Huntable UK waterbird data

Life history characteristics, harvest data, population trends and
conservation statuses of huntable waterbirds in the UK. Wintering bird
populations for the UK were obtained from the latest published estimates
(Frost et al. 2019). The estimate for mallard was increased by 2.6 million
birds to account for the annual release of captive-raised birds for
shooting purposes (Madden 2021). We estimated a standard deviation for the
population estimates by averaging the Wetland Bird Survey (WeBS; Frost et
al. 2021) index for each species for the winters 2012/13 – 2016/17, which
corresponded to the period used to estimate duck populations. We treated
this mean index as equal to the estimate from Frost et al. (2019) and then
calculated population estimates for each year based on their WeBS indices
and calculated the standard deviation of these estimates. Population
estimates for greylag goose, pink-footed goose, golden plover, snipe and
woodcock were based on single years, but the same time frame was applied
to standard deviation estimates in order to account for any interannual
differences. The latest (2016) harvest estimates and 95% confidence
intervals were taken from Aebischer (2019). Species specific body mass was
taken from Robinson (2005). Where sex-specific body mass was reported we
averaged male and female masses.