Learn Terns Observed in Lithuania
Breeding
In the course of the last decade five species of terns are regular breeders in Lithuania, i.e. Little Tern (Sternula albifrons), Common Tern (Sterna hirundo) and three terns of the Chlidonias genus – Black, White-winged and Whiskered Terns (Ch. niger, Ch. leucopterus, Ch. hybrida). Habitats for breeding, distribution and abundance of the species in the country differ. The term “regular“ does not reverberate their existing situation and abundance.
Common, Little and Black Terns were included in the first national Bird Lists as regular breeders. Unfortunately, they have become endangered, mainly due to scarce breeding habitats. Due to this the Project for protection of two species of terns, i.e. Common and Little Terns, breeding on islands and coasts was started.
Common Tern. Photo by Gediminas Petkus
Little Tern. Photo by Renatas Jakaitis
Black Tern. Photo by Dalios Račkauskaitės
The first colony of White-winged Terns (10 pairs) was found in lake Žuvintas by Teofilis Zubavičius, an ornithologist, in 1955. However, in 1921 the species - several dozens of birds - was observed in lake Žuvintas presuming they bred there but no nests were found. Later throughout several decades in lake Žuvintas 5-20 pairs bred, though not each year, and in the XX century individual pairs among colonies of Black Terns were found in other places in Lithuania, but not each year.
White-winged Tern. Photo by Marius Karlonas
The first fact of breeding Whiskered Terns was identified also by Teofilis Zubavičius in lake Žuvintas in 1959. Later, in the XXI century breeding individual or several pairs were found in different areas in the country. The species was a very rare breeder in our country.
Since the beginning of the XXI century these two species have become regular breeders. The Whiskered Tern, though not abundant initially, was observed in the Nemunas Delta (lake Dumblis and the Kniaupas bay), and later – in fluvial origin lakes in the Pagėgiai municipality where up to 50 breeding pairs are observed each year. In the XXI century the White-winged Tern breeds nearly every year choosing the same breeding site for one or few seasons. Besides, their abundance varies greatly – from several to dozens of pairs. In recent years they are permanent breeders only in the Nemunas lowland sites, and today we can firmly state this species is a permanent breeder in our country, though its abundance varies.
Whiskered Tern. Photo by Dalia Račkauskaitė
Observed in Migration Season Each Year
Earlier publications included the other three species of terns - Caspian (Hydroprogne caspia), Arctic (Sterna paradisaea) and Sandwich Terns (S. sandvicensis) – observed in Lithuania as breeding ones.
However, concerning the Caspian Tern, in 1979 parents feeding their flying youngs were observed in the fish ponds of Arnionys. It is a typical situation that as soon as youngs learn flying they together with their parents migrate to further migration destinations. Such cases are often observed along the migration routes. Besides, the Caspian Tern is least expected to breed in fish ponds as the species breeds on open off shore islands in a sea or lagoon.
Breeding of the Arctic Tern on small islands of the river mouth of Atmata in 1985 is disputable, including the opinion of few observation authors. Possibly, an identification mistake of the species was made. Furthermore, the species‘ breeding sites are in northern latitudes.
Arctic Tern. Photo by Marius Karlonas
In 2017, the Sandwich Tern attempted to breed on the island of Kiaulės Nugara in the Klaipėda seaport area. Several clutches of the species were found, however, breeding was unsuccessful due to the raised water level. The species breeds solely on open off shore marine islands and the island of Kiaulės Nugara is the only island here to match the requirements. However, the island is short of habitats necessary for the species, i.e. open sandy or overgrown with poor vegetation areas. In the future, having formed habitats necessary for the species, its breeding may be expected here. For this, it is necessary to form habitats necessary for the species; or to produce a new island in expanses of the Curonian Lagoon...