Avocet

The Avocet (Recurvirostra avosetta) breeds on the coasts of Europe, except in the far north, and is rarer in the interior of the continent. It is very rare in Slovenia, breeding in only two locations, the Sečovlje salt pans and the NRŠZ.

It first attempted to nest in the Sečovlje salt pans in 1994, but was unsuccessful. Nesting was confirmed for the first time in Slovenia in June 2001. There were two eggs in a nest on the sand in the middle of an abandoned salt field, and one chick hatched, but disappeared after a few days. In 2005, Avocet successfully nested on Lera. All three chicks hatched and were ringed. In 2006 and 2007, the Snowy Owl did not nest. Since 2008, it has been nesting regularly and the number of nesting pairs has been increasing rapidly; 28 pairs nested in 2014 and 40 pairs in 2016. The entire Slovenian Avocet population nests just a few metres above sea level. It inhabits mostly open areas, seashores, other saltwater shores, marine lagoons, salt marshes, river estuaries, irrigation areas, flood plains in arid areas and also brackish marshes with islands, wherever there is only some vegetation. It is also found in inland waters. It nests on bare dykes and muddy islands with little vegetation, even in the middle of salt pans. It builds its nest on a clump of vegetation, using bits of shells, snails, stones and plant parts, or by digging a hollow in the ground and lining it with finer nesting material. Water levels, which drop during the summer months, play an important role in the feeding of the species. As a highly social species, the Avocet nests mainly colonially, so that individual nests may be less than 1 m apart. In the Sečovlje salt pans, during the initial colonisation period (2008-2009), it nested on 8 ha, with 3-4 pairs, which translates to a density of 0.4-0.5 pairs/ha. Subsequently, in the period 2010-2015, both the colonisation area within the salt pans and the population (20 ha, 8-27 pairs) have increased, which translates into a density of 0.4-1.4 pairs/ha. The nesting density has further increased with the construction of artificial islands. The larger islands have higher nest densities than the smaller islands. As a distinct local breeder with a small breeding population, the Avocet can be classified as a threatened species in our country. Although the number of breeding pairs in the Sečovlje salt pans is increasing, the breeding population is threatened mainly by terrestrial predators, but also by magpies and grey crows that prey on the eggs. The conservation trend of the population is uncertain at global level and its abundance fluctuates in Europe. In Europe, the Avocet is threatened by pollution of wetlands with PCBs, insecticides, lead and mercury. In important wintering areas, it is threatened by human disturbance, development and pollution.

*In the Sečovlje salt pans it is considered a qualifying species in favourable conservation status.