Abstract
Poole Park is Dorset’s only known moult-gathering site for Greylag Geese Anser anser, with around 200 geese utilising the park during the summer months. However, movements of these geese away from Poole Park were poorly known. A colour-ringing study during 2019–21 has shown that birds make only short-distance movements away from the park, with no movement of more than 16 km recorded. There was no significant difference in the distances moved between birds ringed as adults and birds ringed as juveniles. A high proportion of birds were recorded moving east, into Hampshire.IntroductionDespite being a widespread and familiar species, the Greylag Goose Anser anser has a relatively complex history in Britain. By the late 1900s, when the population had been decimated by hunting, the breeding range of the species in Britain was restricted to north and west Scotland. Populations were re-established in southern Scotland, Wales and areas of England during the 1930s–1960s (https://monitoring.wwt.org.uk/our-work/goose-swan-monitoring-programme/species-accounts/british-greylag-goose). With reduced hunting pressure, the species has continued to increase and spread in Britain, and the re-established populations have now merged with the northern and western Scottish populations. Together, these birds form a single British population of Greylag Geese, estimated to be around 140,000 individuals (Frost et al. 2021). The population continues to increase, with a 21% rise in numbers between 2009 and 2019 (Frost et al. 2021). Numbers of Greylag Geese in Britain are bolstered in winter by migrant birds from the Icelandic population, of which around 60,000–90,000 winter annually (Brides et al. 2021; Frost et al. 2021); this population is not discussed further in this paper.Movements within the British populations of Greylag Geese are surprisingly understudied, although several colour-ringing projects do exist – for example, in Cumbria, Gloucestershire, Greater London, Norfolk and Yorkshire (Brides et al. 2019). A small number of Greylag Geese breed in Poole Park, Dorset, and adult birds gather at the site in late summer to moult. This is the only know site in Dorset where Greylag Geese gather like this to moult – elsewhere in the county, moulting birds are those that have bred or summered locally. Although it was known that birds moved to Poole Park to moult, it was not known how many birds were coming to the park, nor if these moulting birds were using the park at other times of year. Anecdotal evidence from birders in the local area suggested that Greylag Geese did not use Poole Park throughout the year, and that numbers fluctuated, with geese occasionally being absent entirely. However, given the often-lacklustre feelings that many birders have towards Greylag Geese and the lack of any systematic study, it wasn’t clear whether there really was a pattern of temporal movements by birds at the park or whether they were simply being ignored or overlooked for parts of the year. Additionally, if birds were moving out of Poole Park after moulting, it was unclear where they were going to.