![]() ![]() We detected a genetic bottleneck in the contemporary Biebrza Valley subpopulation, and (less certainly) in both historical and contemporary Polesie. This is regarded to be sufficient to protect populations from inbreeding depression, but not to retain their evolutionary potential in the long term (Frankham 2014). We also found a moderate effective population size of approximately 200 individuals. The expected heterozygosity (0.44-0.48) was comparable to that of endangered avian species (Evans & Sheldon 2008). The Aquatic Warblers from the studied subpopulations had low genetic diversity, which did not change over the study period. Grey circles denote numbers of singing males as estimated between 20 © Kubacka et al. We then compared these metrics both in space and in time.įigure 2 The sampled breeding sites and the breeding range of the Aquatic Warbler. We determined genetic diversity, expansions and reductions of population size, genetic structuring and exchange of individuals between subpopulations. Aquatic Warblers were sampled from about one quarter of their complete breeding range, in two subpopulations: Biebrza Valley and eastern Polesie in Poland (Fig. The contemporary samples were collected about 10-15 years after launching conservation actions to improve the breeding habitat, such as mowing to reduce overgrowth by reeds and bushes. We used genetic markers (11 microsatellites) determined from blood samples recently collected in breeding areas (in 2014 contemporary) and about two decades earlier (in 1990-1998 historical). In our recent study, we measured the genetic health of a large fraction of the Aquatic Warbler population. It helps indicate population management units, identify areas where habitat should be restored to reconnect isolated populations, and assess extinction risk more precisely (Holderegger et al. ![]() For this reason, studying population genetics is vital for effective species conservation. All of these processes negatively affect population growth and increase extinction risk, especially in habitat specialists (Pflüger et al. This can slow down exchange of individuals between subpopulations (genetic isolation), induce loss of genetic diversity if a subpopulation is small (genetic drift), and enhance breeding of more related individuals (causing inbreeding depression). schoenobaenus) (BirdLife International 2022).įigure 1 A fen mire, breeding habitat of the Aquatic Warbler © Szczepan Skibicki.īreeding habitat loss can lead to fragmentation of populations. As of the 1990s, the rate of decline has decelerated but the global population is 18,000-29,000 mature individuals, about three orders of magnitude less than in other common Acrocephalids such as the Sedge Warbler ( A. Today, the breeding range of the Aquatic Warbler is constrained to east-central Europe (Belarus, Ukraine, Poland and Lithuania), which holds c. Only between the 1950s and 1980s the population shrank by 95% (Briedis & Keiss 2016). Following the loss of breeding habitats, the Aquatic Warbler, once widespread in temperate Europe, suffered a steep decline. For centuries, fens have been lost and fragmented due to peat extraction, river regulation, drainage for agricultural use, excess of nutrients and abandonment of farming (Tanneberger & Kubacka 2018). 1), which formed thousands of years ago, mainly in river valleys. Fens are grassland-type wetlands low in nutrients and typically dominated by sedges (Fig. ![]() It is a migratory bird wintering south of the Sahara, specialised to breed in lowland open marshland – fens. The Aquatic Warbler ( Acrocephalus paludicola) is one of the rarest European songbirds, listed as vulnerable to extinction by IUCN (BirdLife International 2022). Kubacka J., Dubiec A., Korb J., Salewski V., Dyrcz A., Foucher J., Giessing B., Leisler B., Schulze-Hagen K., Wink M & Panagiotopoulou H. Low genetic diversity and high gene flow in the Aquatic Warbler ( Acrocephalus paludicola), a threatened marshland songbird with a fragmented breeding range. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |