Tuesday, September 8, 2009

Rock Wren Nest's

A correspondent sent me through this extract from Herbert Guthrie Smith, a famous New Zealand naturalist and author of the classic "Tutira".



"Guthrie–Smith, H., Sorrows and Joys of a New Zealand Naturalist, 1936.



Extract
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The orifice of the nest pierced into a fibrous mass of overhanging roots. Partly within and partly beneath this densely matted live growth was built the nest. As we discovered afterwards when ransacking the deserted structure, its remarkable bulk was composed of skeleton leaves, finely shredded grass, and feathers. On this comfortable cushion — the feathers were laid most thickly on the bottom of the nest, or, rather, within this overarching bower — reposed the chicks.



Of the 791 feathers counted, over seven hundred were those of Ocydromus australis (weka), and perhaps O. finschi and O. brachypterus. There were feathers also of considerable numbers of the kakapo and kiwi, showing how high these species ascend in their alpine wanderings; there were also a few kea and a few pigeon feathers. When counted by us, in spite of the deluges of the two preceding days, the interior of the nest and the feathers themselves were fresh and sweet, they betrayed no signs of mould or damp.



Unlike the bush wren which is constantly taking dry feathers in and wet feathers out both during incubation of the eggs and rearing of the young, the rock wren seemed to prefer to make a thorough job at the beginning. Warmth and dryness are obtained once for all by bulk of material, the natural oil of the feathers massed together helping to exclude any dampness that might penetrate, firstly through the live root mass, and, secondly, through the exterior shield of shredded grass and skeleton leaves.



Really interesting stuff. It would be tempting to think that the absence of weka, the vacumn cleaner of the New Zealand forest might have a positive aspect for rock wren, but maybe not! Below is a photo we took of a weka on a recent trip to Kapiti Island.



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