Friday, 6 March 2009

Antics in the tree-tops

It may seem a little early but the Great Spotted Woodpeckers at West Stow are just starting their breeding season. As well as the familiar drumming, there is plenty of chasing as rival males cavort through the tops of trees uttering short, sharp sounding calls. Breeding proper will not begin until April but the courtship taking place now may have been initiated back in December.

The birds usually only pair for a single season, choosing to maintain individual feeding ranges once the business of rearing chicks has finished, but pair bonds lasting up to three years have been recorded. An established male will tend to retain ownership of his breeding territory from one year into the next, drumming from favoured trees in an attempt to attract a mate. If successful, the pair will cement their bond and excavate a new nest hole into which the eggs will be laid.

Great Spotted Woodpeckers are not the only species to be drumming at the moment; although less common, Lesser Spotted Woodpeckers may also be heard, their drumming somewhat weaker and of more even tempo. The changing fortunes of these two species have been rather different, with great spots increasing and lesser spots in decline. The sparrow-sized lesser spot seems to have been constrained by being more selective in its requirements than its larger relative. Great Spotted Woodpeckers have shown their adaptability by exploiting garden feeding stations and also the rich protein available from wooden nestboxes used by nesting tits. Lesser Spotted Woodpeckers feed almost exclusively on invertebrates, taken from the surface of bark during summer and extracted from dead wood in the winter. Our increasing tendency to remove dead wood and to maintain over-tidy woodlands may have reduced the amount of invertebrate food available to the species, bringing about the pronounced decline witnessed since the early 1980s. Great Spotted Woodpeckers exploit a wider range of foods, including tree seeds, and this may have helped them to do well, buffering the effects of changing woodland management practices.

Early spring is a great time to catch up with these two woodpecker species. With their breeding seasons and associated courtship behaviour in full swing, there is plenty to see. Not only are they especially vocal at this time of the year but there is virtually no foliage on the trees to mask their courtship behaviour from prying eyes. Choose a bright, warm and still day and take a wander along a belt of mature trees or through one of Norfolk’s blocks of deciduous woodland. One of the best places to try is Holkham Park, particularly the woodland to the right of the entrance and around the lake. Here you are likely to encounter both species.

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