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Population History, Genetic Variability, and Horn Growth in Bighorn Sheep

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Abstract

Bighorn sheep (Ovis canadensis) are restricted in distribution and numbers relative to presettlement conditions. Some populations have alledgedly suffered losses of fitness resulting from small, insular populations and a breeding system that reduces effective population size. Large horns in rams, which confer breeding superiority, are absent from some populations, and this absence may result in part from loss of genetic variability. We investigated the relationship among allozyme variability, population history, and horn growth in bighorn sheep from the Rocky Mountains. Heterozygosity was higher for bighorn sheep than has been reported for Dall sheep (O. dalli). Heterozygosity and allelic variability were marginally related to effective population size for the proceeding 15 years. Horn growth was significantly higher in more heterozygous than in less heterozygous rams for years 6, 7, and 8 of life. By the end of year 8, more heterozygous rams had 13% higher horn volumes than less heterozygous rams. Mos

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... Populations established through releases will often have less genetic diversity than those that are the source of released individuals; this loss is related to the number of individuals released (Grobler and Van de Bank 1994, Tarr et al. 1998, Le Page et al. 2000, Stockwell and Leberg 2002. For example, Fitzsimmons et al. (1997) found that populations established with translocated mountain sheep (Ovis canadensis) often had low levels of genetic diversity compared to the source of the released individuals. These releases were often between 8 and 69 individuals per population. ...
... Slow population growth following translocation appears to be responsible for a loss of heterozygosity in a population of elk (Williams et al. 2002). Not surprisingly, allele frequencies of translocated populations often differ from those of their sources (Scribner 1993, Fitzsimmons et al. 1997, Rowe et al. 1998, Tarr et al. 1998. Founder events associated with translocations can also create large differences among translocated populations from the same sources (Leberg 1991, Scribner 1993, Tarr et al. 1998). ...
... Many studies have found that individuals that are heterozygous for one or more allozyme loci have traits that might enhance fitness such as high growth, increased survival and fecundity, or developmental stability Leary 1986, Reed andFrankham 2003). Examples of fitness-related traits of wildlife associated with specific allozyme genotypes at single or with multiple locus heterozygosity include spur length in wild turkeys (Leberg 1994), horn growth in mountain sheep (Fitzsimmons et al. 1995), developmental stability in the brown hare (Lepus europaeus) (Hartl et al. 1995a) and survival in marbled salamanders (Ambystoma opacum) and red deer (Pemberton et al. 1988, Chazal et al. 1996. In white-tailed deer, single or multiple locus heterozygosity has been associated with many traits (Smith et al. 2001b) including fetal and adult growth (Cothran et al. 1983), fat accumulation (Cothran et al. 1987), and antler size (Scribner et al. 1989). ...
... Genetic diversity is crucial for individual fitness (Piertney andOliver 2006, Hoover et al. 2018), population persistence (Saccheri et al. 1998, Holmes et al. 2016, and adaptation to novel conditions ( Jump et al. 2009, Creech et al. 2017). In sheep, higher genetic diversity is associated with lower parasite abundance (Coltman et al. 1999); greater horn growth (FitzSimmons et al. 1995), a male trait associated with reproductive success (Coltman et al. 2002); and higher lamb survival (Rioux-Paquette et al. 2010). Although the high elevation, rocky habitats of bighorn sheep are intrinsically disconnected (Geist 1971, Bleich et al. 1990), connectivity has likely been reduced in the past century by anthropogenic barriers such as roads and highways (Epps et al. 2005) and by climate fluctuations in the past (Hewitt 2000). ...
... Although the high elevation, rocky habitats of bighorn sheep are intrinsically disconnected (Geist 1971, Bleich et al. 1990), connectivity has likely been reduced in the past century by anthropogenic barriers such as roads and highways (Epps et al. 2005) and by climate fluctuations in the past (Hewitt 2000). Gene flow among herds was likely correspondingly higher prior to human population expansion (FitzSimmons et al. 1995), promoting the introduction of new alleles into herds and maintaining adaptive potential. Quantification of genetic diversity can provide information for assessing the effects of management actions, disease outbreaks, habitat alterations, and climate change. ...
... Large herds (Absaroka, Whiskey Mountain) and herds receiving high numbers of translocations (Devil's Canyon, Laramie Peak) had higher expected heterozygosity than the other herds (Table 2; Fig. S13). This is consistent with an earlier molecular genetic study of bighorn sheep in Wyoming using 4 allozyme loci that showed the highest diversity in the most populous and largest hunt areas within the Absaroka herd unit, compared to the Jackson and Whiskey Mountain herds (FitzSimmons et al. 1995). Consistent with our results, the same allozyme study found low diversity in a western South Dakota herd founded by translocation (FitzSimmons et al. 1997 has been documented within South Dakota (South Dakota Department of Game, Fish andParks 2013, Parr 2015), but the Kouba Canyon herd remains isolated from the larger herds in Wyoming, which is likely contributing to the low genetic diversity of the population. ...
Article
Aligning wildlife management boundaries with accurate biological units promotes effective conservation and management practices that reflect ecological and evolutionary processes. Neutral genetic markers allow for quantitative delineation of population structure without a priori assumptions or biases. In the United States, bighorn sheep (Ovis canadensis) are a charismatic component of Wyoming's biodiversity and a species that provides important viewing and hunting opportunities. Bighorn sheep abundances are relatively stable throughout Wyoming, and the species is managed by administrative units identified using expert knowledge, distribution and movement data, and geographic and administrative boundaries. We used a panel of 38 variable microsatellite loci and 512 base pairs of mitochondrial DNA sequence to identify the genetic structure throughout the state and in translocation source herds, quantify the extent of genetic diversity within each genetic cluster, and estimate the degree of gene flow among herds using blood and tissue samples collected 1989–2017. We identified genetic structure of Rocky Mountain bighorn sheep in the major mountain ranges of Wyoming, with strong support for ≥5 genetic clusters using microsatellite loci. These genetic clusters generally aligned with current management units, whereas mitochondrial data showed a more complex mosaic that was not geographically patterned. Genetic variation estimated from both markers was high within each herd and comparable among herds. The assignment of individuals reflected a combination of geographic isolation and translocation, which has been extensive. Our results provide a state‐wide assessment of genetic diversity and structure that will enhance management by understanding the outcomes of translocation, identifying the source of unknown individuals, and parameterizing disease ecology models. © 2020 The Wildlife Society. Population genetic analyses of bighorn sheep in Wyoming, USA, 2012–2017 identified genetic clusters that reflect biogeographic and management history. Concern for maintaining genetic connectivity should be balanced against the potential for disease transmission.
... Horn growth in rams is related to allozyme heterozygosity in Rocky Mountain bighorn sheep Ouis canadensis canadensis (Fitzsimmons 1992, Fitzsimmons et al. 1995. Horns of males are used in displays, and as weapons and shock absorbers in collision fighting (Geist 1966). ...
... Hogg (1987) speculated that by choosing males with large horns, females gain mates of superior genetic quality, for both disease resistance and superior foraging ability are needed to grow large horns. Fitzsimmons et al. (1995) measured the horns of 113 bighorn rams taken by hunters in Wyoming in 1989 and 1990, and estimated the annual increase in the volume of the horns. Samples of tissue from each animal were analyzed with electrophoresis to identify their genotypes at four polymorphic loci. ...
Article
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Regular development of morphology is challenged by any environmental influence that draines energy from developing individuals. For half a century biologist have recognized that developmental stability, measured as the capability to regulate development of normal morphological structures, is influenced by genetic variation. This review considers the influence of enzyme polymorphism upon developmental stability. Empirical studies in a wide variety of animals have reported morphological variability and bilateral assymmetry to decrase with the heterozygosity of enzyme polymorphism. A controversy focuses on the question of whether the enzymes are neutral markers that either reveal variation in levels of inbreeding or are in linkage disequilibrium with genes directly influencing development. Another controversy focuses on whether the relationships between enzyme heterozygosity and development stability, most commonly reported in poikilotherms, will also be found homeotherms. These controversies are addressed by considering recent empirical studies of enzyme polymorphism and developmental stability.
... Hartl et al. (1991a); (3) Roed (1986); (4)Hartl et al. (1991b); (5)Gavin & May (1988); (6)Hartl et al. (1992a); (7)Fitzsimmons, Buskirk & Smith (1995); (8)Sage & Wolff (1986); (9)Miller & Hartl (1986); (10)Georgiadis et al. (1990); (11)Bigalke et al (1995); (12)Bigalke et al (1993); (13) De Meneghi,Apollonio & Hartl (1995); (14)Lee, Bickham & Douglas Scott (1994);(15)Hartl et al. (1993a); (16) Danielsdottir, Duke & Joyce (1991); (17) Winans & Jones (1988); (18) McDermid & Bonner (1975); (19) Testa (1986); (20) Lidicker, Sage & Calkins (1981); (21) Simonsen, Born & Kristensen (1982); (22) Hartl et al. (1988); (23) Randi & Ragni (1991); (24) Wildt et al. (1987); (25) Hamilton & Kennedy (1986); (26) Hartl et al (1996); (27) Hartl et al. (1993b); (28) Peterka & Hartl (1992); (29) Tolliver et al. (1985); (30) Hartl et al (1995); (31) Nozawa et al. (1991); (32) Kawamoto et al. (1988); (33) Shotake, Nozawa & Santiapillai (1991); (34) Melnick, Jolly & Kidd (1986); (35) Shotake (1981); (36) Kawamoto, Shotake & Nozawa (1982); (37) Bruce & Ayala ...
