Phyllis K. Kennedy

GENETIC VARIABILITY OF WOLVERINES (GULO GULO) FROM THE NORTHWEST TERRITORIES, CANADA: CONSERVATION IMPLICATIONS

Abstract Because of anthropogenic factors in the early 1900s that caused populations to decline dramatically, wolverines (Gulo gulo) currently are designated as endangered in eastern Canada and classified as vulnerable throughout the Holarctic Region by the International Union for Conservation of Nature and Natural Resources. Although numerous examples exist that illustrate the utility of genetic data for development of conservation plans, no study has investigated the genetic structure of natural populations of wolverines. We assessed allozymic and mitochondrial DNA (mtDNA) variability of wolverines within and among 5 sites from the Northwest Territories, Canada. Five of 46 presumptive allozyme loci were polymorphic. Estimates of heterozygosity (2.6%) and polymorphism (11.6%) were lower than values reported for most mammals but were within the range reported for Carnivora. To evaluate levels of variation in mtDNA, we sequenced the left domain of the control region. Six variable nucleotide sites were observed, resulting in 9 haplotypes of mtDNA. Within-site diversity of haplotypes (h) was high, but within-site diversity of nucleotides (π) was low, indicating little sequence divergence among the 9 haplotypes. Sequence data for mtDNA revealed considerably more genetic partitioning among sites (ϕST = 0.536) than did allozyme data (FST = 0.076). Based on fixation indices, gene flow estimates (Nm) were moderate for nuclear markers but low for mtDNA loci. These findings suggest that, although wolverines maintain large home ranges, they exhibit fidelity to discrete areas, gene flow is predominantly male-mediated, and most sites in the Northwest Territories are genetically independent and thus represent populations. Therefore, any conservation plan for wolverines in the Northwest Territories must consider preservation of populations if genetic diversity of this taxon is to be maintained.

GEOGRAPHIC VARIATION IN THE BLACK BEAR (URSUS AMERICANUS) IN THE EASTERN UNITED STATES AND CANADA

The pattern of geographic variation in morphologic characters of the black bear (Ursus americanus) was assessed at 13 sites in the eastern United States and Canada. Thirty measurements from 206 males and 207 females were recorded to the nearest 0.01 mm using digital calipers and subjected to principal components analysis. A matrix of correlations among skull characters was computed, and the first 3 principal components were extracted. These accounted for 90.5% of the variation in the character set for males and 87.1% for females. Three-dimensional projection of localities onto principal components showed that, for males and females, largest individuals occurred in the more southern localities (e.g., males-Louisiana-Mississippi, eastern Texas; females-Louisi- ana-eastern Texas) and the smallest animals occurred in the northernmost locality (Quebec). Gen- erally, bears were similar morphologically to those in nearby geographic areas. For males, correla- tions between morphologic variation and environmental factors indicated a significant relationship between size variation and mean January temperature, mean July temperature, mean annual precip- itation, latitude, and actual evapotranspiration; for females, a significant relationship was observed between morphologic variation and mean annual temperature, mean January temperature, mean July temperature, latitude, and actual evapotranspiration. There was no significant correlation for either sex between environmental factors and projections onto components II and III.

Biochemical Genetics of Mosquitofish. V. Perturbation Effects on Genetic Organization of Populations

Biochemical variation encoded by six loci was assessed for mosquitofish (Gambusia affinis) from 19 sites within a stream altered by water level reduction. Sites included temporary (isolated and nonisolated) pools and a main stream area. Populations exhibited significant genetic differentiation at two loci (isocitrate dehydrogenase-1 and phosphoglucomutase-2) and a significant association between genetic characters and geographic distance was indicated. Relationships between demographic and genetic characters and between reproductive and genetic characters were minimal. Genetic differences were generally greater between juveniles and adults than between adult males and females. Patterns of allele distribution among sites were different for each adult group and juveniles, with only juveniles exhibiting a relationship between allele frequencies and geographic distance. Juveniles from sites in closer proximity were more similar, probably reflecting juvenile behavior rather than parental associations. Population substructure seems to be maintained during population disruption and colonization events.

