sou · GZB337 · 2011-04-20 00:00:00 — group pointed out that it was in fact difficult to obtain funding for this type of monitoring. The panel finds that monitoring of possible inbreeding depression is such an important and fundamental part of the scientific basis of the management of Scandinavian wolves that funding for this purpose should be secured. To sum up the discussion with both groups and internally within the panel, it is particularly recommended to make use of the pedigree for -identifying individuals to be protected from hunting, first and foremost immigrants, F1s, F2s, backcross wolves, but also other individuals that may represent a particularly high proportion of the founder genetic diversity. Several measures can be calculated for quantifying the genetic value of individuals, such as mean kinship coefficient, and there are several empirical examples in the literature of how to use such approaches in practical conservation (et al. 2001; Goncalves et al. -assessing the degree to which hunting affects the inbreeding coefficient. -identifying packs for cross-fostering of introduced pups, if such a strategy is to be implemented, for increasing gene flow. -monitoring the future development of inbreeding depression by monitoring physical deformities and changes in life-history parameters and associating them with the pedigree. The panel reiterates its view that funding for this type of monitoring is important and should be available. III) In a subsequent report (Laikre & 2010) the Laikre & group evaluates the genetic consequences if the number of wolves in should be kept at a maximum of 210 and additionally 30 wolves are allowed in , corresponding to a total number of 240 individuals. Moreover, they evaluate the consequences if at most 20 foreign individuals are introduced into . The conclusions regarding these issues are as follows: 1.If the population size of the Scandinavian grey wolf is kept at 240 individuals and no gene flow occurs (either natural or via translocations), then the inbreeding coefficient will increase to after 20 generations. If an Ne/N ratio of ca. 0.2 is assumed, then this will correspond to an Ne of around 50 and a rate of inbreeding, F, of > . This is higher than the recommended rates of inbreeding when a time scale of more than a few generations is considered and may lead to further inbreeding depression. Genetic variation will also be lost quickly and there is a high risk that, some harmful alleles will increase in frequency. 2.The inbreeding coefficient will be reduced to just above if 20 genetically effective immigrants are introduced. Inbreeding will, however, increase again to the same level after 20 generations if no further immigration takes place and N is kept at 240, corresponding to Ne of ca. The higher the population size, the slower the increase of inbreeding. 3.It is suggested that the goal should be to reduce the inbreeding coefficient to below and keep it there. a time frame of 20 generations (100 years) this can only be achieved if immigration is continued after the introduction of 20 genetically effective individuals. 4.The discussion concerning the distribution of deleterious alleles addressed in the previous report (Liberg et al. 2009) is taken up again. The specific distribution of deleterious alleles is difficult to assess. It is reiterated that detrimental/harmful recessive alleles are present in Scandinavian wolves and that the low number of founders have led to a situation where deleterious recessive alleles from the onset occur at high frequencies. It is also pointed out that when the effective population size is low as in Scandinavian wolves, then selection cannot act properly to eliminate deleterious alleles (genetic drift overrides selection). Finally, it is pointed out that a recent study of grey wolves on Isle Royal suggests extensive inbreeding depression, expressed as physical deformities (Raikkonen et al. The case of the highly inbred Isle Royale wolf population has previously been used to argue that severe inbreeding can occur in wild populations without associated inbreeding depression, but the new study disproves this conclusion. 5.It is important to establish an international collaboration with the aim of connecting the Northern European grey wolf population genetically. The aim should be to create a population network facilitating natural genetic exchange among subpopulations to conserve genetic variation and keep the levels of inbreeding at an acceptable level. This point was also raised in the previous report (Liberg et al. The panels assessment of these points is as follows: 1.The panel agrees. This is in line with conservation genetics principles. 2.The panel also agrees with this. This is in accordance with conservation genetics principles. 3.The panel also agrees with this (see also the response to point 4 above related to Laike & Rymans conclusions in the Liberg et al. (2009) report). 4.The panel agrees with these considerations (see also the response to point 5 above related to Laike & Rymans conclusions in the Liberg et al. (2009) report). 