|
Culling badgers, biometrics, population dynamics and movement
Journal
Journal of Animal
Ecology, Volume 69,Number 4, July 2000, pp. 567-580(14) -
Blackwell Publishing
Authors
Tuyttens F.A.M.; Macdonald D.W.; Rogers L.M.; Cheeseman
C.L.; Roddam A.W. from the Wildlife Conservation Research Unit,
University of Oxford, the Central Science Laboratory, Sand Hutton, York
and the Wellcome Trust Centre for the Epidemiology of Infectious
Disease, at Oxford
Abstract
-
Capture–mark–recapture data were used to describe
the process of recovery from a typical badger removal operation (BRO) at
North Nibley, Gloucestershire, UK, which was carried out as part of the
government's strategy to control bovine tuberculosis. Data on
biometrics, demographics and movement from this low-density disturbed
population were compared with those of two nearby high-density
undisturbed populations (Wytham Woods and Woodchester Park, UK) in order
to study fundamental principles of population dynamics and
density-dependence.
-
Badgers moved more between social groups at North
Nibley than in the other study areas, particularly in the immediate
aftermath of the removal operation.
-
Recolonization of the vacated habitat occurred in
the first instance by young females.
-
Although in the first year after the BRO no cubs had
been reared in any of the culled groups, and although the shortage of
sexually mature boars may have limited the reproductive output of sows
in the following year, the population took only 3 years to recover to
its (already lowered) preremoval density.
-
Losses from the adult (and cub) population due to
mortality or emigration were smaller at North Nibley than at the other
sites.
-
There was much evidence that during 1995 and 1996
density-dependent effects constrained the reproductive output of the
high-density populations, and some support for the hypothesis that
badgers exhibit the non-linear ‘large mammal’ type of functional
response to density.
-
Badgers at North Nibley were younger, heavier and in
better condition than badgers at Wytham Woods and Woodchester Park.
-
We argue that the disease dynamics are likely to be
different in disturbed compared with undisturbed badger populations, and
that this could affect the effectiveness of BROs.
Keywords
demography; density dependence; Mycobacterium bovis;
population regulation; reproductive suppression
Web site
|