Publisher
Royal Society Publshing
Abstract
Culling wildlife to control disease can lead to both decreases and increases in
disease levels, with apparently conflicting responses observed, even for the
same wildlife-disease system. There is therefore a pressing need to understand
how culling design and implementation influence culling's potential
to achieve disease control. We address this gap in understanding using a
spatial metapopulation model representing wildlife living in distinct
groups with density-dependent dispersal and framed on the badger-
bovine tuberculosis (bTB) system. We show that if population reduction is
too low, or too few groups are targeted, a 'perturbation effect' is observed,
whereby culling leads to increased movement and disease spread. We also
demonstrate the importance of culling across appropriate time scales, with
otherwise successful control strategies leading to increased disease if they
are not implemented for long enough. These results potentially explain a
number of observations of the dynamics of both successful and unsuccessful
attempts to control TB in badgers including the Randomized Badger Culling
Trial in the UK, and we highlight their policy implications. Additionally, for
parametrizations reflecting a broad range of wildlife-disease systems, we
characterize 'Goldilocks zones', where, for a restricted combination of
culling intensity, coverage and duration, the disease can be reduced without
driving hosts to extinction.
Year
2019
Links
Category
Refereed journal