The black-crowned night heron (Nycticorax nycticorax) is the most numerous species in the heron family.
It is a migratory species, which comes to Romania in April and it leaves in November, heading to Africa. Sometimes, it successfully winters in the reed areas.
It has a robust and thick body. It has a shorter neck and shorterlegs compared to the other species of herons.
It is a nocturnal species and its big, red eyes are adapted to dim light. Its plumage is a combination of dark grey, black and white feathers on its abdomen.
This heron feeds itself in shallow waters. It prowls or it slowly walks trying to catch frogs and other aquatic animals.
It nests in mixed colonies, alongside the glossy ibis, the egret or the Eurasian spoonbill. Rarely it forms specific colonies.
The nests have a diameter of 35 to 45 cm and a height of 25 to 30 cm and they are built on the superior sides of the trees.
During pairing season, its legs become yellow or pink and sometimes even reddish. The pairing ritual takes place during night time.
The female lays 4 or 5 green to blue eggs. The eggs are incubated for 22 days by both parents.
Every 2 to 4 days, during a specific ritual, the partners exchange places in the nest. While doing this, the birds communicate through their nape feathers.
The number of black-crowned night herons is dropping. This species is protected by both local and international legislation.