The Raven by Ratcliffe Derek;Rose Chris;

Author:Ratcliffe, Derek;Rose, Chris;
Language: eng
Format: epub
Publisher: Bloomsbury Publishing Plc
Published: 1997-11-15T00:00:00+00:00

18. Nest in a traditional site on the Raven Crag shown on p. 141 being examined by Geoff Horne (photo: D. A. Ratcliffe)

Ravens are quite adept at building a nest on small or sloping rock ledges or tree limbs, where it would seem to the human eye that there is insufficient lodgement for such a structure. A few are, indeed, insecure and easily toppled by high winds or a careless human visitor. A Raven nest is nevertheless often a remarkably solid and durable structure, and the weathering of the base of an old eyrie helps to solidify the foundations. Nests from which young have fledged tend to disintegrate more quickly if they are not subsequently rebuilt, for they are usually trampled almost flat by the youngsters before they fly, and their droppings tend to promote decomposition of the nest materials. When nests are rebuilt, the older sticks at the base are often green and decaying, in contrast to the fresh material of the current year. A nest in which eggs have not hatched can last for quite a long time – 10 years at least, and perhaps a good many more in dry, sheltered rock sites. Sometimes, however, nests in well-protected sites disappear between the end of summer and the following nesting season, and it appears, from the litter of sticks below, that they have been pulled down. Birds from non-breeding flocks have been seen to destroy nests (Davis & Davis, 1986; Hurrell, 1956) but, in most instances, it is impossible to know whether such dismantling has been done by intruders or the owners themselves.

Raven nests have the reputation of being difficult to reach, but much depends on site availability, whether in rocks or trees. When the choice of situations allows, Ravens will nearly always build in a site that is awkward of access to a human or an animal predator. Yet, where the choice of sites is more limited, the birds will often take their chance with easily accessible nests, rather than forgo the opportunity to breed.

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