Arild Johnsen

Utvalgte publikasjoner

• Grøndahl, Finn Audun & Johnsen, Arild (2024). Combining biometrics and genetics to distinguish two subspecies of the Great Cormorant Phalacrocorax carbo carbo and P. c. sinensis at an inland lake in southeast Norway. Ornis Norvegica. ISSN 1892-9737. 47, s. 25–40. doi: 10.15845/on.v47.4019. Fulltekst i vitenarkiv
• Benjaminsen, Stine Charlotte; Dehnhard, Nina; Herzke, Dorte; Johnsen, Arild; Anker-Nilssen, Tycho & Bourgeon, Sophie [Vis alle 10 forfattere av denne artikkelen] (2024). The challenges of opportunistic sampling when comparing prevalence of plastics in diving seabirds: A multi-species example from Norway. Marine Pollution Bulletin. ISSN 0025-326X. 199. doi: 10.1016/j.marpolbul.2024.116037. Fulltekst i vitenarkiv Vis sammendrag

  There is a need for baseline information about how much plastics are ingested by wildlife and potential negative consequences thereof. We analysed the frequency of occurrence (FO) of plastics >1 mm in the stomachs of five pursuit-diving seabird species collected opportunistically. Atlantic puffins (Fratercula arctica) found emaciated on beaches in SW Norway had the highest FO of plastics (58.8 %), followed by emaciated common guillemots (Uria aalge; 9.1 %) also found beached in either SW or SE Norway. No plastics were detected in razorbills (Alca torda), great cormorants (Phalacrocorax carbo), and European shags (Gulosus aristotelis) taken as bycatch in northern Norway. This is the first study to report on plastic ingestion of these five species in northern Europe, and it highlights both the usefulness and limitations of opportunistic sampling. Small sample sizes, as well as an unbalanced sample design, complicated the interpretation of the results.

• Johannessen, Lars Erik; Johnsen, Arild; Koppetsch, Thore; Lifjeld, Jan Terje; Matschiner, Michael & Søli, Geir Einar Ellefsen [Vis alle 7 forfattere av denne artikkelen] (2023). Arctic Specimens in the Zoological Collections at the Natural History Museum, University of Oslo, Norway (NHMO). Collections: A Journal for Museum and Archives Professionals. ISSN 1550-1906. doi: 10.1177/15501906231167574. Vis sammendrag

  In the NHMO zoological collections, specimens from the Arctic include about 9,000 mammals and 7,100 birds, whereas the Insect Collection holds about 105,000 specimens plus more than hundred jars with unsorted material. The Fish Collection contains approximately 1,400 specimens, while the Herptile Collection (amphibians & reptiles) holds only thirty-one specimens of three taxa. Many of these specimens originate from expeditions to E Greenland, N Canada, Svalbard, Novaya Zemlya, Finnmark, and NE Siberia in the period 1898 to 1966. Furthermore, the DNA Bank has about 5,600 tissue and extracted DNA samples, mostly sampled from wild animals during the last decades but also from specimens in the voucher collections. Most of the Arctic specimens have been digitized and are available in online data portals like GBIF, except for the Insect Collection, where only the type material and about 30 percent of the total specimens are digitized.

• Johnsen, Arild; Dobbe, Kristine; Sætre, Camilla Lo Cascio; Eybert, Marie-Christine; Marquet, Matthieu & Bonnet, Patrick [Vis alle 7 forfattere av denne artikkelen] (2023). Genetic diversity and sperm characteristics are not associated in two bluethroat (Luscinia svecica) populations. Journal of Avian Biology. ISSN 0908-8857. s. 1–9. doi: 10.1111/jav.03125. Fulltekst i vitenarkiv
• Rekdal, Silje Larsen; Anmarkrud, Jarl Andreas; Lifjeld, Jan Terje & Johnsen, Arild (2023). Do female bluethroats without extra-pair offspring have more MHC-compatible social mates? Behavioral Ecology and Sociobiology. ISSN 0340-5443. 77(3). doi: 10.1007/s00265-023-03311-z. Fulltekst i vitenarkiv
• Poignet, Manon; Baránková, Lucie; Reif, Jiri; Stopka, Pavel; Stopková, Romana & Frolikova, Michaela [Vis alle 13 forfattere av denne artikkelen] (2022). Sperm morphology and performance in relation to postmating prezygotic isolation in two recently diverged passerine species. Scientific Reports. ISSN 2045-2322. 12(1). doi: 10.1038/s41598-022-26101-5. Fulltekst i vitenarkiv
• Grønstøl, Gaute; Danielsen, Marie; Cramer, Becky; Johannessen, Lars Erik; Johnsen, Arild & Whittington, Emma [Vis alle 7 forfattere av denne artikkelen] (2022). Effects of fixatives and storage duration on avian sperm morphology. Journal of Ornithology. ISSN 2193-7192. doi: 10.1007/s10336-022-02015-x. Fulltekst i vitenarkiv
• Magnussen, Trude; Johnsen, Arild; Kjærandsen, Jostein; Struck, Torsten H & Søli, Geir Einar Ellefsen (2021). Molecular phylogeny of Allodia (Diptera: Mycetophilidae) constructed using genome skimming. Systematic Entomology. ISSN 0307-6970. s. 1–15. doi: 10.1111/syen.12529. Fulltekst i vitenarkiv
• Rekdal, Silje Larsen; Anmarkrud, Jarl Andreas; Lifjeld, Jan Terje & Johnsen, Arild (2021). Elevated phytohaemagglutinin‐induced skin‐swelling response at an intermediate number of MHC class II alleles in bluethroat nestlings. Journal of Avian Biology. ISSN 0908-8857. doi: 10.1111/jav.02734. Fulltekst i vitenarkiv
• Cramer, Emily Rebecca A; Garcia-del-Rey, Eduardo; Johannessen, Lars Erik; Laskemoen, Terje; Marthinsen, Gunnhild & Johnsen, Arild [Vis alle 7 forfattere av denne artikkelen] (2021). Longer Sperm Swim More Slowly in the Canary Islands Chiffchaff. Cells. ISSN 2073-4409. 10(6). doi: 10.3390/cells10061358. Fulltekst i vitenarkiv
• Omotoriogun, Taiwo Crossby; Albrecht, Tomas; Gohli, Jostein; Horák, David; Johannessen, Lars Erik & Johnsen, Arild [Vis alle 12 forfattere av denne artikkelen] (2020). Sperm length variation among Afrotropical songbirds reflects phylogeny rather than adaptations to the tropical environment. Zoology. ISSN 0944-2006. 140. doi: 10.1016/j.zool.2020.125770. Fulltekst i vitenarkiv Vis sammendrag