... Hartl & Pucek (1994); (3)Hartl (1986); (4)Hartl (1990); (5)Fitzsimmons et al. (1995); (6)Miller & Hartl (1986); (7)Pemberton et al (1989); (8)Bigalke et al. (1993); (9)Corbet, Grant & Robinson (1994); (10)Hartl & Hell (1994); (11)Randi, Lucchini & Francisci (1993);(12)Wildt et al. (1987); (13)Forman et al (1986).nl, sample size of individuals; nL, sample size of loci (only data based on >25 loci were considered); P, proportion of polymorphic loci (mostly 99% criterion); H, expected average heterozygosity; H: P, ratio of H:P; Ref., reference. ...
Article
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Based on enzyme electrophoretic data, genetic diversity of various medium-sized and large mammalian species is presented. Following various hypotheses under discussion, body size (small v. large), feeding type (herbivorous v carnivorous), mating system (polygynous v. panmictic), and geographic distribution (population structure influenced v. not influenced by Pleistocene glaciations) of species were tested as to their influence on differences in allozyme variation among species. Expected average heterozygosity (H) did not differ significantly among the categories of taxa established according to the above criteria, whereas the proportion of polymorphic loci (P) and the H:P-rate did in most of the comparisons. The same was found in comparisons of undisturbed with bottlenecked populations of various species, whereby only in part of the above categories comprising undisturbed populations genetic variation was higher than in bottlenecked populations. Compared to P and the H:P-rate, H is regarded as less a sensible indicator of genetic erosion. The implications of natural differences in genetic diversity among populations and species for conservation are discussed.
... In polygynous ungulates where mate choice and intrasexual competition are influenced by secondary sexual characteristics, large horns and antlers can be a key factor in reproductive success (Coltman et al. 2002, Preston et al. 2003. The size of such traits is thought to be correlated with individual quality, with larger individuals typically having greater fitness (Fitzsimmons et al. 1995, Moller and Alatalo 1999, Kruuk et al. 2002. Harvest regulations targeting large phenotypes may remove high-quality individuals and favor smaller or slower-growing individuals (Jachmann et al. 1995. ...
... Our results are consistent with previous studies which suggested that selective removal of high-quality males through trophy hunting can produce an undesirable response in horn size (Fitzsimmons et al. 1995, Festa-Bianchet et al. 2004, Garel et al. 2007. We suggest that minimum horn curl regulations without severe restrictions on harvest intensity do not protect bighorn sheep populations from negative effects of selective harvests. ...
Article
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Wild sheep in North America are highly prized by hunters and most harvest regulations restrict legal harvest to males with a specified minimum horn curl. Because reproductive success is skewed toward larger males that are socially dominant, these regulations may select against high-quality, fast-growing males. To evaluate potential selective effects of alternative management strategies, we analyzed horn increment measures of males harvested over 28 yr (1975–2003) in 2 bighorn sheep (Ovis canadensis) ecotypes in British Columbia, Canada. Using mixed-effect models we examined variation in hunter selection for horn size, early horn growth, and male age under different harvest regulations (Full Curl, Three Quarter Curl, Any Ram). Under all regulations, males with the greatest early horn growth were harvested at the youngest ages, before the age at which large horns influence reproductive success. Early growth decreased with harvest age and until ≥7 yr of age it was greatest in males harvested under Full Curl regulation. Permit type (General vs. Limited Entry Hunt) and hunter origin (British Columbia Resident vs. Non-Resident) had little effect on horn size of harvested males. Full Curl regulations increased the average age of harvested males by <1 yr relative to Three-Quarter Curl regulations. Age-specific horn measures in the California ecotype harvested under Three-Quarter Curl regulations declined over time but we observed no temporal declines in the Rocky Mountain ecotype, primarily harvested under Full Curl regulations. Management strategies that protect some males with greater early horn growth or provide harvest refuges to maintain genetic diversity are likely to reduce potential for negative effects of artificial selection. © 2010 The Wildlife Society
... One factor in determining ideal source populations should be genetic diversity, which can affect population viability. Populations with low levels of genetic diversity are more likely to suffer from inbreeding effects (Packer et al. 1991; Roelke et al. 1993; Fitzsimmons et al. 1995; Halverson et al. 2006) and may be less able to adapt to selection pressures in their new environment (Lacy 1997; Saccheri et al. 1998; Reed and Frankham 2003). Consequently, using genetically diverse populations should, in general, increase the likelihood of a successful reintroduction. ...
... Three criteria connected to our study can be used to evaluate northern leopard frog populations as possible sources for Alberta reintroductions: (i) genetic variability, (ii) genetic similarity to the original inhabitants of a region identified for reintroduction and surrounding areas, and (iii) evolutionary history. Genetic variability is an important consideration when choosing populations as sources for translocations, as populations with higher diversity also tend to have higher fitness (Packer et al. 1991; Roelke et al. 1993; Fitzsimmons et al. 1995; Halverson et al. 2006), thereby increasing the probability of long-term population viability. Based on this consideration, populations in Manitoba and Ontario are the best sources, as they displayed the highest levels of diversity with all three measures. ...
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The northern leopard frog (Rana pipiens Schreber, 1782) underwent I large decline in the western portion of its range and only Occurs in 20% of historically occupied sites in Alberta. Its absence may reflect all inability to disperse to these sites because of habitat fragmentation, and human-mediated translocation has been proposed. In this Study, we used three criteria to examine the genetic suitability of potential translocation sources: diversity, similarity to area of reintroduction, and evolutionary history. We genotyped 197 samples and sequenced 812 bp of the mitochondrial NADH dehydrogenase I gene from 14 Canadian northern leopard frog populations. Nuclear and mitochondrial diversity were highest in Manitoba and western Ontario and declined westward. There was no significant relationship between genetic and geographic distance, suggesting that genetic drift is a driving force affecting the genetic relationships between populations. Regions separated by more than similar to 50 kin were quite differentiated. Therefore, Source Populations similar to the original inhabitants of an area for reintroduction may be uncommon.. Mitochondrial analyses revealed that all populations share 11 close evolutionary history, belonging to the western haplotype group. While genetic criteria Support the use Of Manitoba and Ontario as sources, the desirability of environmental similarity to the reintroduction site suggests that ecologically exchangeable Alberta Populations should also be considered.
... Heterozygosity refers to how different alleles are paired at loci and reflects recent breeding history. Heterozygosity may be positively correlated with bighorn sheep fitness (Fitzsimmons et al. 1995), and loss or lack of variability may lead to decreased growth, survival, fertility, and development rate Leary 1986, Ralls et al. 1988). Additionally, lack of variation in heterozygosity can increase susceptibility to epizootics (O'Brien and Evermann 1988) and reduce a population's ability to adapt to new environments (Allendorf and Leary 1986). ...
... In contrast, genetic variability estimates for the SR population fell within the range of values for other bighorn sheep populations. Effective population size (N e ; Fitzsimmons et al. 1995) for all Oregon populations we studied was initially extremely low (4-12) as a result of small founding populations of likely related individuals. Except for HM at its maximum population size of 572 in 1988, effective population size for the Oregon populations has generally remained low (N e = 337 in HM, 97 in SM, 116 = in LG, 109 in AM, and 172 in JD) relative to other species (DeWoody and Avise 2000). ...
Article
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Of the approximately 2,500 California bighorn sheep in Oregon, the majority descend from a single transplant of 20 animals from British Columbia in 1954. Recently, several populations have experienced poor recruitment, raising concerns that populations may be experiencing inbreeding depression resulting from a genetic bottleneck. We sampled 117 animals from 5 populations in Oregon and 1 population in Nevada to determine genetic variability within and among populations. We found that Oregon populations had fewer mean alleles per locus (2.2-2.4), lower heterozygosity (0.28-0.36), and higher inbreeding potential than animals from Nevada (3.8 alleles/locus, H = 0.53). These results now provide the baseline for rigorous ongoing evaluation of changes to allelic variability, inbreeding potential, variation among populations, and their effects on population demographics for Oregon's California bighorn sheep program. We suggest that evaluation of genetic variability in other source and recipient populations sho
... In Wyoming, for example, bighorn sheep (Ovis canadensis) have declined from over 150 000 individuals to Ͻ7000 in 70 yr. Allozyme sampling of this population indicated that horn growth was significantly higher (up to 13%) in more heterozygous adult rams than in less heterozygous adult rams (FitzSimmons et al. 1995). Since hunting these sheep involves selective removal of large-horned rams, status of the population may be further threatened if these animals continue to be removed. ...
Article
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Recent advances in molecular technology have opened a new chapter in species conservation efforts, as well as population biology. DNA sequencing, MHC (major histocompatibility complex), minisatellite, microsatellite, and RAPD (random amplified polymorphic DNA) procedures allow for identification of parentage, more distant relatives, founders to new populations, unidentified individuals, population structure, effective pop- ulation size, population-specific markers, etc. PCR (polymerase chain reaction) amplifi- cation of mitochondrial DNA, nuclear DNA, ribosomal DNA, chloroplast DNA, and other systems provide for more sophisticated analyses of metapopulation structure, hybridization events, and delineation of species, subspecies, and races, all of which aid in setting species recovery priorities. Each technique can be powerful in its own right but is most credible when used in conjunction with other molecular techniques and, most importantly, with ecological and demographic data collected from the field. Surprisingly few taxa of concern have been assayed with any molecular technique. Thus, rather than showcasing exhaustive details from a few well-known examples, this paper attempts to present a broad range of cases in which molecular techniques have been used to provide insight into conservation efforts.
