Large brains and great intelligence are metabolically costly, but the social complexity hypothesis suggests that these traits were favored nonetheless in primates by selection pressures associated with life in complex societies. If so, then cognitive abilities and nervous systems with primatelike attributes should have evolved convergently in nonprimate mammals living in large, elaborate societies in which social dexterity enhances individual fitness. Societies of spotted hyenas (Crocuta crocuta) are remarkably similar to those of cercopithecine primates with respect to size, structure, and patterns of competition and cooperation. These similarities set an ideal stage for comparative analysis of social intelligence and nervous system organization. As in cercopithecine primates, spotted hyenas use multiple sensory modalities to recognize their kin and other conspecifics as individuals, they know that some group-mates are more valuable social partners than others, they recognize 3rd-party kin and rank relationships among their clan-mates, and they use this knowledge adaptively during social decision-making. Examination of the available data strongly suggests convergent evolution of intelligence between spotted hyenas and primates. Evidence that less gregarious members of the family Hyaenidae lack some of the cognitive abilities found in spotted hyenas would provide further support for the idea that social complexity favors enhancement of intelligence in mammals.

Detection of predators, social monitoring, and avoidance of infanticide have been invoked to explain patterns of vigilance. To test these hypotheses, I examined the vigilance of 120 Utah prairie dogs (Cynomys parvidens) using “one–zero” sampling on individuals of known sex, reproductive state, and genealogy. Male and female prairie dogs increased vigilance during periods of heightened predation risk (i.e., with few surrounding conspecifics) unless the risk resulted from spatial positioning in the colony. Reproductive males and females were more vigilant than their nonreproductive counterparts during breeding, and estrous females increased vigilance in the presence of prospective mates. In contrast to predictions of the infanticide-avoidance hypothesis, lactating females were less vigilant than females without litters when neonates were in a nursery burrow and vulnerable to infanticide by males. Males were more vigilant than females, but not when the offspring of their sexual partners were vulnerable to infanticide or opportunities to kill offspring increased. I conclude that vigilance in Utah prairie dogs varies mostly in relation to the risk of predation. Mate competition also increases vigilance in males and females. However, prevention or facilitation of infanticide does not appear to influence vigilance in males or females.

Few investigators have considered whether predictors of species occurrence from 1 locality are useful predictors in others, or how regional factors may constrain occurrence. We used landowner questionnaires over 6 regions in Indiana to test the performance of predictors from prior studies of more limited spatial extent. Logistic regression and classification tree models were constructed using data on 577 forest patches supplied by 362 landowners. Consistent with predictions, probability of occurrence of eastern gray squirrels (Sciurus carolinensis) was related positively to forest patch size and percent of forest in the surrounding landscape. Also, probability of occurrence of North American red squirrels (Tamiasciurus hudsonicus) was related positively to the presence of black walnut trees (Juglans nigra) and conifers in forest patches, and negatively to the presence of gray squirrels. Occurrence rates of S. carolinensis increased from north to south, whereas occurrence rates of T. hudsonicus increased from south to north and from west to east. Based on landowner perceptions, abundance of T. hudsonicus was more likely to increase in north and central regions, and to decline in patches with walnuts and at sites with longer periods of observation by landowners. Although less detailed than studies restricted to a particular locality, questionnaire data permit ecologists to test the generality of local findings and to further formulate and refine hypotheses about processes underlying large-scale patterns.

The composition of the landscape between patches (the matrix) can have important effects on movement rates that potentially outweigh the effects of patch size and isolation. We conducted a small-scale experiment with radiocollared meadow voles (Microtus pennsylvanicus) to quantify the effects of matrix habitat on movement behavior of voles. Habitat patches were created within an enclosure and connected by pathways of different vegetation heights designed to represent different levels of predation risk to the voles. Voles were fitted with radiocollars and tracked 4 times daily for 1–3 weeks. We quantified the probability that a vole would transition through a particular matrix type (i.e., cross a habitat edge) and estimated transition probabilities using multinomial random effects models. These methods along with permutation tests were used to test whether the transition probabilities of voles could be modeled by assuming common movement rules such as “random,” “static choice” when all voles always choose the same type of pathway, or “probabilistic” when voles are most likely to choose a pathway of tall vegetation and select other pathway types in inverse order of the relative risk associated with the pathway. Vole movement decisions in our experimental landscapes reflected a probabilistic approach to decision making in which pathways were chosen in proportion to risk associated with travel. Quantification of transition probabilities through different matrix types is necessary for modeling animal movements in complex environments.