  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 in this group stems from studies of species in the Northern temperate zone, while little is known about the numerous species in the tropics. Here we examined sperm size in 125 Afrotropical songbird species with emphasis on the length of the major structural components (head, midpiece, flagellum), and total sperm length measured using light microscopy. Mean total sperm length varied from 51 μm to 212 μm across species. Those belonging to the Corvoidea superfamily had relatively short sperm with a small midpiece, while those of the three major Passeridan superfamilies Passeroidea, Muscicapoidea and Sylvioidea showed large interspecific variation in total sperm length and associated variation in midpiece length. These patterns are consistent with previous findings for temperate species in the same major clades. A comparative analysis with songbird species from the Northern temperate zone (N = 139) showed large overlap in sperm length ranges although certain temperate families (e.g. Parulidae, Emberizidae) typically have long sperm and certain Afrotropical families (e.g. Cisticolidae, Estrildidae) have relatively short sperm. Afrotropical and temperate species belonging to the same families showed no consistent contrasts in sperm length. Sperm length variation among Afrotropical and Northern temperate songbirds exhibits a strong phylogenetic signal with little or no evidence for any directional latitudinal effect among closely related taxa.

• Lindsay, Willow R.; Andersson, Staffan; Bererhi, Badreddine; Höglund, Jacob; Johnsen, Arild & Kvarnemo, Charlotta [Vis alle 16 forfattere av denne artikkelen] (2019). Endless forms of sexual selection. PeerJ. ISSN 2167-8359. doi: 10.7717/peerj.7988. Fulltekst i vitenarkiv
• Albrecht, Tomas; Opletalová, Kamila; Reif, Jiri; Janousek, Vaclav; Pialek, Lubomir & Cramer, Emily Rebecca A [Vis alle 8 forfattere av denne artikkelen] (2019). Sperm divergence in a passerine contact zone: Indication of reinforcement at the gametic level. Evolution. ISSN 0014-3820. 73(2), s. 202–213. doi: 10.1111/evo.13677. Fulltekst i vitenarkiv
• Rekdal, Silje Larsen; Anmarkrud, Jarl Andreas; Lifjeld, Jan Terje & Johnsen, Arild (2019). Extra‐pair mating in a passerine bird with highly duplicated major histocompatibility complex class II: Preference for the golden mean. Molecular Ecology. ISSN 0962-1083. doi: 10.1111/mec.15273. Fulltekst i vitenarkiv
• Lifjeld, Jan Terje; Gohli, Jostein; Albrecht, Tomas; Garcia-del-Rey, Eduardo; Johannessen, Lars Erik & Kleven, Oddmund [Vis alle 10 forfattere av denne artikkelen] (2019). Evolution of female promiscuity in Passerides songbirds. BMC Evolutionary Biology. ISSN 1471-2148. 19(1). doi: 10.1186/s12862-019-1493-1. Fulltekst i vitenarkiv Vis sammendrag

  Background: Female promiscuity is highly variable among birds, and particularly among songbirds. Comparative work has identified several patterns of covariation with social, sexual, ecological and life history traits. However, it is unclear whether these patterns reflect causes or consequences of female promiscuity, or if they are byproducts of some unknown evolutionary drivers. Moreover, factors that explain promiscuity at the deep nodes in the phylogenetic tree may be different from those important at the tips, i.e. among closely related species. Here we examine the relationships between female promiscuity and a broad set of predictor variables in a comprehensive data set (N = 202 species) of Passerides songbirds, which is a highly diversified infraorder of the Passeriformes exhibiting significant variation in female promiscuity. Results: Female promiscuity was highly variable in all major clades of the Passerides phylogeny and also among closely related species. We found several significant associations with female promiscuity, albeit with fairly small effect sizes (all R2 ≤ 0.08). More promiscuous species had: 1) less male parental care, particularly during the early stages of the nesting cycle (nest building and incubation), 2) more short-term pair bonds, 3) greater degree of sexual dichromatism, primarily because females were drabber, 4) more migratory behaviour, and 5) stronger premating sexual selection. In a multivariate model, however, the effect of sexual selection disappeared, while the other four variables showed additive effects and together explained about 16% of the total variance in female promiscuity. Female promiscuity showed no relationship with body size, life history variation, latitude or cooperative breeding. Conclusions: We found that multiple traits were associated with female promiscuity, but these associations were generally weak. Some traits, such as reduced parental care in males and more cryptic plumage in females, might even be responses to, rather than causes of, variation in female promiscuity. Hence, the high variation in female promiscuity among Passerides species remains enigmatic. Female promiscuity seems to be a rapidly evolving trait that often diverges between species with similar ecologies and breeding systems. A future challenge is therefore to understand what drives within-lineage variation in female promiscuity over microevolutionary time scales. Keywords: Extrapair paternity, Life history, Mating system, Pair bond, Parental care, Sexual selection