... Festa-Bianchet (1986b) documented males up to 48 km from the site of their capture in southern Alberta, and Singer et al. (2000a) monitored 24 cases of dispersal of translocated Rocky Mountain bighorn sheep from release patches to neighboring unoccupied patches. Although movements of this type can enable gene flow and rescue effects, they also may serve as a disease vector, to which bighorn populations have proven very vulnerable (Bunch et al. 1999;DeForge et al. 1979;Fitzsimmons et al. 1995;Sausman 1984). As a result, issues of habitat quality (Johnson and Swift * Correspondent: nick_decesare@hotmail.com ...
Article
Species that exist in naturally fragmented subpopulations can maintain long-term viability through inter-population connectivity and recolonization of suitable habitat. We used radiotelemetry to study movements of 3 herds of bighorn sheep (Ovis canadensis) that recently colonized previously unoccupied parts of western Montana. These herds also provided a unique opportunity to compare resource-selection patterns in newly colonized habitats, and we used logistic regression in a global information system framework to generate predictive models for females in each herd. We detected relatively long (19- to 3 3-km) extra-home range movements by males in all 3 herds, and connectivity with nearby bighorn and domestic sheep herds. An information-theoretic approach to model selection revealed greater differences in resource selection among herds than anticipated. Initial evaluation of resource-selection models by resubstituting data showed excellent predictive accuracy (P ≤ 0.002), but testing models across sites gave mixed results, and in many cases, poor fit (0.001 d P ≤ 0.960). High vagility of males and variability in resource selection by females suggests increased potential for future recolonization and connectivity.
... Our estimates of N e /N (range: 0.10-0.46) were comparable to other published values for Ovis canadensis (Fitzsimmons et al., 1995). Low N e can result in loss of genetic diversity from a population through either inbreeding or genetic drift (Charlesworth, 2009;Frankham et al., 2010). ...
Conference Paper
Background/Question/Methods Peninsular bighorn sheep (Ovis canadensis nelsoni, PBS) are a federally endangered metapopulation of desert bighorn sheep endemic to the Peninsular Ranges of southern California, extending to the U.S./Mexico border. This metapopulation declined to <300 animals prior to listing in 1999, and is currently managed within a series of recovery regions approximating ewe home range groups. The goal of this project was to examine genetic diversity and spatial structure within the metapopulation and determine the extent of gene flow among selected recovery regions. Genetic data was generated by amplifying 39 microsatellite loci and a 515 bp fragment of the mtDNA control region from blood samples collected from sheep (n= 165) captured in seven recovery regions from 1992 to 2013. Results/Conclusions STRUCTURE analysis of microsatellite genotypes clustered sheep into two distinct genetic groups (north vs. south). Significant pairwise FST estimates among sheep from seven recovery regions (0.03 to 0.12) generally supported the presence of two genetic groups, with the possibility of additional substructure in the north (pairwise FST = 0.03 to 0.04, amova P = 0.02). Mitochondrial DNA analyses revealed five distinct haplotypes and indicated a similar pattern of north vs. south population structure (pairwise ΦST = 0.27 to 0.50). Considerable microsatellite diversity was found within both northern and southern groups (mean HO = 0.496; allelic richness = 3.47; FIS = 0.02), comparable to published accounts for desert bighorn sheep in other regions. We identified first-generation migrants of both sexes using GENECLASS2, but significantly lower assignment indices (AIc) among rams (Mann-Whitney U-test: P < 0.01) suggested dispersal was primarily male biased. Despite past population declines and ongoing deterministic threats, PBS have retained substantial genetic variation and gene flow among regions. Future conservation efforts should not only focus on sustaining population numbers, but also maintaining functional connectivity so the recovering metapopulation can expand into available habitat throughout the Peninsular Ranges.
... Second, reduced heterozygosity and increased inbreeding of black-footed ferrets resulting from many generations of captive breeding could have reduced body size through the general mechanisms that affect heterozygosity-mediated development. Multilocus heterozygosity was positively correlated with horn or antler size in bighorn sheep (Ovis canadensis, FitzSimmons et al. 1995) and white-tailed deer (Odocoileus virginiaus, Scribner et al. 1989). We found no correlation, however, between pedi- gree-based inbreeding coefficients and skull size, suggesting that the reduced genetic diversity of captive-bred black-footed ferrets was not associated with decreased body size. ...
Article
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Captive breeding of endangered species carries risks associated with small population size and domestication. The black-footed ferret (Mustela nigripes) was among the first endangered species bred in captivity. We documented morphological changes to the species after >10 years of captive breeding. We measured 9 dental or cranial traits on 109 skulls; 85 specimens were collected prior to captivity and 24 specimens were of captive-born animals. Skulls of captive animals were 5-6% smaller than skulls from precaptive animals and were 3-10% smaller than skulls of animals collected near the founding population, suggesting that changes occurred in captivity rather than from sample bias in the founders of the captive population. Skull size did not correlate with inbreeding coefficients of captive animals, eliminating the possibility that black-footed ferrets were smaller because of the effects of inbreeding depression or overdominance. Although reintroduced animals were smaller than historical animals, we recommended no alterations to the current management because intentional selection for body size might further reduce genetic variation in a geneti - cally impoverished species. We hypothesize that reintroduced individuals will return to historical body sizes rapidly, owing either to release of environmental stresses or to natural selection for larger size.
... Accordingly, various studies have shown bottleneck effects in number of alleles but not in He (e.g. Biebach and Keller, 2009;Clegg et al., 2002;Dlugosch and Parker, 2008;Fitzsimmons et al., 1995;Williams et al., 2000). We found a similar pattern: the number of released founders did not influence He, but influenced sNa significantly. ...
Article
Reintroductions and other conservation translocations have become increasingly important conservation tools, albeit with variable success. Genetic variation is one factor, which may influence reintroduction success. Genetic variation in reintroduced populations can be augmented by increasing the number of founders or by admixing animals from different source populations. At present there is no clear understanding of the relative importance of the two. Here we address this question by combining detailed demographic information about the reintroduction history of 40 Alpine ibex populations with genetic data from neutral markers, including coalescent-based estimates of the number of genetic founders. Number of genetic founders was a better predictor of present-day genetic variation than number of released founders, indicating that differential survival of founders can substantially affect the genetic variation of reintroduced populations. The degree of admixture in the founder group had about twice as much impact on genetic variation than the number of founders. Thus, to maintain genetic variation in reintroduced populations, releasing animals from different sources might be more important than releasing many animals from a single source. This even applies to cases such as the Alpine ibex where all individuals descended from a single ancestral population, and where the admixture was only between sub-populations created by the reintroduction program and thus between populations with relatively little genetic differentiation.
... Despite the apparent robustness of this species to exploitation, the reduction of genetic variation through harvest may lead to inbreeding depression that could cause reduction in survival and reproductive output and thus increase the probability of extinction at low population sizes (Frankham et al. 2002). Sex-biased harvest regimes (for example, targeting large males only) can also result in an overall reduction in genetic diversity (FitzSimmons et al. 1995). Perhaps a more serious shortterm concern is the reduction in size of highly heritable traits such as body mass with sustained harvest of large males (Coltman et al. 2003, Birkeland andDayton 2005), so avoiding the eradication of these individuals is advisable. ...
... Deer with small antlers were more inbred, based on the heterozygosity of allozymes, than deer with larger antlers [12]. Individuals that were more heterozygous had greater antler sizes or points in white-tailed deer [13][14][15][16] and greater horn growth in bighorn sheep [17]. ...
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The increased use of antler restrictions by state game agencies has led to a focus on antlers by the hunting public, particularly the potential for an association between genetics and antler characteristics. We analyzed microsatellite data from 1231 male white-tailed deer (Odocoileus virginianus) from three states (Oklahoma, Mississippi, and Texas) within USA to determine if genetic relatedness, internal relatedness (IR), homozygosity weighted by locus (HL), or correlations among uniting gametes (Fis) influenced total antler points, antler score, non-typical points or antler malformations. Within each location, deer in the lower and upper quartile intervals for number of antler points and score were unrelated (95% CI included 0 or was <0) and relatively heterozygous for four measures of inbreeding. Antler score and points were positively influenced by age but negatively influenced by IR and HL, except for antler score in Mississippi. Relatedness, HL, IR and Fis did not differ between groups of deer with and without antler malformations. Perceived differences in antler quality do not appear to be affected by heterozygosity or a result of close inbreeding because we found deer were unrelated and measures of inbreeding and genome-wide heterozygosity were not correlated with antler characteristics.
... These declines have been attributed to an array of environmental and demographic factors including: unregulated hunting, predation, habitat loss, and diseases [2,3]. While transplant efforts have proved effective in increasing overall bighorn numbers, many herds remain genetically and geographically isolated and often fail to recover to historical levels [4]. One of the major challenges currently facing managers attempting to restore these populations is low lamb recruitment. ...