Genetic relatedness estimates and capture records were used to examine population ecology of endangered Alabama beach mice (Peromyscus polionotus ammobates). Because of their monogamous mating strategy, biparental natal care, and limited dispersal patterns, we hypothesized that beach mice form gamodemes with family groups representing the core units. Under this hypothesis, we predicted that groups of related individuals would utilize common habitat spaces and that nonrandom age or sex associations could occur. To test these predictions, livetrapping data from an 8-year study were used to examine demography and relatedness of mice involved in joint and single captures (4,683 capture events involving 1,404 individuals, of which 949 were genotyped using microsatellite data). Mice were observed in joint captures nonrandomly with respect to age and sex, implying that there are nonrandom spatial associations among beach mice. Specifically, adult females were captured more often than expected with adult males and subadults were involved in joint captures more often than expected. Subadults captured with adults were the most related cocaptures, which, along with parental assignment, provided evidence of familial clustering. Adult male–female cocaptures were among the least related pairings, suggesting that inbreeding avoidance may play a role in mate choice.

Information on the spatial ecology of nonnative roof rats (Rattus rattus) is important for developing management strategies to reduce their impacts on native wildlife in riparian habitats. We determined home-range size and movement patterns of nonnative roof rats (Rattus rattus) in an old-growth riparian forest in California by radiotracking 12 individuals in August and September 2002. Males had larger home ranges than females. There was considerable overlap of ranges within and between sexes. Rats nested from 2 to 15 m high in trees, and used multiple nests that were sometimes shared simultaneously with other rats. Rats were most active at night, spending most of their time on, or close to the ground, and favoring areas of dense cover of blackberry and grape.

Although predatory behavior is traditionally described by a basic ethogram composed of 3 phases (search, pursue, and capture), behavioral studies of large terrestrial carnivores generally use the concept of a “hunt” to classify and measure foraging. This approach is problematic because there is no consensus on what behaviors constitute a hunt. We therefore examined how the basic ethogram could be used as a common framework for classifying large-carnivore behavior. We used >2,150 h of observed wolf (Canis lupus) behavior in Yellowstone National Park, including 517 and 134 encounters with elk (Cervus elaphus) and American bison (Bison bison), respectively, to demonstrate the functional importance of several frequently described, but rarely quantified, patterns of large-carnivore behavior not explicitly described by the basic ethogram (approaching, watching, and attacking groups). To account for these additionally important behaviors we propose a modified form of the basic ethogram (search, approach, watch, attack-group, attack-individual, and capture). We tested the applicability of this ethogram by comparing it to 31 previous classifications and descriptions involving 7 other species and 5 other wolf populations. Close correspondence among studies suggests that this ethogram may provide a generally useful scheme for classifying large-carnivore predatory behavior that is behaviorally less ambiguous than the concept of a hunt.

We present a detailed description of the acoustic structure of howls emitted by Iberian wolves and a comparison with published descriptions of North American wolf howls. We recorded and analyzed 176 howls emitted by 11 wolves held in captivity in social groups of 1–5 individuals. Our sample included solo howls as well as howls included in choruses. Iberian wolf howls are long (1.1- to 12.8-s) harmonic sounds, with a mean fundamental frequency between 270 and 720 Hz. Our results revealed striking similarities between Iberian and North American wolf howls in all variables analyzed except for the number of discontinuities in the frequency of the howl, which was lower for Iberian wolves. Using discriminant function analysis we could assign 84.7% of howls to the correct individual. Variables related to fundamental frequency (mean and maximum) and the coefficient of fundamental modulation best discriminate individuals. We suggest that Iberian wolves could use howls for individual recognition.

