Published in: BMC Evolutionary Biology 2011, 11:100
Abstract
Background
Recent theoretical and empirical work points toward a significant role for sex-chromosome linked genes in the evolution of traits that induce reproductive isolation and for traits that evolve under influence of sexual selection. Empirical studies including recently diverged (Pleistocene), short-lived avian species pairs with short generation times have found that introgression occurs on the autosomes but not on the Z-chromosome. Here we study genetic differentiation and gene flow in the long-lived greater spotted eagle (Aquila clanga) and lesser spotted eagle (A. pomarina), two species with comparatively long generation times.
Results
Our data suggest that there is a directional bias in migration rates between hybridizing spotted eagles in eastern Europe. We find that a model including post divergence gene flow fits our data best for both autosomal and Z-chromosome linked loci but, for the Z-chromosome, the rate is reduced in the direction from A. pomarina to A. clanga.
Conclusions
The fact that some introgression still occurs on the Z-chromosome between these species suggests that the differentiation process is in a more premature phase in our study system than in previously studied avian species pairs and that could be explained by a shorter divergence time and/or a longer average generation time in the spotted eagles. The results are in agreement with field observations and provide further insight into the role of sex-linked loci for the build-up of barriers to gene flow among diverging populations and species.
Re: Greater Spotted Eagles and Hybrids
Posted: April 8th, 2012, 11:15 pm
by Felis silvestris
17. Eesti kotkaste seire – näiteid haruldaste liikide staatuse ja arvukuse määramisest = Monitoring Estonian eagles: examples of following status and abundance of rare species. By Väli, Ü.; Männik, R.; Nellis, R.; Sein, G.; Tuvi, J. (2011)
Chapter in a book: Eesti Loodusuurijate Seltsi Aastaraamat, Tartu: Eesti Looduseuurijate Selts, 2011
p. 92-106
Greater Spotted Eagle Aquila clanga and Lesser Spotted Eagle Aquila pomarina are hybridising Eurasian raptors, but our knowledge of hybrid fertility is poor. Here, I present a case of interbreeding between a F1 hybrid spotted eagle male and a Lesser Spotted Eagle female in Estonia. The hybrid was first studied and ringed as a nestling in 1999, showing characters of both species. In 2009, the same bird was caught and, surprisingly, this ten-year-old individual had retained several immature characters. Again, characters of both species were recorded in the hybrid, as well as in his backcross-offspring. At the nest site level, the habitat of the hybrid’s hatching site was intermediate but its nesting site was typical of A. pomarina. At the landscape level hatching and breeding sites resembled habitat typical of A. clanga in Estonia.
Presentation at: International Meeting on Spotted Eagles (Aquila clanga, A. pomarina and A. hastata) – Research and Conservation, Osowiec, Poland, 16–18 September 2005
Re: Greater Spotted Eagles and Hybrids
Posted: April 9th, 2012, 4:28 pm
by Felis silvestris
22. Habitat use by the Vulnerable greater spotted eagle Aquila clanga interbreeding with the lesser spotted eagle Aquila pomarina in Estonia. By Asko Lõhmus and Ülo Väli (2005)
24. Genetic structure of Greater Aquila clanga and Lesser Spotted Eagle A. pomarina populations: implications for phylogeography and conservation. By Väli, Ü.; Treinys, R.; Poirazidis, K. (2004)
Published in: Molecular Ecology. 11.2002,10 p. 2189-2194
Abstract
The mitochondrial pseudo-control region was analysed in five species of Aquila eagles. Indels caused great length differences in the nonrepetitive part of the region, whereas tandem repeat units were highly conserved among the genus. In a reconstructed phylogenetic tree, the clade formed by A. clanga and A. pomarina showed approximately the same distance to A. chrysaetos as did the clade A. heliaca/nipalensis. In Estonian subpopulations, 12 haplotypes were found among 51 A. pomarina
individuals and 7 haplotypes among 8 A. clanga individuals. Nucleotide diversity in A. clanga was greater, and may be caused bydecreased breeding density or by gene flow from other subpopulations.