Article
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Estimating survival and documenting causes and timing of mortality events in neonate bighorn sheep (Ovis canadensis) improves understanding of population ecology and factors influencing recruitment. During 2010-2012, we captured and radiocollared 74 neonates in the Black Hills, South Dakota, of which 95% (70) died before 52 weeks of age. Pneumonia (36%) was the leading cause of mortality followed by predation (30%). We used known fate analysis in Program MARK to estimate weekly survival rates and investigate the influence of intrinsic variables on 52-week survival. Model {S1 wk, 2-8 wks, >8 wks} had the lowest AIC c (Akaike's Information Criterion corrected for small sample size) value, indicating that age (3-stage age-interval: 1 week, 2-8 weeks, and >8 weeks) best explained survival. Weekly survival estimates for 1 week, 2-8 weeks, and >8 weeks were 0.81 (95% CI = 0.70-0.88), 0.86 (95% CI = 0.81-0.90), and 0.94 (95% CI = 0.91-0.96), respectively. Overall probability of surviving 52 weeks was 0.02 (95% CI = 0.01-0.07). Of 70 documented mortalities, 21% occurred during the first week, 55% during weeks 2-8, and 23% occurred >8 weeks of age. We found pneumonia and predation were temporally heterogeneous with lambs most susceptible to predation during the first 2-3 weeks of life, while the greatest risk from pneumonia occurred from weeks 4-8. Our results indicated pneumonia was the major factor limiting recruitment followed by predation. Mortality from predation may have been partly compensatory to pneumonia and its effects were less pronounced as alternative prey became available. Given the high rates of pneumonia-caused mortality we observed, and the apparent lack of pneumonia-causing pathogens in bighorn populations in the western Black Hills, management activities should be geared towards eliminating contact between diseased and healthy populations.
... Horn or antler size of many ungulates is affected by non-genetic characteristics, including age, population density, habitat and soil quality, and weather conditions (Bunnell 1978, Hoefs 1984, Wehausen 1989, Jorgenson et al. 1993, Fandos 1995, Hoefs and Nowlan 1997, Jorgenson et al. 1998, Toïgo et al. 1999, Festa-Bianchet et al. 2000, Mysterud et al. 2005. Horn and antler size, however, are also dependent on genotype (Stewart and Butts 1982, Fitzsimmon et al. 1995, Lukefahr and Jacobson 1998, Wehausen and Ramey 2000, Kruuk et al. 2002, Coltman et al. 2003. In bighorn sheep at Ram Mountain, Alberta, both horn size and body mass have a strong inheritable component (Réale et al. 1999, Coltman et al. 2003. ...
Article
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Male bighorn sheep (Ovis canadensis) complete about 80% of horn growth by age 5, yet horn size appears to play little or no role in their mating success until they are 6-8 yr old. Only the most dominant rams, typically 8 yr and older, can tend estrous ewes. Subordinate rams use alternative mating tactics whose success appears independent of their horn size. Rams with fast-growing horns may become 'legal' to harvest a few years before those large horns lead to higher mating success. If hunting pressure is high, rams with rapidly growing horns will have lower lifetime mating success than rams with slow- growing horns that do not become legal until an older age. Because ram horn size is inheritable, harvest of rams with rapidly growing horns may favor genetically small- horned rams. We documented this phenomenon at Ram Mountain, where rams with horns of 4/5 curl or greater were 'legal' and hunting by Alberta residents was unrestricted, leading to an average harvest rate of about 30% of 'legal' rams. Because traits that affect horn size in rams are genetically correlated with fitness-related traits in ewes, selective hunting may have affected the demographic performance of the population. The selective effects of trophy hunting should increase with hunting pressure and decrease with immigration of rams from protected areas. BIENN. SYMP. NORTH. WILD SHEEP AND GOAT COUNC. 15: 42-49
... For example, morphological abnormalities in wildlife populations, including malformation of sperm in the Florida panthers (Puma concolor coryi; Hedrick, 1995) and failure of testicular development in koala bears (Phascolarctos cinereus; Seymour et al., 2001), have been linked to inbreeding and low genetic diversity. Horn or antler size and growth in bighorn rams (Ovis canadensis) and white-tailed deer (Odocoileus virginianus) also seem to be influenced by genetic variability (Scribner and Smith, 1990;Smith et al., 1991;Fitzsimmons et al., 1995). ...
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Históricamente, el borrego cimarrón presentó una distribución amplia en Coahuila, México, llegando al sur hasta la latitud 25°43′02″N. La subespecie Ovis canadensis mexicana probablemente fue extirpada en Coahuila para 1970. Determinamos la distribución histórica del borrego cimarrón mediante una revisión de literatura disponible, entrevistas con ancianos residentes del área, y un análisis subjetivo del hábitat. Encontramos registros históricos del borrego para 14 sierras, (Sierra Alamitos, Sierra Maderas del Carmen, Sierra la Encantada, Sierra Hechiceros, Sierra del Pino, Sierra Mojada, Sierra el Rey, Sierra San Marcos y del Pino, Sierra Gavia y Sierra la Paila) incluyendo 4 que no habían sido registradas (Sierra el Fuste, Sierra el Almagre, Sierra de la Madera y Sierra la Fragua). Adicionalmente, un sitio con registros arqueológicos de la especie fue identificado (La Cueva de la Candelaria). La introducción de ganado doméstico, particularmente borregos y cabras, y la cacería sin regulación probablemente fueron los principales factores que contribuyeron a la extirpación de la subespecie en Coahuila. Estos factores persisten en 7 áreas, y nos enteramos de la presencia de aoudad (Ammotragus lervia) en 3 sierras (Sierra Mojada, Sierra Hechiceros, y Sierra la Fragua).
... By selecting males with the largest trophy traits, hunters may induce morphological change within the population by artificially favouring individuals with smaller sexually selected traits, for example shorter or thinner horns (Coltman et al., 2003;Garel et al., 2007). Ultimately, smaller horns may reduce individual fitness (Hartl, Zachos & Nadlinger, 2003), or be associated with lower genetic variability (Scribner, Smith & Johns, 1989;Fitzsimmons, Buskirk & Smith, 1995). ...
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The persistence of large African herbivores in trophy hunting areas is still unclear because of a lack of data from long-term wildlife monitoring outside national parks. We compared population trends over the last 30 years in Hwange National Park, Zimbabwe, and the neighbouring Matetsi Safari Area where large herbivores were harvested at an average yearly rate of 2%. We investigated whether trophy hunting altered densities and the proportion of adult males in several large herbivore species. Large herbivores generally thrived as well, or even better, in the hunting areas than in the national park. The proportion of adult males did not differ between the two zones, except for species with higher harvest rates and proportionally more males harvested. Densities were not lower in the hunting areas than in the national park, except for elephant and impala. Large herbivores generally declined throughout the 30-year period in both zones, particularly selective grazers. This is probably because of their greater sensitivity to variation in rainfall compared with other herbivores. Rainfall indeed declined during the study period with droughts being particularly frequent during the 1990s. Browsers, mixed feeders and non-selective grazers generally declined less in the hunting areas than in the national park, possibly because of lower densities of natural predators and elephants outside the park. Our study highlighted that large herbivores may persist in trophy hunting areas as well as in national parks. When rigorously managed, trophy hunting areas may be relevant conservation areas for large herbivores, particularly under the current global decline of wildlife abundance across Africa.
... By selecting males with the largest trophy traits, hunters may induce morphological change within the population by artificially favouring individuals with smaller sexually selected traits, for example shorter or thinner horns (Coltman et al., 2003;Garel et al., 2007). Ultimately, smaller horns may reduce individual fitness (Hartl, Zachos & Nadlinger, 2003), or be associated with lower genetic variability (Scribner, Smith & Johns, 1989;Fitzsimmons, Buskirk & Smith, 1995). ...
Article
Trophy hunting in ungulates may favour individuals with smaller horns. A decrease in horn/antler size may jeopardize the conservation potential of hunting areas, which would be a major concern in Africa where hunting zones represent over half of the total area of protected lands. We investigated horn length trends of harvested male impalas Aepyceros melampus, greater kudus Tragelaphus strepsiceros and sable antelopes Hippotragus niger, from 1974 to 2008 in Matetsi Safari Area, Zimbabwe. Horn length declined by 4% in impalas, partly because male harvest age decreased. In greater kudus, surprisingly, horn length increased by 14%, while mean age of harvested male greater kudus increased during the study period. Reduced hunting pressure on this species during the study may have allowed males to live longer and to grow longer horns before being harvested. Horn length declined by 6% in sable antelopes, independent of age, suggesting that trophy hunting selected male sable antelopes with smaller horns through time, provided that horn length is heritable. Hunting pressure and trophy value were higher for sable antelopes than for impalas and greater kudus. Accordingly, the decline of horn length in this species was more pronounced. More valuable trophy species, such as sable antelopes, require special attention because they may be exposed to higher hunting pressure, and are therefore more likely to experience a decrease in horn size.
... Lions in the Ngorongoro Crater, Tanzania, reduced to around ten animals in 1962, are less variable and have more sperm abnormalities than nearby lion populations (Packer et al. 1991). Evidence for inbreeding depression has been found in an ungulate population where researchers observed that horn growth is faster in bighorn sheep that have higher levels of heterozygosity (Fitzsimmons et al. 1995). As horns are used during mate competition, faster growing horns could result in an increase in fitness. ...
