Xenicus longipes and Xenicus gilviventris
The narrow tracks of the island (Kotiwhenu) originally hewn out by "birders" for their own purpose and from time to time opened afresh, these paths were a boon to us both for convenience of travel and as woodland rides, across which no creature could pass without observation. It was in the light admitted by one of them that a tiny unknown bird fluttered its feeble way late in the afternoon of our first day. About the size of the wren of the Old Country, and as inconspicuous in appearance, the small stranger proved on further acquaintance to be the bush wren of New Zealand.
I waited to see more of the stranger whose proximity could be detected by stir of the vegetation into which it had pitched shivering of fronds, rustle of rough sedge. After many momentary, tantalising glimpses of the bird, which was feeding in company with a mate - I could hear them talking - one of the pair crossed the path, affording a good view, and corroborating what I had suspected as to species. A few minutes later the second bird, evidently the male, followed, and at once became engaged in warfare with another male, these Lilliputans fighting only a few yards from the tree trunk against which I stood. There was something in the air of the victor and in the determination with which he hustled the trespasser of his domain which showed how keen was his desire for seclusion.
In the bird world, too, there are vested interests, and the tenacity with which an owner will uphold his rights usually gives him the victory in anything like an even match. I judged there must be some special reason for my small companion's wrath, and I was right, for by the time my mates had boiled the billy I had thrice noticed one of the pair disappear beneath a particular iron-wood bole. The locality was close to our hut, and during the next two or three days all odd quarter hours and half hours were devoted to the observations and movements of these particular wrens. Thus we discovered there was certainly a pair, male and female, equally often to be found near the great log. Later again we were able to ascertain a certain route constantly followed. At last one evening I spotted one of the pair bearing a feather in its beak flutter up into the gloom of a frond-hung trunk.
Nests of the bush wren are unusually difficult of detection, the openings into them even in good light almost imperceptible. Of the three nests discovered, not one of them was as we had imagined it might be. The first was built somewhere within the mouldering bulk of a huge fallen ironwood already mentioned. Half-way down its dark side, corded thickly with the brown-green vigorous roots of the spotted polypod, was the entrance to the nest. So small was it, even when compared to the size of the little builders, that they could scarcely enter, always having to haul themselves in by many minute, grasping, scrambling movements. The edges of the circular hole, shaded by great dark overlapping fronds, were firmly bound with fibre collected from the durable cores of fallen tree ferns, its dull blue-black hue matching exactly the rooty coating of the log.
The ingress to our second nest was even more difficult to determine. It was actually down a petrel's burrow, an earthy cavern scraped out like a rabbit hole, a vestibule whose disproportionate size made utilisation seem impossible. Although, repeatedly, the wren was lost to sight in its proximity, none of us could credit that so small a creature would enter its nesting quarters by so vast a cavity. The petrel passage was not, however, followed far, the wren relinquishing it for some infinitesimal tunnel passing upwards into the roots of the fern clump which thereabouts covered many yards of ground.
A third nest was found in the rotting centre of a half-dead green tupari - a small tree which in its fall had been wrenched and twisted, and was seemed with longitudinal cracks.
Nothing at first did more to mislead us than the wren's toleration for dampness in its nesting site. With most species dryness is a prime consideration: hollows, holes, and crannies in the least degree moist or clammy are eschewed. Wetness is impossible always to avoid but nearly all species secure as perfect drainage as possible, in rainy districts even seeming to select vegetation that rapidly dries itself. No one. however, of the three nesting sites described was other than damp; one was actually wet. After every shower, into the nest of the ironwood bole, dry feathers were carried in and wet feathers taken out; after every shower in the nest built amongst the fern roots, wet feathers were replaced by dry. The nest in the Tupari trunk was the most sodden of all, pressed, as it were, against green wet wood. reached by a long moist hollow way, and with stagnant water lying within a few inches of the eggs. Into it also dry feathers were carried, and from it wet feathers removed.
The conversational note of the birds amongst the low vegetation, where their lives are passed, is a faint rasping sound, the noise of a small wrist-watch in process of winding. When excited or alarmed they utter a loud cheep.
At the distance of only a few feet, many hours were spent pleasantly, if not profitably, speculating as to the why and wherefore of the lives of these little wrens and as to the enormous terrestrial changes that has forced innovation upon such tiny creatures. The activities of the breed are altogether restricted to movements two or three feet from the ground. They never stray more than a few yards from the tangle where safety lies. Even when close to his own nest, I have watched the male wait and hesitate unable to harden his heart sufficiently to dare to make a forward movement. The lives of the little harmless fellows are overshadowed by an enduring dread - the dread of the robin. Passing from log to log, taking cover beneath each gloomy bole, they listen for the snap of its terrible mandibles; they cower before its swoop.
They are at least as active, however, on their legs as on their wings. The hop of the bush wren is a remarkable performance. During the first salutary movement the bush wren carries himself parallel to the earth; at the termination, however, of each leap he telescopes upwards on his toes, momentarily erecting himself in the oddest way to his full height. When the two movements are blended in rapid action, what with his whitish feet, short toes and long thin legs, and tightly folded body plumage, he resembles in no small degree a barefooted bairn running on sands with tucked-up garments firmly fastened around the waist. He passes through the darkling underscrub like a forest gnome, like a woodland brownie.
In the island wren we may see perchance a minute example of the pressure of a species one upon the other in a congested area. We can picture the wren as he was and as he is. By a very limited exercise of imagination we may visualise him, not confined as now to a few acres on a tiny island, but ranging over the forests of a mainland; not laying a clutch of two eggs, the sign of a failing, or at any rate of a curtailed, food supply; his choice of building sites not relegated to damp chinks and cracks; his domed nest not built in the dark; his flight not limited to a flutter of a few yards; himself during incubation not forbidden the warm precincts of the natural day.
Abridged from Guthrie-Smith's Birdlife on Island and Shore, 1925. Note: The extinction of these wrens is directly attributable to the arrival of ship rats at Kotwhenu and Big South Cape Islands in the early 1960s.
The birds: a thriller made in NZ
Thursday July 22, 2004
The Guardian
The DNA clock is a complex timepiece: measure the changes in a length of DNA common to a large group of creatures and you will get a clue not just to the network of evolutionary relationships, but to the whole family tree.
Keith Barker, of the University of Minnesota, and colleagues report in the Proceedings of the National Academy of Sciences that they studied the lineages of the Passeriformes or perching birds to arrive at a kind of pecking order of seniority. There are 5,739 of these songbirds - crows, starlings, thrushes, robins, tanagers, mockingbirds, jays and so on - on all the continents except Antarctica. Near the root of the Passeriforme tree, they report, are the Acanthisittidae, or New Zealand wrens.
The implication is that the first passerines evolved in the Cretaceous era, somewhere near what is now New Zealand, and spread their wings with the break-up of the old Gondwana continent, from Australasia to Eurasia, Africa and the New World. In the course of this, they came to comprise "nearly half of all extant avian species, and represent the largest identifiable radiation of birds, encompassing a staggering ecological and behavioural diversity".
Maori name: Matuhi
source for info for entry
Re: New Zealand wrens
« Reply #3 on Jun 4, 2005, 9:51am »
www.nzbirds.com/Matuhi.html
