scale are required.
Keywords
molecular scatology; population size; survey
technique
Web site
|
