In the breeding season, birdwatchers usually need to visit a favourite, wetland birdwatching spot to find Reed Buntings but at this time of year birds pop up in gardens, with 3% of BTO Garden BirdWatchers reporting them in the latter half of March. Where are they during the rest of the year? In this month’s Bird of the Month article,we show how Breeding Bird Survey figures and winter Bird Atlas maps provide complementary information about the Reed Bunting, an amber-listed species of conservation concern.
Reed Buntings move out of wetland in the late autumn and spend the winter on farmland. They are looking for small seeds, typically those of weeds rather than the bigger cereal seeds, and these can be found in unsprayed stubbles, game-cover strips and, in some parts of the country, sugar-beet fields.
Once arable fields have been ploughed and sown for the next season there is no food left for Reed Buntings, Yellowhammers and finches. At this stage, birds are associated with crops such as sugar beet and fields sown with seed mixes that are designed to provide extra help at this tough time of year. Fortunately, the sugar beet harvest continues much later into the autumn and winter than other farming operations and there is much more tolerance of weeds in the crop; both of these features suit the Reed Buntings very nicely. While the crop remains in the ground, they can feed amongst the rows of beets and then, until the land is prepared for the next crop, there is an open field with scattered seeds of species like Fat-hen to keep them satisfied.
By March, however, sugar beet fields have been cleared and ploughed and many Reed Buntings turn to garden feeding stations, in search of small seeds like linseed, rape-seed or sunflower hearts, provided on the ground, in relatively open areas, or in hanging feeders.
The Reed Bunting was previously red-listed as a species of conservation concern, due to the rapid declines from the high numbers of the 1970s, and is now amber-listed, after a period of recovery.
Combining the Common Birds Census and Breeding Bird Survey results over the period from 1983 to 2008 reveals a 28% increase in breeding numbers. The ends of this period match with the two winter atlases of 1981-84 and 2007-11.
In the map alongside, Reed Buntings were located during both winter atlas periods in the blue shaded area, with blue upward-pointing triangles indicating gains and black downwards ones losses.
Interestingly, Reed Buntings can now be found in the winter months in many more upland squares than 30 years ago. Why? Some of these areas may have received better coverage during Bird Atlas 2007-11 than in the first winter atlas. Alternatively, “winter” gains may reflect birds returning to marginal upland breeding grounds earlier in spring than they have in the past.
One of the new suite of maps being used to tell the stories coming out of the Bird Atlas 2007-11 project, shows local trends in relative abundance, as indicated by change in the proportion of surveyed tetrads which contain birds.
On the map, 20-km squares shaded grey/black indicate ever greater local declines whereas pink/red areas show local increases. Using timed tetrad information in this way provides a finer degree of information, beyond the absolute gains and losses of the distribution change maps.
The map alongside is an interesting tapestry of salmon and grey. Reed Buntings are faring really poorly in southern counties (as are many species) but what lies behind the expansion between 1988-91 and 2008-11 in many parts of Ireland, eastern Scotland and counties such as Cambridgeshire and Lincolnshire?
Working out why the numbers and distributions of a whole range of species have changed over the last forty years is an important next phase for BTO sceintists involved in the Bird Atlas project.
Recent changes for Reed Buntings
Birdwatchers haven’t stopped watching birds just because Bird Atlas 2007-11 has come to an end – which is great! Many are now entering their records using BirdTrack, a project run by BTO with partners RSPB, BirdWatch Ireland and SOC. The species is reported on up to 25% of bird lists, reflecting our tendencies to watch birds in wet places, presumably?
During winter days, Reed Buntings are hard to count. A flock of birds on a sugar beet field may include one thousand or more finches, with just a few buntings hiding in their midst. In the evenings, however, they often exchange fields for reed beds, roosting together in large numbers, which makes counting them somewhat easier. At the RSPB’s Fowlmere Reserve in Cambridgeshire, for instance, up to 500 birds have been gathering each evening this winter – and there was a maximum count of 1,200 two years ago.