The feared invasion of cormorants inland has failed to materialise – Pori’s Enäjärvi colony is also declining

Food availability is an important criterion for cormorants when choosing a nesting site. Therefore, the formation of large inland colonies is not considered likely.

The Finnish Environment Institute assures that the controversial cormorant is not spreading inland to nest.

The bird, which eats a lot of fish and destroys the habitat of its nesting site with its droppings, has only managed to breed inland in three places in Finland.

By far the largest inland community is in Pori Enäjärvi, where last year nearly two thousand nests of cormorants protected by nature conservation legislation were counted. Now the number has started to fall.

The cormorants arrived to nest on Enäjärvi in \u200b\u200b2020 and has been considered the first success of the bird inland.

In addition to Lake Enäjärvi in \u200b\u200bPori, the Finnish Environment Institute has an observation from the 2020s from small communities of less than 15 nests in Lahti Vesijärvi and Vanajanselkä from Valkeakoski.

There is plenty of food at sea

No signs that the species is spreading to nest elsewhere inland has been observed.

There is no nest in the community of Vanajanselkä.

The big inland community of Lake Enäjärvi in \u200b\u200bPori is explained by the fact that it is located only a couple of kilometers from the seaside, ie Enäjärvi cormorants acquire their nourishment from the sea. Therefore, it is not considered a pure cormorant inland community.

Indeed, dietary intake is a key criterion when the cormorant chooses a nesting site. There is plenty of fish at sea, so the cormorant may not be worth expanding the nesting area to Lake Inland.

– In deep inland, the amount of dietary dietary limits the growth of cormorants, which is probably why these communities in Vesijärvi and Vanajanselkä have remained small, says Rusanen.

A total of about 32,000 cormorants of cormorants were lowered in Finland last summer. The number increased by about four thousand nests from the previous year.

Clearly the largest cormorant community in Finland lives in the area of \u200b\u200bthe Port of Rauma, where last year, 7,650 cormorants, almost a quarter of the country’s cormorant stock, was lowered.

In addition, this is the largest bird community in Finland ever.