There are plenty of surveys that concentrate on birds in the breeding season, and a lot of effort goes into ringing and tracking birds on migration, but what happens in winter? The Gloucestershire Winter Bird Survey (GWBS) aims to monitor the abundance and distribution of the county’s birds in this less-considered season.
The survey takes place each November and each February. Volunteers visit randomly-allocated one-kilometre squares on any morning in November and record every bird found in a two-hour period. The same thing happens again in February, when a new square is allocated – birds move around more in the winter compared to the breeding season. Depending on how you count Gloucestershire’s borders there are almost 3 000 squares.
The survey has been running in this form since the winter of 2014-15, with a single year gap for lockdown in 2020-21. The data is sent to the County Bird Recorder, the Gloucestershire Centre for Environmental Records and the British Trust for Ornithology.
There have ben 133 species recorded – give or take a couple, depending on how you count Feral Pigeon, White Dove, Domestic Duck and the like. Up until 2023-24 the most common bird has been Woodpigeon at 68 081 birds recorded, with Starling a distant second at 42 294.
At the other end of the scale there have been species where only a single bird has been recorded in the entire survey: Great Grey Shrike, Grey Plover, Kittiwake, Short-eared Owl, Wheatear, White-rumped Sandpiper and Yellow-legged Gull.
This survey is a good way for people new to birding or wildlife surveying to get their eye in. Nearly all the birds you record will (necessarily) be common ones. If you are interested in taking part please email glosbirdsurvey@btinternet.com