Ups and Downs of Spotted Woodpeckers
News from the BTO
26th June 1996
The woodpeckers of Britain include two which are basically black and white - with some red on them. These are the Great and Lesser Spotted. The Great is about the size of a Starling and the Lesser only that of a House Sparrow. Results of the Common Birds Census, published in the most recent copy of the newsletter of the British Trust for Ornithology, show that their fortunes over the last 20 years could hardly be more different.
The Common Birds Census documents the populations of birds breeding in Britain annually from detailed plotting of numbers at over 200 sites nationwide. Both species increased during the 1970's. Great Spotted probably three-fold and Lessers at least doubled. This increase, in both species, may have been helped by the huge amounts of dead wood created by the epidemic of Dutch Elm disease. However from their peak in 1979 Lesser Spotted Woodpeckers their population has dropped to almost a quarter of this level. Greats, on the other hand, have increased further - by about 50%.
In 1979 there were about four Great Spotted Woodpeckers on CBC plots for every Lesser territory registered. Now there are about 20 Greats to just one Lesser. These results are backed up by the first analysis of the new monitoring scheme just set up by the British Trust for Ornithology. From the Breeding Bird Survey with 1,500 100 hectare plots through the country there were 678 Great Spotted Woodpecker registrations and only 23 Lessers. A ratio for 1995 of about 30:1.
It would seem that the clearance of masses of dead wood after the elms died has harmed the prospects for the smaller species. Great Spotted are much more capable of demolishing large branches and even tree trunks themselves to get the biggest insect larvae. They are also becoming very regular feeders in gardens at fat and other food offered for the birds. This is a habit that the Lesser Spotted eschews - to it great disadvantage.