Understanding limiting factors and interspecific interactions is fundamental to wildlife management and can be inferred from multiscale patterns of resource selection. We studied winter resource selection and overlap of white-tailed deer (Odocoileus virginianus) and translocated female elk (Cervus elaphus) over 2 winters in central Ontario, Canada. Microhabitat data were collected along 4 organism-centered spatial scales: site, trail, feeding station, and diet. Although winter conditions varied between years, white-tailed deer consistently traveled and fed in habitats with greater coniferous basal area than elk. Neither species demonstrated selection for coniferous basal area or snow depth across scales. At successively finer scales, female elk selected increased understory cover of trembling aspen (Populus tremuloides). For white-tailed deer, across-scale selection of sugar maple (Acer saccharum) understory cover was exhibited when winter conditions were more severe. Dietary overlap was moderate during both winters (50–57%) and coniferous forage was more important to deer than elk. Using canonical variate analysis, a gradient from shade-intolerant hardwoods to mature coniferous vegetation was found to discriminate significantly between elk and deer habitat use at trails and feeding stations. These results indicate that deer were closely associated with conifers regardless of winter conditions and that both ungulates may have been limited by forage abundance.

Arctic ruminants consume cold water and food that increase costs of thermoregulation and potentially impair the bacterial fermentation on which these animals rely for digestion. We fed castrated adult muskoxen (Ovibos moschatus) a consistent diet throughout winter to correlate changes in ambient temperature with water flux, ingestive behavior, rumen temperature, and bacterial counts in the rumen. Ambient temperatures declined to −40°C but average ruminal temperatures were 39°C in muskoxen fed grass hay throughout winter. Rumen temperatures were not static but were punctuated by cold shocks to 26°C in each month. Water turnover rates were high in October (11.1 kg/day⁻¹) and low in January and March (9.8–7.7 kg/day⁻¹), which indicated a concomitant decline in food intake. Numbers of bacteria in rumen fluid decreased with water turnover and thus food intake from October (18.0 × 10⁹/ml) to January and March (9.4 and 8.8 × 10⁹/ml, respectively). The cost of warming ingesta was estimated at 25, 79, and 57 kJ/kg^0.75 in October, January, and March, respectively, and was 3–14% of the predicted intake of digestible energy. Muskoxen spent more time consuming water as snow than as free water, which may reduce the cold shock of water ingestion in winter. Concerted ingestion of food and water may also allow muskoxen to substitute heat increment of feeding for the cost of warming ingesta.

In species in which one sex experiences greater variation in lifetime reproductive success than the other, the Trivers–Willard hypothesis predicts greater parental investment in offspring of the more variable sex. Support for this hypothesis has been inconsistent and few studies have determined whether differential allocation of resources can be attributed to the parent (as predicted by sex-biased parental investment) or to efforts by offspring to extract resources. We addressed this issue by characterizing maternal investment in wild white rhinoceros (Ceratotherium simum). In a 3-year study, we radiotracked 14 adult females and recorded behavioral activities related to both maternal investment and offspring extraction of maternal resources. Investment in sons appeared to be greater than in daughters: sons suckled significantly longer and more frequently and were weaned significantly later than daughters. Although mothers did not respond differentially to individual nursing solicitations from male versus female offspring, our results suggest that mothers invested more in sons that vocalized at higher rates, but did not alter their investment in daughters in response to call rate. This may indicate that mothers, in part, facilitate access to resources depending on the sex of their offspring. This study provides a useful model for determining whether sex-biased investment is under maternal control or is a consequence of sex differences in the offspring's efforts to extract parental resources.

New Zealand fur seals (Arctocephalus forsteri) are common in the Australian-New Zealand region, but vital demographic data are lacking. Accurate determination of the age of individuals is critical to the study of age-specific life-history parameters. A cross-sectional sample of female and male New Zealand fur seals was caught and animals were individually marked on Kangaroo Island, South Australia, between 2000 and 2003. Seals were aged through examination of a postcanine tooth, which was removed from each animal. Annual formation of cementum layers was confirmed and accuracy in age estimation was determined by examination of teeth removed from individuals of known age. Indirect methods of assessing reproductive maturity based on characteristics of mammary teats indicated that females 1st gave birth between 4 and 8 years of age, with an average age at reproductive maturity (ARM) of 5 years. No females were observed to breed beyond 22 years. Age of 1st territory tenure in males ranged from 8 to 10 years. Variation in ARM between individuals appears to be related in part to body size and condition. Classification of mammary teat status in combination with techniques for aging live animals provided a means of assessing ARM in the absence of extensive longitudinal data.

