Tuesday, 12 September 2017

Sooty Oystercatchers at Bastion Point Mallacoota

Given the last post featured an Australian Pied Oystercatcher (Haematopus longirostris) I thought I would follow it with a post on the closely related Sooty Oystercatcher (Haematopus fuliginosus).

APO’s are far more common than Sooties with the estimated Australian populations of the species respectively of 10,000 and 4,000 birds (1). Both APO’s and Sooties are found right around the Australian coast including Tasmania, however, APO’s are mostly a bird of sandy and muddy habitats while Sooties prefer rocky coastal areas. While this is generally the case it is not strictly so with both species being found in the other’s habitat at times, sometimes together. The different habitat preferences and associated foods probably helps explain the population differences, with more habitat and food resources open to the more generalist APO’s.

On a recent trip to the south coast of NSW we found pairs of Sooty Oystercatchers at many of the rocky habitats we visited. I caught up with a pair resting on rocks at the Bastion Point Mallacoota Boat Ramp.

Please click on photos to enlarge.

Some of the colours in the sedimentary rocks compliment the birds bill, eye and leg colours.
The bill is long but stout and the blunt tip is a sign of hard wear from levering molluscs from their rocky habitat and hammering them open.
Both birds were loafing and this one preened a little.
The other bird was lying down – I had hoped they might come together for a photo but they did not oblige.
While the plumage is black, in some light it can have a definite brown tinge.

The Sooty is a powerfully built Oystercatcher with sturdy legs and a heavy bill.  

 
There are two sub-species of Sooty Oystercatcher in Australia (2):

Sooty Oystercatcher
Haematopus fuliginosus
Southern Sooty Oystercatcher
Haematopus fuliginosus fuliginosus
Northern Sooty Oystercatcher
Haematopus fuliginosus ophthalmicus

The northern Sooty has a large yellow orbital ring while the southern’s ring is small and red. Hybrids are possible where the two sub-species overlap.

(1)  Population estimates taken from Shorebirds of Australia by Gerring, Agnew and Harding, 2008 edition.

(2)  From BirdLife Australia Working List V2.