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In this report we review issues in conservation genetics, which pertain directly to genetic management and captive breeding of wildlife. Our goal is to evaluate genetic management options for the Hook Lake Wood Bison Recovery Project (HLWBR), a community-based wildlife conservation project that was initiated in 1996 and is run co-operatively between the Government of the Northwest Territories (NWT), the Aboriginal Wildlife Harvesters’ Committee (AWHC) and Deninu Kue’ First Nation in Fort Resolution. A principal aim of the project is to salvage genetic diversity from the Hook Lake herd, a wild, free-ranging herd of wood bison in the Slave River Lowlands that is diseased with bovine tuberculosis (Mycobacterium bovis) and brucellosis (Brucella abortus). The long-term goal of the co-operative project is to use a captive, disease-free herd to re-establish a healthy herd of free-ranging bison in the Hook Lake area. The current phase of the project, genetic salvage and captive-breeding, is based on a combination of techniques to propagate a healthy captive herd. From 1996 to 1998, a total of 62 calves were captured from the wild Hook Lake herd. At the time of writing (Nov 2002), 57 individuals comprised the founder herd with an additional 84 captive-born animals ranging in age from calves to three-year olds. To date there have been no cases of tuberculosis or brucellosis; all founder animals have been repeatedly tested using a combination of serologic tests for brucellosis and tuberculosis. As the HLWBRP proceeds into a growth phase through captive breeding and total herd size approaches the upper capacity of the facility, it becomes critically important to manage reproduction of the captive herd so as to minimize the loss of genetic diversity in future generations of captive-born bison. This report represents the first of two parts of an overall genetic management review of the HLWBRP. Here our objectives were to 1) detail the rationale for conservation of genetic diversity, 2) provide an overall framework and rationale for genetic management of captive breeding herds, and 3) explore the various tools available to the conservation geneticist in developing options for breeding management of the recovery project.
... For example, morphological abnormalities in wildlife populations, including malformation of sperm in the Florida panthers (Puma concolor coryi; Hedrick, 1995) and failure of testicular development in koala bears (Phascolarctos cinereus; Seymour et al., 2001), have been linked to inbreeding and low genetic diversity. Horn or antler size and growth in bighorn rams (Ovis canadensis) and white-tailed deer (Odocoileus virginianus) also seem to be influenced by genetic variability (Scribner and Smith, 1990;Smith et al., 1991;Fitzsimmons et al., 1995). ...
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El charalito del Colorado (Ptychocheilus lucius) es un pez catalogado en peligro de extinción por el gobierno federal, que anteriormente fue abundante y con una distribución amplia en la cuenca del río de Colorado. Durante el proceso de remover el pez exótico en la primavera de 2003, 2004 y 2005, se colectaron 2 charalitos río arriba del hábitat crítico en el río Yampa en Colorado. La colecta de estos especimenes puede ser un artefacto del bajo esfuerzo histórico del muestreo, pero sirve para documentar el uso potencial del hábitat del charalito del Colorado fuera del hábitat crítico.
... En muchas especies la caza furtiva ha tenido efectos devastadores en el ratio sexual y en la tasa reproductiva. Por otro lado, en algunos estudios hechos en los Estados Unidos de América sobre el muflón de las Rocosas Ovis canadensis (Fitzsimmons et al. 1995) se ha visto que la caza de individuos con unas determinadas características puede reducir la diversidad genética, si bien el impacto genético puede ser limitado si se compensa con un traslado de individuos o migraciones naturales. Así pues, los impactos genéticos y evolutivos del aprovecha- miento selectivo merecen una mayor atención a la prestada hasta el momento. ...
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Biology, pathology and management of the Pyrenean chamois
... above the RW trophy standard for bulls between 48 and 54 months in the present study, comparable with the results reported by Crosmary et al. (2013) on trophy-hunted sable in the Matetsi Safari area of Zimbabwe. The assumption of inferior performance of captive bred herds is based on the possible effects of inbreeding in small populations (Scribner et al., 1989;Fitzsimmons et al., 1995), but the evaluation of these herds showed a low average level of inbreeding (0.0043). ...
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Much of the economic value of wildlife can be attributed to horn size, which is an important trait for trophy hunters. The main objective of the study was to estimate genetic parameters for the economically important horn traits of sable antelope that are currently being measured in the South African industry. To date, no quantitative genetic analysis has been done for any traits in sable antelope. The total number of records included in the evaluation were n = 1713 for horn length (SHL), n = 1503 for circumference (SHC), n = 1486 for tip to tip (SHTT), n = 1505 for tip length (SHT), and n = 1447 for rings (SHR). Males and females were considered separately in six-month age clusters. A Markov chain Monte Carlo (MCMC) multi-trait analysis was used to estimate (co)variance parameters for the horn traits. The results indicate a sex effect for all the traits and suggest that it is not economically viable to measure horn length of either sex after 54 months old. The horns of females are on average 40% shorter compared with bulls at maturity. Continuous horn growth throughout the lifetime of sable is suggested by the formation of ring posts, but is often masked by horn attrition and inadequate measuring techniques. An inbreeding coefficient of 0.0043 suggests adequate genetic diversity in the studied population. Heritability estimates of horn traits varied from 0.085 to 0.52, while genetic correlations ranged from 0.1 to 0.6 with the highest correlation being found between horn length and tip to tip. Further studies are recommended to confirm these results.
... Inbreeding depression and inability of population to respond to long-term environmental changes are considered to be the aftereffect of loss of genetic variability (Meffe and Carroll 1994;FitzSimmons et al. 1995). The growth rate and resilience of populations could also be adversely affected because of loss of genetic variability (Lacy 1997). ...
Chapter
In this chapter, taxonomy, natural history and distribution of the snakes of the genus Bungarus from Northeast India are described in detail.
... Inbreeding depression and inability of population to respond to long-term environmental changes are considered to be the aftereffect of loss of genetic variability (Meffe and Carroll 1994;FitzSimmons et al. 1995). The growth rate and resilience of populations could also be adversely affected because of loss of genetic variability (Lacy 1997). ...
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Biodiversity is integral to the direct benefits that humans receive from nature besides ecosystem services. However, human activities and the negative consequences of climate change are accelerating the loss of biodiversity. There are multiple indications of continuing decline in biodiversity in all three of its components – ecosystems, species and genes. In order to receive continuous ecosystem services and protect the species from extinction, 35 global biodiversity hotspots have been identified for conservation. It is nothing but a biogeographic region with significant levels of biodiversity that is threatened with destruction. The tropical island of Andaman and Nicobar is part of the global biodiversity hotspot having a large number of flora and fauna besides exhibiting great endemism. The recent assessment showed that the plant diversity of these islands comprises 3219 species under 1251 genera belonging to angiosperms, gymnosperms, pteridophytes, bryophytes, lichens and algae. Similarly 1463 species of fishes, 600 species of corals, 120 species of sponges, 290 species of butterflies, 300 species of birds and 36 species of mangroves were recorded. They are imperative for the livelihood of local people, a treasure for humankind; therefore, efforts should be made to strengthen the conservation efforts and preservation of threatened floral and faunal diversity of these islands.
... In another Alberta population where ram horns generally grow faster than at Ram Mountain, 2 rams had 4/5-curl horns at 3 years and 4 4-yearolds were legally shot in 1982-91 (Festa-Bianchet 1989). Rams shot as 4 or 5 years old rams are well short of their horn growth potential (Fig. 5) (Heimer et al. 1984) and that trophy hunting may reduce genetic variability in a population (Hartl et al. 1991, Fitzsimmon et al. 1995, we recommend that management of trophy species should direct the harvest to a limited proportion of mature males that are near the end of their natural lifespan. For bighorn sheep, harvest should be directed to rams -8 years old. ...
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Trophy hunting is a management goal for many populations of ungulates and has important implications for conservation because of the economic value of trophy males. To determine whether population density affected horn growth of males, a marked population of bighorn sheep (ovis canadensis) in Alberta, Canada, was studied for 27 years. For the first 9 years, population density was kept stable by removing adult females; afterwards, the numbers of ewes and yearlings tripled before beginning to decline. Horns were measured during repeated captures of marked rams. As the number of adult ewes and yearlings increased, ram horns were shorter and thinner because of decreased horn growth before 4 years of age. Some compensatory horn growth may have occurred at 5 years of age. The effects of population density on horn growth ceased when rams left the nursery groups to join all-male groups. Doubling of male numbers had no detectable effect on net annual horn growth of males greater than or equal to 4 years old. Sp
... Heterozygosity is an important component of population genetic analyses, because it is often positively correlated with increased fitness, resistance to disease and long-term persistence of natural populations (Keller and Waller 2002, Jannikke et al. 2006, Xu et al. 2007, O'Grady et al. 2006. Positive correlations between heterozygosity and both fitness (FitzSimmons et al. 1995) and resistance to disease have also been documented in bighorn sheep (Coltman et al. 1999, Luikart et al. 2008a. Disease is often a significant factor in long-term persistence, of bighorn populations because they are particularly susceptible to pneumonia outbreaks which can result in large die-offs or local extinctions (Bailey 1986, Shackleton et al. 1999, Cassirer and Sinclair, 2007, Wehasausen et al. 2011. ...
... The ungulates are without question the best-studied animals with weapons, and countless field studies on their behavior, life history, and reproductive biology have documented weapon use, as both visual signals assessed by rival males and weapons in escalated fights (13-15, 42, 114, 174, 255). Males with the largest weapons are generally the largest and best-conditioned males (42,44,46,85,255), almost always the most likely to maintain access to females (14,15,43,44,114), and usually achieve the highest fertilization success (46,156,171,207). ...
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Males in many species invest substantially in structures that are used in combat with rivals over access to females. These weapons can attain extreme proportions and have diversified in form repeatedly. I review empirical literature on the function and evolution of sexually selected weapons to clarify important unanswered questions for future research. Despite their many shapes and sizes, and the multitude of habitats within which they function, animal weapons share many properties: They evolve when males are able to defend spatially restricted critical resources, they are typically the most variable morphological structures of these species, and this variation honestly reflects among-individual differences in body size or quality. What is not clear is how, or why, these weapons diverge in form. The potential for male competition to drive rapid divergence in weapon morphology remains one of the most exciting and understudied topics in sexual selection research today.
