Page:Territory in Bird Life by Henry Eliot Howard (London, John Murray edition).djvu/331

Rh return to the coast or tidal estuaries for the remainder of the year. Here, at low water, they find an abundant supply of food—crustaceans amongst the sea-weed upon the rocks, and lobworms (Arenicola piscatorum ) in the mud as the tide advances or recedes. But when the tide is full, they retire to those parts of the shore that remain uncovered—to isolated rocks, or to sanddunes, or it may even be to pasture-land in the neighbourhood. During this period of repose large numbers of individuals gather together on a comparatively small space of ground. They are not constrained to do so by any shortage of accommodation, nor by any question relative to food, nor, for the matter of that, by any circumstance in the external environment; they are brought together solely, this at least is the impression that one gains, by some inherited impulse working towards that end. And their subsequent course of behaviour tends to confirm that impression. For if we watch the gathering together of the different units of which the flock is composed, and study more particularly the emotional manifestation which accompanies their arrival and departure, we shall find that the coming of a companion arouses some emotion which is expressed by a vocal outburst that sweeps through the flock.

Now each call, and the Curlew has a great variety, is not only peculiar, generally speaking, to certain occasions, but is accompanied by a specific type of behaviour, whence we can infer in broad outline the type of emotion which is