Patterns of growth and development provide information critical for documenting population demographics. Herein we document the reproductive biology for and provide equations that accurately predict the ages of 2 widely sympatric species of bats from central Indiana—the northern myotis (Myotis septentrionalis) and the little brown myotis (Myotis lucifugus). Young of M. septentrionalis were born synchronously (within a 6-day period) and within a narrow size range (mean length of forearm = 12.78 mm, 95% confidence interval [95% CI] = ± 0.52 mm; mass = 1.91 g, 95% CI = ± 0.11 g). Young of M. lucifugus were born during a 42-day period and within a narrow size range (mean length of forearm = 14.26 mm, 95% CI = ± 0.23 mm; mean body mass = 2.19 g, 95% CI = ± 0.08 g). Young of M. septentrionalis were born significantly smaller (t = 4.52, d.f. = 137, P < 0.001) and lighter (t = 2.57, d.f. = 137, P < 0.05) than were young of M. lucifugus. We developed species-specific equations that made it possible to estimate the age of both species of bat to within 1 day. These results indicate that similar-sized and closely related bats grow at comparable rates and provide the 1st detailed information about reproductive biology of M. septentrionalis.

Because absolute mammalian age is difficult to measure directly, various methods have been used for its estimation. Among these methods, the degree of molar eruption and wear are considered to be the most reliable indicators of relative age. We used the nature and extent of maxillary molar toothrow eruption and wear to assign individuals of the solitary South African endemic Cape dune mole-rat (Bathyergus suillus) collected from a single population on the grounds of Cape Town International Airport, Cape Town, South Africa, to 9 relative age classes. We then used cranial morphometric analysis, and for comparative purposes, an assessment of the nature and extent of variation in body mass and body length, to investigate the nature and extent of sexual dimorphism and age variation in this little-studied species of mole-rat. Both univariate and multivariate analyses distinguished relative age classes 2 and 3 from 6–9, but age classes 4 and 5 were intermediate between the 2 other age-class groupings, suggesting that individuals of age classes 4 and 5 may be at a point on a hypothetical growth curve where the curve begins to stabilize. Examination of our data showed the absence of sexual dimorphism in younger individuals of age classes 2–5, and its presence in older individuals of age classes 6–9. Together with a proposed study of microsatellites, our analyses may improve our understanding of the population structure of the Cape dune mole-rat.

The common European mole (Talpa europaea) has been the focus of many studies because of its fossorial lifestyle and related sensory and postcranial specializations. However, because of extensive fusion and pneumatization of the adult skull, many aspects of the cranial morphology of T. europaea are poorly understood. Here we present the 1st detailed study of cranial development in T. europaea, using an ontogenetic series of cleared and stained prenatal specimens to examine bone homologies, sequence of ossification, and prenatal allometry. The enigmatic lacrimal, jugal, and mastoid bones are all identified in prenatal specimens. The jugal and lacrimal bones fuse with the maxilla during prenatal growth, explaining previous difficulties with their identification in adults. T. europaea is anomalous among placental mammals in delaying the ossification of the alisphenoid and the orbitosphenoid until after birth. Analyses of allometry for 16 measures of individual bones show marked differences when postnatal specimens are included or excluded. Coefficients of allometry based on prenatal specimens are nearly twice those of analyses including subadult specimens. Comparisons with other taxa are limited by the lack of similar prenatal data, but the pattern exhibited by T. europaea differs significantly from those observed in studies of postnatal allometry in other mammals. These results may reflect differences among taxa or between prenatal and postnatal stages.