... However, the morphology of the horns is influenced not only by genetic factors but also by the environment. In fact, it has been reported that hunting pressures highly influence horn size as well as the genetic diversity of bighorn populations (Fitzsimmons et al. 1995). ...
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The current distribution of the bighorn sheep in Mexico represents a reduced proportion of its original area. Previous population genetics studies conducted in Mexico have only included data from Tiburon Island in the Gulf of California and few individuals from the continent. The aim of this article was to describe aspects of the population genetics of Mexican bighorn sheep in order to aid in the management and conservation of the species. We analyzed 117 samples from the states of Sonora and Baja California Sur using 91 intersimple sequence repeat loci. Our results indicated that the Mexican samples of bighorn sheep have relatively low levels of genetic diversity (H ≈ 0.26) and low genetic differentiation (ϴ ≈ 0.07) that may be the result of the recent colonization and origin of the populations in Mexico. The individuals from Southern Baja California are genetically different from the Sonoran sample, but this genetic differentiation is low, perhaps due to the low levels of genetic variation of the Mexican populations. The results obtained in this study are relevant for population management of the bighorn sheep in Mexico in order to design translocation plans and management strategies to maintain genetic diversity and, in consequence, the health and future survival of the populations.
... Additionally, population sizes are typically small, making herds susceptible to genetic drift, which can result in loss of allelic variation and decreased heterozygosity (Schwartz et al. 1986, Bleich et al. 1990, Guti errez-Espeleta et al. 2000. Estimating heterozygosity is therefore important because positive correlations between heterozygosity and both fitness (FitzSimmons et al. 1995) and resistance to disease have also been documented in bighorn sheep (Coltman et al. 1998, Luikart et al. 2008. We found estimated heterozygosities in the RMNP herds to be comparable to the highest values reported in other studies of native bighorn sheep populations (Boyce et al. 1997, Forbes and Hogg 1999, Epps et al. 2010, Johnson et al. 2011) and higher than those reported for some restored bighorn sheep populations . ...
Article
Five native herds of Rocky Mountain bighorn sheep (Ovis canadensis) occupy Rocky Mountain National Park and the immediate surrounding area. One of these herds, the Mummy herd, suffered a significant die-off following a suspected pneumonia outbreak in the mid-1990s with subsequent low population size and low yearling recruitment, as compared to the other 4 herds. To test the hypothesis that the Mummy herd's failure to thrive is due to decreased genetic variation as a result of a genetic bottleneck, we analyzed both microsatellite and mitochondrial data to estimate genetic differentiation, gene flow, and the extent of metapopulation substructure among all 5 herds. Our microsatellite analyses showed no evidence of a recent genetic bottleneck or inbreeding. Our comparisons of overall and pairwise population differentiation (Fst) and effective migration (Nm) from both microsatellite genotypes and mitochondrial haplotypes indicated that low population substructure was being maintained by moderate levels of gene flow among all 5 herds. Effective migration rates were both higher and more uniform among herds for microsatellite genotypes than for mitochondrial haplotypes, which exhibited an asymmetrical pattern among herds. A significant isolation-by-distance relationship for mitochondrial (but not microsatellite) data suggests that gene flow is primarily due to ram migration. Past translocations of sheep into, out of, and among these 5 herds are an important consideration when interpreting these results; however, our data clearly show that all 5 Rocky Mountain bighorn sheep herds have reasonable and equivalent levels of genetic variation. Thus, herd management and restoration efforts should be focused on other factors that might be detrimental to herd health, such as stress, nutritional deficiencies, habitat fragmentation, climactic factors, or disease. © 2015 The Wildlife Society.
... In winter, an annual ring is formed (e.g. in cows and rams) [14], [5]. Sometimes annual rings can be worn off [3]. Instead, we can often observe a different kind of ring, created more frequently. ...
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This paper describes a method suitable for creating animated modular models of horns for mammals belonging to the Bovidae family. Our method uses time-dependent positioners—fragments of modules with their own coordinate systems. Positioners are used in two ways: for placing modules appropriately next to each other and for creating the lateral surfaces of modules. Thanks to this double usage of the positioners, a continuous surface is achieved, regardless of the complexity of the time-dependent parameters. Different connections between parameters of modules are considered, justified from the point of view of modeling horns. The method is illustrated with the example of creating a time-dependent model of a ram's horn.
... Our estimates of N e /N (range: 0.10-0.46) were comparable to other published values for Ovis canadensis (Fitzsimmons et al., 1995). Low N e can result in loss of genetic diversity from a population through either inbreeding or genetic drift (Charlesworth, 2009;Frankham et al., 2010). ...
... Future studies on the role of individual genetic features in the development of annulus growth (cf. FitzSimmons et al., 1995) would be necessary to better clarify this issue. ...
... It was suggested that these negative developments were a result of inbreeding because multiple crossbreeding between closely related individuals enhances the likelihood of two recessive alleles appearing in the same gene (Selwa-Żurawska 1968). It is known that adult heterozygotic rams of bighorn sheep are characterised by larger horns compared with individuals with a higher level of heterozygosity (Fitzsimmons et al. 1995). It was decided to augment the local population of mouflons with animals from Slovakia and the Czech Republic. ...
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The research was carried out in the Sowie Mountains that are located in central part of the Sudety Mountains (South-western Poland). In 1902, 5 mouflons Ovis aries musimon were brought from Slovakia into this region. Over years there was an increase in population size until it reached 778 animals in 1995. Changes in improper proper development of horns have been noticed for a long time. The older the males were the more curved horns they had, which eventually started to stab into the animal’s neck. This process eliminated older animals and it was suggested that inbreeding is the main reason. In order to increase genetic variability it was decided to introduce more mouflons from Slovakia and Czech Republic. Between 2002 and 2004, 76 mouflons were bought and placed to reproduce in three enclosures located in the Bielawa (Forest District Świdnica, n=1) and the Jemna (Forest District Bardo Śląskie, n=2). In June 2006 mouflons from both enclosures (n= 177) were released. All released animals were given ear tags and 10 females and 10 males got radio collars produced by Televilt. In the following years location of animals was registered through telemetry receivers. The results suggest that released mouflons colonized the area of 850 ha near the Bielawa enclosure and 690 ha near the Jemna enclosure. The animals were located max. 1.0 km - 3.1 km from the enclosures apart from one male that was found 9.1 km away from the original enclosure. The average home range of males was 287.5 ha whereas for females it was 175.0 ha. After 4 years 19 out of 20 animals were still alive. Forest area in the Sowie Mountains inhabited by local population of mouflons comprise surface of 26600 ha. The degree of integration of released animals with the local mouflons was low as they occupied only 5.8% of range distribution of local population. Eight years after the introduction no essential improvements were seen in the horns of the harvested rams, probably because of high population density which amounted to 68.8 animals/1000 ha.
Article
The level of genetic diversity in free-living populations is not normally restrictive for conservation, since it tends to be enhanced in stressed outlier populations. At the physiological level, this enhancement is supported by the favouring of heterozygotes, especially when energy demands needed to adapt to stress are high. Therefore ecophysiological considerations are important for conservation strategies, whereby survival depends upon the metabolic potential of organisms to counter the energy cost of stress in their environments. While abiotic stresses are primary, biotic stresses, in particular competition, can be consolidated into this model as second-order effects. Irrespective of levels of genetic diversity, any species can be incorporated into this approach to conservation. I therefore regard the monitoring of stress response traits to be primary to the preservation of genetic diversity in developing conservation strategies. In arriving at this conclusion, Fisher's 1930 discussions of the environment and consequences for adaptation, as presented in the Genetical Theory of Natural Selection, play an initiating role.
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Horns of bovids are important social organs, their growth is often indicative of population characteristics and habitat quality, but Little is known of the factors affecting their growth in individuals. We studied horn growth of 135 (51 males, 84 females) marked mountain goats (Oreamnos americanus) in Alberta, Canada, for 9 years. In both sexes, horn growth was quadratic during the first 5 years of life and not significant after 5 years of age. Goats completed 93% of horn growth by 3 years of age. Horns of males grew more than those of females during the first 1.5 years of life. Horns of females grew more than those of males during the third year. Although males maintained longer horns than females because of their longer first increment, adult males had shorter horns than females for a given body size. Males had thicker horns than females at all ages, absolutely or relative to body size. Horn growth early in life was correlated negatively with later growth. Annual growth increments of horns of females
Article
En poblaciones naturales las anormalidades morfológicas se pueden asociar con la depresión por cruzamiento consanguíneo o la heredabilidad. Exploramos una base genética para las deformidades de cuerno y de pedú nculo (base del cuerno) documentadas en una población reintroducida del alce (Cervus elaphus) en la Hualapai Indian Reservation en el noroeste de Arizona. Usamos 12 loci de microsatélites para comparar la heterozigosidad individual de mú ltiples loci (IH) y parentesco interno (IR) entre alces adultos machos con malformaciones (n = 23) e individuos que presentaron formación normal de cuerno (n = 17). Adicionalmente, utilizamos 3 coeficientes de parentesco pareados para determinar si los machos con cuernos deformados estuvieron más estrechamente relacionados entre sí que los machos con cuernos normales. La media de IH y la media de IR no fueron significativamente más altas para el grupo de cuernos deformados. Asimismo, la relación entre las malformaciones de cuerno y los coeficientes de parentesco pareados tampoco fue significativa, lo que sugiere que los machos deformados no comparten esta característica entre sí debido a una relación genética más cercana. Otras causas, como factores nutricionales o ambientales, podrán estar asociadas con estas deformidades. Se necesita investigación adicional para determinar las causas fundamentales de las malformaciones de cuerno y de pedúnculo documentadas en el grupo de alces introducidos en el norte de Arizona.