• Støstad, Hanna Nyborg; Rowe, Melissah; Johnsen, Arild; Tomasek, Oldrich; Albrecht, Tomas & Lifjeld, Jan Terje (2019). Sperm head abnormalities are associated with excessive omega-6 fatty acids in two finch species feeding on sunflower seeds. Journal of Avian Biology. ISSN 0908-8857. 50(3), s. 1–12. doi: 10.1111/jav.02056. Fulltekst i vitenarkiv
• Cramer, Emily Rebecca A; Rowe, Melissah; Eroukhmanoff, Fabrice; Lifjeld, Jan Terje; Sætre, Glenn-Peter & Johnsen, Arild (2019). Measuring sperm swimming performance in birds: effects of dilution, suspension medium, mechanical agitation, and sperm number. Journal of Ornithology = Journal fur Ornithologie. ISSN 0021-8375. s. 1–11. doi: 10.1007/s10336-019-01672-9. Fulltekst i vitenarkiv
• Støstad, Hanna Nyborg; Rowe, Melissah; Johnsen, Arild & Lifjeld, Jan Terje (2019). Sperm head abnormalities are more frequent in songbirds with more helical sperm: A possible trade-off in sperm evolution. Journal of Evolutionary Biology. ISSN 1010-061X. s. 1–9. doi: 10.1111/jeb.13446. Fulltekst i vitenarkiv
• Králová, Tereza; Albrecht, Tomas; Bryja, Josef; Horák, David; Johnsen, Arild & Lifjeld, Jan Terje [Vis alle 10 forfattere av denne artikkelen] (2018). Signatures of diversifying selection and convergence acting on passerine Toll-like receptor 4 in an evolutionary context. Molecular Ecology. ISSN 0962-1083. 27(13), s. 2871–2883. doi: 10.1111/mec.14724. Fulltekst i vitenarkiv
• Støstad, Hanna Nyborg; Johnsen, Arild; Lifjeld, Jan Terje & Rowe, Melissah (2018). Sperm head morphology is associated with sperm swimming speed: a comparative study of songbirds using electron microscopy. Evolution. ISSN 0014-3820. 72(9), s. 1918–1932. doi: 10.1111/evo.13555. Fulltekst i vitenarkiv Vis sammendrag

  Sperm exhibit extraordinary levels of morphological diversification across the animal kingdom. In songbirds, sperm have a helically shaped head incorporating a distinct acrosomal membrane or “helical keel,” the form and extent of which varies across species. The functional significance of this helical shape, however, remains unknown. Using scanning electron microscopy, we quantified inter‐ and intraspecific variation in sperm head morphology across 36 songbird species (Passeriformes: Passerida). Using phylogenetic comparative methods, we investigated the relationship between sperm head morphology and both sperm swimming speed and the frequency of extra‐pair young (EPY). We found that species whose sperm had a relatively more pronounced helical form (i.e., long acrosome, short nucleus, wide helical membrane, and a more pronounced waveform along the sperm head “core”) had faster‐swimming sperm. We found no evidence of a relationship between interspecific variation in sperm head morphology and EPY, although we did find that among‐ and within‐male variation in sperm head traits were negatively correlated with EPY. Applying principles of fluid mechanics, we discuss how the helical form of the sperm head may influence swimming speed, and suggest that further studies considering aspects of sperm morphology beyond sperm length are needed to improve our understanding of sperm structure‐function relationships.

• Magnussen, Trude; Kjærandsen, Jostein; Johnsen, Arild & Søli, Geir Einar Ellefsen (2018). Six new species of Afrotropical Allodia (Diptera: Mycetophilidae): DNA barcodes indicate recent diversification with a single origin. Zootaxa. ISSN 1175-5326. 4407(3), s. 301–320. doi: 10.11646/zootaxa.4407.3.1. Fulltekst i vitenarkiv
• Kearns, Anna Marika; Restani, Marco; Szabo, Ildiko; Schrøder-Nielsen, Audun; Kim, Jin Ah & Richardson, Hayley M. [Vis alle 10 forfattere av denne artikkelen] (2018). Genomic evidence of speciation reversal in ravens. Nature Communications. ISSN 2041-1723. 9(1). doi: 10.1038/s41467-018-03294-w. Fulltekst i vitenarkiv Vis sammendrag

  Many species, including humans, have emerged via complex reticulate processes involving hybridisation. Under certain circumstances, hybridisation can cause distinct lineages to collapse into a single lineage with an admixed mosaic genome. Most known cases of such ‘speciation reversal’ or ‘lineage fusion’ involve recently diverged lineages and anthropogenic perturbation. Here, we show that in western North America, Common Ravens (Corvus corax) have admixed mosaic genomes formed by the fusion of non-sister lineages (‘California’ and ‘Holarctic’) that diverged ~1.5 million years ago. Phylogenomic analyses and concordant patterns of geographic structuring in mtDNA, genome-wide SNPs and nuclear introns demonstrate long-term admixture and random interbreeding between the non-sister lineages. In contrast, our genomic data support reproductive isolation between Common Ravens and Chihuahuan Ravens (C. cryptoleucus) despite extensive geographic overlap and a sister relationship between Chihuahuan Ravens and the California lineage. These data suggest that the Common Raven genome was formed by secondary lineage fusion and most likely represents a case of ancient speciation reversal that occurred without anthropogenic causes.

