Fifty-year trends in UK hunting bags of birds and mammals, and calibrated estimation of national bag size, using GWCT's National Gamebag Census
The Game and Wildlife Conservation Trust's National Gamebag Census (NGC) has been collecting voluntary bag returns from shoots across the UK since 1961. Methods similar to the ones used for bird census data are applied to NGC data to derive annual bag indices for the UK, assess temporal trends and evaluate changes in bags over 50, 25 and 12 years for 30 bird species and 15 mammal species, as well as for numbers released of four bird species. Total UK bags and numbers released in the 2004 and 2012 seasons are obtained by splitting up aggregate bags from two independent surveys (PACEC 2006, 2014) in relation to their NGC species composition. These are used to calibrate NGC species-specific bag indices and obtain estimates of total UK bags and numbers released for the 2016 season. Over 50 years, large changes have taken place in the bags and numbers released of some species whereas bags of others have remained approximately constant. This work contributes to pan-European efforts seeking a rational assessment of hunting effects within a policy combining conservation and the sustainable use of wildlife, in line with national and international legislation.