DISSEMINATION
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DISSEMINATION |
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| Kingdom | Animalia |
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| Phylum | Chordata | |
| Class | Aves | |
| Order | Charadriiformes | |
| Family | Laridae | |
| Genus | Sterna | |
| Species | hirundo | |
| Classification | Linnaeus, 1758 | |
| Common name | common tern | |
| Size | 31 - 35 centimeters | |
| Wing Span | 82 - 95 centimeters | |
| Male weight | 90 - 150 grams | |
| Female weight | 90 - 150 grams |
| Geographic Range | Europe, Asia, North America. |
| Physical Characteristics | it's a bird with long wings and elegant flight. The upper part of its head is black, while the rest of the plumage is white and ash-coloured, like the seagulls. The beak is red with a black dot, the paws are reddish. The adults during wintertime and the chicks have a black nape and dark beak. It takes three years for the adult plumage to be complete. |
| Call | it has several calls. |
| Behaviour | the territory in which the common tern usually looks for food is defended strenuously by the male, especially during the period of the laying of the eggs, in order to assure the female with a sufficient amount of food to positively accomplish the clutch. In the inside of the colony the pair defends a small area around the nest from other birds. When a predator enters a colony the adults fly up and pounce upon the intruder, sometimes hitting it with their droppings. |
| Habitat | it is found along littorals and along the banks of internal waters (rivers and lakes). In the internal zones of Europe a great deal of them nest only in some natural water courses in France, Italy, Poland. In central Europe a lot of sites of nidification of the common tern have been destroyed by the diversion of water courses and by pollution. |
| Food habits | it feeds on small fishes that it catches with its beak in the water, diving after having spotted them flying over water surface. It also feeds on insects that it catches while flying. |
| Nidification | it is a monogamous species, it nests in colonies or isolated pairs. The nest is built on the ground and covered with seaweeds, grass and shells. The female lays 2 or 3 eggs and the incubation lasts 22-26 days. The third egg is smaller than the other two, and it is the one that survives with more difficulties. The chicks stay in the nest little longer than three weeks. Both parents take care of the chicks. Parents feed their chicks on the food they regurgitate until the chicks can provide for food on their own. |
| Status in the lagoon | it nests in the salt marshes of Venice open lagoon, inside some fish farms in the lagoons of Venice and Caorle. |
| Sources | |
| References | Canada's AquaticEnvironment Atlante degli Uccelli Nidificanti in Provincia di Venezia - a cura di M. Bon, G. Cherubini, M. Semenzato, E. Stival - Provincia di Venezia, Assessorato Caccia e Pesca. |
| Web References | http://www.aquatic.uoguelph.ca/ http://www.oiseaux.net/oiseaux/ |
| FSource of the photo | http://www.oiseaux-nature.com |
| Source of the call | http://www.oiseaux.net/ |
| Source of the video | http://www.rspb.org.uk/ |
Sterna hirundo