• Sætre, Camilla Lo Cascio; Johnsen, Arild; Stensrud, Even & Cramer, Emily Rebecca A (2018). Sperm morphology, sperm motility and paternity success in the bluethroat (Luscinia svecica). PLOS ONE. ISSN 1932-6203. 13(3). doi: 10.1371/journal.pone.0192644. Fulltekst i vitenarkiv
• Rekdal, Silje Larsen; Anmarkrud, Jarl Andreas; Johnsen, Arild & Lifjeld, Jan Terje (2018). Genotyping strategy matters when analyzing hypervariable major histocompatibility complex-Experience from a passerine bird. Ecology and Evolution. ISSN 2045-7758. 8(3), s. 1680–1692. doi: 10.1002/ece3.3757.
• Johnsen, Arild; Kearns, Anna Marika; Omland, Kevin E. & Anmarkrud, Jarl Andreas (2017). Sequencing of the complete mitochondrial genome of the common raven Corvus corax (Aves: Corvidae) confirms mitogenome-wide deep lineages and a paraphyletic relationship with the Chihuahuan raven C. cryptoleucus. PLOS ONE. ISSN 1932-6203. 12(10). doi: 10.1371/journal.pone.0187316. Fulltekst i vitenarkiv
• Johnsen, Arild; Pauliny, Angela; Lifjeld, Jan Terje & Blomqvist, Donald (2017). Is telomere length associated with mate choice in a songbird with a high rate of extrapair paternity? PLOS ONE. ISSN 1932-6203. 12(8). doi: 10.1371/journal.pone.0182446. Fulltekst i vitenarkiv
• Garcia, Javier; Johnsen, Arild; Fuertes, Benito & Suarez-Seoane, Susana (2017). Evolutionary divergences in Luscinia svecica subspecies complex - New evidence supporting the uniqueness of the Iberian bluethroat breeding populations. Ornis Fennica. ISSN 0030-5685. 94(3), s. 141–149. Fulltekst i vitenarkiv
• Boumans, Louis; Hogner, Silje; Brittain, John Edward & Johnsen, Arild (2017). Ecological speciation by temporal isolation in a population of the stonefly Leuctra hippopus (Plecoptera, Leuctridae). Ecology and Evolution. ISSN 2045-7758. 7(5), s. 1635–1649. doi: 10.1002/ece3.2638. Vis sammendrag

  Stream dwelling invertebrates are ideal candidates for the study of ecological speciation as they are often adapted to particular environmental conditions within a stream and inhabit only certain reaches of a drainage basin, separated by unsuitable habitat. We studied an atypical population of the stonefly Leuctra hippopus at a site in central Norway, the Isterfoss rapids, in relation to three nearby and two remote conspecific populations. Adults of this population emerge about a month earlier than those of nearby populations, live on large boulders emerging from the rapids, and are short-lived. This population also has distinct morphological features and was studied earlier during the period 1975–1990. We reassessed morphological distinctness with new measurements and added several analyses of genetic distinctness based on mitochondrial and nuclear sequence markers, as well as AFLP fingerprinting and SNPs mined from RAD sequences. The Isterfoss population is shown to be most closely related to its geographical neighbors, yet clearly morphologically and genetically distinct and homogeneous. We conclude that this population is in the process of sympatric speciation, with temporal isolation being the most important direct barrier to gene flow. The shift in reproductive season results from the particular temperature and water level regime in the Isterfoss rapids. The distinct adult body shape and loss of flight are hypothesized to be an adaptation to the unusual habitat. Ecological diversification on small spatial and temporal scales is one of the likely causes of the high diversity of aquatic insects.

• Lifjeld, Jan Terje; Anmarkrud, Jarl Andreas; Calabuig, Pascual; Cooper, Joseph E.J.; Johannessen, Lars Erik & Johnsen, Arild [Vis alle 12 forfattere av denne artikkelen] (2016). Species-level divergences in multiple functional traits between the two endemic subspecies of Blue Chaffinches Fringilla teydea in Canary Islands. BMC Zoology. ISSN 2056-3132. doi: 10.1186/s40850-016-0008-4.
• Mutanen, Marko; Kivelä, Sami M.; Vos, Rutger A.; Doorenweerd, Camiel; Ratnasingham, Sujeevan & Hausmann, Axel [Vis alle 23 forfattere av denne artikkelen] (2016). Species-level para- and polyphyly in DNA barcode gene trees: Strong operational bias in European Lepidoptera. Systematic Biology. ISSN 1063-5157. 65(6), s. 1024–1040. doi: 10.1093/sysbio/syw044.
• Støstad, Hanna Nyborg; Rekdal, Silje Larsen; Kleven, Oddmund; Laskemoen, Terje; Marthinsen, Gunnhild & Johnsen, Arild [Vis alle 7 forfattere av denne artikkelen] (2016). Weak geographical structure in sperm morphology across the range of two willow warbler Phylloscopus trochilus subspecies in Scandinavia. Journal of Avian Biology. ISSN 0908-8857. 47(5), s. 731–741. doi: 10.1111/jav.00981. Fulltekst i vitenarkiv Vis sammendrag

  Sperm 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. Geographical divergences in sperm traits might imply the formation of a reproductive barrier in a speciation process. Here we study sperm morphology variation of willow warblers Phylloscopus trochilus in a geographical context in Scandinavia, across the range of two subspecies that are differentiated in certain genetic markers, morphology and migratory routes. We describe geographical patterns in genotypes (two previously described single-nucleotide polymorphism (SNP) markers and four polymorphic microsatellites); in wing length, tarsus length and body mass; and in sperm traits of 330 male willow warblers sampled at 33 localities across Norway (58°N–69°N). Birds were on average larger and longer-winged in the north (spp. acredula) than in the south (spp. trochilus), and showed a sigmoid change in the SNP allele frequencies and body morphology around 65°N. We found no evidence of genetic structuring in the microsatellites. There was no geographical variation in sperm traits across Norway, except that sperm heads were on average longer in the south. Sperm head length was also associated with the two SNP markers, with longer sperm heads for the southern alleles, and midpiece length was weakly associated with one of the SNP markers. Similar among-male variances in total sperm length among the 33 sampling sites indicate uniform levels of sperm competition across Norway. We conclude that sperm morphology remains a rather undifferentiated trait between the two willow warbler subspecies in Scandinavia, which is consistent with a pattern of a shallow genetic divergence. This indicates that sperm morphology is not a reproductive barrier maintaining the narrow hybrid zone.

