How to Identify Black Tern Feathers
A guide to the sooty-black body and pale gray wings of this small marsh tern, distinct from the mostly white plumage of typical terns.
Read the full Black Tern encyclopedia entry →
What Black Tern Feathers Look Like
In breeding plumage, Black Tern is unusual among terns for having a sooty black head and body, contrasting with pale gray wing and tail feathers and white undertail coverts — a strong departure from the mostly white bodies of typical terns. In non-breeding and juvenile plumage, the bird looks quite different: a white head with a dark cap or ear patch and a paler, patchier gray-and-white body. Wing and tail feathers are consistently a soft pale gray rather than the bright white seen in most other tern species, and the tail is only shallowly forked, much less deeply notched than the elegant long fork of Common or Forster's Tern. Overall size is small for a tern, with contour feathers around 2-3 cm and flight feathers around 10-13 cm.
Step-by-Step: Is This Feather From a Black Tern?
- Check wing and tail color. A pale gray (rather than bright white) flight or tail feather is a strong clue, since most other terns show whiter wings and tails.
- Look for sooty black body feathers. In breeding plumage, black body contour feathers combined with pale gray wing feathers is close to diagnostic for this species.
- Assess the tail fork. A shallow, modest fork (not the long, deep, streamer-like fork of Common or Forster's Tern) supports Black Tern.
- Measure it. Small overall size (contour 2-3 cm, flight feathers 10-13 cm) fits this species better than the larger "typical" terns.
- Consider non-breeding plumage. A white head feather with a dark cap patch, paired with pale gray body feathers, can still indicate this species outside the breeding season.
Similar Species & How to Tell Them Apart
Common Tern and Forster's Tern are larger, have white bodies even outside the breeding season, gray wings, and a deeply forked white tail — never showing the black body of a breeding Black Tern. White-winged Tern, a close relative, also has a black body in breeding plumage, but its wings and tail are whitish rather than gray, and its underwing coverts are white rather than the darker gray underwing of Black Tern — checking underwing tone is the best way to separate the two where ranges overlap.
Where & When You'll Find Them
Black Terns breed in freshwater marshes and wetlands across North America, Europe, and Asia, then migrate to winter along tropical coastlines. Molt into duller non-breeding plumage happens in late summer, before or during migration, so many feathers found in fall are the paler post-breeding type rather than the striking black breeding-plumage feathers. Feathers turn up most often near freshwater marsh breeding colonies in summer or along coastal migration routes in late summer and fall.
Frequently asked questions
Why are the wing feathers gray instead of white?
Black Tern is unusual among terns for having pale gray rather than white wings and tail, a helpful distinguishing feature from most other tern species.
How is this different from a Common Tern feather?
Common Tern has a white body even in breeding plumage and a deeply forked white tail, unlike Black Tern's sooty black breeding body and shallow tail fork.
What about White-winged Tern?
White-winged Tern also has a black breeding body, but its wings and tail are whitish rather than gray, and its underwing is white instead of gray.
Why does this feather look pale and patchy rather than solid black?
That pattern matches non-breeding or juvenile plumage, when the head turns white with a dark cap and the body becomes paler and patchier.
When are feathers most often found?
Near freshwater marsh breeding colonies in summer, or along coastal migration routes in late summer and fall as birds molt into non-breeding plumage.