Keywords: bird, endangered species, mtDNA, phylogeny, population diversity, spotted eagle
Re: Greater Spotted Eagles and Hybrids
Posted: April 19th, 2012, 10:36 pm
by Felis silvestris
27. Schelladler Aquila clanga brütet in partiellem Jugendgefieder. By B.-U. Meyburg, Tadeusz Mizera, Grzegorz Maciorowski und Jan Kowalski (1997)
The Capital will soon have a bird conservation programme for 30-40 species of birds. The Bombay Natural History Society (BNHS) will monitor 40-50 common birds ... [among them the Greater Spotted Eagles] ... to know their population and area-specific distribution before it starts the conservation project.
Thanks to Maertha for suggesting the article!
Re: Greater Spotted Eagles and Hybrids
Posted: February 10th, 2013, 2:44 pm
by Felis silvestris
33. Adler im Anflug
Mention in a Journal article
Tõnn's brother/sister Tore was visiting Switzerland on his first migration and was mentioned in Swiss ornithological journal Ornis, 2013, No. 1 - page 26: Birder's Corner
Full text available by finding a Subscribing Institution or buying the journal
Thanks to Manu for finding it!
Re: Greater Spotted Eagles and Hybrids
Posted: July 16th, 2013, 10:25 pm
by Felis silvestris
34. The diet of the greater spotted eagle (Aquila clanga) in Belarusian Polesie : Potrava orla hrubozobého (Aquila clanga) v Bieloruskom Polesí. 2010
by Valery Dombrovsky
Published in: Slovak Raptor Journal, 2010, 4 p. 23–36
During 1999-2009 the food remains from the nests of 43 breeding pairs of the greater spotted eagle in Belarusian Polesie (southern Belarus) were collected. 797 prey items were determined, including mammals (40%, 15 species and Sylvaemus sp., 4 orders), birds (36%, 35 species and Phylloscopus sp., Corvidae sp., 11 orders), evertebrates (16%, Coleoptera, Odonatoptera, Gastropoda), reptiles (6%, 4 species and Lacerta sp.), amphibians (1%, Rana sp.) and fish (1%, 3 species). Small rodents from the genus Microtus (M. arvalis and M. oeconomus) as well as Arvicola amphibius were the most numerous mammal species, followed by Erinaceus roumanicus and Talpa europaea. Rallidae (mostly Rallus aquaticus, Porzana porzana and Crex crex), waders (mainly Galinago gallinago), dabbling ducks (mainly Anas platyrhynchos and Anas querquedula), Galliformes (Lyrurus tetrix), Ciconiiformes (Ardea cinerea and Botaurus stellaris) were the most numerous bird prey species. Emberiza schoeniclus was predominated prey species among Passerines. Reptiles were frequently represented by snakes (mainly Natrix natrix, but also Vipera berus and Coronella austriaca). Biomass predominance in diet of the greater spotted eagles is as follows: birds (67.9%), mammals (25.3%), reptiles (3.4%), fish (3.0%) and amphibians (0.3%). Prey species with a body mass of 51-200 g (41.9%) and 11-50 g (38.3%) were predominant in the food spectrum of the greater spotted eagles. In the weight category of 1-50g, mammals were dominant, but from the categories of 51-200 g and heavier, birds occupied the leading position. The prey which made the largest contribution in total biomass of the greater spotted eagle were in the prey weight category from 601 to 1200 g (34%), then from 51 to 200 g (24%), from 11 to 50 g (16.6%) and more than 1200 g (16%). The species of the genus Microtus were equally represented in prey set of the greater spotted eagle in habitats with different degrees of anthropogenic transformation (24% in each habitat type). The share of Arvicola amphibius in the diet of the greater spotted eagle decreased from 12% in natural habitats to 4% in transformed habitats; the share of birds decreased from 41% to 26% correspondingly. The share of Insectivora and Evertebrata, on the contrary, increased to 3% and 11% in natural habitats and to 6% and 27% in transformed habitats correspondingly.