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Article
Thore Koppetsch, Auteur ; Laima Bagdonaitė, Auteur ; Ana Teresa Capucho, Auteur ; Bjørn Olav Tveit, Auteur ; Arild Johnsen, AuteurIdentifying inconspicuous hybrids in the wild can be challenging and might cause a low rate of detectability for phenotypically similar species. Here, we report on a record of a hybrid between Marsh Tit (Poecile palustris) and Willow Tit (P. mon[...]
Article
Gaute Grønstøl, Auteur ; Marie Danielsen, Auteur ; Emily R. A. Cramer, Auteur ; Lars Erik Johannessen, Auteur ; Arild Johnsen, Auteur ; Emma Whittington, Auteur ; Jan T. Lifjeld, AuteurSperm cells are variable both within and among species. To be able to accurately measure sperm cells and understand their function, it is important that sperm cells are preserved in a manner that maintains their structural integrity. Formalin is[...]
Article
Emily R. A. Cramer, Auteur ; Melissah Rowe, Auteur ; Fabrice Eroukhmanoff, Auteur ; Jan T. Lifjeld, Auteur ; Glenn-Peter Sætre, Auteur ; Arild Johnsen, AuteurSperm swimming performance, including swimming speed and the proportion of motile cells, may strongly affect fertilization success. However, little is known about how methodological factors affect in vitro measurement of these parameters. We com[...]
Article
Silje Hogner, Auteur ; Albert Burgas Riera, Auteur ; Margrethe Wold, Auteur ; Jan T. Lifjeld, Auteur ; Arild Johnsen, AuteurHybridization between members of different genera is relatively rare in nature. Here, we present the first molecular evidence of an intergeneric hybrid within the avian Muscicapidae family. The suspected hybrid was captured at Lista Bird Observa[...]
Article
Aleš Svoboda, Auteur ; Gunnhild Marthinsen, Auteur ; Václav Pavel, Auteur ; Bohumír Chutný, Auteur ; Lucia Turčoková, Auteur ; Jan T. Lifjeld, Auteur ; Arild Johnsen, AuteurLong-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,[...]
Article
Arild Johnsen, Auteur ; Eirik Rindal, Auteur ; Per G. P. Ericson, Auteur ; Dario Zuccon, Auteur ; Kevin C. R. Kerr, Auteur ; Mark Y. Stoeckle, Auteur ; Jan T. Lifjeld, AuteurBirds are a taxonomically well-described group of animals, yet DNA barcoding, i.e., the molecular characterization of species using a standardized genetic marker, has revealed unexpected patterns of genetic divergences among North American birds[...]
Article
Jan T. Lifjeld, Auteur ; Terje Laskemoen, Auteur ; Frode Fossoy, Auteur ; Arild Johnsen, Auteur ; Oddmund Kleven, AuteurInformation about male infertility in free-living birds is scarce, but anecdotal and circumstantial evidence suggests that it does occur regularly at a low frequency. In this paper we document three cases of azoospermia in two passerine species,[...]
Article
Eduardo Garcia-Del-Rey, Auteur ; Gunnhild Marthinsen, Auteur ; Pascual Calabuig, Auteur ; Loly Estevez, Auteur ; Lars Erik Johannessen, Auteur ; Arild Johnsen, Auteur ; Terje Laskemoen, Auteur ; Jan T. Lifjeld, AuteurThe Blue Chaffinch (Fringilla teydea) is endemic to the Canary Islands and restricted to the pine forests on Tenerife (ssp. teydea) and Gran Canaria (ssp. polatzeki). While the teydea population is large and stable, the polatzeki population unde[...]
Article
Hanna N. Stostad, Auteur ; Silje L. Rekdal, Auteur ; Oddmund Kleven, Auteur ; Terje Laskemoen, Auteur ; Gunnhild Marthinsen, Auteur ; Arild Johnsen, Auteur ; Jan T. Lifjeld, AuteurSperm morphology is highly diversified among species and at higher taxonomic levels. In birds, there is also increasing evidence of geographical differentiation in sperm traits within species, especially in those with strong sperm competition. G[...]
Article
Jan T. Lifjeld, Auteur ; Gunnhild Marthinsen, Auteur ; Magne Myklebust, Auteur ; Deborah A. Dawson, Auteur ; Arild Johnsen, AuteurWe present photographic and molecular evidence of a wild Marsh Warbler x Sedge Warbler (Acrocephalus palustris x A. schoenobaenus) hybrid that occurred over three breeding seasons (2007-2009) near Trondheim, Central Norway. The bird had the appe[...]
