312 TIMELIID^. 



During the past seven years, in the neighbourhood of Middle Harbour and Lane Cove 

 River, I have had frequent opportunities of observing the habits of this species. It is usually 

 met with in pairs, and resorts chiefly to the vicinity of rocky ravines and gullies, and is never 

 found far away from permanent water. In actions it is extremely lively, and it passes with 

 great rapidity over the surface of rocks and fallen logs. Only on two occasions have I seen it 

 perch on a branch, and then when I was in the vicinity of their nests. 



It is strictly insectivorous, and most of its food, wiiich consists of small moths, is 

 captured in the crevices of rocks. 



The clear notes of this bird, which are uttered at intervals, resemble those of Sencoi'itis 

 frontalis, more than any other species, but are much louder. ^ . 



Caley's vernacular name of "Cataract-bird" is a more appropriate one for this species 

 than that of " Rock Warbler," for its nests are almost invariably built in close proximity to 

 running water, and it cannot by any means be regarded as a warbler. During the late spring 

 and summer months, when many of these small mountain rivulets cease to run, these places 

 are abandoned by the birds for more favoured localities, water apparently being essential. 



Owing to the peculiar situations resorted to by these birds as nesting-sites, — several within 

 half-a-mile of my house, — I have paid particular attention to their nesting habits. 



The nest of the Rock Warbler is a dome-shaped structure with a rounded entrance in 

 the side, occasionally more or less protected with a hood. The walls are formed of short 

 strips of bark or bark-fibre, which are externally coated with fine green moss and a slight 

 addition of cob-web and the silky covering of the egg-bags of spiders. As a rule, at the bottom 

 of the nest inside, it is sparingly lined with feathers; but several I have examined, containing 

 eggs, were lined only with fine bark-fibre. An average nest, found by me at Roseville, 

 measures ten inches in length by four inches and a half in breadth, and across the entrance 

 one inch and a quarter. The upper portion of the nest, where it is attached to the ceiling of 

 the cave, is formed almost entirely of cob-web. In some nests there may be two or three inches 

 of the upper portion fastened to the rock; in others I have seen the top run to a point no 

 thicker than a pen-holder. Typically there are only a few inches of nesting material above the 

 domed portion of the nest, but it varies in length considerably, even in nests built by the same 

 pair of birds. A nest taken by Mr. R. Grant, at Lithgow, was abnormally long and measured 

 three feet over all. The upper portion of it was very thin, and it is remarkable that the 

 material of which it was formed did not pull asunder by the weight of the nest. The nest is 

 usually attached to a flake of rock in the roof of a cave or rock-shelter, and preferably in those 

 close to running water. The nests I have found were mostly built in partially darkened chambers, 

 sufficiently large to walk into erect, or in a slightly stooping posture; others in crevices I 

 could just manage to crawl into; and one where the entrance was only a foot from the ground. 

 A favourite place, judging by the nests found at various times, and the remains of others, was 

 under the rocky sides of a deep well-like hole in the bed of a creek near Middle Harbour. 

 Around this place, which resembled the crater of an extinct volcano, one could walk in a 

 slightly stooping position or crawl for a distance of fifteen to twenty feet, and in the most 

 obscure parts of it the nests were built. Low shallow rock-shelters, over which water con- 

 tinually drips, partially hidden by low ferns and other moisture-loving vegetation, are used as 

 nesting-sites; also cavities formed by large masses of rock placed one against another. About 

 coal-mining localities in the Blue Mountains, it is frequently fastened to the timbers in the 

 roof of disused tunnels. .At Jenolan there is one attached to a stalactite in the Nettle Cave. 

 Once I found two nests within a foot of each other, but one was, judging by its appearance, 

 probably the work of the same pair of birds during the pre\ious season, .^s a rule they are 

 built within a few feet of the ground, and seldom out of hand's reach. I have never found 

 more than one tenanted nest in the same cave or rock-shelter. I found the very same nesting- 