Article
The relationship between individual heterozygosity and characteristics likely to be associated with fitness was investigated in the labyrinth spider Metepeira ventura. Adult females and their egg sacs were collected at a coastal site in southern California, and three measures of bodily condition (carapace width, weight, residual index) and six measures of reproductive output (number of egg sacs, variation in egg number among sacs [coefficient of variation], total number of eggs, mean eggs/sac, mean eggs/sac divided by carapace width, mean eggs/sac divided by weight) were determined for each spider. The sample was polymorphic at three allozyme loci that were in Hardy–Weinberg equilibrium, and individual females were heterozygous at up to two of the three loci, forming three heterozygosity classes (0, 1, and 2). None of the bodily condition measures were significantly related to the number of heterozygous loci, while four of the reproductive output estimators (total number of eggs, mean eggs/sac, mean eggs/sac divided by carapace width, mean eggs/sac divided by weight) were significantly influenced by heterozygosity. In each significant case, values for class 2 females were less than those for class 0 and 1 females, whose values were usually more similar. Thus, while female bodily condition was comparable among classes, the most heterozygous females produced fewer total eggs and eggs per sac than their less heterozygous peers. The fact that females of M. ventura engage in a reproductive investment-number trade-off suggests that high-variability and low-variability females may be pursuing distinct reproductive strategies in the wild, with more heterozygous females being K-selected (smaller clutches, heavier eggs) and more homozygous females being r-selected (larger clutches, lighter eggs). Further investigation will be needed to assess more fully the fitness value of heterozygosity in M. ventura.
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Human-mediated species dispersal across the Mediterranean stretches back at least 10,000 years and has left an indelible stamp on present-day biodiversity. Believed to be a descendant of the Asiatic mouflon (Ovis gmelini gmelinii), the Corsican mouflon (O. g. musimon) was translocated during the Neolithic as ancestral livestock by humans migrating from the Fertile Crescent to the Western Mediterranean. Today, two geographically limited and disconnected populations can be found in Corsica. Whether they originated from distinct founders or one ancestral population that later split remains unknown, although such information is pivotal for the species' management on the island. We genotyped 109 and 176 individuals at the Cytochrome-b gene and 16 loci of the microsatellite DNA, respectively, to gain insights into the natural history of the Corsican mouflon. We found evidence confirming that the Asiatic was the ancestor of the Corsican mouflon, which should thus be unvaryingly referred to as O. g. musimon, i.e. as a subspecies of the Asiatic mouflon. Haplotype divergence dating and the investigation of genetic structure highlighted a strong and ancient genetic differentiation between the two Corsican populations. Approximate Bayesian Computation pointed to the introduction of a single group of founders as the most reliable scenario for the origin of the entire Corsican population. Later, this ancestral stock would have decreased in number, facing genetic bottlenecks and eventually resulting in two divergent demes. Splitting most likely occurred several hundred years ago. Their shared past notwithstanding, we discuss whether the two relic Corsican mouflon populations should be now considered as distinct management units.
Article
Historically, novel molecular techniques have been developed by the human genetics community, adapted for nonhuman organisms by evolutionary biologists, and gradually adopted by the wildlife and fisheries communities. Today, evolutionary biologists routinely rely on molecules to assess mate choice, dispersal, parentage, sex ratios, and other population parameters. All in all, the use of molecular genetic markers has revolutionized population biology—human and otherwise. Prescient wildlife and fisheries biologists have recognized the importance of this revolution and are now using molecular genetic tools to evaluate captive or supplemental breeding programs, population dynamics, stocking strategies, and taxonomic issues. Herein, I explore the use of molecular genetic markers to address questions in wildlife biology and management. Specifically, I review how—among other topics—cannibalism, sex-ratios, dispersal, enumeration, genotoxicology, hybridization, and genetically modified organisms can be evaluated in the context of parentage, relatedness, and fitness. As science becomes more integrative and complex, it is easy to envision a future where collaborations between geneticists (who may not have the expertise to obtain the field samples) and wildlife biologists (who may not have the expertise and/or facilities to obtain the genotypes) are common and serve to answer both fundamental and applied questions.
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Nygrén, Tuire, Biology and policies in Finnish moose population regulation and management - University of Joensuu, 2009, 227 pp. University of Joensuu, PhD Dissertations in Biology, No. 64, ISSN 1795-7257 (printed), ISSN 1457-2486 (PDF) ISBN 978-952-219-313-1 (printed), ISBN 978-952-219-314-8 (PDF) Key words: Age structure, Alces alces, antler types, cervid genetics, exploitation, moose, moose management, moose policy, population dynamics, productivity, rapid contemporary evolution, regulation goals, sex ratio, weight development Intensified forest management after the last war and taking up the practice of calf hunting in the 1970’s created the prerequisites for a growing population of moose in Finland. The population has been regulated with varying success during the last few decades. This study looks at the history of the development of the regulation of the Finnish moose population, the biological foundations for it and the policies concerning it. The study also considers the effect of the management practices on the moose in Finland. The observations presented here are used to discuss future alternatives and for presenting a utopia of regulation which aims at reaching a stable and sustainably exploited population. The effects on the moose population of the regulation practiced to date have been sizeable. The population growth has been curtailed for the purpose of minimising moose damage. It has been done by harvesting one third of the animals each year and the harvest has been implemented so as not to reduce its production efficiency. This has given rise to a highly productive and extremely well exploited moose population. It seems that at the turn of the millennium, Finland housed a population of moose that appears to be more productive than anywhere else in the world. Changing the population structure by selective hunting has had an effect on the development of moose population density. There have been intermittent phases of explosive growth and falling population densities. Nevertheless, even the highest population densities have been reasonable compared to Finland’s western neighbours and symptoms of fitness and health from wear on grazing areas, in individual moose, have been negligible. At the end of the observation period, in 2007, the population densities were more or less within the target. The proportion of males, however, was lower than ever before and the number of calves per female and the proportion of twins were decreasing. The population has also changed genetically, as the proportion of males with cervina type antlers has increased in relation to those with the palmated type. Moose population regulation and management has been a multilateral series of events in natural resource policy, which has been based on scientific research and the experience gained from the continual follow-up of the population. Continual change has been characteristic of this process. The size and structure of the population, the aims of its regulation and management and the methods of follow-up and hunting have all undergone change. Information has been imprecise, the matters have been complicated and politically controversial, as well as socially difficult and polarised and decisions have had to be made in a hurry. Values have also changed. A valued game animal has become one that is harmful to the national economy. Its value has become interpreted as negative from the point of view of the social economy. On average, the results of the population regulation have been unsatisfactory. The population developed more or less according to target only during 1984–1992, which is when the co-operation between the relevant actors was efficient, aims and responsibilities were clear, the decision making was centralised and the biological sustainability of the populations had higher priority than the economic and harvesting aims. During the course of the 1990’s, however, the hunting law was renewed, the Hunters’ Central Organisation was reorganised and the responsibility for moose management shifted to the local level. In this process of re-organisation and law renewal, previous follow-up methods and practices lost their effectiveness. The development of the moose population became more unpredictable. Aiming for a biologically and socially sustainable population is the objective of the regulation utopia which looks to the future and is presented at the end of the study. One of its characteristics is discarding the aim of maximising the production efficiency of the population, which is what has been increasing the occurrence of problems caused by moose.
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Our objective was to survey genetic variability and examine population structure in the endangered Red-cockaded Woodpecker, a species whose distribution has been fragmented by land-use patterns. Sixteen presumptive gene loci were resolved from feather pulp of nestlings and adults from 26 populations rangewide. Mean heterozygosity in the Red-cockaded Woodpecker was 7.8% and ranged from 3.1%–10.3% across populations. Heterozygosity was significantly but weakly associated with population size; this association was dependent on low heterozygosity in two small populations. The percentage of polymorphic loci and mean number of alleles per locus were also positively correlated with population size. Relative to other species of birds, there is a large among-population component of genetic variance (Fst= 0.14). Genetic distance among populations increased with geographic distance. Although heterozygosity is reduced in some small populations, most exhibit “normal” levels. Small populations should therefore not be considered “lost causes” from the genetic standpoint. Small populations are important as reservoirs of unique genetic combinations and to help facilitate gene flow among larger populations.
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Concerns genetic variability in the nominate subspecies, O. d. dalli, from 3 parts of its N Alaskan distribution: the Alaskan Range, the Tanana Hills and the Brooks Range. These areas are 150-200 km apart. Their populations have been isolated from each other since the end of the Wisconsinan glaciation. -from Authors
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Rocky mountain bighorn (Ovis canadensis canadensis) lambs grew rapidly from birth to a weight of 70 lb in October, but gained little or no weight through their first winter. Males increased in weight and chest girth until at least 7 years of age, but increased in hind foot length only until 4 years of age. Females grew in weight, chest girth, and hind foot length until at least 4 years of age after which their age could not be accurately determined. Average weights, in spring, of 54 rams and 65 ewes in Waterton Lakes National Park, Alberta, all at least 4 years of age, were 207 and 159 lb, respectively. Maximum weights of rams and ewes were 265 and 200 lb, respectively. Increase in weight of skull and horns was not sufficient to account for continued weight gain in adult rams. The idea that the disparity in weight between rams and ewes increased northward is questioned.
