8 THE SURROUNDINGS OF 



green woodpeckers, a bird to whose habits the district 

 was well adapted. This is difficult to explain, but was 

 possibly connected with a recurrence of very severe 

 winters, which kill these birds in great numbers by 

 preventing them from feeding on the ground, as they 

 are much in the habit of doing. On the other hand, 

 the lesser spotted woodpecker, in many parts of England 

 regarded as rare, is at Lilford the commonest species 

 of the three ; and Lord Lilford has this interesting 

 note upon them : ' — 



" In the first sunny days of February, and sometimes 



even earlier, the loud, jarring noise produced by this 



species may be heard amongst the tall elms and other 



trees closely surrounding Lilford, often proceeding from 



two or three birds at the same moment, and continued at 



intervals from daylight till dusk. From long and close 



observation we long ago convinced ourselves that this 



noise is a call, and has nothing to do with intentional 



disturbance of insect food, as has often been supposed 



and stated ; nor is it produced, as we with many others 



formerly imagined, by the rapid vibration of the bird's 



beak in a crack of rotten wood, but simply by a 



hammering or tapping action which the human eye cannot 



follow. On a calm day, or with a light, favouring 



breeze, the sound then produced may be heard at a distance 



of quite half a mile, or even more." 



^ The Birds of Northampton shire, i., 271. 