5.The panel agrees that the key to a long-term solution involves transnational collaboration. This is further described above in the sections concerning Favourable Conservation Status. IV) Finally, the panel has assessed the population viability analysis and individual based modelling conducted by in the report by Liberg et al. (2009). Some of the results and the analyses conducted by Laikre & that assume mainland-island or finite models can be seen as different alternative methods. The panel does not see major discrepancies between the methods, and from a general point of view the integration of ecological and population genetic parameters in simulations are endorsed. In some important aspects, notably the modelling of inbreeding depression, the panel concurs with the view that this has likely been underestimated, as only reduction of size is considered (indeed, it would be highly relevant to include the lethal equivalents reported by Bensch et al. (2006) in the model as well). Also, it is assumed that environmental variation does not influence the demographic parameters, which is unlikely to be the case under real circumstances. However, the results are discussed and interpreted cautiously taking these potential shortcomings into account. V) To sum up this long presentation and evaluation of the presented results and hypotheses: a)In many aspects there is agreement between the Liberg et al. group and the Laikre & group regarding the conservation situation and the management recommendations. b)The groups disagree on the numbers of genetically effective immigrants required if the census population size is 200. The Liberg et al. group finds that 2 genetically effective migrants per generation would be sufficient, at least for the next 10–15 years. The group concludes that at least 5–10 genetically effective migrants are required per generation. evaluation panel finds that the inbreeding coefficient of 0.3, the genetic load (deleterious alleles) present in Scandinavian wolves and the demographic history of the sub-population with an extremely low founder number calls for high levels of gene flow in order to decrease the inbreeding coefficient. The panel recommends stating a clear goal for reducing the inbreeding coefficient within a short time span, such as reducing the inbreeding coefficient to 0.1 over 20 years, which according to Laikre & Rymans analyses will indeed require 5–10 genetically effective migrants per generation. c)There is disagreement regarding the urgency of taking action. The group finds that imminent actions should be taken to reduce inbreeding, whereas the Liberg et al. group finds that it would be justified to wait for 5 years, evaluate the natural immigration that occurs and at the same time take measures that could benefit the probability of natural immigration. If 2 genetically effective immigrants have not occurred within the 5 year period, measures should be taken to conduct artificial translocations. As stated above, the panel finds convincing arguments that there should be more than 2 genetically effective migrants per generation; the number should be on the order of 5–10 effective immigrants. Given the very high inbreeding coefficient and the genetic load in Scandinavian wolves the panel finds that management actions to reduce inbreeding should be implemented and that it would not be justified to wait another 5 years. In practice, however, the panel finds that the two strategies could be combined. For instance, immediate action could be taken by using pups from captive populations (zoos) for a first round of artificial translocations. Given the low number of founders of the relevant captive populations this option will only be justified for at most a couple of years. However, at the same time measures could be taken to increase natural immigration of wolves. If this does indeed result in more spontaneous immigration at the necessary rate, then artificial translocation could be discontinued. d)There is disagreement regarding the required effective population size if immigration continues to be low. The Laikre & group argues that for maintaining heterozygosity over a 100 year period, the effective population size should be at least 200. Conversely, the Liberg et al. finds that retaining heterozygosity over 100 years would be sufficient, corresponding to an effective population size of 50. The evaluation panel has been unable to identify really strong arguments as to whether retainment of heterozygosity is sufficient or if should be the minimum target, although obviously from a conservation perspective it would be better to retain . Importantly, however, the panel finds that this discussion also misses the point. The key issue concerns the very high inbreeding coefficient and how to reduce it. Immigration is essential in order to reduce inbreeding, and even allowing an effective population size of 200 without having immigration would result in an inbreeding coefficient >= 0.3, which would not be desirable from a conservation perspective. VI) Finally, the evaluation panel makes the following recommendations for a short-term and a longer-term conservation goal. In the short term, the main priority should be to reduce inbreeding. A reasonable goal would be to reduce the inbreeding coefficient to below 0.1 over a 20 year period (4 generations) and – importantly – keep it at this low level. This goal can be fulfilled by different combinations of effective population size and numbers of effective immigrants. Based on Fig. 2.a by Laikre & in the report by Liberg et al. (2009), this could be obtained by immigration corresponding to 5–10 genetically effective migrants per generation, if the effective population size is 50. If the effective population size could be higher than 50, then lower immigration would be required, but the specific effective population sizes and immigration rates should be determined analytically. There would furthermore be benefits by obtaining a higher effective population size than 50, as this would reduce further spread of deleterious recessive alleles that are already present in the population. In the longer term, the panel recommends transnational collaboration and agreements involving , , and in order to secure a total population of at least 3000– 5000 individuals (or an effective population size of at least 500), where the individual sub-populations, including that in , are connected by gene flow. This could secure Favourable Conservation Status of the total population. What would be a relevant measure of population size? The panel was asked to provide recommendations for a relevant measure of population size. In short, the most relevant measure depends on the question asked. If it concerns the demography of the population, then the most relevant measure is the census population size (N), which