Temporal Genetic Variation in the Raccoon, Procyon lotor

Starch-gel electrophoresis was used to assess temporal genetic variation in a population of raccoon, Procyon lotor . Specimens ( n = 1,056) were collected during nine annual hunts (1984–1992) at Reelfoot National Wildlife Refuge, Obion Co., Tennessee, and Fulton Co., Kentucky. Of 41 loci examined, 35 were monomorphic; 6 exhibited polymorphism and were used in statistical analyses. Heterozygosity ranged from 0.033 (1990) to 0.046 (1992) with a mean of 0.042; however, differences across years were not significant. Significant deviations from Hardy-Weinberg equilibrium were minimal. Chi-square contingency analysis revealed significant differences in allelic frequencies among years for four of the six polymorphic loci. Wrights F -statistics indicated significant differentiation among years ( F st = 0.042). Rogers’ genetic similarity coefficients ranged from 0.836 to 0.973. The matrix of all pairwise comparisons indicated a random pattern of relationships among years. Hunting appears to have had little influence on the genetic composition of raccoons in the study area over the 9-year period. The observed pattern of low-level temporal variation is probably the result of stochastic events.

Microgeographic genetic organization of populations of largemouth bass and two other species in a reservoir

GERKING, S. D. 1953. Evidence for the concept of home range and territory in stream fishes. Ecology 34:347-365. IMHOF, M., R. LEARY AND H. E. BOOKE. 1980. Population or stock structure of lake whitefish, Corregonus clupeaformis, in northern Lake Michigan as assayed by isozyme electrophoresis. Canad. J. Fish. Aquat. Sci. 37:783-793. KUDRNA, J. J. 1965. Movement and homing of sunfish in Clear Lake. Proc. Iowa Acad. Sci. 72:263271. KozHov, M. 1963. Lake Baikal and its life. Monogr. Biol. 11.

Using Morphologic Characters to Identify Peromyscus in Sympatry

Abstract To assess the usefulness of morphologic characters in identifying deer mice (Peromyscus maniculatus), white-footed mice (P. leucopus) and cotton mice (P. gossypinus) in sympatry, cranial and external measurements were recorded for two groups of these rodents. Each group contained individuals of the three species. One assemblage represented known individuals (species identifications verified using electrophoretic techniques) and the other unknowns (species identification not verified; test group). With the known group, we developed a system of identification based on selected morphologic features. These features were used to determine the identification of individuals in the test group. Following identification, individuals identified in the test group were confirmed using electrophoretic procedures. Two characters (greatest length of skull and length of hindfoot) separated 100% and 91% of P. gossypinus in the known group and 94.6% and 98% in the test group, respectively. A single external metric (tail length/total length) correctly classified 95% of P. maniculatus in both the known and test groups. A suite of four cranial (greatest length of skull, length of nasal, post-palatal length and length of diastema) and one external character (length of tail) correctly classified all of the individuals in the initial group and 90%, 91% and 100% of P. maniculatus, P. leucopus and P. gossypinus, respectively, in the test group. We concluded that morphologic characters can be used to accurately detect species of Peromyscus in sympatry.

VARIATION, SEXUAL DIMORPHISM, AND ALLOMETRY IN MOLAR SIZE OF THE BLACK BEAR

Abstract We investigated molar-crown–size variation, sexual dimorphism, and allometry in the black bear (Ursus americanus), using hunter-shot specimens (n = 429) from the island of Newfoundland, and museum specimens from elsewhere in Canada and the continental United States (n = 502). We predicted higher variation in and weaker correlations among molar size in this omnivorous species than in other species of Carnivora with dentition more specialized for carnivory, because of relatively weak normalizing selection on food-processing mechanisms in U. americanus. Molar-size variation in Newfoundland bears (mean coefficient of variation ∼ 5.6%) was intermediate between species of Carnivora with simpler (e.g., pinnipeds) and more complex (e.g., canids) postcanine dentition. There was negligible size variation within the molar teeth, unlike some mammals. Bilateral symmetry was strong, especially in mandibular length (r ∼ 1.0 between left and right sides; r ∼ 0.95 for other mandibular and maxillary variables and molar size); symmetry in molar size was higher than in phocid seals. Size was positively correlated across molars, especially between adjacent (but not occluding) molars; patterns were similar between sexes and geographic regions, and correlation levels did not differ from other species of Carnivora. We also predicted (and found) smaller sexual differences (= 100[(male/female) − 1]) in molar size than in body size, because definitive molar size is attained early in life: differences in molar size averaged ∼5.5% in Newfoundland (higher in continental subsamples), which is less than differences in cranial size (7–9%) or body mass1/3 (21%). Sexes did not differ in relative molar size. Molar size was mainly isometric or positively allometric to adult body size (using mandibular and maxillary size as proxies).

