62 Zoology 



This roosting habit is of interest in that there is no native European tree 

 that has a bark sufficiently soft to allow of it, yet, since the introduction 

 of the Sequoia in 1853, the habit has become established throughout the 

 British Isles. Where undergrowth is found, buHfinch, goldfinch and 

 hawfmch breed, and the nightingale, lesser redpoll, and spotted fly- 

 catcher also occur ; wliile, most notable of all, is the recently established 

 nesting of the black redstart in the centre of the town. 



The trees of Cambridge also provide nesting sites for the rook, which 

 is so common that the town may be described as one large rookery. 

 While at Madingley Hall, a few iniles to the west, is a rook roost which 

 accommodates 15,000 or more birds in winter: here come the birds which 

 feed within a radius of six to eight miles or more. 



There are also starUng roosts in the district, some accommodating as 

 many as 120,000 birds, but these sliift very considerably and the Annual 

 Reports of the Cambridge Bird Club should be considted for details. 



The natural vegetation of the chalk upland with its occasional beech 

 woods is found at Royston Heath, Newmarket Heath, and in very 

 restricted portions of the Gogmagog HiUs.' The characteristic birds here 

 are the woodpigeon, skylark, meadow pipit, and corn bimting. Stone 

 curlews nest regidarly in small numbers, and quails breed in some years — 

 mere remnants of their former vast hordes. In winter, bramblings frequent 

 the beech woods in considerable numbers. Elsewhere, the chalk country 

 is under crops, and birds are sparse, though large flocks of lapwing, golden 

 plover, redwings, and fieldfares are a feature of the whiter landscape. 



East of Newmarket Heath, hes that great area of sands, gravels and boulder 

 clay, the Breck country, occupying 400 square miles of Norfolk and 

 Suffolk, and bordering Cambridgeshire.* Its barren sandy heaths and 

 pine woods are characterised by stockdove, woodlark, nightjar, wheatear, 

 stone curlew, and crossbill. There is also that curious inland breeding 

 "race" of ringed plover wliich perhaps represents a rehc of the littoral 

 fauna of the old Fen Estuary. The Forestry Commission is however 

 rapidly altering the aspect of much of this country,^ and this close planting 

 has had considerable effect upon the distribution of certain species."* 



The last and the most characteristic type of country in die Cambridge 

 district is, of course, the Fenland. By far the greater part of this area is now 

 under cultivation, and the corn bunting, sedge warbler, reed bunting, and, 

 more rarely, the corn crake, are among the characteristic species. The 

 tree sparrow and magpie are also abundant — in unexplained contrast to 

 their comparative scarceness south ot the Cambridge-Newmarket road. 



' See p. 57 above. ' See p. 208 below. ^ See p. 217 below. 



t D. Lack, "Habitat Selection in Birds", Jouni. Animal Ecology, ii, 239 (i933)-- 



