Haematopus unicolor J.R. Forster 1844, New Zealand. Pied morph occasionally considered separate species (H. reischeki) or race.
OTHER COMMON NAMES
English: New Zealand black oystercatcher, New Zealand sooty oystercatcher, northern oystercatcher; French: Huоtrier variable; German: Neuseelдndischer austernfischer; Spanish: Ostrero Variable.
18.50–19.29 in (47–49 cm); male averages 1.49 lb (678 g), female 1.59 lb (724 g). Only oystercatcher species with black and pied morph. Dominant morph is black overall with red eye, bill, and eye ring; pied morph has white breast, belly, back, and small wingbar. Frequent intermediate morphs are larger overall and are called “smudgies.”
Coast and islands of New Zealand.
Rocky and sandy shores.
Territorial and sedentary, occasionally flock in harbor and estuaries.
FEEDING ECOLOGY AND DIET
Feeds on sandy beaches and rocky shores. Varied diet includes crabs, gastropods, bivalves, and polychaetes.
Frequent interbreeding between morphs. Breeds from December through January (occasionally as early as September) on dunes and sandy beaches. Clutches are most often three eggs incubated for 25–32 days. Chicks of black morph have dark underparts and crown, while those of pied morph have white breasts and grayish-brown upperparts.
Not considered threatened, even though total population is estimated at 3,900 birds. Threats include human disturbance and mammalian predation, but several populations were increasing in 1980s and 1990s, especially on North Island where over two-thirds of variable oystercatchers reside.
SIGNIFICANCE TO HUMANS
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