BIRDS The avi-fauna of the county of Essex is rich in respect both of number of species and abundance of individuals. From the ornitholo- gist's point of view indeed the county has been favoured in many ways, both by Nature and by circumstance. Essex is, in the first place, a maritime county, and as such it possesses naturally a far richer avi-fauna than any inland county, however large. It is also exceptionally well placed, ornithologically speaking, even for a maritime county. Situated on the east coast of England, in close proximity to continental shores, it lies upon the main highway followed by the majority of our migrant species as they pass and repass across the North Sea. Furthermore the county is of great extent, covering some 1,542 square miles and standing, in respect of area, tenth among the English counties. Its surface is considerably diversified, and therefore offers attractions to many different species. The regions or districts into which the county may be divided, according to its natural and physical features, require brief notice. First come what may be called the lowlands, covering probably at least two-thirds of the county and occupying the whole of its central portion. This is, for the greater part, a region of stiff clay mainly the London Clay, though this is overlaid in places by the Chalky Boulder Clay. It presents everywhere the same features, with very little varia- tion. It is, and long has been, generally under cultivation, a small pro- portion of pasture mingling with a much larger proportion of arable land. In all parts old hedgerows, wide overgrown ditches and quiet lanes abound, while there is a large number of small copses. These afford homes for innumerable warblers, finches, and other small birds. Interspersed throughout this region, and forming strictly speaking a part of it, are several fairly extensive stretches of forest and woodland. The aggregate area covered by them is not however very large. They occupy for the most part the high ground and hill-tops, where the pre- valence of Bagshot Sands and gravels renders the soil of little value for agricultural purposes. Such are Epping Forest (about 6,000 acres), in the south-western portion of the county ; Takeley or Hatfield Forest (about 1,500 acres), near the western border ; the Writtle High Woods and the woods around Danbury and Little Baddow, near the centre ; the Bull Wood at Hockley, in the south-east ; the woods around Thorndon Park ; and others of less extent elsewhere. These still form a home for many woodland species, but the hand of the game preserver has greatly reduced, even exterminated, many others, especially the larger birds of 232
