Trappability of badgers
Journal of Applied Ecology, December 1999, Vol. 36, No. 6, pp. 1051-1062(0)
Differences in the trappability of badgers in three
populations in England
- Many ecological studies on the badger, as well as certain programmes to control
btb, would benefit from a greater understanding of the
factors that influence the probability of capturing this animal in
cage-traps. We investigated differences in trappability between three badger populations
in England: the high-density protected populations of Wytham Woods
and Woodchester Park, and the low-density culled population of North
- Trappability (the percentage of all individuals known
alive that were actually captured) did not differ between sexes or
adult age classes, but significant differences were found between
cubs and adults, study areas, seasons and years, and various
interactions between these variables.
- Circumstantial evidence suggests that the culling of
badgers in North Nibley may have resulted in a decrease of adult
trappability in the following year.
- Adult badgers at Wytham Woods and Woodchester Park were
significantly more likely to be trapped zero times (‘trap-shy’) or
all three times (‘trap-happy’) in 1996 than predicted by the
estimated capture probabilities under the assumption of equal
- Wytham Woods differed from the other study areas in
that trappability of its badgers was positively related to their
body weight and its adult badgers were more likely to be trapped
than cubs. These differences could be a consequence of differences
in trapping procedures that were followed at Wytham (no prebaiting
and fewer traps per badger).
- Trappability of badgers was not associated with social
group size. Although it is difficult to determine precisely the
movement and tuberculosis status of badgers based on mark–recapture
data, our analyses did not suggest that either variable affected the
likelihood of being trapped.
- Studies that compare demographic, biometric and
epidemiological parameters based on data collected from badgers
captured at different times or places ought to account for the
observed differences in trappability.