• Cramer, Emily Rebecca A; Ålund, Murielle; McFarlane, S. Eryn; Johnsen, Arild & Qvarnström, Anna (2016). Females discriminate against heterospecific sperm in a natural hybrid zone. Evolution. ISSN 0014-3820. 70(8), s. 1844–1855. doi: 10.1111/evo.12986.
• Lemoine, Melissa; Lucek, Kay; Perrier, Charles; Saladin, Verena; Adriaensen, Frank & Barba, Emilio [Vis alle 27 forfattere av denne artikkelen] (2016). Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits. Biological Journal of the Linnean Society. ISSN 0024-4066. 118(3), s. 668–685. doi: 10.1111/bij.12745.
• Eroukhmanoff, Fabrice; Rowe, Melissah; Cramer, Emily Rebecca A; Haas, Fredrik; Hermansen, Jo Skeie & Runemark, Anna [Vis alle 8 forfattere av denne artikkelen] (2016). Experimental evidence for ovarian hypofunction in sparrow hybrids. Avian Research. ISSN 2053-7166. 7. doi: 10.1186/s40657-016-0038-1.
• Cramer, Emily Rebecca A; Stensrud, Even; Marthinsen, Gunnhild; Hogner, Silje; Johannessen, Lars Erik & Laskemoen, Terje [Vis alle 10 forfattere av denne artikkelen] (2016). Sperm performance in conspecific and heterospecific female fluid. Ecology and Evolution. ISSN 2045-7758. doi: 10.1002/ece3.1977. Fulltekst i vitenarkiv
• Hogner, Silje; Riera, Albert Burgas; Wold, Margrethe; Lifjeld, Jan Terje & Johnsen, Arild (2015). Intergeneric hybridization between Common Redstart Phoenicurus phoenicurus and Whinchat Saxicola rubetra revealed by molecular analyses. Journal of Ornithology. ISSN 2193-7192. 156, s. 829–836. doi: 10.1007/s10336-015-1165-x.
• Rowe, Melissah; Albrecht, Tomas; Cramer, Emily Rebecca A; Johnsen, Arild; Laskemoen, Terje & Weir, Jason T [Vis alle 7 forfattere av denne artikkelen] (2015). Postcopulatory sexual selection is associated with accelerated evolution of sperm morphology. Evolution. ISSN 0014-3820. 69(4), s. 1044–1052. doi: 10.1111/evo.12620.
• Cramer, Emily Rebecca A; Laskemoen, Terje; Stensrud, Even; Rowe, Melissah; Haas, Fredrik & Lifjeld, Jan Terje [Vis alle 8 forfattere av denne artikkelen] (2015). Morphology-function relationships and repeatability in the sperm of Passer sparrows. Journal of morphology. ISSN 0362-2525. 276(4), s. 370–377. doi: 10.1002/jmor.20346.
• Boumans, Louis & Johnsen, Arild (2015). Stonefly duets: vibrational sexual mimicry can explain complex patterns. Journal of Ethology. ISSN 0289-0771. 33(2), s. 87–107. doi: 10.1007/s10164-015-0423-y. Vis sammendrag

  Stoneflies of the suborder Arctoperlaria exchange vibration signals for intersexual communication. The exchange takes the form of a duet with a male Call and female Answer. Some species and populations have three-way duets, with the male responding to the Answer with a third signal, termed Reply. We review duet descriptions of 106 species in terms of their temporal organisation and mate guarding tactics as identified by Bailey (2003), and propose a functional explanation in terms of concealment of the female for three recurrent phenomena: (1) In the case of large temporal overlap between Call and Answer, the overlapping part of the Call masks the Answer; (2) In three-way duets, the Reply mimics the female; (3) In a Call with two distinct phases, one phase mimics the female. It turns out that the Reply can be interpreted as mimicking the Answer in virtually all three-way duets. In two-way duets with a diphasic Call, the first phase typically mimics the Answer. Three-way duets with a diphasic Call are heterogeneous. Evidence for eavesdropping behaviour comes from the observation that males of the genus Zwicknia produce a Call in response to duetting sequences more often than in response to single male Call signals. We conclude with proposals for further research.

• Svoboda, Ales; Marthinsen, Gunnhild; Pavel, Václav; Chutný, Bohumír; Turčoková, Lucia & Lifjeld, Jan Terje [Vis alle 7 forfattere av denne artikkelen] (2014). Die prävalenz von blutparasiten beim blaukehlchen ist verknüpft mit der unterart und dem bruthabitat. Journal of Ornithology = Journal fur Ornithologie. ISSN 0021-8375. 156(2), s. 371–380. doi: 10.1007/s10336-014-1134-9.
• Gohli, Jostein; Leder, Erica H.; Garcia-Del-Rey, Eduardo; Johannessen, Lars Erik; Johnsen, Arild & Laskemoen, Terje [Vis alle 8 forfattere av denne artikkelen] (2014). The evolutionary history of Afrocanarian blue tits inferred from genomewide SNPs. Molecular Ecology. ISSN 0962-1083. 24(1), s. 180–191. doi: 10.1111/mec.13008.
• Wojczulanis-Jakubas, K; Kilikowska, A; Harding, AMA; Jakubas, D; Karnovsky, NJ & Steen, Harald [Vis alle 11 forfattere av denne artikkelen] (2014). Weak population genetic differentiation in the most numerous Arctic seabird, the little auk. Polar Biology. ISSN 0722-4060. 37(5), s. 621–630. doi: 10.1007/s00300-014-1462-5.
• Rukke, Bjørn Arne; Cholidis, Symira; Johnsen, Arild & Ottesen, Preben (2014). Confirming Hypoderma tarandi (Diptera: Oestridae) human ophthalmomyiasis by larval DNA barcoding. Acta Parasitologica. ISSN 1230-2821. 59(2), s. 301–304. doi: 10.2478/s11686-014-0242-2.
• Johnsen, Arild; Brabrand, Åge; Anmarkrud, Jarl Andreas; Bjørnstad, Gro; Pavels, Henning & Saltveit, Svein Jakob (2014). Impact of human-induced environmental changes on genetic structure and variability in Atlantic salmon, Salmo salar. Fisheries Management and Ecology. ISSN 0969-997X. 21(1), s. 32–41. doi: 10.1111/fme.12049.
• Anttila, K; Couturier, Christine Stephanie; Øverli, Øyvind; Johnsen, Arild; Marthinsen, Gunnhild & Nilsson, Göran Erik [Vis alle 7 forfattere av denne artikkelen] (2014). Atlantic salmon show capability for cardiac acclimation to warm temperatures. Nature Communications. ISSN 2041-1723. 5. doi: 10.1038/ncomms5252.
• Cramer, Emily Rebecca A; Laskemoen, Terje; Eroukhmanoff, Fabrice; Haas, Fredrik; Hermansen, Jo Skeie & Lifjeld, Jan Terje [Vis alle 9 forfattere av denne artikkelen] (2014). Testing a post-copulatory pre-zygotic reproductive barrier in a passerine species pair. Behavioral Ecology and Sociobiology. ISSN 0340-5443. 68(7), s. 1133–1144. doi: 10.1007/s00265-014-1724-9.

