Some further notes on the BTO Atlas

I have been recording in the five tetrads (SY C, H, M, S & X) that form a strip extending from Park Farm and Great Trill in the east, through Musbury, Whitford, north Colyton and Colcombe to Southleigh in the west. This is perhaps less exciting and less varied than the areas that Donald has been surveying; most of it is lowland farmland, with some coniferous plantations and few natural deciduous woods, although there are plenty of hedgerow and streamside trees. I have also been able to spend only one hour in each tetrad (two in M), although I have made additional visits to accumulate roving records. For obvious reasons, my home tetrad of Musbury is the best worked, with 52 species.   

So how do my results compare with Donald’s? I have recorded only 40 species in total in my 6 hour-long timed counts. This is probably because Donald’s patch includes the estuary as well as some good areas of woodland and also of arable farmland. Some of his common species I have not recorded at all. Skylarks are absent from the low-lying grass fields of the Axe Valley, but common on the higher arable behind Axmouth. Meadow Pipits are also scarce in my patch, although I came across one flock in a field of bullocks being fed hay. Worryingly, I have not recorded a single Goldcrest. Is this because my hearing has deteriorated so that I can no longer pick up their calls? But I would have surely seen at least one in the bare branches if they had been there.

More reassuringly, some of our results are pleasingly similar. I have recorded 17 Blackbirds per hour; Donald, 18. We have both recorded six Pheasants and six Longtailed Tits per hour. Donald sees 28 Woodpigeons per hour; I see 15. The difference may be random, because Woodpigeons tend to be in big flocks, or they may be genuinely commoner on Donald’s ground where there are more arable crops. The extra availability of spilt grain and seeds in the arable areas may also explain why he sees more Chaffinches (19 per hour) than I do (12 per hour). I see slightly more House Sparrows (13 per hour against Donald’s 10). I see more Rooks (62 per hour; Donald 21) and Jackdaws (19 per hour; Donald 16) than he does – Rooks and Jackdaws tend to feed in sheltered grass fields rather than in open arable. Other species are too scarce for meaningful comparisons, but as we both accumulate more timed visits, we should be better able to understand the apparent differences between bird populations in the various parts of our area. 

[The cover illustration of Newsletter 65 (as above) shows a robin superimposed on the 10 x 10 km square SY 29, with the tetrads within it lettered using the DINTY convention (see Newsletter 64) and containing the numbers of robins seen in one-hour timed tetrad walks in February. (Robin picture by Kevin Baker, from ‘Robins’ by Chris Mead. Whittet Books 1984). ]