Macquarie Shag

The Macquarie shag, also known as the Macquarie Island shag or Macquarie Island cormorant, is a striking marine bird with a distinctive appearance. It boasts largely black upperparts contrasted with white underparts. The upper cheeks and ear-coverts are also black, while the wings are adorned with white bars. A notable feature is the black, recurved crest that arches over the forehead. The feet are a delicate pink, and the bird measures approximately 75 cm in length, with a wingspan of 110 cm and a weight ranging from 2.5 to 3.5 kg.

Identification Tips

During the breeding season, adult Macquarie shags can be identified by a pair of vibrant orange caruncles situated above the base of the bill, just in front of the eyes. The facial skin at the base of the lower mandible is orange-brown, and the eye-rings are a striking blue, adding to the bird's colorful allure.

Habitat

The Macquarie shag is a marine bird that, outside of breeding and roosting, spends its life at sea. It is native to the subantarctic waters surrounding Macquarie Island and the nearby Bishop and Clerk Islets.

Distribution

This species is endemic to Macquarie Island and the adjacent Bishop and Clerk Islets, which are part of the Macquarie group located in the Southern Ocean, roughly equidistant between Australia and Antarctica.

Behaviour

Macquarie shags are sociable creatures, often found roosting in groups that can range from just a few individuals to several hundred. Their gregarious nature is evident in these communal gatherings.

Breeding

Macquarie shags are year-round residents of Macquarie Island, where they breed annually. They form colonies of varying sizes on the bare rocky shores and stacks. Nest construction begins in June, with nests resembling truncated cones made of vegetation, guano, and mud. The breeding season sees the laying of two or three eggs between mid-September and January, with hatching predominantly occurring by late December. By mid-February, most chicks have gained independence from their parents.

Feeding

In the shallow coastal waters near Macquarie Island, these birds forage for their primary diet of benthic fish. They may feed in flocks, indicating a level of cooperation among individuals during foraging.

Conservation status

As of the year 2000, the Macquarie shag population was estimated to consist of approximately 760 breeding pairs. However, a subsequent survey in October 2003 indicated a concerning 30% decline, with only 472 nesting pairs identified. The species is currently listed as Vulnerable under Australia's Environment Protection and Biodiversity Conservation Act 1999. The small and localized population is susceptible to fluctuations in breeding success due to variable weather conditions and food availability. Additional threats include predation of nestlings by Subantarctic skuas and black rats.