is simply the number of individuals. If the question concerns genetic processes, such as minimizing inbreeding and assessing the minimum immigration required, then effective population size (Ne) is the most relevant measure. Molecular markers may be used to estimate the effective population size through a variety of statistical methods; for instance Aspi et al. (2006) estimated the effective size of the Finnish population to be ca. 40 based on analysis of molecular markers. The effective population size is nearly always much lower than the census population size, but if the ratio between the two (the Ne/N ratio) is known, then this can be used as a conversion factor. However, Ne/N ratios should be treated with caution, as they can depend on the situation and the specific species. The mean Ne/N ratio for a large number of species has been found to be 0.1 (Frankham 1995), but with considerable variation among organisms. The suggested Ne/N ratios in grey wolves (and elsewhere) range from ca. 0.2 – 0.4 (Aspi et al. 2006; Liberg et al. 2009; Laikre & 2010; vonHoldt et al. 2008) and will be complicated to estimate precisely. The best approach therefore is to take a cautionary approach and assume a range of possible values, as is also done in most of the publications assessed by the panel. The panel would discourage use of alternative measures of population size, such as numbers of . They do not have a rigorous theoretical definition, which would preclude their translation into census and effective population sizes. Priority research if management should encompass a total transnational population involving Fennoscandia and Karelia- Kola. If the Scandinavian, Finnish and Russian Kola-Karelian wolf subpopulations are to be treated as one transnational management unit, there is urgent need for increased co-operation between researchers and management authorities within these countries. There are already good databases with genetic profiles for individual wolves in and . To allow better genetic identification of individuals and comparison between populations, standardization of the applied genetic markers is necessary. There is already some co-operation between Finnish and Russian large carnivore researchers, but broader international co-operation should be established. There should also be closer co-operation between management authorities from the countries. It could be particularly useful if the action of the SKANDULV working group could be expanded to include Finnish and Russian managers and researchers, or some other organization should be established. The status and genetic structure of the Swedish and Finnish wolf populations are well known. Less is known about northwestern Russian wolf populations, and there is urgent need to investigate the present status and genetic connectivity of these subpopulations. The Russian Karelian and Archangelsk subpopulations and their immigration between and have been studied (Aspi et al. There are small genetic differences between the populations, but they are probably due to isolation by distance. However, migration in recent years between the populations seems to be low. Genetic diversity of the Finnish population has been decreasing during the last fifteen years (Roininen et al., unpublished). This is partly due to lowered population size, but probably also reflects lowered migration from Russian populations. populations in Eastern Europe have been studied (Pilot et al. 2006), and it has been shown that there is non-random spatial genetic structure even in the absence of obvious physical barriers to movement. It was found that the genetic differentiation among local populations was correlated with climate, habitat types, and wolf diet composition. Accordingly, it seems that ecological processes may also have a significant influence on the amount of gene flow among wolf populations. Pilot et al.s (2006) study did not involve samples from Russian Karelia. , genetic differences between Russian Karelian and other eastern European wolf populations have not been quantified. Connectivity between Russian Karelian and adjacent southern and eastern wolf populations should therefore be investigated. However, given that estimated migration rates from Karelian to Finnish wolves have been estimated to be less than 0.03 (Aspi et al. 2009), connectivity between Finnish wolves and subpopulations further apart is expected to be very low. Recently several cases of alleged wolf-dog hybridization in near the Russian border has been reported. Alleles typical to some dog-breeds have also been reported in supposed wolf migrants from (Roininen et al. Possible hybridization between dogs and wolves should be surveyed on a larger scale, and the wolves potentially to be translocated should be genotyped to avoid possible introgression. Captive populations – how useful are they for reintroduction? The captive Nordic population may constitute a source of genetic material to reduce inbreeding in the Scandinavian wolf subpopulation. There are nine founder individuals in the captive Scandinavian-Finnish wolf population. Five of these originated from or , two from Estonia, one from and one from . There is a possibility that there is some introgression from domestic dogs into the Estonian founders (Laikre & 2010). The average inbreeding level is around 0.1, which is much lower than that of the wild population (around 0.3). The evaluation panel finds that the captive wolves could be a useful source of genetic material in the short term for reducing the inbreeding in Scandinavian wolves (in practise, this would involve cross-fostering of pups). It would be important first to verify whether or not introgression from domestic dogs has occurred, which could be done using molecular markers (Verardi et al. It could also be debated if captive wolves even after a few generations could have experienced some degree of adaptation to the captive environment. Although this possibility is difficult