The impact of founder events and introductions on genetic variation in the muskox Ovibos moschatus in Sweden
The muskox Ovibos moschatus (Zimmerman 1780) is a specialised arctic mammal with a highly fragmented circumpolar distribution, with native populations in Canada and east Greenland and introduced populations in west Greenland, Alaska, Siberia and Eurasia. In 1971, five O. moschatus individuals from an introduced population in Norway migrated to Sweden. After a peak population of 36 individuals in the mid-1980s, the Swedish population now numbers seven individuals, making it vulnerable to both demographic and genetic stochasticity (i.e. inbreeding). Here, we analyse genetic variation among native and introduced populations of O. moschatus to evaluate the genetic effect of sequential founder events in this species. Our results show that genetic variation among native and introduced O. moschatus populations do not conform entirely to the expectations from sequential founder events, most likely because of random processes associated with introduction. In the Swedish population, a calf resulting from the mating of a wild cow and a captive Greenlandic bull contributes significantly to the current genetic variation. Thus, even a single outbreeding event may, at least momentarily, increase the genetic variation and potentially prevent inbreeding depression. Our results should aid the long-term preservation of O. moschatus in Sweden and Europe.
KeywordsSupplemental release Conservation Restoration Microsatellites Bottleneck Sequential
We thank Kris Hundertmark and two anonymous referees for suggestions that improved the manuscript. We are also grateful to Helena Königsson for technical support in the lab and the following persons for samples: Daniel Ottosson, Lars Rehnfeldt, Stefan Mörtberg, Ronny Stålfjäll, Olle Larsson, Bengt Röken, Anna Martinsson, Mats Höggren, Staffan Åkeby, Bengt Holst, Carsten Grøndahl, Helle Flaga, Hans-Ove Larsson, Peter Mortensen, Torsten Mörner, Jessica Åsbrink, Göran Frisk, Arne Söderberg, Peter J. Van Coeverden De Groot, Patricia Reynolds, Mads Forchhammer, Niels Martin Schmidt, Peter Aastrup, Katrine Raundrup, Gunnar Mylius Pedersen, Jon Arnemo, Bjørn Rangbru, Bjørnar Ytrehus, Johan Schulze, Marthe Opland and Nina Brekke Tvedt. We thank the Faculty of Forest Sciences, Swedish Agricultural University in Umeå, the County Administration Board of Jämtland and the Muskox project in Härjedalen for financial support. CGT acknowledge the Swedish Association of Hunting and Wildlife Management for research grant (Project Number: 5880/2007).
Sample collections comply with the current law in Sweden.
Conflict of interest
The authors declare that they have no conflict of interest.
- Alendal E (1974) The history of muskoxen in Sweden. Fauna Flora 2:41–46 [In Swedish]Google Scholar
- Andersson A-C, Andersson S, Lönn M (2007) Genetic variation in wild plants and animals in Sweden. Naturvårdsverket, Rapport 5712:1–179 (in Swedish)Google Scholar
- Barr W (1991) Back from the brink: the road to muskox conservation in the Northwest Territories. Arctic Institute of North America, Komatik series 3, University of Calgary, pp 1–127Google Scholar
- Belkhir K, Borsa P, Chikhi L, Raufaste N, Bonhomme F (2004) GENETIX 4.05, logiciel sous Windows TM pour la génétique des populations. Laboratoire Génome, Populations, Interactions, CNRS UMR 5171, Université de Montpellier II, Montpellier, FranceGoogle Scholar
- Campos PF, Willerslev E, Sherb A, Orlando L, Axelsson E, Tikhonov A, Aaris-Sørensen K, Greenwood AD, Kahlke R-D, Kosintsev P, Krakhmalnaya T, Kuznetsova T, Lemey P, MacPhee R, Norris CA, Shepherd K, Suchard MA, Zazula GD, Shapiro B, Gilbert MTP (2010) Ancient DNA analyses exclude humans as the driving force behind late Pleistocene musk ox (Ovibos moschatus) population dynamics. P Natl Acad Sci USA 107:5675–5680CrossRefGoogle Scholar
- Ericson M (2002) [Muskoxen. A local management plan to improve the possibility for muskoxens to survive in the Swedish mountain range]. Projekt Myskoxe, Framtidsfjäll 2000 (in Swedish)Google Scholar
- Fleischman CL (1986) Genetic variation in muskoxen (Ovibos moschatus). M.Sc. thesis, University of Alaska, Fairbanks, AK, USAGoogle Scholar
- Gunn A, Forchhammer M (2008) Ovibos moschatus. The IUCN red list of threatened species. Available at http://www.iucnredlist.org/apps/redlist/details/29684/0. Accessed 6 October 2008
- Hundertmark KJ (2009) Reduced genetic diversity in two introduced and isolated moose populations in Alaska. Alces 45:137–142Google Scholar
- Lent PC (1999) Muskoxen and their hunters: a history. Animal Natural History 5, University of Oklahoma Press, Norman, OK, USAGoogle Scholar
- Lundh NG (1996) The muskoxen in Sweden. Naturvårdsverket Förlag, Rapport 4545:1–142 [In Swedish]Google Scholar
- Nyqvist J (2004) Ecological possibilities for musk oxen (Ovibos moschatus) in the Swedish mountain range. M.Sc. thesis, Swedish University of Agricultural Sciences, Uppsala, SwedenGoogle Scholar
- Park SDE (2001) Trypanotolerance in West African Cattle and the population genetic effects of selection. Ph.D. thesis, University of Dublin, Dublin, IrelandGoogle Scholar
- Rangbru B, Andreassen S (2006) [Management plan for the muskoxen in Dovre Mountains]. Fylkesmannen i Sør-Trøndelag, Rapport Nr 1. Trondheim: 1–33 [In Norweigan]Google Scholar
- Uspenski SM (1984) Muskoxen in the USSR: some results of and perspectives on their introduction. Biological Paper, University of Alaska, Special Report Vol. 4, pp 12–14Google Scholar
- Vibe C (1967) Arctic animals in relation to climatic fluctuations. The Danish Zoogeographical Investigations in Greenland. C. A. Reitzels Forlag, Copenhagen, pp 1–127Google Scholar