Abstract
The Swedish wolf population (Canis lupus) descends from five individuals and is isolated and highly inbred with an average inbreeding coefficient of 0.27. In addition, inbreeding depression has led to reduced litter size and a high frequency of spinal disorders. To achieve the management goal of reducing the mean level of inbreeding, introductions into the wild population from a zoo conservation breeding program have been proposed by authorities. We used pedigree data of the wild and zoo populations to evaluate the extent to which the captive population can contribute genetic variation to the wild one. We measure genetic variation as founder alleles and founder genome equivalents. The two populations have three founders in common, but in spite of this common ancestry, our results show a potential to almost double genetic variation from 11.2 to 21.1 founder alleles. Similarly, the number of founder genome equivalents in the wild population can increase from the present 1.8 to 3.2, but this requires that almost 50 % of the wild gene pool consists of genes from the zoo population. Average kinship in the joint zoo and wild population is 0.15, which is above the management target of 0.1. Genetic contribution from the zoo has the potential to improve, but not solve, the genetically precarious situation of the wild population.
References
Åkesson M, Bensch S (2010) Investigation concerning migration and hunting of wolves; interim report from Supplier 4 for the Environmental Protection Agency ref no 235-3697-10. (In Swedish)
Amundin M (2012) SAZA Regional wolf breeding programme. In: Nordic Ark Annual Report for 2011, pp 19–21. http://www.nordensark.se/assets/pdf/rsredovisningar/nordensarkengwebb.pdf
Ballou JD, Lacy RC, Pollak JP (2011) PMx: software for demographic and genetic analysis and management of pedigreed populations (version 1.0). Chicago Zoological Society, Brookfield http://www.vortex9.org/PMx.html
Ekström S (1999) Rovdjursutredningen 1999. Report of the Predator Investigation SOU 1999:146, Swedish Governments Public Investigation. (In Swedish.), Available at www.regeringen.se
Faust LJ, Bergstrom YM, Thompson SD, Bier L (2012) PopLink Version 2.3. Lincoln Park Zoo, Chicago
Frankham R (2008) Genetic adaptation to captivity in species conservation programs. Mol Ecol 17:325–333
Jansson M, Ståhl I, Laikre L (2013) mPed: a computer program for converting pedigree data to a format used by the PMx-software for conservation genetic analysis. Conserv Genet Resour 5:651–653
Kitchen AM, Knowlton FF (2006) Cross-fostering in coyotes: evaluation of a potential conservation and research tool for canids. Biol Conserv 129:221–225
Lacy RC (1995) Clarification of genetic terms and their use in the management of captive populations. Zoo Biol 14:565–578
Lacy R, Alaks G, Walsh A (2013) Evolution of Peromyscus leucopus mice in response to a captive environment. PLoS One 8(8):e72452. doi:10.1371/journal.pone.0072452
Laikre L (1999) Conservation genetics of Nordic carnivores: lessons from zoos. Hereditas 130:203–216
Laikre L, Ryman N (1991) Inbreeding depression in a captive wolf (Canis lupus) population. Conserv Biol 5:33–40
Laikre L, Ryman N, Thompson EA (1993) Hereditary blindness in a captive wolf (Canis lupus) population: frequency reduction of a deleterious allele in relation to gene conservation. Conserv Biol 7:592–601
Laikre L, Jansson M, Allendorf FW, Jakobsson S, Ryman N (2013) Hunting effects on favourable conservation status of highly inbred Swedish wolves. Conserv Biol 27:248–253
Liberg O, Sand H (2009) Measures to strengthen the genetic situation of the Swedish wolf population. Swedish Environmental Protection Agency Report to the Swedish Government: Dnr 429-8585-08 Nv (In Swedish)
Liberg O, Andrén H, Pedersen C-H, Sand H, Sejberg D, Wabakken P, Åkesson M, Bensch S (2005) Severe inbreeding depression in a wild wolf Canis lupus population. Biol Lett 1:17–20
Liberg O, Guillaume C, Wabakken P, Pedersen HC, Thompson Hobbs N, Sand H (2012) Shoot, shovel and shut up: cryptic poaching slows restoration of a large carnivore in Europe. Proc R Soc B 279:910–915
Liljelund L-E (2011) Predator Conservation Status. Interim report of the Predator Investigation SOU 2011:37, Governments Public Investigation (In Swedish)
Räikkönen J, Bignert A, Mortensen P, Fernholm B (2006) Congenital defects in a highly inbred wild wolf population (Canis lupus). Mamm Biol 71:65–73
Räikkönen J, Vucetich JA, Vucetich LM, Peterson RO, Nelson MP (2013) What the inbred Scandinavian wolf population tells us about the nature of conservation. PLoS One 8(6):e67218. doi:10.1371/journal.pone.0067218
Scharis I, Amundin M (2015) Cross-fostering in gray wolves (Canis lupus lupus). Zoo Biol 34:217–222
Swedish EPA (2009) Decision on license hunting for wolves 2010. Decision of December 17, 2009, Dnr 411-7484-09 Nv (In Swedish, available at: www.naturvardsverket.se)
Swedish EPA (2013a) Decision on license hunting for wolves 2014. Decision of December 19, 2013, NV-08512-13 (In Swedish, available at: www.naturvardsverket.se)
Swedish EPA (2013b) Genetic support of the wolf population. Information from the Swedish Environmental Protection Agency, Stockholm, Sweden. (In Swedish, available at: www.naturvardsverket.se)
Swedish Government (2009) Swedish Government bill 2008/09:2010. A new large carnivore management plan (In Swedish)
Vilà C, Sundqvist A-K, Flagstad Ø, Seddon J, Björnerfeldt S, Kojola I, Casulli A, Sand H, Wabakken P, Ellegren H (2003) Rescue of a severely bottlenecked wolf (Canis lupus) population by a single immigrant. Proc R Soc Lond B 270:91–97
Wright S (1977) Evolution and the genetics of populations. A treatise in four volumes. Volume 3. Experimental results and evolutionary deductions. The University of Chicago Press, Chicago
Acknowledgments
We thank Drs. Nils Ryman, Love Dalén, Liselotte Wesley Andersen, Torsten Nygaard Kristensen, Mats Höggren, Rolf Gustavsson, Holly Ernest, and three anonymous reviewers for valuable suggestions; Drs. Olof Liberg and Mikael Åkesson for access to wild population pedigree data; and Benjamin Jöngren for PopLink assistance. Financial support from the Swedish Environmental Protection Agency (M.A. and L.L.) and the Swedish Research Council Formas (L.L.) is acknowledged.
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Jansson, M., Amundin, M. & Laikre, L. Genetic contribution from a zoo population can increase genetic variation in the highly inbred wild Swedish wolf population. Conserv Genet 16, 1501–1505 (2015). https://doi.org/10.1007/s10592-015-0738-9
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DOI: https://doi.org/10.1007/s10592-015-0738-9