Sügisränne Põõsaspeal 2014. aastal

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)


Interna författare/redaktörer


Publikationens författare: Margus Ellermaa, Andreas Lindén
Förläggare: Eesti Looduseuurijate Selts, Eesti Ornitoloogiaühing
Förlagsort: Tartu, Estonia
Publiceringsår: 2015
Tidskrift: Hirundo
Volym: 28
Nummer: 1
Artikelns första sida, sidnummer: 20
Artikelns sista sida, sidnummer: 49


Abstrakt

The article provides an overview of the autumn migration of birds in Cape Põõsaspea (North-Western Estonia: 59°13’N, 23°30’E) in 2014. The counts took place on a daily basis between 1st of July and 6th of November. Altogether, 1.94 million waterbirds (orders Gaviiformes, Podicipediformes, Anseriformes, Pelecaniformes and Charadriformes) passed through the monitoring point. The corresponding value for 2009 was 2.14 million birds. In this paper we examined sex and age ratios of the species that concentrate at the monitoring site in high numbers related to their North-European flyway populations.

Long-tailed ducks (Clangula hyemalis), globally red listed as vulnerable, were recorded in similar numbers compared with 2009 (ca 0.3 million individuals). Velvet scoter (Melanitta fusca), globally red listed as endangered, was more abundant in 2014 (74 000 individuals) compared with 2009 (58 000 individuals). The proportion of juvenile birds – as a proxy for breeding success – for observed species was similar to 2009 counts. As in 2009, the proportion of juvenile birds tended to be lower for species which are breeding mainly in the arctic areas and northern boreal zones compared with species breeding in more temperate breeding areas (e.g. across the Baltic Sea basin). The latter group tended to have, however, interspecific differences: some species almost lacked juvenile birds in their migration flocks (e.g. little gull, Hydrocoleus minutus) and some had apparently had very good breeding success (e.g. Sandwich tern, Sterna sandwichensis). An extended summary in English is presented in the online supplementary material.

Senast uppdaterad 2019-23-11 vid 01:56