Se alle arbeider i Cristin

• Grøndahl, Finn Audun & Johnsen, Arild (2024). To underarter av storskarv er vanlige i Randsfjorden. Birdlife.no.
• Johnsen, Arild & Nilsen, Torbjørn Tumyr (2024). Fuglearkitektene. [Fagblad]. Arkitektur.
• Johnsen, Arild & Arntsen, Marte Kaasa (2024). Måker (Hadia Tajik). [TV]. NRK Kveldsnytt.
• Johnsen, Arild & Nordhus-Kristoffersen, Mathias (2024). Tar DNA-prøver av mossehval. [TV]. NRK Østlandssendingen.
• Vogt, Yngve & Johnsen, Arild (2023). Blåstrupens utroskap bedrer immunforsvaret til avkommet. [Tidsskrift]. Apollon.
• Melteig, Elina; Johnsen, Arild & Lifjeld, Jan Terje (2023). Far er utro for å få flere barn. Mor er utro for å få bedre barn. [Tidsskrift]. Titan.no.
• Cramer, Becky & Johnsen, Arild (2022). Hvorfor er sædceller så forskjellige når de alle har den samme enkle oppgaven? https://forskning.no/.
• Cramer, Becky & Johnsen, Arild (2022). Why are sperm cells so diverse when they all have the exact same job? sciencenorway.no.
• Rekdal, Silje Larsen; Anmarkrud, Jarl Andreas; Lifjeld, Jan Terje & Johnsen, Arild (2022). MHC-based mate choice in bluethroats.
• Cramer, Emily Rebecca Alison; Garcia-del-Rey, Eduardo; Johannessen, Lars Erik; Laskemoen, Terje; Marthinsen, Gunnhild & Johnsen, Arild [Vis alle 7 forfattere av denne artikkelen] (2021). Sperm evolution in the Canary Islands chiffchaff .
• Johnsen, Arild (2021). Øvre Heimdalen field station - past, present and future.
• Johnsen, Arild (2021). MHC-based mate choice in bluethroats.
• Ekrem, Torbjørn; Alsos, Inger Greve; Baussant, Thierry; de Boer, Hugo; Carson, Siri Granum & Dahle, Geir [Vis alle 14 forfattere av denne artikkelen] (2020). BIOSCAN Norway - Enabling next generation biodiversity research.
• Cerca, Jose; Johnsen, Arild; Struck, Torsten H & Bachmann, Lutz (2020). Naturhistoriske samlinger i den molekylære æraen: En kostbar hobby eller en bærebjelke for moderne forskning? Naturen. ISSN 0028-0887. s. 110–116. doi: 10.18261/issn.1504-3118-2020-03-07.
• Johnsen, Arild (2020). Female extra-pair mating in birds: is there a universal adaptive explanation?
• Johnsen, Arild (2019). Female extra-pair mating in birds: is there a common adaptive explanation?
• Marthinsen, Gunnhild & Johnsen, Arild (2019). DNA-strekkoding: genetisk identifisering av arter. Biolog. ISSN 0801-0722. 37(3-4), s. 24–29.
• Ekrem, Torbjørn; Alsos, Inger Greve; Johnsen, Arild; Willassen, Endre; Aspaas, Aina Mærk & Merkel, Marie Kristine Føreid [Vis alle 8 forfattere av denne artikkelen] (2019). Five years as national research infrastructure: status of the Norwegian Barcode of Life Network (NorBOL).
• Ekrem, Torbjørn; Alsos, Inger Greve; Johnsen, Arild; Willassen, Endre; Aspaas, Aina Mærk & Merkel, Marie Kristine Føreid [Vis alle 8 forfattere av denne artikkelen] (2019). Five years as national research infrastructure: status of the Norwegian Barcode of Life Network (NorBOL). Genome. ISSN 0831-2796. 62(6). doi: 10.1139/gen-2019-0083.
• Johnsen, Arild & Gjesdal, Trine-Lise (2018). Møt en forsker: zoolog Arild Johnsen. [Tidsskrift]. Nysgjerrigper.
• Torgersen, Eivind & Johnsen, Arild (2018). To ravner er blitt én. [Internett]. Forskning.no.
• Marthinsen, Gunnhild; Bendiksby, Mika; Brandrud, Tor Erik; Dima, Bálint; Hansen, Lars Ove & Johnsen, Arild [Vis alle 8 forfattere av denne artikkelen] (2017). Discordance between morphology and DNA barcodes in lichens, fungi and insects.
• Johnsen, Arild (2017). DNA barcoding at NHM. Science and application .
• Johnsen, Arild (2017). Speciation reversal in ravens.
• Johnsen, Arild (2017). Sperm competition in birds: from individual to sperm behaviour.
• Magnussen, Trude; Søli, Geir Einar Ellefsen; Johnsen, Arild & Kjærandsen, Jostein (2017). DNA barcode libraries - A treasure chest for alpha taxonomy .
• Ekrem, Torbjørn; Alsos, Inger Greve; Johnsen, Arild; Willassen, Endre; Aspaas, Aina Mærk & Merkel, Marie Kristine Føreid [Vis alle 9 forfattere av denne artikkelen] (2017). Progress and prospects of the Norwegian Barcode of Life Network (NorBOL). Genome. ISSN 0831-2796. 60(11), s. 930–930. doi: 10.1139/gen-2017-0209.
• Ekrem, Torbjørn; Alsos, Inger Greve; Johnsen, Arild; Willassen, Endre; Aspaas, Aina Mærk & Merkel, Marie Kristine Føreid [Vis alle 9 forfattere av denne artikkelen] (2017). Progress and prospects of the Norwegian Barcode of Life Network (NorBOL).
• Johnsen, Arild (2017). Øvre Heimdalen field station. Summary and future prospects.
• Johnsen, Arild (2017). Utroskap, sjalusi og spermier hos småfugl.
• Johnsen, Arild (2017). Cryptic female choice at the intra- and interspecific level in passerines: what are the molecular mechanisms?
• Ekrem, Torbjørn; Alsos, Inger Greve; Johnsen, Arild; Willassen, Endre; Aspaas, Aina Mærk & Kongshavn, Katrine [Vis alle 8 forfattere av denne artikkelen] (2017). The Norwegian Barcode of Life Network (NorBOL).
• Ålund, Murielle; Cramer, Emily Rebecca A; McFarlane, Eryn; Johnsen, Arild & Qvarnström, Anna (2017). Females discriminate against heterospecific sperm in a natural hybrid zone.
• Johnsen, Arild & Danielsen, Dag Inge (2016). Utroskap blant fluesnappere gir færre hybridfugler. [Internett]. Forskning.no.
• Johnsen, Arild (2016). Nå kommer fuglene - møt eksperten og entusiasten. [Radio]. NRK P2 - Ekko helg.
• Johnsen, Arild & Rekdal, Silje Larsen (2016). Drifter. [TV]. NRK - Ut i naturen.
• Johnsen, Arild (2016). Heimdalen: Bird research and future prospects.
• Ekrem, Torbjørn; Alsos, Inger Greve; Johnsen, Arild; Willassen, Endre; Aspaas, Aina Mærk & Merkel, Marie Kristine Føreid [Vis alle 9 forfattere av denne artikkelen] (2016). The Norwegian Barcode of Life Network (NorBOL).
• Ekrem, Torbjørn; Alsos, Inger Greve; Johnsen, Arild; Willassen, Endre; Aspaas, Aina Mærk & Føreid, Marie Kristine [Vis alle 8 forfattere av denne artikkelen] (2015). The Norwegian Barcode of Life Network (NorBOL). Genome. ISSN 0831-2796. 58(5). Vis sammendrag

