Tern (Sternidae)


Terns are seabirds in the family Sternidae that have a worldwide distribution and are normally found near the sea, rivers, or wetlands. Previously considered a subfamily of the gulls, Laridae, they are now usually given full family status and divided into eleven genera. They are slender, lightly built birds with long, forked tails, narrow wings, long bills, and relatively short legs. Most species are pale grey above and white below, with a contrasting black cap to the head, but the marsh terns, the Inca tern, and some noddies have dark plumage for at least part of the year. The sexes are identical in appearance, but young birds are readily distinguishable from adults. Terns have a non-breeding plumage, which usually involves a white forehead and much-reduced black cap.
The terns are birds of open habitats that typically breed in noisy colonies and lay their eggs on bare ground with little or no nest material.
Terns are long-lived birds and are relatively free from natural predators and parasites; most species are declining in numbers due directly or indirectly to human activities, including habitat loss, pollution, disturbance, and predation by introduced mammals.

Further Information: Wikipedia

Genus Sternula

Little Tern (Sternula albifrons) Summer Visitor
Little Tern (Sternula albifrons) Copyright Peter Drury

Little Tern (Sternula albifrons) Copyright Peter Drury

There are three subspecies, the nominate albifrons occurring in Europe to North Africa and western Asia; guineae of western and central Africa; and sinensis of East Asia and the north and east coasts of Australia.
The little tern breeds in colonies on gravel or shingle coasts and islands. It lays two to four eggs on the ground. Like all white terns, it is defensive of its nest and young and will attack intruders.
Like most other white terns, the little tern feeds by plunge-diving for fish, usually from saline environments. The offering of fish by the male to the female is part of the courtship display.
These birds nest on the RSPB managed Langstone Harbour Islands. You may see them entering the Oysterbed lagoon to fish.

Where these can be seen: These may be seen entering the lagoon to fish. the chances of seeing them here increases as fishing in the harbour becomes difficult.

Genus Sterna

Common tern (Sterna hirundo) Summer Visitor
Common tern (Sterna hirundo) Copyright Peter Drury

Common tern (Sterna hirundo) Copyright Peter Drury

This bird has a circumpolar distribution, its four subspecies breeding in temperate and subarctic regions of Europe, Asia and North America. It is strongly migratory, wintering in coastal tropical and subtropical regions. Breeding adults have light grey upperparts, white to very light grey underparts, a black cap, orange-red legs, and a narrow pointed bill. Depending on the subspecies, the bill may be mostly red with a black tip or all black.
Breeding in a wider range of habitats than any of its relatives, the common tern nests on any flat, poorly vegetated surface close to water, including beaches and islands, and it readily adapts to artificial substrates such as floating rafts. The nest may be a bare scrape in sand or gravel, but it is often lined or edged with whatever debris is available. Up to three eggs may be laid, their dull colours and blotchy patterns providing camouflage on the open beach. Incubation is by both sexes, and the eggs hatch in around 21–22 days, longer if the colony is disturbed by predators. The downy chicks fledge in 22–28 days. Like most terns, this species feeds by plunge-diving for fish, either in the sea or in freshwater, but molluscs, crustaceans and other invertebrate prey may form a significant part of the diet in some areas.
Many pairs of these birds can be found on the Oysterbed Lagoon Islands.

Where these can be seen:From June to August, this Tern forms a breeding colony on the oysterbed islands. We have the great privilege to see all aspects of life at close quarters.

Genus Thalasseus

Sandwich tern (Thalasseus sandvicensis) Summer Visitor
Sandwich Tern (Thalasseus sandvicensis) Copyright Peter Drury

Sandwich Tern (Thalasseus sandvicensis) Copyright Peter Drury

The Sandwich tern is a medium-large tern with grey upperparts, white underparts, a yellow-tipped black bill and a shaggy black crest which becomes less extensive in winter with a white crown. Young birds bear grey and brown scalloped plumage on their backs and wings. It is a vocal bird. It nests in a ground scrape and lays one to three eggs.
Like all Thalasseus terns, the Sandwich tern feeds by plunge diving for fish, usually in marine environments, and the offering of fish by the male to the female is part of the courtship display.
For the last few years, pairs of these Tern have started to breed on the Oysterbed Islands.

Where these can be seen: These have started to nest on the oysterbed islands which allows us to learn about this large Tern.