Why do we age the geese? Assessing the proportion of young birds present in wintering flocks enables us to estimate the annual breeding success of the UK’s Dark-bellied Brent Goose population. In turn, this can help us understand why any changes in the abundance of the population have occurred.
How do we age the geese? Like many other goose species, during their first winter young Dark-bellied Brent Geese can be easily separated from adults by differences in plumage characteristics. Counters are, therefore, able to record the proportion of young birds by scanning through a flock and checking as many birds as possible for these particular plumage features. An assessment of brood size can also be made, either during this flock scan or afterwards – this gives us an estimate of average brood size for all the families in the flock.
Dark-bellied Brent Geese are found at numerous locations throughout the UK and the counter network does an amazing job of covering many of the key areas. Inevitably, however, gaps in coverage appear from time to time, particularly when counters retire or move away. Therefore, in order for this important work to continue we’d like to expand the counter network and coverage of sites, particularly in the areas around Chichester and Langstone Harbours (Hampshire/West Sussex) and Hamford Water (Essex).
If you are interested in contributing to the survey it would be great to hear from you. Please get in touch by using the online contact form or by e-mailing firstname.lastname@example.org for further information. Please note, it is important that counters are confident in identifying young (first-winter) Dark-bellied Brent Geese and understand the methods for sampling flocks – we can of course provide further details.
Age assessments are carried out annually and results from these surveys can be found on the species account pages. For further information on age assessments and what is involved, please visit the Get involved page.
We look forward to hearing from you!