  Background: NorBOL (www.norbol.org) was formed in 2007 as a national network to (i) advance barcoding of Norwegian and Arctic biodiversity, (ii) raise funding, (iii) curate barcode reference material, (iv) coordinate and initiate new barcoding projects, and (v) increase public awareness of DNA barcoding and barcoding results in Norway. NorBOL is a regional node within iBOL, with a particular responsibility for Polar Regions. NorBOL is coordinated by the NTNU University Museum in Trondheim and connects 16 institutions, including all four major natural history museums as well as all major research institutes in Norway. Results: Despite strong support among research institutions, substantial external funding was only first achieved in 2012 through a grant from the Norwegian Biodiversity Information Centre. Further funding was obtained in 2014 from both the Research Council of Norway and the Norwegian Biodiversity Information Centre. Since then, barcoding progress of the Norwegian fauna, flora, and fungi has increased, and the Barcode of Life Data Systems database currently holds more than 42 000 published sequence records (27 000 DNA barcodes) of more than 7200 species from Norway. Significance: The goal for NorBOL is to barcode 20 000 species by the end of 2018. NorBOL currently targets barcoding of museum collections, lichens, fungi, marine invertebrates, fish, and material from biosurveillance projects supported by the Norwegian Taxonomy Initiative. We collaborate with Swedish institutions on sampling of marine invertebrates, earthworms, and insects. An expansion of inter-Scandinavian barcoding collaboration is in progress. As the standard barcode gene regions have limited taxonomic resolution for the species level in many vascular plant groups, we are engaged in testing if low-coverage shotgun sequencing of herbarium material is useful to obtain the full plant plastid genomes.

• Johnsen, Arild (2015). Using genetic resources in biosystematic research: examples from the NHMO DNA bank.
• Johnsen, Arild (2015). The early stages of the speciation process - prezygotic reproductive isolation and diversification in passerines: final report.
• Omland, Kevin E.; Kearns, Anna Marika; Restani, Marco; Szabo, Ildiko & Johnsen, Arild (2015). Speciation reversal in Common Ravens: Genomic evidence of the collapse of cryptic lineages in western North America.
• Cramer, Emily Rebecca A; Ålund, Murielle; McFarlane, S. Eryn; Johnsen, Arild & Qvarnström, Anna (2015). A post-copulatory pre-zygotic barrier between collared and pied flycatchers.
• Kearns, Anna Marika; Restani, Marco; Szabo, Ildiko; Fleischer, Robert; Johnsen, Arild & Omland, Kevin E. (2015). Speciation reversal in ravens? Evidence for the collapse of cryptic Old World and New World lineages.
• Ekrem, Torbjørn; Alsos, Inger Greve; Johnsen, Arild; Willassen, Endre; Aspaas, Aina Mærk & Føreid, Marie Kristine [Vis alle 8 forfattere av denne artikkelen] (2015). The Norwegian Barcode of Life Network (NorBOL). Vis sammendrag