to rule out entirely, the panel finds that this potential concern would be counterbalanced by the need for reducing inbreeding in Scandinavian wolves. It must be emphasized that using genetic material from the captive populations would only be a short term solution (a few years) due to the low number of founders. In the longer term genetic material from wild populations should be introduced, preferably by natural immigration or alternatively by translocations. What is the potential natural immigration into if wolves were allowed to pass through Northern ? The potential for natural immigration into the Scandinavian wolf population is a crucial point for conservation management. If gene flow is sufficiently high, a smaller population may be viable in the longer term. At present, the reindeer herding areas of Northern and are kept virtually wolf-free, meaning that individuals found to attack livestock are promptly removed or shot. The wolves that are able to pass this area without detection are few and far between: in recent years, 1–2 individuals per year have reached the Southern wolf population in . This depends greatly on the size of the Finnish population, which is currently declining. Of these migrants, on average have bred successfully, adding genetic variation. However, statistical models using longer time series suggest that there is only a probability that 1 genetically effective migrant reaches the South per generation (5 years). That is quite insufficient to maintain variation. But if all migrating wolves were allowed/assisted to pass through Finnish and Swedish Lapland, the gene flow would be substantially higher, even more so if illegal killings could be avoided. A suggested figure in this scenario is 2–3 effective migrants (breeding individuals) per generation. If the Scandinavian sub-population is kept at a effective population size of 50 (corresponding to the presently allowed census population size of 240), this will not be sufficient to reach a goal of reducing inbreeding to below 0.1 (see Laikre & Rymans Fig. 2.a in Liberg et al. However, if a larger population could be tolerated and/or if the Finnish subpopulation increased, thereby increasing immigration into , a more beneficial situation could occur. The combinations of migrants and effective population sizes required should be derived after careful analysis. Issues regarding diseases and quarantine. It has been suggested that translocated wolves should be screened for diseases like rabies, distemper and parvo, as well as internal and external parasites, and should be de-wormed, treated for ectoparasites and vaccinated against rabies. After the treatments the translocated animals should be in quarantined in captivity, or should remain in the wild equipped with gps-transmitters for 120 days. If wolves to be translocated are taken from captive population or from established Finnish wolf packs, the probability of spreading diseases which do not occur in will be very low. Wild animals with rabies in have been found most recently in 1989, and it has never been found in wolves. To prevent the spread of infection from to bait vaccines are annually spread into the at the south-eastern border. The prevalence of Echinococcus granulosus infection among Finnish wolves is , but endemic foci of E. granulosus have also been known to occur in northern and (even though they have not been found during recent years). Echinococcus multilocularis has not so far been found in , even though it is known to occur in Russian Karelia in voles (pers. comm., prof. , Safety Authority ). Some sporadic cases of parvovirus have been found in raccoon dogs in , but not in wolves. Single de-worming is able to remove all endoparasites, and animals in quarantine for 120 days is more than enough to prove that there are no rabies symptoms. the animals in the wild equipped with gps-transmitters for 120 day would be difficult to organize. The Finnish authorities have expressed their willingness to vacate Finnish wolves mainly from the reindeer herding area, and wolves alive there for 120 days could be difficult. Moreover, wolves in have been mainly captured for gps-collaring with snow mobiles, and the seasonal time window for that practice is definitely shorter than 120 days (only possible with thick snow cover). However, wolves have been very recently caught with the help of helicopters. The evaluation panel finds it puzzling that the vaccinations and de-worming is not required if immigrant wolves appear spontaneously into , whereas these procedures are required for animals to be translocated. Monitoring the effects of introduced individuals. The evaluation panel emphasizes the need for continued monitoring of the Scandinavian wolf sub-population. In particular, it would be important to monitor the effect of introduced individuals through continued pedigreeing. The ratio between genetically effective migrants and the census number of migrants might be similar to the Ne/N ratio, but it is also possible that the two ratios differ. On one side, translocated individuals could exhibit reduced reproductive performance due to effects of handling or, in the case of offspring of captive wolves, adaptation to a captive environment. On the other side, it is also likely that introduced non-inbred individuals and their outcrossed offspring would exhibit higher reproductive success (et al. 2002; Saccheri & Brakefield 2002). This would have the beneficial effect of increasing the ratio between effective migrants / census number of migrants. In other words, it could turn out that a lower census number of migrants would be needed than originally assumed. Allendorf FW, (2002) The role of genetics in population viability analysis. In: Population Viability Analysis (eds. Beissinger SR, ), pp. 50–85. Aspi J, Roininen E, Ruokonen M, Kojola I, (2006) Genetic diversity, population structure, effective population size and demographic history of the Finnish wolf population.