Xenicus lyalli Rothschild, 1894.
OTHER COMMON NAMES
English: Stephens wren; French: Xйnique de Stephen; German: Stephenschlьpfer; Spanish: Reyezuelo de Stephen.
A typical individual was 4 in (10 cm). Both sexes were colored similarly, the female being merely duller. Both had small but stout, strong bills. The lower mandible was light brown, as were legs and feet, the upper mandible dark brown with a horn-colored tip. The tail was little more than a stub. Although the overall body color was brown, the superciliary streak, chin, and throat were greenish yellow. Light-brown feather margins on partly overlapping body feathers decorated male and female with rows of roundish, fuzzy-edged spots on a darker brown backround. Rows, parallel to one another while following body contours, ran head to tail and covered the entire body, lending the birds a passing resemblance to pinecones. The female’s spots were more softly applied.
The species inhabited only this small island, a mere 100 ft (30.5 m) square, but steep-sided, with an elaborate ecology.
Steep, rocky outcroppings; a small forest, grass, and scrub.
All that is known about this species, including its
, was recorded by a single person, George Lyell. The birds ran and skittered about on the ground, similar to mice, whose niche the birds likely filled. The species could not fly, or flew very little and ineffectively—a handy adaptation to life on a very small island, but marking them for certain death from introduced predators. The short, rounded wings and soft plumage attest as well to diminished or lost powers of flight. The voice was never described.
FEEDING ECOLOGY AND DIET
The wrens were apparently most active during twilight hours and may have been nocturnal. They would emerge from holes in rocks and spend some time poking about, alternately running about and hiding, most likely hunting for small arthropods.
The Stephens Island wren is emphatically extinct. Its discovery and extirpation are a masterpiece of cruel irony. The birds went unnoticed and were safe until the New Zealand government built a lighthouse on the islet and in 1894 staffed it with George Lyell, who brought his cat, Tibbet, to the island with him. The consequences are predictable. Within a few months, Tibbet killed, then ate or brought home as show-off gifts for his master, the entire population of Stephens Island wrens. Lyell sent nine corpora to prominent ornithologists Walter Lawry Buller and Walter Rothschild, who declared them a previously unknown species of New Zealand wren. By the time the glad news reached Lyall, the wrens were extinct. As if in a final petulant jest, the birds were scientifically dubbed Traversia lyalli, later changed to Xenicus lyalli, after the owner of the cat who wiped them out. Ten specimens still exist, distributed throughout five museums.
SIGNIFICANCE TO HUMANS
Among biologists and conservationists, the Stephens Island wren has become a poignant symbol of the fragility of isolated island species with limited space and populations.
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