Short-tailed Shearwater
Ardenna tenuirostris
Medium-sized, dark brown shearwater. Has narrow, crooked wings and flies with quick, snappy wingbeats. Variable underwing pattern, usually rather dark with a less distinct silvery flash than Sooty Shearwater, but difficult to judge depending on lighting. Common in the Pacific Ocean, especially around Australia and New Zealand and up to the Bering Sea. Unknown from South America. Can be abundant in ocean waters off Alaska, gathering in enormous flocks; less common further south. Extremely similar to Sooty Shearwater. Short-tailed is lighter and has more crooked wings; also look for slightly shorter bill and more rounded head.
Taxonomy
This shearwater appears to be related to the sooty and great shearwaters, which are also blunt-tailed, black-billed species, but its precise relationships are obscure (Austin, 1996; Austin et al., 2004). These are among the larger species of shearwater, which have been moved to a separate genus, Ardenna based on a phylogenetic analysis of mitochondrial DNA (Penhallurick & Wink, 2004).
- Scientific name
- Ardenna tenuirostris
- Authority
- (Temminck, 1836)
- Order
- Procellariiformes
- Family
- Procellariidae
- Genus
- Ardenna
Range and habitat
- Breeding range
- PO : islets off s, se Australia, Bass Strait and Tasmania (se Australia)
- Non-breeding range
- to Antarctic ice edge waters then to Sea of Okhotsk, Bering Sea (North Pacific Ocean)
- Migration
- Complete migrants
Behavior
Each parent feeds the single chick for 2–3 days and then leaves for up to three weeks in search of food. These foraging trips can cover a distance of 1,500 km (930 mi) and mean the chick may be left unattended for over a week. When the chicks fledge they weigh around 900 g (2 lb), and may be heavier than their parents. In Tasmania, and especially on the muttonbird islands of the Furneaux Group, the chicks are harvested at this time for food and oil. The largest population in the world (2.8 million pairs - about 12% of the species) seems to be located on Babel Island. Adult birds foraging for food on the open ocean mistake plastic debris for food and then feed it to their chicks. This ingested plastic, as well as other factors, likely contribute to contamination of chicks.Thousands of Short-tailed shearwater fledglings are attracted to artificial lights during their maiden flights from nests to the open ocean. Fledglings are vulnerable to injury or death by collisions with human infrastructure and once grounded, to predation or becoming road casualties.
Conservation
- Population trend
- declining
Photos
Distribution
Bird Calls
Other Birds
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