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Prague, Czech Republic

Hogner S.,University of Oslo | Laskemoen T.,University of Oslo | Lifjeld J.T.,University of Oslo | Pavel V.,Palacky University | And 5 more authors.
Behavioral Ecology and Sociobiology | Year: 2013

Spermatozoa are among the most variable animal cell types, and much research is currently directed towards explaining inter- and intraspecific variation in sperm form and function. Recent comparative studies in passerine birds have found associations between the level of sperm competition and both sperm length and sperm velocity. In species with sperm competition, postcopulatory sexual selection may shape the morphology of sperm as adaptations to the female environment. The speed of evolutionary change in sperm morphology at the species level is largely unknown. In this study, we analysed variation in sperm morphology among morphologically distinct and geographically isolated bluethroat subspecies in Europe. Consistent with previous studies, our analyses of mtDNA and nuclear introns suggest recent divergence and lack of lineage sorting among the subspecies. We found significant divergence in total sperm length and in the length of some sperm components (i.e. head and midpiece). There was a significantly positive relationship between pairwise divergences in sperm morphology and mitochondrial DNA, suggesting a role for genetic drift in sperm divergence. The magnitude of sperm length divergence was considerably higher than that in other geographically structured passerines, and even higher than that observed between several pairs of sister species. We hypothesize that the rapid sperm evolution in bluethroats is driven by sperm competition, and that strong postcopulatory sexual selection on sperm traits can lead to rapid speciation through reproductive incompatibilities. © 2013 Springer-Verlag Berlin Heidelberg. Source


Pavel V.,Katedra Zoologie A Ornitologicka Laborator PrF | Chutny B.,Malinova 27
Sylvia | Year: 2010

We present an interesting source of colour leg rings for birds - HAMA beads. These inexpensive beads are available in toy stores, they are made from durable plastic and easy to apply. The product is imported to the Czech Republic by Lowlands International (http://www.lowlands.cz). The rings are lost by the birds in the same rate as the standard professional colour rings (the interseasonal loss rate tested in the Bluethroat Luscinia svecica svecica was 3.17 versus 2.93%) and their colours are mostly resistant to wear (except for brown and orange). Their major limitation is that only two sizes are available (HAMA MIDI and HAMA MAXI, with inside diameters of 2.8 and 6 mm, respectively). Source


Turcokova L.,Palacky University | Pavel V.,Palacky University | Chutny B.,Malinova 27 | Petrusek A.,Charles University | Petruskova T.,Charles University
Journal of Ornithology | Year: 2011

Differences in vocalization between subspecies of songbirds may influence intraspecific interactions including mate choice and territorial behavior, and contribute to their further divergence by strengthening pre-mating reproductive isolation. We have recently shown that songs of two Bluethroat subspecies, Luscinia svecica svecia and L. s. cyanecula, differ in spectral characteristics and structure. Here, in a first experimental test of whether these differences are biologically relevant, we compared responses of L. s. svecica males to both types of songs. Altogether 19 males from a subartic population in Abisko, Sweden, were exposed to playbacks of songs from the two subspecies, accompanied by display of a stuffed Bluethroat lacking subspecies-specific colour marks. These stimuli were presented in random order, separated by over 1 h. We evaluated two largely uncorrelated components of male responses: non-vocal territorial behavior, and singing activity. A significant difference in reaction to subspecies playbacks was observed in aggressive behavior: independently of the song order, males generally responded more strongly to playback of their own subspecies. In contrast, playback order rather than subspecies identity significantly influenced the singing activity, which usually increased in the second trial. A more detailed analysis nevertheless suggested that vocal responses of birds exposed first to playback of their own subspecies were stimulated in the subsequent trial but not vice versa. Our results show that Bluethroats clearly discriminate the two song types, indicating the potential for subspecies recognition. Further experimental work is needed to assess the general validity of these patterns. © 2011 Dt. Ornithologen-Gesellschaft e.V. Source


Svoboda A.,Palacky University | Marthinsen G.,University of Oslo | Pavel V.,Palacky University | Chutny B.,Malinova 27 | And 3 more authors.
Journal of Ornithology | Year: 2014

Long-distance migratory birds are potentially exposed to a range of blood sucking arthropods that transmit avian blood parasites. Because of differential vector exposure, the parasite fauna may vary in different habitat types, among populations, or even within populations where individuals travel to different areas during migration. We applied PCR-based molecular techniques to determine patterns of blood parasite occurrence in adults of seven geographically isolated Bluethroat populations, belonging to three distinct subspecies differing in habitat preferences and wintering areas (Luscinia svecica svecica, L. s. cyanecula, L. s. namnetum). Moreover, to elucidate potential transmission of blood parasites on breeding sites, we tested adults of the relatively sedentary White-throated Dipper (Cinclus cinclus) from a Norwegian population. Across populations, we detected infection of at least one blood parasite genus in 68.5 % (139/203) of adult Bluethroats. The most common parasite genus was Plasmodium (10 lineages, 33.5 % of surveyed individuals), present in all seven populations, followed by Leucocytozoon (four lineages, 31.5 %) and Haemoproteus (two lineages, 4.9 %). We recorded multiple infections in 26.1 % of individuals. Leucocytozoon was found only in svecica inhabiting mountainous/subalpine areas with high abundance of blackflies, the main vector for this parasite. In Plasmodium, two lineages (BT6 and GRW4) were confined to specimens from svecica populations. In contrast, Lineage SGS1 was dominated by southern birds of the subspecies cyanecula and namnetum. Our data suggest transmission of Leucocytozoon on the breeding grounds in Norway as the same lineages were found in relatively sedentary White-throated Dippers as in migratory Bluethroats. We discuss these results in light of the ecological differences between the host populations, affecting their exposure to potential blood parasite vectors. © Dt. Ornithologen-Gesellschaft e.V. 2014. Source

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