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The Norwegian Environment Agency (Miljødirektoratet) and the Swedish Environmental Protection Agency (Naturvårdsverket) have co-developed standard methodology and guidelines for the monitoring of wolverines in Scandinavia, that have been implemented in both Norway and Sweden since 2014. To estimate population size, and assess trends, wolverine reproductive areas (female territories) are annually surveyed during late winter and spring to register whether reproductions have occurred. The population size is estimated based on the number of wolverine reproductions that fulfil established criteria for documented or probable reproductions. The monitoring of wolverine reproductions, and registration of data into the shared database Rovbase, is conducted by field staff from the County Administration Boards CAB (Länsstyrelserna) in Sweden and the Norwegian Nature Inspectorate (Statens Naturoppsyn) in Norway. In Sweden, the Sami villages (administra-tive units for reindeer herding) assist the CABs by reporting presumed den sites, which can then be evaluated in the field by CAB field personnel. During the 2022 census, a total of 164 wolverine reproductions were registered in Scandinavia, which are four more than the year before (160 reproductions). Of these, 119 reproductions were found in Sweden and 45 in Norway. This corresponds to an increase of 19 reproductions (19%) in Sweden and a decrease of 15 reproductions (-25%) in Norway, compared to 2021. The model used to estimate population size, i.e., extrapolate number of reproductions to adult individuals in the population, accounts for annual variation in reproductive success by using a three-year floating average of the number of reproductions. Based on the number of wolverine reproductions during 2020-2022, the Scandinavian population size is estimated to 1019 adult wolverines (95% CI = 861–1282), defined as 1-year old or older, which is very similar to last year’s estimate. Of the 1019 wolverines, 351 wolverines (95% CI = 283–456) are estimated to be in Norway and 668 wolverines (95% CI = 540–869) in Sweden. The estimated population size in Norway in 2022 is 9% lower than the estimate for 2021 but within the uncertainty interval of last year (386 wolverines: 95% CI = 324–493). For the Swedish part of the population the estimate is 5% higher than the estimate from 2021 but also within the uncertainty interval of last year (637 wolverines: 95% CI = 518–826). Miljødirektoratet og Naturvårdsverket har utarbeidet felles retningslinjer og metodikk for overvåkingen av jerv som har vært gjeldende i både Norge og Sverige siden registrerings- sesongen 2014. Bestandsstørrelse og –utvikling for jerv i Skandinavia overvåkes ved registrering av ynglelokaliteter (revir) hvor det har blitt født ungekull i løpet av vårvinteren. Det gjøres en årlig beregning av bestandsstørrelsen som baseres på antall påviste ynglinger som er Dokumentert eller Antatt sikre ut ifra de felles skandinaviske overvåkingskriteriene. Jervynglingene overvåkes og registreres i Rovbase i hovedsak av feltpersonell fra Statens Naturoppsyn (SNO) i Norge og Länsstyrelsene i Sverige, som utfører feltkontrollene. På svensk side skjer registreringen i reinbeiteområdene i tett samarbeid med samebyene. De rapporterer mulige hilokaliteter til länsstyrelsens personell, som deretter kvalitetssikrer i felt. I løpet av registreringssesongen 2022 ble det registrert totalt 164 ynglinger av jerv i Skandinavia, noe som er fire ynglinger mer enn i 2021. Av disse ble 119 ynglinger påvist i Sverige og 45 i Norge. I Sverige tilsvarer dette en økning på 19 ynglinger (19 %) og i Norge en reduksjon på 15 ynglinger (-25%) sammenlignet med 2021. Det gjennomsnittlige antallet påviste jervynglinger de tre siste årene brukes som grunnlag for bestandsestimeringen fra antall ynglinger til antall voksne jerver i populasjonen. Modellen som brukes i bestandsestimeringen tar hensyn til at både årets og foregående års reproduksjoner påvirker størrelsen på bestanden. Basert på antall ynglinger i perioden 2020–2022 beregnes den skandinaviske bestanden i 2022 til 1019 voksne jerver som er ett år eller eldre (95 % CI = 861–1282), noe som er omtrent det samme som fjorårets populasjonsestimat for Skandinavia som helhet. Av de 1019 jervene utgjør anslagsvis den norske delen av bestanden 351 individer (95 % CI = 283–456), og den svenske delen av bestanden 668 individer (95 % CI = 540–869). Estimatet for den norske delen av bestanden er 9 % lavere enn estimatet for 2021, men innenfor usikkerhetsintervallet for fjoråret (386 individer, 95% CI=324–493). Estimatet for den svenske delen av bestanden er 5 % høyere enn estimatet for 2021, men også innenfor usikkerhetsintervallet for fjoråret (637 individer, 95% CI=518–826).

The Norwegian Environment Agency (Miljødirektoratet) and the Swedish Environmental Protection Agency (Naturvårdsverket) have co-developed standard methodology and guidelines for the monitoring of wolverines in Scandinavia, that have been implemented in both Norway and Sweden since 2014. To estimate population size, and assess trends, wolverine reproductive areas (female territories) are annually surveyed during late winter and spring to register whether reproductions have occurred. The population size is estimated based on the number of wolverine reproductions that fulfil established criteria for documented or probable reproductions. The monitoring of wolverine reproductions, and registration of data into the shared database Rovbase, is conducted by field staff from the County Administration Boards CAB (Länsstyrelserna) in Sweden and the Norwegian Nature Inspectorate (Statens Naturoppsyn) in Norway. In Sweden, the Sami villages (administra-tive units for reindeer herding) assist the CABs by reporting presumed den sites, which can then be evaluated in the field by CAB field personnel. During the 2022 census, a total of 164 wolverine reproductions were registered in Scandinavia, which are four more than the year before (160 reproductions). Of these, 119 reproductions were found in Sweden and 45 in Norway. This corresponds to an increase of 19 reproductions (19%) in Sweden and a decrease of 15 reproductions (-25%) in Norway, compared to 2021. The model used to estimate population size, i.e., extrapolate number of reproductions to adult individuals in the population, accounts for annual variation in reproductive success by using a three-year floating average of the number of reproductions. Based on the number of wolverine reproductions during 2020-2022, the Scandinavian population size is estimated to 1019 adult wolverines (95% CI = 861–1282), defined as 1-year old or older, which is very similar to last year’s estimate. Of the 1019 wolverines, 351 wolverines (95% CI = 283–456) are estimated to be in Norway and 668 wolverines (95% CI = 540–869) in Sweden. The estimated population size in Norway in 2022 is 9% lower than the estimate for 2021 but within the uncertainty interval of last year (386 wolverines: 95% CI = 324–493). For the Swedish part of the population the estimate is 5% higher than the estimate from 2021 but also within the uncertainty interval of last year (637 wolverines: 95% CI = 518–826).