Black Oystercatcher

The black oystercatcher, Haematopus bachmani, presents itself as a striking figure against the rocky shorelines of western North America. This large shorebird is adorned with a uniform black plumage on its head, neck, and breast, transitioning to a dark brown on the body. Its long, bright red to orange bill, measuring approximately 9 cm (3.5 in), is a distinctive feature, along with its pink legs. The bird's eyes are a vivid yellow, encircled by a red ring, adding to its arresting appearance. The plumage may exhibit subtle variations, generally appearing darker in individuals found further north.

Identification Tips

When identifying the black oystercatcher, look for its solid black head and upperparts, which contrast with the dark brown plumage on the rest of its body. The bird's long, stout bill is a vibrant red or orange, and its legs are a soft pink. The yellow iris and red eye-ring are also key features to note. The species exhibits slight regional plumage variations, with northern birds tending to be darker.

Habitat

The black oystercatcher is a coastal specialist, showing a strong preference for rocky shorelines. It is often found in areas with quieter embayments, such as those protected by jetties, where it can forage with less disturbance from the surf.

Distribution

This bird's range extends from the Aleutian Islands of Alaska down to the Baja California peninsula. It is the sole representative of the oystercatcher family in most of its range, with some overlap with the American oystercatcher on the Baja California coast.

Behaviour

The black oystercatcher is a bird of the intertidal zone, where it is adept at foraging for marine invertebrates. It feeds primarily on molluscs, such as mussels, limpets, and chitons, but will also consume crabs, isopods, and barnacles. It uses its robust bill to dislodge and open shells. During high tides, the bird tends to be inactive, often seen resting as it waits for the tide to recede.

Breeding

Territorial by nature, especially during nesting season, the black oystercatcher is easily detected by its loud calls while defending its foraging and nesting territory. Nesting pairs may remain together for many years, with nests being simple depressions lined with pebbles and shell fragments. Typically, two to three robust eggs are laid, capable of withstanding submersion by high tides. Incubation lasts about 26–28 days, and chicks, though able to leave the nest after a day, remain in the territory for an extended period post-fledging.

Similar Species

The black oystercatcher can be confused with the American oystercatcher (H. palliatus) where their ranges overlap. However, the American oystercatcher has a white belly and a different vocalization, which can help distinguish between the two.

Diet and Feeding

The diet of the black oystercatcher consists mainly of marine invertebrates found in the intertidal zone. It forages by sight, using its strong bill to pry open shells and dislodge prey from rocks.

Conservation status

The black oystercatcher is currently classified as Least Concern by the IUCN. However, it is considered a species of high conservation concern across its range, serving as a keystone indicator species for the health of the north Pacific shoreline. It is also a management indicator species in the Chugach National Forest and a focal species for priority conservation action by the U.S. Fish & Wildlife Service. The global population is estimated to be between 8,900 and 11,000 individuals.