THE NESTS OF • THE SONG THRUSH AND 



BLACKBIRD. 



By WILFRED MARK WEBB, F.L.S. 



Chairman of the Brent Valley Bird Sanctuary Committee. 



Many of the blackbirds and thrushes which nested 

 in the Brent Valley Bird Sanctuary during the past 

 spring and summer built in interesting positions, 

 and a short account of a few of the sites will be 

 given here. 



The first nest to which we may allude was that of 

 a song thrush which was built against a flat-sided 

 post about two feet from the ground. The interest- 

 ing part about the structure, however, is that there 

 was practically no material used on the side towards 

 the post, but it appeared as shown in Figure 368. 

 The hollow was therefore not circular and the nest 

 recalled that of a martin, which is built against a 

 wall. 



In connection with the height of this nest from 

 the ground, it may be mentioned that both blackbirds 

 and thrushes have at various times actually placed 

 their nests directly on the earth, though until the year 

 1912 it was noticed that the birds were usually 

 unsuccessful in rearing their young. In that year, 

 however, a song thrush which constructed a well- 

 hidden nest under some brambles, brought up five 

 young ones, and this spring four young birds flew 

 from a very similar nest which probably belonged to 

 the same old birds. 



Our second illustration (see Figure 369) shows 

 one of the same kind of bird sitting in an old kettle 

 which in previous years has found favour with robins 

 and with wrens. Blackbirds have chosen a similar 

 nesting-place in the Sanctuary, but this is the first 

 time that a thrush has contented itself with such 

 restricted accommodation. The hen bird, it may be 

 mentioned, like others which have chosen artificial 

 surroundings, was very tame, and when perching on 

 the branch outside the kettle would allow us to stand 

 within a couple of feet of it. 



Four or five years ago an old pail was lodged in 

 the fork of a large hazel branch, and during successive 

 seasons since blackbirds have built in it, sometimes 

 rearing two broods of young ones (see Figure 370). 

 Another pair of these birds built a very substantial 

 nest in the disused paint pot which is seen in 

 Figure 371. But some enemy or other interfered 

 with the eggs and the nest was deserted. 



Some years ago a thrush took possession of the 

 top of one of the rough closed nesting boxes with a 

 sloping roof put up for smaller birds, and completed 

 its work of building in a little over a week, but the 

 nest slipped off the box and came to grief. 

 This year, two nests were found in similar positions 

 and these remained quite steady, tree sparrows 

 taking possession of the insides of the boxes. One 

 of the nests is shown in Figure 372, and the box is 



becoming quite an historical one. It was occupied 

 by the first pair of nuthatches which were recorded 

 as breeding in the wood, a wryneck has laid in it, as 

 well as tits and tree-sparrows. 



Quite close at hand, another thrush brought off 

 her brood on the top of a hurdle inside the shed in 

 which the keeper was at work. 



For the benefit of robins and flycatchers nesting 

 boxes made of hazel branches with open fronts have 

 been put up, and on two or three occasions have 

 been taken possession of by blackbirds, with complete 

 success. One of these, which was occupied during 

 the past summer, is shown in Figure 373. Once or 

 twice song thrushes have begun operations in similar 

 receptacles, but they have not completed their work, 

 probably because there is too little room, and as they 

 twist round in nest-building their tails catch against 

 the sides of the box. 



Seeing that blackbirds and thrushes will take to 

 artificial nesting-sites such as have been mentioned, 

 and that bird lovers who were anxious for these 

 birds to nest with some amount of security in their 

 gardens had made enquiries, members of the Bird 

 Sanctuary Committee were led to try the experi- 

 ment of making special arrangements for these birds. 

 Both species very commonly build on the small 

 twigs that grow out from the lower parts of tree 

 trunks, and trays and baskets were made of thicker 

 or thinner branches and nailed up like brackets in 

 their positions, as well as flat trays, which were 

 nailed on the upper sides of horizontal branches. 

 Very few of the latter were used, but as the others 

 became weathered and the artificial look wore 

 off, they came to be occupied more and more 

 generally, until this year probably ten or a dozen 

 were used. 



The first one of which use was made some time 

 ago was of the type shown in Figure 375, where the 

 trays were fastened to a board and supplied with a 

 roof of the same material. This covered bracket 

 tray forms a very snug nesting site and during the 

 winter a field-vole made a roof of moss to the 

 deserted nest, and bored a small round hole in the 

 mud lining, making himself very cosy winter 

 quarters. In Figure 375, just mentioned, some 

 young thrushes of this year can be seen. 



Another type of bracket is similar to the last 

 described, but instead of having at the back boards 

 and a roof, the tray is simply fastened to two vertical 

 piecesof split branch, theflatsides being put againstthe 

 tree and those with the bark on away from it. Still yet 

 another kind resembles the baskets which are made 

 for ferns. This is shown in Figure 374 and contains 



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