As part of an examination of the population structure of short-beaked common dolphins (Delphinus delphis) in the North Atlantic, I tested if there were systematic differences in cranial morphology, in relation to geographic location, for common dolphins both within the western North Atlantic (wNA; n = 141) and between the wNA and eastern North Atlantic (eNA; n = 106). Cranial specimens from the wNA were obtained between Nova Scotia, Canada, and Florida. Those from the eNA came from the Irish Sea and the coasts of Ireland and the United Kingdom. A Wilks' λ canonical discriminant analysis (CDA) was performed on the within-groups covariance matrix to test whether significant differences in group centroids (multivariate means) existed between putative population units separately for males and females. In addition, the CDA was used to reclassify each dolphin into a geographic group based on the discriminant function. The CDA of 35 cranial variables found no evidence (males: Wilks' λ = 0.603, P = 0.286; females: Wilks' λ = 0.145, P = 0.08) of population structure below the species level within the wNA. Thus, the 1-population model for this region was supported. CDAs revealed significant differences between the eNA and wNA for both males and females (males: Wilks' λ = 0.371, P < 0.0001; females: Wilks' λ = 0.260, P < 0.0001). Cross-validated reclassification rates for males were 78.8% (eNA) and 87.6% (wNA) and for females were 90.6% (eNA) and 81.4% (wNA). Measurements associated with the rostrum were important discriminating variables that might reflect differences in feeding habits between these areas.

As a complex skeletal organ consisting of 2 functional and developmental units (ascending ramus and alveolar region), the mandible represents a well-established model in morphological integration studies. The concept of morphological integration assumes that developmentally or functionally related traits are more correlated than others and hence evolve together. We compared the level and pattern of mandibular morphological integration between groups of adult yellow-necked field mice (Apodemus flavicollis), with and without B chromosomes (Bs) in a population from Mt. Avala, Serbia. Bs are dispensable supernumerary chromosomes characterized by irregular and non-Mendelian modes of inheritance. The level of morphological integration was higher in animals with Bs. One of the 2 regions of the mandible tested (alveolar region) was significantly more affected by the presence of Bs than the other, with an increase in intensity of integration of 41.61% versus 15.86%. The hypothesis of morphological integration, which postulates disunion of the mandible into 2 distinct functional and developmental modules, was confirmed in animals with Bs. Bs probably have a function because they affect mandible phenotype (although the mechanism is unknown), increase variability within populations, and could lead to selective advantage.

Five species of dasyurid marsupials endemic to New Guinea and herein referred to as Murexia longicaudata, M. rothschildi, M. habbema, M. naso, and M. melanurus have a varied taxonomic history. Until 1984, the latter 3 species had been assigned to the otherwise strictly Australian genus Antechinus, but comparisons of phallic morphology showed that this arrangement was untenable. Immunological and DNA hybridization studies of dasyurids suggested that New Guinean “antechinuses” were part of a clade that included M. longicaudata and M. rothschildi, a finding that was confirmed by early DNA sequence comparisons. Comprehensive analyses of cytochrome b, 12S rRNA, and protamine P1 sequences from all recognized dasyurid species led to the recommendation that these 5 species be included in a single genus (Murexia) that, along with Phascogale and Antechinus, constitutes the dasyurid tribe Phascogalini. Recently, however, a morphocladistic study concluded that these species are neither closely related to one another nor to any other dasyurid clade, placing them instead as successive basal branches within the family and assigning each to a distinct genus. Here we report results from an expanded DNA sequence data set that includes 2 additional mitochondrial loci (16S rRNA and control region) and 2 nuclear loci (beta-fibrinogen intron 7 and interphotoreceptor retinoid-binding protein exon 1) from phascogalin species and selected dasyurid and myrmecobiid outgroups. Phylogenetic analyses of these sequences show strong support for the monophyly of Murexia and its placement within Phascogalini, and provide the 1st resolved phylogeny of Murexia and Antechinus species. Reassessment of the morphological data suggests that the apparently primitive cranidental anatomy of Murexia may be an artifact of character polarizations or indicative of extreme homoplasy.

