Browsing Museene by Author "Johannessen, Lars Erik"

Now showing items 1-6 of 6

  • Additions and updates to the list of specimens of Imperial Woodpecker Campephilus imperialis (Gould, 1832), including genetic analysis of a putative clutch of eggs 
    Leese, Benjamin E.; Johannessen, Lars Erik; Schrøder-Nielsen, Audun; Mlíkovský, Jiří; Gorney, Don; Schreffler, Leon; Schreffler, Jane (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    We present an addendum to the list of known specimens of Imperial Woodpecker Campephilus imperialis published by Brown & Clark in 2009. The addendum adds a total of 31 specimens, comprising 15 mounts, ten study skins, three ...
  • Collections of Arctic Plants, Lichens, and Fungi in the Natural History Museum, University of Oslo, Norway 
    Bjorå, Charlotte Sletten; Bendiksby, Mika; Johannessen, Lars Erik; Løfall, Bjørn Petter; Timdal, Einar (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2023)
    The Arctic has been, and is, an area of focus for the botanical and fungal (lichenized fungi included) collections at the Natural History Museum of Oslo. These collections house more than 233,000 unique Arctic specimens, ...
  • Effects of fixatives and storage duration on avian sperm morphology 
    Grønstøl, Gaute; Danielsen, Marie; Cramer, Becky; Johannessen, Lars Erik; Johnsen, Arild; Whittington, Emma; Lifjeld, Jan Terje (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    Abstract Sperm 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 ...
  • Longer Sperm Swim More Slowly in the Canary Islands Chiffchaff 
    Cramer, Emily Rebecca A; Garcia-del-Rey, Eduardo; Johannessen, Lars Erik; Laskemoen, Terje; Marthinsen, Gunnhild; Johnsen, Arild; Lifjeld, Jan Terje (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Sperm swimming performance affects male fertilization success, particularly in species with high sperm competition. Understanding how sperm morphology impacts swimming performance is therefore important. Sperm swimming ...
  • Sperm length variation among Afrotropical songbirds reflects phylogeny rather than adaptations to the tropical environment 
    Omotoriogun, Taiwo Crossby; Albrecht, Tomas; Gohli, Jostein; Horák, David; Johannessen, Lars Erik; Johnsen, Arild; Kreisinger, Jakub; Marki, Petter Zahl; Ottosson, Ulf; Rowe, Melissah; Sedlacek, Ondrej; Lifjeld, Jan Terje (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    Sperm cells vary tremendously in size and shape across the animal kingdom. In songbirds (Aves: Passeri), sperm have a characteristic helical form but vary considerably in size. Most of our knowledge about sperm morphology ...
  • Sperm performance in conspecific and heterospecific female fluid 
    Cramer, Emily Rebecca A; Stensrud, Even; Marthinsen, Gunnhild; Hogner, Silje; Johannessen, Lars Erik; Laskemoen, Terje; Eybert, Marie-Christine; Slagsvold, Tore; Lifjeld, Jan Terje; Johnsen, Arild (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2016)
    Divergent sexual selection within allopatric populations may result in divergent sexual phenotypes, which can act as reproductive barriers between populations upon secondary contact. This hypothesis has been most tested ...