Ian’s Bird of the Week – Sooty Oystercatcher ~ by Ian Montgomery
Newsletter – 8-16-12
Back to Australia for this week’s bird, the Sooty Oystercatcher. Oystercatchers are large, conspicuous, noisy and mostly popular waders, though not greatly loved by those who harvest shellfish such as mussels. There are about a dozen closely-related species worldwide, two of which are resident in Australia, the Pied and the Sooty. Both occur right around the coasts of Australia and Tasmania, with the Sooty being the less common. It is primarily an inhabitant of rocky shores, first photo, while the Pied is found mainly in sandy habitats. At 46-49cm/18-19in the Sooty is slightly shorter on average than the Pied 48-51cm and distinguished by its all black plumage.
Two races are recognised, though their status and range are uncertain. The nominate race (fuliginosus) occurs in southern Australia and is characterised by the narrower red eye-ring and finer bill like the bird in the first photo, taken near Sydney. The northern race (opthalmicus) has a fleshier, more orange eye-ring and a thicker bill. It is supposed to occur from Shark Bay in Western Australia to Lady Elliot Island at the southern end of the Great Barrier Reef in Queensland, but the bird in the second photo taken near Lennox Head in northern NSW fits this description. There is disagreement in the field guides about whether opthalmicus has a longer or shorter bill.
The diets of the two species differ. The Pied feeds mainly by probing sand and soil for worm and other burrowing invertebrates. The Sooty feeds mainly on intertidal invertebrates on rocks such as gastropods (third photo), limpets, crustaceans, echinoderms and ascidians.
They will also feed on beaches near rocky headlands and the one in the fourth photo is part of a small flock probing through piles of washed-up seaweed.
There is some overlap in the habitats of the two species, so they are occasionally found together. The fifth photo show two walking in step along a beach at the end of August and look like more than just good friends. The breeding season of southern Sooties starts in September and the two species have been known to hybridise, so draw your own conclusions.
A third species, the South Island Pied Oystercatcher of New Zealand, sometimes turns up on the east coast sometimes and more frequently on Lord Howe and Norfolk Islands. This is subtly different from the Pied Oystercatcher and a challenge for enthusiastic birders to identify.
Ian Montgomery, Birdway Pty Ltd,
454 Forestry Road, Bluewater, Qld 4818
Tel 0411 602 737 firstname.lastname@example.org
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Thanks again, Ian, for sharing your birds with us. We always learn something neat about birds and their behaviors. I have seen our two Oystercatchers, the Black and the American. That Sooty seem similar to our Black.
Oystercatchers belong to the Haematopodidae – Oystercatchers Family. There are 12 members in the family, one of which is extinct.
Who, when he had found one pearl of great price, went and sold all that he had, and bought it. (Matthew 13:46 KJV)
Ian said, “not greatly loved by those who harvest shellfish such as mussels.” Maybe that is because they are looking for those pearls of great price and the Oystercatchers are beating them to it. Humm!
Ian’s Oystercatcher pages and then
The Haematopodidae – Oystercatchers Family here