NATURE NOTES

Evening Post, Volume CXXVI, Issue 134, 3 December 1938, Page 17

NATURE NOTES

WORK OF VERMIN

WARBLERS' NESTS

DESTROYED

(By R. H. D. Stidolph.)

Although it has been stated by. som« writers on New Zealand native birdlife that the grey warbler, on account of the type and situation of it* nest, is able to escape the depredation of vermin, the writer has found this belief to be far from being the case. Several nests of the grey warbler that have been under observation in the last few years have been visited by vermin of some kind, and either had their contents removed or portion of the nest torn away. In some instances only one egg is removed at a time, though the full complement is eventually taken. When the first egg is taken the birds usually desert the nest. This, unfortunately, is what has happened to the warbler's nest containing two eggs of the warbler and one of the shining cuckoo, and, as fate decreed it, it was the cuckoo's egg that disappeared first. These depredations are probably the- work of rats. In other cases 4n which the back or bottom of a warbler's nest is pulled away so as to expose the contents, the writer is not sure as to the identity of the culprit. In any case, there is no doubt that a considerable number of warblers' nests are destroyed in this way. CUCKOOS ALSO SUFFER. The nests that suffer most are not always those located in the more access* ible places. Some placed well up towards the top of a slender-growing' manuka have been found with their * sides torn out, while in other instances nests built low down, not more than five feet from the ground, have escaped the attention^ of these unwelcome marauders and the young have been reared successfully. Not only does the warbler itself suffer, but the shining cuckoo's eggs and young likewise are frequently destroyed. During the last two or three years, out of several nests of the grey warbler in which a cuckoo's _egg had been deposited, not one young cuckoo was reared. One cuckoo chick, after it had thrown out the tiny young warbler, which was found dead caught in a fork of the shrub some inches below the nest, was itself seized a few days later by a bloodthirsty creature that made a small hole in the back of the nest in order to reach it. Another fair-sized young cuckoo met with disaster when the nest was unable to stand the strain of the additional weight and .., broke away in a gale. In other cases the eggs have been taken, so that it can be seen that there is a considerable mortality among the warbler and cuckoo population. , A NIGHT VISITOR. Has any reader of this column ever heard a bird calling out as it flies overhead during the night? There is reason to believe that in the Wellington district at least one species of petrel may be heard under these circumstances. Its notes are not unlike the somewhat peevish cry of the pukeko, a familiar swamp bird. The pukeko itself also flies at night and it is possible that in any locality both the pukeko and a second bird, the identity of which is unknown, may be responsible for these calls. In earlier days the black petrel, one of the rarest species occurring in New Zealand or^* anywhere in the world, for that matter, was reported as breeding in the Rimutaka Ranges, though there is appar.ently no known instance of it having any breeding stations itf the Tararua Ranges. It is possible, however, that its haunts have remained undiscovered to this day and it may b,e this species that is one of the birds that call; out in the night, as it makes its way to its mountain retreats. - Incidentally, a young black petrel was found earlier this year, in a Masterton auction mart, whither it had found its way during the night. : THE CHUKOR. Liberated in New Zealand in comparatively recent years, the chukor, a form of the so-called Greek partridge, is reported to have been seen a week' or two ago on the Waiouru Desert road. In its native country the chukof inhabits the hottest and most barren hillsides, although, according to Mr. Hugh Whistler, in his admirable book on the birds of India, it is equally at home on open grassy hillsides in ;the low, hot valleys, on stony screes covered with a light growth of barberry, and amongst the snow at altitudes of 12,000 to 15,000 feet. The conditions which it cannot stand are incessant dampness, heavy rainfall, and forest. There are not many districts in New Zealand in which it would thrive, though the areas around Mount Tongariro and in some parts of Marlborough, Canterbury, and Otago may prove to its liking. Except in the breeding season, the chukor is to be seen in parties or coveys. It is ashy and brow-n in colour and may be at once distinguished by the black loop on the face and throat and the beautiful barring of the flanks'. It feeds and lives on the ground and its flight is very strong and rapid. After having once been flushed it is extremely diffi* cult to make it rise a second time. INTRODUCED THRUSHES. A correspondent living in Ngaio has written asking if the song thrush and blackbird inteif-breed. The answer ■ is that there is no authentic case of such an occurrence either in.the Bri-. tish Isles or in New Zealand. Every now and again reports are heard of these birds crossing, though invariably, when investigations are made, it is found that the female blackbird has been mistaken for a thrush. There is some excuse for the mistake, as the blackbird, unlike its jet-black mate, is quite brown and has a. lighter area on the throat speckled. It is this speckling on the throat that gives rise to the misconception as to the identity of the bird. On the-other hand, the * male and female song thrush are alike. Both Have yellowish-white underparts, ' clearly speckled, and these markings are quite apparent even in young birds. The blackbird and the- thrush, moreover, have much the same'habits and are frequently seen together in the garden. If the nests are examined it will be found that that of the song thrush has the cup plastered with mud or dung and wood chips, while that of the blackbird, although some mud is used in its construction, has the cup lined with grass or some similar material. Introduced many years ago, both the blackbird and song thrush are now ; exceedingly common almost all over New Zealand.