Birds  /  Waterbirds  /  Caspian Tern

Caspian Tern

Hydroprogne caspiaNativeLeast Concern

About the Caspian Tern

The Caspian Tern is the largest tern in the world, nearly the size of a big gull, and its heavy, blood-red bill is visible at a remarkable distance, making it the easiest tern to identify on Michigan's waters. Pale gray above and white below with a shaggy black cap, it flies with powerful, deliberate wingbeats over the Great Lakes and large lakes, tilting its head down to search the water, then plunge-diving with a splash to seize a fish. Its call is a loud, harsh, raucous croak, deeper and rougher than the calls of smaller terns.

Caspian Terns nest in colonies on sparsely vegetated islands and beaches, and the Great Lakes host an important share of the continent's breeding population. Adults are devoted parents, and young Caspian Terns often stay dependent on their parents well into fall migration, begging loudly to be fed even when nearly full-grown. From spring through fall they are a conspicuous presence along Michigan's shorelines, their size, red bill, and rough calls setting them apart from the smaller Common and Forster's Terns.


Diet

Fish

Feeds almost entirely on fish, caught by hovering over the water and plunge-diving headfirst to seize prey near the surface. It hunts over the Great Lakes, large lakes, and river mouths, taking a range of fish species and often carrying a fish crosswise in its heavy bill.

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Questions birders ask

How do I recognize a Caspian Tern?

By its large size — the biggest tern, nearly gull-sized — and its massive coral-red bill, visible at a distance. Pale gray and white with a black cap, it dwarfs the smaller Common and Forster's Terns.

Where does it nest in Michigan?

In colonies on sparsely vegetated islands and beaches, mainly along the Great Lakes, which support an important part of the continental breeding population.

Why do I hear young ones begging so persistently?

Young Caspian Terns remain dependent on their parents unusually long, often into fall migration, and beg loudly to be fed even when nearly adult-sized. This extended care is characteristic of the species.

How do I age a Caspian Tern?

Juveniles have a scaly, dark-scalloped back and a duller orange bill, and adults after breeding show a streaked rather than solid black cap. The massive coral-red bill is diagnostic at every age.

What do you call a colony of Caspian Terns?

A colony. They nest on open Great Lakes islands, often adjacent to gull and cormorant colonies, and defend the nesting ground collectively.

Easily confused with

Other birds you might be looking at instead.

Common TernSterna hirundo
Forster's TernSterna forsteri
Ring-billed GullLarus delawarensis
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