Temporal and Spatial Genetic Variability in White-tailed Deer (Odocoileus virginianus)

Starch-gel electrophoresis was used to assess temporal and spatial genetic variation in populations of white-tailed deer (Odocoileus virginianus) in western Tennessee. Samples of liver and kidney obtained from animals at five localities during 1985–1992 were analyzed at 11 loci known to be polymorphic in white-tailed deer. There were minimal significant differences in allelic frequencies between sexes and among age groups for each year at each locality and among years at each locality with ages and sexes combined. No significant difference occurred among mean values of heterozygosity. A heterozygote deficiency was detected in white-tailed deer populations from western Tennessee and could reflect limited inbreeding but was more likely due to Wahlund effects. Limited temporal variation occurred among years within a locality and indicated a stasis in terms of minimal genetic drift and harvest effects on genetic structure of the populations. Herd origin, stocking history of populations, and gene flow were probable causes of spatial heterogeneity in deer populations in western Tennessee.

Taxonomic assessment of the black bear (Ursus americanus) in the eastern United States

Results showed skulls of U. a. luteolus, U. a. floridanus, and U. a. americanus to be similar in morphology. However, features of U. a. luteolus, and U. a. floridanus tended, in general, to be larger and shaped differently than those of U. a. americanus. Differences between measurements of U. a. luteolus and U. a. floridanus were less apparent than those between either of these taxa and U. a. americanus. For U. a. luteolus and U. a. floridanus, means of most characters differed only slightly, and ranges of all measurements overlapped to some degree. Yet, small numbers of characters that reflected molar tooth measurements or features relating to dentition, height of frontal region, and skull length and width appeared to correctly classify these taxa in most cases. Results were interpreted to support the subspecific recognition of U. a. luteolus, U. a. floridanus, and U. a. americanus. RESUMEN-Con base en caricteres morfol6gicos se evalu6 el estatus subespecifico del oso negro de Louisiana (Ursus americanus luteolus) y del oso negro de Florida ( U. a. floridanus) con la finalidad de determinar las diferencias entre ellos y con el oso negro (U. a. americanus). Se consideraron 44 caricteres craneales de 125 machos y 127 hembras, todos ellos adultos (4.5 afios de edad o mais). Los resultados muestran que los crineos de U. a. luteolus, U. a. floridanus y U. a. americanus comparten similitudes morfol6gicas. Sin embargo, las caracteristicas craneales de U. a. luteolus y U. a. floridanus tendieron a ser mais largas y de forma diferente que las de U. a. americanus. Las diferencias entre las medidas de U. a. luteolus y U. a. floridanus fueron menos aparentes que las que se encontraron entre estos taxa y U. a. americanus. Para U. a. luteolus y U. a. floridanus, los promedios de la mayoria de los carfcteres difirieron ligeramente, y los rangos de todas las medidas se sobrepusieron en algfin grado. Sin embargo, los cardicteres que permitieron clasificar a estos taxa correctamente en la mayoria de los casos fueron: las medidas de los molares, los caricteres relacionados con la dentici6n, la altura de la regi6n frontal, y la longitud y anchura del crfneo. Los resultados se interpretaron para apoyar el reconocimiento subespecifico de U. a. luteolus, U. a. floridanus y U. a. americanus.

Geographic variation in sexual-size dimorphism of the American black bear (Ursus americanus) in areas of western North America

Abstract Patterns of geographic variation in cranial characters of the American black bear (Ursus americanus) were examined for 11 localities in the western US and Canada. Forty-four dimensions were recorded from skulls of 290 (149 males, 141 females) adult (≥4.5 years old) animals using digital calipers. Results showed that males are generally larger than females and the degree of sexual-size dimorphism for characters among localities is relatively consistent. Most averages (84.1%) of mean values across characters varied from 7.0% to 18.0%. The majority (90.9%) of character ranges (difference between highest and lowest value for a trait at each locality) of mean values for sexual dimorphism varied from 5.0% to 14.0%. Overall, there was no significant statistical difference in the degree of sexual dimorphism across localities in 43 of 44 characters. Measurements for males were significantly correlated with those of females for 38 of 44 characters. Results indicated that the level of sexual-size dimorphism remained relatively low and constant across localities. No statistically significant relationship existed between degree of sexual-size dimorphism and selected environmental variables. Although overall causes for levels of sexual differences in morphological features of black bears remain uncertain, bioenergetics appears to be a determining factor associated with sexual-size dimorphism in black bears.