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This report concerns the effect of weather on lamb survival in desert mountain sheep (Ovis canadensis nelsoni) to 6-8 months of age in the River Mountains, Nevada, and how it integrates with density to limit the population. Regression analyses were used to examine relationships between lamb survival and weather variables from 1970 to 1982. Autumn precipitation (Sep-Dec) of the preceding year (during gestation) had a significant (P < 0.05), positive effect on lamb survival. Herd density was significantly (P < 0.05) and inversely related to lamb survival. Spring winds had a positive and significant (P < 0.05) effect on lamb survival. Multiple regression revealed that 87% of the variability in lamb survival was accounted for by autumn precipitation during gestation (52%) and sheep density (35%).
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Article
The survival rate of North American bighorn sheep, Ovis canadensis, housed in several zoological gardens was analyzed. Complete herd histories, including birth and death data as well as causes of mortality, were collected from seven institutions. Lambs were divided into inbred and noninbred animals, with lambs being considered inbred if they had an inbreeding coefficient greater than zero. The rate of survival of inbred and noninbred lambs was compared using “survival equalling one year” and “survival equalling six months.” Another analysis compared the survival rate of male and female inbred lambs and male and female noninbred lambs. Age at death was also compared in inbred and noninbred lambs. The analysis of the data for the seven collections, located in various geographic areas and housing various subspecies, indicates that inbreeding depression is a mortality factor in the captive management of North American bighorn sheep. Therefore, long-term survival of captive or isolated wild populations will depend on maintaining genetic diversity within the herds through careful selection of breeding stock in captive populations and introduction of nonrelated animals into isolated wild populations.
Article
The small group of wolves on Isle Royale has been studied for over three decades as a model of the relationship between large carnivores and their prey. During the last ten years the population declined from 50 individuals to as few as 12 individuals. The causes of this decline may be food shortages, disease, or reduced genetic variability. We address the issues of genetic variability and relationships of Isle Royale wolves using allozyme electrophoresis, mtDNA restriction-site analysis, and multilocus hypervariable minisatellite DNA analysis (genetic fingerprinting). Our results indicate that approximately 50% of the allozyme heterozygosity has been lost in the island population, a decline similar to that expected if no immigration had occurred from the mainland. The genetic fingerprinting data indicate that the seven sampled Isle Royale wolves are as similar as captive populations of siblings. Surprisingly, the Isle Royale wolves have an mtDNA genotype that is very rare on the mainland, being found in only one of 144 mainland wolves. This suggests that the remaining Isle Royale wolves are probably derived from a single female founder.
Article
Starch‐gel electrophoresis was used to screen 101 bison from Badlands National Park, South Dakota, for variation at 24 genetic loci. The population was descended from founder groups of about 6 and 3 individuals, separated geographically for a minimum of 64 years. The purpose of this study was (1) to estimate levels of genic variability in this bison population, (2) to assess the extent to which descendents of the two founder groups differ genetically, and (3) to compare the genetic characteristics of the Badlands population with other bison populations. The Badlands herd was found to be polymorphic for only a single locus (MDH–1). Descendents of the founder groups were homogeneous with respect to allelic and genotypic frequencies at this locus. The MDH–1 polymorphism has not been observed in other bison populations, while several polymorphism reported in other bison populations were not detected in the Badlands herd. A mean heterozygosity of 0.012 was observed in the Badlands herd; this value is lower than that typically reported for mammals, though not as low as heterozygosities seen in other populations that have passed through severe bottlenecks in size. These results underscore the need for genetic data in planning breeding programs for species in captivity or managed in isolate reserves.
Article
Recent hypotheses have proposed that mountain sheep were suffering from inbreeding depression. Here we present an alternative hypothesis. We have examined sheep migration abilities, the distances required for migration, and sheep mating patterns to challenge the inbreeding hypothesis and conclude that the sound application of more traditional wildlife management techniques will likely preclude short- and long-term genetic problems.
Article
"Wright's views about population genetics and evolution are so fundamental and so comprehensive that every serious student must examine these books firsthand. . . . Publication of this treatise is a major event in evolutionary biology."-Daniel L. Hartl, BioScience
Article
A procedure for the multisystem analysis of bloodstains using the simultaneous separation of the enzymes glyoxalase I, esterase D, and phosphoglucomutase has been developed. The amount of bloodstain required has therefore been reduced threefold without any loss in resolution and sensitivity. Bloodstains at least seven weeks old have been correctly phenotyped in all three systems.
Article
Electrophoretic variants of the enzyme mannosephosphate isomerase (E.C. 5.3.1.8) (MPI) have been discovered in the mouse. The MPI-IA phenotype was found in Mus castaneus and in the inbred strain MA/J of Mus musculus. Other inbred strains of Mus musculus examined possessed the MPI-1B phenotype. Genetic studies show that the MPI variants segregate as codominant alleles of a single autosomal locus, designated Mpi-1 in linkage group II. The gene order Mod-1-d-Mpi-1 has been established. Human and murine forms of MPI differ and can be detected in in vitro fibroblasts and somatic cell hybrid populations.
Article
Blood samples from northern elephant seals (Mirounga angustirostris), representing five breeding colonies in California and Mexico, were surveyed electrophoretically for protein variation reflecting underlying genetic differences. No polymorphisms were found among 21 proteins encoded by 24 loci. This uniform homozygosity may be a consequence of fixation of alleles brought about by the decimation of this species by sealers in the last century.
Article
Pieces of chicken heart or skeletal muscle were placed in a dilute solution of the antimicrobial agent 2-phenoxyethanol and stored at room temperature. Under these conditions, the serum albumin, lactate dehydrogenase, and malate dehydrogenase in these tissues survived in easily detectable amounts for at least 2 weeks. The surviving proteins appeared to be identical with those of fresh tissues in physical, catalytic, and immunological properties. Phenoxyethanol also preserved heart and muscle proteins of representatives of other vertebrate classes. Tissue samples collected in the analysis by biochemical taxonomists.
Article
Rocky Mountain bighorn rams obtained copulations by defending single estrous ewes (tending), fighting tending rams for temporary access to defended ewes (coursing), or moving and holding ewes away from other rams beyond the periphery of a traditional tending area (blocking). Coursing and blocking illustrate a feature of many male alternative mating strategies: the ability of males regularly to create mating opportunities.
Article
The marine environment is characterized by few physical barries, and pelagic fishes commonly show high migratory potential and low, albeit in some cases statistically significant, levels of genetic divergence in neutral genetic marker analyses. however, it is not clear whether low levels of differentiation reflect spactially separated populations experiencing gene flow or shallow population histories coupled with limited random genetic drift in large, demographically isolated populations undergoing independent evlolutionary processes. using information for nine microsatellite loci in a total of 1951 fish, we analyzed genetic differentiation among Atlantic herring from eleven spawning locations distributed along a longitudinal aradient from the North Sea to the Western Baltic. Overall genetic differentiation was low (θ=0.008) but statistically significant. The area is characterized by a dramatic shift in hydrography from the highly saline and temperature stable North Sea to the brackish Baltic Sea, where temperatures show high annual variation. We used two different methods, a novel computational geometric approach and partial Mantel correlation analysis coupled with detailed environmental information form spawning locations to show that patterns of reproductive isolation covaried with salinity differences among spawning locations, independent of their geographical distance. We show that reproductive isolation can be maintained in marine fish populations exhibiting substantial mixing during larval and adult life stages. Analyses incorporating genetic, spatial, and environmental parameters indicated that isolation mechanisms are associated with the specific salinity conditions on spawning locations.
A strategic plan for the comprehensive management of wildlife in Wyoming
  • Wyoming Game
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Wyoming Game and Fish Department. 1990. A strategic plan for the comprehensive management of wildlife in Wyoming 1990-1995, vol. 5. Cheyenne, Wyoming. ( Conservation Biology Volume 9, No. 2, April 1995
Bighorn sheep history, distributions, and habitat relationships in the Teton Mountain Range
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Whitfield, M. B. 1983. Bighorn sheep history, distributions, and habitat relationships in the Teton Mountain Range, Wyoming. M.S. thesis. Idaho State University, Pocatello, Idaho.
Measuring and scoring North American big game trophies. The Boone and Crockett Club
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Nesbitt, W. H., and P. L. Wright. 1985. Measuring and scoring North American big game trophies. The Boone and Crockett Club, Alexandria, Virginia.
On the large sheep of the Thian Shan and other Asiatic argali
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Brooke, V., and B. Brooke. 1875. On the large sheep of the Thian Shan and other Asiatic argali. Proceedings of the Zoological Society of London 33:509-526.
Criteria of sex and age. Pages 143-202 in
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Larson, J. S., and R. D. Taber. 1980. Criteria of sex and age. Pages 143-202 in S. D. Schemnitz, editor. Wildlife management techniques. The Wildlife Society, Washington, D.C.
Analysis of horn growth rates of male bighorn sheep (Ovis canadensis canadensis) Harvested in Wyoming, 1977-1983
  • A T Perry
  • T V Sansalone
  • L Mcdonald
Perry, A. T., T. V. Sansalone, and L. L McDonald. 1985. Analysis of horn growth rates of male bighorn sheep (Ovis canadensis canadensis) Harvested in Wyoming, 1977-1983. Department of Statistics and Wyoming Cooperative Wildlife Research Unit, University of Wyoming, Laramie, Wyoming.
Relationship of genetic variation to growth and reproduction in the white-tailed deer. Pages 168- 177 in
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Chesser, R. K, and M. H. Smith. 1987. Relationship of genetic variation to growth and reproduction in the white-tailed deer. Pages 168- 177 in C. M. Wemmer, editor. Biology and Management of the Cervidae. Smithsonian Institution Press, Washington, D.C.