Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2025
Sammendrag
Large herbivores at northern latitudes often forage on agricultural farmland. In these populations, the presence of both resident and migrant individuals (termed partial migration) is common, but how migrants and residents differ in their selection of farmland is not well-understood. Higher access to farmland may provide benefits to residents compensating for not following the ‘green wave’ of emerging vegetation such as migrants. According to sexual segregation theory, males and females differ in body-size-related nutritional needs and risk sensitivity associated with farmland. Yet, how the sexes differ in the selection of farmland through an annual cycle remains unclear. We quantified seasonal variation in the selection of farmland by partially migratory red deer (Cervus elaphus) at broad, landscape scale and at fine, within-home range scale using 16 years of data (2005–2020) from 329 females and 115 males in Norway. We tested predictions related to the partial migration and sexual segregation theories using resource selection functions. We predicted higher selection for farmland by residents than by migrants, and higher selection by females than by males due to higher nutritional needs, but that higher perceived predation risk would impact their diurnal selection patterns. The time spent on farmland was higher in winter (14%–18%) than in summer (8%–14%). Residents selected farmland more than migrants mainly at broad, landscape scale, while differences were smaller and less consistent at a fine, within-home range scale. Females showed higher broad-scale selection for farmland in winter, whereas males showed higher selection in summer. At a fine, within-home range scale, females selected farmland more in summer during darkness, whereas sex differences were small otherwise. The fine-scale selection of farmland was markedly higher during low-light conditions than in daylight. A high population density index was correlated with high broad-scale selection of farmland, i.e. high farmland availability in the home ranges, whereas the effect of the density index was weak at a fine, within-home range scale. Our study emphasises how hypotheses deriving from the theories of partial migration and sexual segregation can improve our understanding of ungulates' selection of farmland. The higher selection by residents during summer highlights the importance of retaining landscape connectivity, allowing for migration and reducing pressure on local resources.
Forfattere
Magnus StenbrendenSammendrag
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Randi Berland FrøsethSammendrag
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Chloé GrieuSammendrag
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Forfattere
Johan A. Stenberg Daniel Flø Lawrence Richard Kirkendall Anders Nielsen Selamawit Tekle Gobena Beatrix Alsanius Jorunn Børve Paal Krokene Christer Magnusson Mogens Nicolaisen Line Nybakken May-Guri Sæthre Iben Magrete Thomsen Sandra A.I. WrightSammendrag
Citripar, a biological plant protection product containing the parasitic wasp Anagyrus vladimiri, is requested to be approved for use in Norway. The product is intended to be used against mealybugs, particularly Planococcus citri (citrus mealybug) and Planococcus ficus (vine mealybug) feeding on fruits, berries, vegetables and herbs in greenhouses and plastic tunnels, and on indoor plants. The Norwegian Food Safety Authority, therefore, asked the Norwegian Scientific Committee for Food and Environment to perform a risk assessment of the product. Occurrence and distribution in Norway: No observations of Anagyrus vladimiri have been reported from Norway. Potential for establishment and spread: VKM assesses that Anagyrus vladimiri will not be able to establish and spread in Norway under current conditions due to the absence of host organisms and too low winter temperatures, even in the warmest parts of the country. Potential effects on biodiversity: VKM assesses that Anagyrus vladimiri will not affect biodiversity in Norway, as there are currently no known native hosts for the wasp to parasitize. Taxonomic challenges that may affect the risk assessment: Anagyrus vladimiri belongs to the wasp family Encyrtidae, a family that includes the genus Anagyrus, many of which have quite tangled taxonomic histories. Individuals of what is now known as Anagyrus vladimiri were for many years identified as belonging to Anagyrus pseudococci. Anagyrus pseudococci and A. vladimiri are members of a complex of nearly indistinguishable species that are informally referred to as the Anagyrus pseudococci complex: A. pseudococci, A. vladimiri, A. kamali, A. dactylopii, A. kivuensis, and A. callidus. These species have been used for biological control of various mealybug species. Should incorrectly identified Anagyrus be imported to Norway, there would be no consequences for biological diversity, since the other species in the Anagyrus pseudococci complex are also host specific to mealybug genera that are not found in the Norwegian fauna, and they are physiologically unfit for the current Norwegian climate.
Forfattere
Emmanuel O. Anedo Dennis Beesigamukama Benson Mochoge Nicholas K. Korir Solveig Haukeland Xavier Cheseto Moses Nyongesa Patrick Pwaipwai Sevgan Subramanian Abdou Tenkouano Betty Kibaara Chrysantus M. TangaSammendrag
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