Teesmouth's Terns

Terns are the most elegant of seabirds, with long narrow wings and tail streamers they are much slimmer and more streamlined than their relatives, the gulls. The pointed pale grey wings of terns also lack the black-tips and markings that are characteristic of many species of gull. Two species of tern, Common Tern and Little Tern, nest regularly around the Tees Estuary and several others are regular visitors. All are migrants, travelling to the tropics and beyond during our winter and returning again to nest in Britain and Europe in spring.

Several species of tern can be seen all around the coast of the Tees Bay. In mid-summer Common Tern, and even the much rarer Little Tern, can be seen fishing offshore from the beaches at Seaton Carew and Redcar, but probably the best viewing points are the breakwaters of North Gare and South Gare. It is much better watching terns from the gares than trying to track them down on their breeding sites. Not only does this prevent disturbing the nesting birds but since they often fish very near the breakwaters it is possible to get excellent, close views. With luck in late summer up to five species of terns can be seen at any one time.

Arctic Tern (Sterna paradisea)
Common Tern (Sterna hirundo)
Little Tern (Sterna albifrons)
Sandwich Tern (Sterna sandvicensis)
Other Terns
Play Your Part in Protecting our Terns
Watching Terns at Teesmouth

Arctic Tern (Sterna paradisea)

This species is very similar to Common Tern but has greyer under parts and a whiter looking rump. The tail streamers are also longer than in Common Tern. The best identification feature however, is the blood-red bill without the Common Tern's characteristic black tip. Nevertheless separating the two species is rarely easy, especially with immature birds, and even the experts are often unsure referring to some individuals as "Comic" Terns!

Arctic Terns do not nest at Teesmouth, but birds migrating to and from breeding grounds further north pass through the estuary in spring and autumn. Although never as numerous as Common Terns up to 300 Arctic's can be present at Teesmouth in some years.

The first Arctic Terns are usually seen at Teesmouth in early May and the last birds have usually departed on their long migration by the end of September. These terns have the longest migration route of any bird. In some cases Arctic Terns nesting literally in the Arctic can spend the northern winter on the edge of the Antarctic! Such birds experience more daylight than any other animal on earth.

Common Tern (Sterna hirundo)

Up to 500 pairs of Common Terns nest around Teesmouth and in late summer several thousand birds congregate in the lower estuary. Common Terns have long, pointed grey wings and white undersides, but like all terns the best identification features are around the head. The nape, crown and forehead are black and the blood-red bill has a characteristic black tip.

Common Terns usually start arriving at Teesmouth in late April with numbers building up rapidly during May. Birds are present throughout the summer and large numbers from local and more distant colonies congregate in the lower estuary in late summer and autumn. By October most birds have departed.

Little Tern (Sterna albifrons)

This is one of the rarest of the seabirds nesting in Britain and is a species of international conservation concern. As its name suggests this is by far the smallest of the terns, but it still has the long narrow grey wings of its larger relatives. It also has the characteristic black cap, but in this case the bird's forehead is white. The bill is also quite different being yellow with a black tip.

The beaches around Teesmouth are traditional nesting sites for Little Tern, but until volunteer wardens from local conservation groups started patrolling the nesting areas few young birds ever fledged. In recent years the protection of Little Tern nesting sites has improved with a full-time paid warden, supported by a team of dedicated volunteers, in place throughout the breeding season. Over the years the warden scheme has had a wide range of supporters from industry to English Nature, the Tees Valley Wildlife Trust to the Local Authorities. All of this effort has been well worthwhile with 60 chicks fledged in some years. Teesmouth birds usually arrive in force during early May and depart for their wintering areas off the west coast of Africa in early autumn.

Sandwich Tern (Sterna sandvicensis)

In contrast to the previous species the Sandwich Tern is the largest tern that regularly visits the Tees Estuary. Whilst still obviously a tern, the Sandwich is heavier built than its relatives and is somewhat more gull-like. It still has a forked tail but no long streamers. The black cap has longer feathers at the back giving the bird a rather shaggy crest. As with the other species the best identification feature is the bill, this is long, black and has a distinctive yellow tip.

Sandwich Terns do not nest at Teesmouth, but migrants moving to and from nesting colonies further north, such as those on the Farne Islands off the Northumberland coast, pass through the estuary. In late summer and early autumn large numbers of Sandwich Terns can be found in the lower estuary.

At times this population can exceed 1500 individuals making the site of International Importance for this species. Sandwich Terns begin to arrive in the Tees Bay earlier than the other terns with some individuals seen in late March. By the end of September, however, most birds have usually left the area.

Other Terns

Every year two other species of tern occur at Teesmouth, but in much smaller numbers. Two or three of the globally endangered Roseate Tern (Sterna dougallii) are recorded most years but identification involves comparative lengths of its tail streamers, fine variations of bill colour and knowledge of its calls. Such critical identifications are best left to the experts. Black Terns (Chlidonias niger) are more or less regular visitors to the area but are quite different from the other terns. These are "marsh" terns feeding over the pools and lagoons of the wetland habitats rather than the open sea and estuary. Some Black Terns are seen on Teesside in spring when their black breeding plumage makes identification easy, but most occur in autumn after they have moulted. Then they look dull and grey and are not so easily recognised.

All other species of tern such as Gull-billed (Sterna nilotica), Caspian (Sterna caspia) and Lesser Crested (Sterna bengalensis) are extreme rarities at Teesmouth and are unlikely to be seen by most visitors.

Play Your Part in Protecting our Terns

Please enjoy your tern watching from the various vantage points around the Tees Bay, but please do not try to approach nesting colonies. All species are protected and it is illegal to disturb nesting birds.

Little Terns are particularly vulnerable to disturbance and all known colonies have signs requesting people to avoid the area during the nesting season. Please respect these nesting colonies. Also please leash your dog in these areas, he thinks chasing terns is fun: you know different!

If you do find terns nesting in beach areas where there are no warning signs please leave as soon as possible and inform INCA. You could have discovered a new nesting site.

Tel: 01642 370319 e-mail: plover@inca.uk.com

Watching Terns at Teesmouth

Terns can be seen throughout the summer anywhere around the Tees Bay, but there are a number of sites that are particularly favoured.

 TEESSIDE ENVIRONMENTAL TRUST
 creating the International Nature Reserve