Common Tern { Birds of Europe}

Common Tern with fish

Source

Introduction

The Common Tern belongs to the order of birds known as the Charadriiformes and the family Sternidae within that order. { Some place them in Laridae with the gulls}. They have been allocated the genus name of Sterna from the old English stearn a tern,and the specific name of Hirundo Latin for swallow.

They breed in Eurasia and North America and winter in Southern Europe ans Southern Asia, Africa Australia and south America. { In America they are listed as endangered or of Special Concern in many states.}

In the UK they are placed on the Amber list of Conservation concern the criteria for this listing is declines of between 25-50% over the last forty years or so. In the UK there are an estimated 10,000 pairs in summer. They are classed as Migrant breeders and passage visitor in the UK. In Ireland they are also listed on the Amber list of conservation concern.

In Europe they are not a species of concern with an estimated population of between 220,000-320,000 pairs. The above information is courtesy of the BTO.

The European population varies greatly from country to country here are some examples-Austria 200-300 breeding pairs, Belgium 2,500-2,600 breeding pairs,Croatia 500-1,000 breeding pairs, France 4,500-5,000 breeding pairs, Germany 8,900-9,600 breeding pairs Spain 2,500-10,000 breeding pairs and Ukraine 40,000-50,000 breeding pairs. { Source Birdlife}

The Gaelic name for the bird Sternag-chumanta the Welsh Morwennol Gyffredin and the Irish Geabhrg.

Courtesy of groene lantaarn

One of the most beautiful terns is the Inca tern

Source

What are terns ?

Terns are allied to the gulls and have a world wide distribution. Many of the terns that breed in temperate zones are long distant migrants. They have longish bills and webbed feet. They are more streamline than the gulls and are much more elegant in flight with long tails and long narrow wings. Despite having webbed feet they very rarely swim. Most nest in large densely packed colonies.

They are for all intents and purposes aerial fish feeders. Almost two thirds of the species are 'typical' terns in the genus Sterna,such as the Elegant tern of the Pacific Coast of California and West Mexico. These are members which are referred to as the crested terns.

Another group of species are the 'Noddies' which are restricted to the tropical oceans. A species of Noddy terns of the genus Anous,nests in trees and small bushes. One of the most beautiful of all terns is the Inca tern Larosterna inca,that breed on the coast of Peru and Chile.

Terns are related to the Skimmers. It is generally accepted that they evolved from Larid-like ancestors. The Arctic tern is renowned for its exceptional long migration route from the high Arctic Circle winter grounds. { Fellow hubber, Ann1Az2, has an excellent article on the Arctic Tern }.

Many terns are Pelagic species ,but some, for example the Little Tern S.albifrons,and the Least tern follow rivers and wetlands to nest well inland.

However, here we review the common Tern and as always commence with a description of the subject under review.

Tern and habitat

Crossley's ID Guide to Eastern Birds Richard Crossley.
Crossley's ID Guide to Eastern Birds Richard Crossley. | Source

Arctic Tern is a similar looking bird.

Note there is no black tip to the bill of the Arctic tern
Note there is no black tip to the bill of the Arctic tern | Source

Description of the Common Tern

The common tern is remarkably similar in appearance to the Arctic tern and both were once referred to as 'commic' terns. However, a dark tipped bill,paler plumages, a shorter tail streamers and a more rounded head should help to identify this bird. It also frequently nests far in land ,unlike its cousin.

Tern identification can be confusing,other similar birds such as the Forster's , but this species has longer,brighter orange legs,more orange bill that has a more extensive black tip;whiter wings and belly,paler back,longer tail and a white leading edge to the wings in breeding plumage and the black is restricted to a small mask around the eye and ear in winter.

The Roseate tern much paler, with long white tail streamers,less dark in the wings and usually all dark bill.

Our subject is a medium sized tern,with a long forked tail. Black cap and dark orange/red bill with a black tip.. The legs are bright orange as are the feet. The white wings have a dark tip when in breeding plumage. In non-breeding plumage the adults are medium grey above with black stripe visible when the wings are folded. The bill is darker almost black as are the feet. The black covers only the rear portion of the crown.

The tail streamers have earned this species the alternative common name of sea swallow.

Common tern 'dance'

Source

General and historical information

The common tern is the most widely distributed tern along the coasts of the UK, once being especially abundant in Ireland and in the more southern parts of the UK. It occurs in summer in suitable localities on the islands all along the western side of Scotland.

The largest colony in Great Britain during the 1800's were on Walney Island in the west and Farne Islands on the east coast.

The common tern begins to arrive in Britain in small flocks mostly composed of older birds early in April {sometimes March if conditions are favourable} often during the prevalence of an east wind. After arrival these terns spend a week or so inspecting their whereabouts.By this time they are or very nearly in full breeding plumage. However, hardly has the breeding season concluded when the parent bird change into their winter attire.

Breeding habits an historical observation

The authors of ' A fauna of the Outer Hebrides' remarks that however punctually the birds may make their first appearance, their actual time of occupying the nesting sites varies greatly with the weather,as also to some extent in different localities," especially, we have noticed, in the Hebrides and Western districts of Scotland."

They go on to note, " It is not until some time after the appearance of the terns that the ova of many species of fish hatch out, nor do the fry at once approach shore-wards and surface-wards. Many are hatched out in shoals and deep water far out to sea and the terns and other birds have to seek their food some distance from their haunts on that account."

" The time of laying for the terns coincide with the time their food supplies are most accessible to them. The natural history of birds and fishes in similar respects is therefore closely connected with each others existence"

These terns prefer for their nesting place low lying sandy islands, little above the water level,gravelly or pebbly shores,and other bare rocks. many tend to nest in large colonies.


