An interim harvest strategy for Taiga Bean geese

In 2016 the AEWA European Goose Management International Working Group (EGM
IWG) adopted document AEWA/EGM IWG 1.8 (Johnson et al. 2016), which contained initial
elements of an Adaptive Harvest Management programme for Taiga Bean Geese. This report
addresses a number of limitations with the population model presented in that document, and
provides up-to-date population projections for the Central Management Unit under a range of
constant harvest rates. Based on simulations for the 2017-2025 timeframe, median population
size was near the median goal of 70,000 in 2019, 2020, and 2021 for harvest rates of birds aged
one year or more of 0.00, 0.02, and 0.04, respectively. Simulated population sizes generally
increased over the timeframe, albeit with a lot of variation and with the degree of uncertainty
increasing over time. With a harvest rate of 0.02, harvests averaged 1,848 (95% CI: 1,403 – 2,492) over the timeframe; a harvest rate of 0.04 produced an average harvest of 3,484 (95% CI: 2,617 – 4,884). Future work for the Central Management Unit will involve development of a dynamic harvest strategy by employing a Markov decision process, in which multiple, possibly competing, management objectives can be addressed.