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Article
Sarah Malick-Wahls, Auteur ; Ingvar Byrkjedal, Auteur ; Barbara Ganter, Auteur ; Jan T. Lifjeld, Auteur ; Gunnhild Marthinsen, Auteur ; Hans-Ulrich Rösner, Auteur ; Terje Lislevand, AuteurThe sex of Dunlins from two widely separated Norwegian breeding populations can be determined using morphometrics, with the Dunlins’ sizes differing between populations. We aimed to understand the Dunlin’s physical characteristics within and out[...]
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
Taiwo C. Omotoriogun, Auteur ; Terje Laskemoen, Auteur ; Melissah Rowe, Auteur ; Tomáš Albrecht, Auteur ; Rauri C. K. Bowie, Auteur ; Ondřej Sedláček, Auteur ; David Hořák, Auteur ; Ulf Ottosson, Auteur ; Jan T. Lifjeld, AuteurBirds show considerable variation in sperm morphology. Closely related species and subspecies can show diagnostic differences in sperm size. There is also variation in sperm size among males within a population, and recent evidence from passerin[...]
Article
Terje Laskemoen, Auteur ; Frode Fossoy, Auteur ; Geir Rudolfsen, Auteur ; Jan T. Lifjeld, AuteurIn passerine species with frequent extrapair mating, young (second calendar year) males often have a lower fertilization success than older (after second calendar year) males. This pattern might be explained by male- or female-driven mechanisms,[...]
Article
Liv Wennerberg, Auteur ; Gunnhild Marthinsen, Auteur ; Jan T. Lifjeld, AuteurBreeding populations of southern dunlin Calidris alpina schinzii in South Fennoscandia and the Baltic are severely fragmented and declining dramatically. Information on the genetic structure and diversity is therefore of importance for the conse[...]
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
Trond Oigarden, Auteur ; Thomas Borge, Auteur ; Jan T. Lifjeld, AuteurPasserine bird species vary considerably in the frequency of extrapair paternity, but the factors causing this variation are not well understood. There is some comparative evidence that extrapair paternity is associated with the population level[...]
Article
Eduardo Garcia-Del-Rey, Auteur ; Oddmund Kleven, Auteur ; Jan T. Lifjeld, AuteurBirds breeding on islands often exhibit lower rates of extrapair paternity than their mainland counterparts, perhaps explained by low genetic variation, slower life histories and reduced sexual selection in island populations. Extrapair paternit[...]
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
Oddmund Kleven, Auteur ; Bjorn-Aksel Bjerke, Auteur ; Jan T. Lifjeld, AuteurExtrapair paternity seems to be common in socially monogamous passerines, but the genetic mating system of most species is currently unknown. Here, we report the first study of paternity in the socially monogamous Common Crossbill (Loxia curviro[...]
Article
Lars E. Johannessen, Auteur ; Dianhua Ke, Auteur ; Xin Lu, Auteur ; Jan T. Lifjeld, AuteurThe Ground Tit is a large parid species endemic to the Tibetan Plateau. Here we describe its genetic breeding system based on 2 years of fieldwork on a population from Damshung, Tibet. Genetic relatedness and parentage were analysed using 16 mic[...]
Article
Terje Laskemoen, Auteur ; Oddmund Kleven, Auteur ; Frode Fossoy, Auteur ; Jan T. Lifjeld, AuteurSperm cells are highly diversified in birds and considerable research effort has focused on variation in sperm morphology between species. However, surprisingly little is known about intraspecific variation in sperm morphology in birds. We analy[...]
Article
Oddmund Kleven, Auteur ; Trond Oigarden, Auteur ; Bjorn E. Foyn, Auteur ; Arne Moksnes, Auteur ; Eivin Roskaft, Auteur ; Geir Rudolfsen, Auteur ; Bard G. Stokke, Auteur ; Jan T. Lifjeld, AuteurSocial monogamy is common among passerines whereas genetic monogamy is regarded as rare. Here we report the first study of paternity in the genus Phoenicurus (Aves, Muscicapidae). In the socially monogamous common redstart (Phoenicurus phoenicur[...]
Article
Tycho Anker-Nilssen, Auteur ; Oddmund Kleven, Auteur ; Tomas Aarvak, Auteur ; Jan T. Lifjeld, AuteurWe investigated extra-pair paternity (EPP) among 46 young in 32 broods of 19 social pairs of Black Guillemot Cepphus grylle, using a combination of three polymorphic microsatellite markers. The analysis was based on blood samples collected over [...]
Article
Oddmund Kleven, Auteur ; Gunnhild Marthinsen, Auteur ; Jan T. Lifjeld, AuteurGenetic studies have shown that extra-pair paternity is widespread among socially monogamous bird species. Yet, the role of males and females and their behavior leading to this mixed reproductive strategy is poorly understood. Here, we analyze p[...]
Article
Tycho Anker-Nilssen, Auteur ; Oddmund Kleven, Auteur ; Tomas Aarvak, Auteur ; Jan T. Lifjeld, Auteur
Article
Primary sex ratios vary with clutch size in the size-dimorphic White-throated Dipper Cinclus cinclus
Trond Oigarden, Auteur ; Jan T. Lifjeld, AuteurSex allocation theory explains how parents should allocate reproductive effort to the rearing of sons and daughters. A central premise is that there is room for individual optimization of brood sex ratios as a function of the relative rearing co[...]
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
Terje Laskemoen, Auteur ; Oddmund Kleven, Auteur ; Lars Erik Johannessen, Auteur ; Frode Fossoy, Auteur ; Raleigh J. Robertson, Auteur ; Jan T. Lifjeld, AuteurSperm morphometry and motility are important male traits affecting fertility and post-copulatory competitive ability. However, studies examining consistency in sperm traits over time for individual males are rather scarce, particularly in free-l[...]
Article
Terje Lislevand, Auteur ; Gunnhild Marthinsen, Auteur ; Jan T. Lifjeld, AuteurThere have been very few reports of body size measurements of live Temminck's Stints, but earlier studies have shown sex differences in body mass and tarsus length. Here we use molecular techniques to determine the sex of Temminck's Stints from [...]
Article
Oddmund Kleven, Auteur ; Terje Laskemoen, Auteur ; Jan T. Lifjeld, AuteurHow long is a sand martin Riparia riparia spermatozoon? In a recent study, Helfenstein et al. (2008) presented data on the intraspecific variation in sperm length, swimming speed and longevity in this species and some interesting correlations be[...]
Article
Emily R. A. Cramer, Auteur ; Terje Laskemoen, Auteur ; Oddmund Kleven, Auteur ; Jan T. Lifjeld, AuteurIt is well documented that sperm size and structure varies considerably among avian species, but we know much less about the extent of intraspecific variation in sperm morphometry and its possible co-variation with somatic traits like body size [...]
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[...]