Common tern nest,three eggs and three rocks.

Originally posted to Flickr
Originally posted to Flickr | Source

Tern colony an historical account.

Macgillivray, gives the following observations on a tern colony.

" On going up to a breeding place which may be discovered from a distance,as some birds can be seen flying about it, one is sure to be met with several of them which hasten to remonstrate with him by harsh cries and threatened blows. As he draws nearer, more of them leave their nests,and at length they are all on the wing,wheeling and bounding, now high,now low.at times quite close,and increasing their cries"

" When walking along a sandy shore,no bird nearer perhaps than a quarter of a mile, you may see one or two of them coming up from a distance, increasing their cries as they approach,then wheeling and plunging over and around you,and a length flying off." "Proceeding at a moderate height , they stop now and then and hover a moment, dip into the water, and secure a sand eel or young fish. Many attend as the fisherman or others who are catching sand eels for bait or food, to fish up those that slip from them disabled. On such occasions they are very voracious, as they are when they have fallen in with a shoal of fry."

" They never dive,but I have often seen them alight on the water and swim a little,and sometimes a whole flock may be observed reposing on the placid bosom of the water,affording a very pleasing spectacle. They are very bad walkers, but on the wing their movements are easy and elegant. They skim along, bounding by with great speed,ascend or descend, deviate to either side,stop short in an instance, hover in one spot like a hawk,drop,dive or plunge headlong with surprising adroitness. Their mode of flying, however, does not resemble that of the swallow,and they obtain the name of Sea Swallow, on account of their forked tail. If a luckless Black-headed gull happens to enter the Ternery, the terns swoop at him savagely,and frequently with fatal results"

Tern with Prey

Source

Nest ,eggs and young.

The nest itself is merely a rock depression, or a hollow in the ground,occasionally lined with a few strands of vegetable fibre,dry grass or seaweed.the female will deposit two to three eggs. These have a general ground colour varying, but generally stone coloured or Olive to buff marked with numerous small spots and blotches of dark brown often concentrated around the larger end.

The eggs are incubated for twenty one to twenty three days by the female,occasionally relieved by the male. when the young hatch out the chicks are downy and their eyes are open, they are able to walk but generally stay in the nest for a while. They are emerged with a brownish yellow down,spotted or mottled with black. The edge of the wing and under parts { except the throat,which is brown} being white. The forehead brown and the feet yellow.

They grow rapidly during the first few hours and it is hard to believe that just a sparse time ago they were packed away in a small roundish egg case.! As the chicks grow older the brown spots and mottling become more distinct. When fully fledged the forehead is brownish white, the nape and rest of the head,including the ear coverts are black.

The hind neck, the throat, the chest,the rump and upper tail coverts are white. The shoulders and back are bluish grey,barred and mottled with greyish brown. A broad band on the upper wing coverts,brownish grey over the upper parts with, generally a flush of buff. All the undersides are white. The bill is sometimes scarlet its base reddish yellow. The legs and feet are scarlet or reddish brown. These and the bill intensify in colour, according to Saunders, up to the autumn and often quite rapidly change in October to dark, not resuming the light colour till next spring, the rump and upper tail coverts becoming grey.

During the immaturity which lasts until their second,and sometimes their third spring the forehead is white,and the grey on the wings become less conspicuous and extensive.

Common Tern Sitting at Nest

originally posted to Flickr transferred by Fae
originally posted to Flickr transferred by Fae | Source

Away till next spring

During the autumn both old and young birds may be encountered feeding together during the day,and sometimes under moonlight in large flocks,or sitting during rough weather on a sandy shore under the lea of a bank,

In September they begin to leave the northern parts of the UK,on their southern migration,and before October,all, except a few stragglers,who may remain all winter,have taken themselves off from our shores to less sunless skies.

Young immature tern

Fire Island New York
Fire Island New York | Source

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7 comments

D.A.L. profile image

D.A.L. 2 years ago from Lancashire north west England Author

avainnovice,

Hi Deb terns are fantastic birds and your right about them being entertaining and friendly enough away from their breeding colonies. Best wishes to you.


aviannovice profile image

aviannovice 2 years ago from Stillwater, OK

Wonderful information on terns of the world. When in Maine, I had the Common Tern, which was always very entertaining, as well as rather friendly. Carry along a little fish, and you'll have friends for life!


D.A.L. profile image

D.A.L. 2 years ago from Lancashire north west England Author

DDE,

Hi Devika, I am so happy that you are interested in birds{and nature in general} and it is a pleasure to share with you. Thank you once again for your vote up it means a great deal to me. Best wishes to you.


DDE profile image

DDE 2 years ago from Dubrovnik, Croatia

I have not seen this beautiful bird. A very different kind of bird with such amazing features. I can always count on you to share your best. Voted up!


D.A.L. profile image

D.A.L. 2 years ago from Lancashire north west England Author

Ericdieker,

Hello Eric, I agree that terns are a great species to watch, thank you for your visits and kind comments. Best wishes to you.

JKenny, you are welcome, here in Lancashire they are often seen in land at certain times of the year. Thank you for your kind comments. Best wishes to you.


Ericdierker profile image

Ericdierker 2 years ago from Spring Valley, CA. U.S.A.

Our Terns are browner but otherwise look just the same. We have really cool sanctuaries for them. Great bird to watch. Thank you.


JKenny profile image

JKenny 2 years ago from Birmingham, England

Another fantastic article. I quite often see common terns flying quite far inland. I've seen Arctic terns while in Jersey and also while in Northumberland. Thank you.

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