Data for: Harvest and decimation affect genetic drift and the effective population size in wild reindeer

Harvesting and culling are methods used to monitor and manage wildlife
diseases. An important consequence of these practices is a change in the
genetic dynamics of affected populations that may threaten their long-term
viability. The effective population size (Ne) is a fundamental parameter
for describing such changes as it determines the amount of genetic drift
in a population. Here, we estimate Ne of a harvested wild reindeer
population in Norway. Then we use simulations to investigate the genetic
consequences of management efforts for handling a recent spread of chronic
wasting disease, including increased adult male harvest and population
decimation. The Ne/N ratio in this population was found to be 0.124 at the
end of the study period, compared to 0.239 in the preceding 14-year
period. The difference was caused by increased harvest rates with a high
proportion of adult males (older than 2.5 years) being shot (15.2 % in
2005-2018 and 44.8 % in 2021). Increased harvest rates decreased Ne in the
simulations, but less sex-biased harvest strategies had a lower negative
impact. For harvest strategies that yield stable population dynamics,
shifting the harvest from calves to adult males and females increased Ne.
Population decimation always resulted in decreased genetic variation in
the population, with higher loss of heterozygosity and rare alleles with
more severe decimation or longer periods of low population size. A very
high proportion of males in the harvest had the most severe consequences
for the loss of genetic variation. This study clearly shows how the
effects of harvest strategies and changes in population size interact to
determine the genetic drift of a managed population. The long-term genetic
viability of wildlife populations subject to disease will also depend on
the population impacts of the disease and how these interact with
management actions.