THEMES

Sterna, all the information

Sterna, all the information

Thereterncommon is asea ​​birdbelonging to the Laridae family, the same as theseagulls.

Where does he live? Therecommon tern, scientific nameSterna hirundo, is very widespread. It is found from North America to the Caribbean, from Europe to North Africa, to the Middle East and Siberia. And theternmore common in Europe and is also present in the Mediterranean coasts.

Sterna in Italy: where he lives

In Italy, thetern hirundoit lives mainly in the upper Adriatic, in the coastal areas of Friuli Venezia Giulia and in Sardinia. It is found in the Po Valley and in many wet and brackish areas of the north. There is no shortage of small populations observed on the central and southern coasts of Italy. For example, thetern hirundo, together withtern zampenere, are present in the list of birds often observed in Campania.

Its favorite habitat is sandy or pebble beaches, dunes, brackish marshes, pools of water ... It prefers meadows and moors, but also lives on rocky coasts. Unlike thearctic tern, thecommon terntolerates the presence of denser vegetation, but avoid areas where the vegetation is very high (more tolerated, however, by the speciessterna dougallii).

Therecommon ternit has a great ability to adapt: ​​it can also settle on large artificial floating platforms, wharfs and even nestle on the flat roofs of factories near the sea.

Theretern hirundouse anything as a roost: buoys, docks, rafts, boats, rocks… InItalyit is present both as a migrant and for the preparation of the nest.

Sterna hirundo and nilotic tern

As stated, inItalythere is also thetern zampenere (or nilotic tern). The first nesting areas of this tern date back to 1954, in the Comacchio Valleys. Today, thetern zampenereit can be easily spotted throughout Southern Italy, in particular Campania, Puglia, Sicily and Sardinia.

It is easy to distinguish thenilotic ternfrom the common tern: the nilotic tern has a massive black beak and dark legs.

A careless eye can confuse the different species of terns. Therecommon ternit is distinguished above all by the conformation of the tail, which is particularly long and forked. This bird is appreciated for its wide wingspan: 80 cm may seem few, but when compared to the 40 cm in length of the body (including the tail) we understand that this bird is a real spectacle in flight.

In the photo above, a chick fromcommon tern. It is important to point out that the nest of thetern it can be easily attacked by other seabirds, especially the herring gull. The reproduction of the tern, especially of the Nilotic species, is very threatened by the strong presence of predators both from the disturbance and the presence of man. Variations in the water level can also greatly damage nesting: the Nilotic tern nests especially at the foot of the marshy areas and a minimum increase in water can destroy the nest.

Sterna: what it eats

Feeding is common among the different types of terns: these birds share the same marine / brackish habitat.

There are differences in behavior. The speciessterna dougalliishows a "kleptoparasitic" behavior. Have you never heard this term? The term "kleptoparasitoco" indicates that behavior that leads an animal toto stealfood to other animals, rather than finding it on one's own. Theresterna dougalliiit has an enormous predatory ability. When the weather is bad, thesterna dougalliiit dives and collects fish that swim deeper, which are out of reach of other terns capable of diving. Despite its capabilities, commonly thesterna dougalliisteals food preyed upon by other seabirds, commonly from puffin.

What does the tern eat?
It mainly feeds on fish, amphibians, small reptiles and small mammals. It can also prey on small, newly hatched birds and the eggs of other nests.

Arctic tern or Tern paradisaea

A separate paragraph should be dedicated toarctic tern. As its name suggests, it lives in the arctic and subarctic regions of Europe, Asia and North America.

This species is stronglymigratory. Recent studies have shown that hismigrationcan take it to travel about 70,900 km (round trip) for nesting birds in Iceland and Greenland and up to 90,000 km forarctic ternsbreeding in the Netherlands. These are thelonger migrationsknown throughout the animal kingdom.

Therearctic ternit nests once every 1- 3 years, depending on the mating cycle. The Arctic tern is not present in Italy because in its migratory routes it flies over the westernmost coasts of Europe. Thearctic ternsthey are very long-lived birds: they can reach 30 years of age. The diet is the same as described above: they feed on fish and marine invertebrates.


Video: Spain vich 3 saal vadh pakka hon di information (September 2021).