Page:The Zoologist, 4th series, vol 2 (1898).djvu/531

Rh regularly have a second nest. It is not, I think, difficult to see why they respectively lay their five and ten eggs a season, and neither more nor less. These birds, resident and migratory alike, feed their young on various forms of insect-life—flies, grubs, aphides, the smaller kinds of caterpillars, and the ova of these insects. The two parent birds would be unequal to catering for the wants of a larger brood than five; neither could a hen of this size well produce more than five eggs. Indeed, four is not an uncommon clutch by any means in districts where insect-food is not specially abundant. On the other hand, a Blackcap Warbler must produce five young in a season to prevent her species diminishing; and as the breeding season is curtailed by migration, which the young must be old enough to undergo when the time arrives, we see that a smaller clutch would not be convenient. The resident small birds, however—Finches, Buntings, &c.—are not hampered by the approach of the period of migration, and they indulge in a second brood. It is necessary for them to produce eight or ten of their kind in a season to aid in killing off from the cultivated lands the vast swarms of insects to which the summer has given birth, and which the efforts of the parents when feeding have proved utterly inadequate to cope with. Although the Finches thus produce four or five times their own number, yet by the next spring each family of Finches will usually have dwindled down to a pair once more; for what the birdcatcher spares, God and the winter take.

—These birds during the season feed on a very similar diet to those described under 1, and they lay from six to twelve eggs in each nest, though one cannot say definitely how often they have a second brood. Still, taking into consideration the number of Finches' nests that the small boys destroy, I should be inclined to say that the Tits rear more young than the Finches. They are not the prey of the birdcatcher, who annually robs our woods and fields of tens of thousands of Finches. Why then are they so prolific? Simply because they feed mainly on an insect diet all the year round, and in the depth of winter insect-food is scarce and difficult to obtain. I have found a score of Tits lying dead on the snow in a single walk in a winter that was not specially severe, All were dead from starvation, not from cold; their