  Background: NorBOL (www.norbol.org) was formed in 2007 as a national network to (i) advance barcoding of Norwegian and Arctic biodiversity, (ii) raise funding, (iii) curate barcode reference material, (iv) coordinate and initiate new barcoding projects, and (v) increase public awareness of DNA barcoding and barcoding results in Norway. NorBOL is a regional node within iBOL, with a particular responsibility for Polar Regions. NorBOL is coordinated by the NTNU University Museum in Trondheim and connects 16 institutions, including all four major natural history museums as well as all major research institutes in Norway. Results: Despite strong support among research institutions, substantial external funding was only first achieved in 2012 through a grant from the Norwegian Biodiversity Information Centre. Further funding was obtained in 2014 from both the Research Council of Norway and the Norwegian Biodiversity Information Centre. Since then, barcoding progress of the Norwegian fauna, flora, and fungi has increased, and the Barcode of Life Data Systems database currently holds more than 42 000 published sequence records (27 000 DNA barcodes) of more than 7200 species from Norway. Significance: The goal for NorBOL is to barcode 20 000 species by the end of 2018. NorBOL currently targets barcoding of museum collections, lichens, fungi, marine invertebrates, fish, and material from biosurveillance projects supported by the Norwegian Taxonomy Initiative. We collaborate with Swedish institutions on sampling of marine invertebrates, earthworms, and insects. An expansion of inter-Scandinavian barcoding collaboration is in progress. As the standard barcode gene regions have limited taxonomic resolution for the species level in many vascular plant groups, we are engaged in testing if low-coverage shotgun sequencing of herbarium material is useful to obtain the full plant plastid genomes.

• Kearns, Anna Marika; Johnsen, Arild; Szabo, Ildiko; Kim, Jin; Richardson, Hayley & Gobbert, Matthias [Vis alle 9 forfattere av denne artikkelen] (2014). Deep Mitochondrial Divergence Within Common Ravens: Speciation Reversal in Western North America?
• Rowe, Melissah; Albrecht, Tomas; Cramer, Emily Rebecca A; Johnsen, Arild; Laskemoen, Terje & Weir, Jason T [Vis alle 7 forfattere av denne artikkelen] (2014). Postcopulatory sexual selection accelerates rates of evolutionary divergence in sperm morphology.
• Boumans, Louis; Brittain, John Edward; Johnsen, Arild & Hogner, Silje (2014). Ecological speciation by temporal isolation in a population of the stonefly Leuctra hippopus (Plecoptera, Leuctridae).
• Johnsen, Arild & Graver, Gjermund (2014). Første blekbrynsanger for Akershus bekreftet ved hjelp av DNA-strekkoding. Toppdykker'n. ISSN 0333-1687. 37(2), s. 64–67.
• Ekrem, Torbjørn; Alsos, Inger Greve; Johnsen, Arild; Willassen, Endre; Aspaas, Aina Mærk & Føreid, Marie Kristine [Vis alle 8 forfattere av denne artikkelen] (2014). The Norwegian Barcode of Life Network (NorBOL). Vis sammendrag

  NorBOL (www.norbol.org) was formed in 2007 as a national network to 1) advance barcoding of Norwegian and Arctic biodiversity, 2) raise funding, 3) curate barcode reference material, 4) coordinate and initiate new barcoding projects, and 5) increase public awareness of DNA barcoding and barcoding results in Norway. NorBOL is a regional node within iBOL, with a particular responsibility for Polar Regions. NorBOL is coordinated by the NTNU University Museum in Trondheim and connects 16 institutions, including all four major natural history museums as well as all major research institutes in Norway. Despite strong support among research institutions, substantial external funding was only first achieved in 2012 through a grant from the Norwegian Biodiversity Information Centre. Further funding was obtained in 2014 from both the Research Council of Norway and the Norwegian Biodiversity Information Centre. Since then, barcoding progress of the Norwegian fauna, flora and fungi has increased and the Barcode of Life Data Systems database currently holds more than 30 000 DNA barcodes of more than 5000 species from Norway. The goal for NorBOL is to barcode 20,000 species by the end of 2018. NorBOL currently targets barcoding of museum collections, lichens, fungi, coastal marine invertebrates, and material from biosurveillance projects supported by the Norwegian Taxonomy Initiative. Collaboration with Swedish institutions on sampling of marine invertebrates for barcoding was initiated in 2006 and on earthworms in 2010. An expansion of inter-Scandinavian barcoding collaboration is in progress.

• Ekrem, Torbjørn; Alsos, Inger Greve; Johnsen, Arild; Willassen, Endre; Aspaas, Aina Mærk & Føreid, Marie Kristine [Vis alle 8 forfattere av denne artikkelen] (2014). Norwegian Barcode of Life.
• Johnsen, Arild; Cramer, Emily Rebecca A & Grydeland, Ivar (2014). Fugleforskerne i Heimdalen. [Radio]. Ekko, NRK P2.
• Cramer, Emily Rebecca A; Ålund, Murielle; Laskemoen, Terje; Eroukhmanoff, Fabrice; Eybert, Marie-Christine & Haas, Fredrik [Vis alle 12 forfattere av denne artikkelen] (2014). Post-copulatory, pre-zygotic isolating barriers in passerine birds?
• Finstad, Anders Gravbrøt; Boer, Hugo de; Brurberg, May Bente; Dahle, Geir; Edgar, Kristin Skarsfjord & Eiler, Alexander [Vis alle 25 forfattere av denne artikkelen] (2020). Kriterier for lagring av miljø-DNA prøver og data, herunder henvisning til referansemateriale. Criteria for depositing eDNA samples and data, including vouchered specimens. Miljødirektoratet.

Se alle arbeider i Cristin