We karyotyped and sequenced 1,140 base pairs of the mitochondrial DNA cytochrome b of a specimen of Zarudny's rock shrew (Crocidura zarudnyi) from Baluchestan, southeastern Iran, to clarify its cytogenetic and molecular relationships with other Eurasian species of Crocidura. According to the karyotype (2N = 40, FN = 50), Zarudny's rock shrew belongs to the group of the lesser white-toothed shrew (C. suaveolens), which is different from other known crocidurine karyotypes, considering the combination of the diploid and fundamental number of chromosomes. Molecular results revealed that C. zarudnyi is included in a monophyletic clade with the C. suaveolens group, where it is a sister taxon to the others (mean Kimura 2-parameter distance = 9.7%).

The phylogenetics and phylogeography of the Jamaican fruit-eating bat (Artibeus jamaicensis) were examined based on analysis of DNA sequence variation in the mitochondrial cytochrome-b gene for 176 individuals representing all 13 subspecies of A. jamaicensis (sensu Simmons 2005). Results document that A. jamaicensis (sensu Simmons 2005) comprises 3 monophyletic assemblages that are separated phylogenetically by the presence of A. obscurus, A. lituratus, and A. amplus. According to the mitochondrial DNA sequence variation, A. jamaicensis, A. schwartzi, and A. planirostris are appropriate species-level names for these lineages. Haplotypes identifiable as A. jamaicensis were absent east of the Andes Mountains in South America; haplotypes of A. schwartzi were documented throughout the Lesser Antilles and from northern Venezuela, and haplotypes of A. planirostris were identified east of the Andes Mountains in South America, north of the Orinoco River in Venezuela, and from the southern Lesser Antilles. Haplotypes of Artibeus jamaicensis, A. schwartzi, and A. planirostris were identified sympatrically on Carriacou, a small island in the southern Lesser Antilles that is ecologically monotypic. The magnitude of genetic divergence separating A. jamaicensis, A. planirostris, and A. schwartzi essentially equals the magnitude of genetic divergence distinguishing A. lituratus, A. obscurus, and A. jamaicensis. Studies of the nuclear genome will be required to understand the biological implications of these patterns in the mitochondrial genome.

We studied the great evening bat (Ia io) in India (Meghalaya) and China (Guizhou), and present the 1st account of its feeding behavior. We analyzed droppings collected from 119 bats between November and May 2001–2002 and 2002–2003 from India; 28 included bird feathers, with most of these containing 90–100% feathers by volume. The main constituent of the diet overall was Coleoptera, although Lepidoptera and traces of Diptera, Orthoptera, and Hemiptera also were found. In China, bats were captured in early November, and fresh droppings also were collected from underneath the roost. Bird feathers comprised 82% of the droppings of bats by volume. I. io emits relatively low-frequency echolocation calls and sometimes produces 2-toned calls, a characteristic of species that echolocate distant targets. I. io has a high wing loading (15.4 Nm⁻²), average aspect ratio (6.9), and a high tip shape index (1.1), features associated with fast efficient flight. Phylogenetic analysis of a concatenation of mitochondrial ND1 and cytochrome-b genes indicated that I. io is phylogenetically close to Scotomanes ornatus, in a clade (Nycticeiini) distinct from bats in the genus Pipistrellus with which it has been previously allied. Although I. io converges in wing shape and echolocation call design with the carnivorous, fast-flying Nyctalus lasiopterus, its carnivorous behavior likely evolved independently because the 2 species are not close relatives. It is unlikely that I. io captured birds nesting or roosting at the study caves, and its morphology and echolocation behavior seem well adapted for the capture of large aerial insects and flying birds.

The comparative biology of the hipposiderid genus Aselliscus has been little studied. Here we report studies of echolocation, diet, and phylogeny of Aselliscus stoliczkanus. The phylogenetic relationships of Aselliscus were investigated based on sequence comparisons of mitochondrial cytochrome-b and nicotinamide adenine dinucleotide dehydrogenase subunit 1 genes. Dates of divergence within the hipposiderid radiation also were estimated. The echolocation call frequency of A. stoliczkanus is quite high, with the dominant constant frequency component at 119–120 kHz, and a terminal sweep down to 104.5 kHz. The call duration is about 5.4 ms. The diet of A. stoliczkanus is mainly composed of lepidopterans (78.5%), beetles (14.9%), and hemipteran insects (6.5%) in November. Our results indicate that Aselliscus is monophyletic and is correctly classified in the Hipposideridae, and the divergence time for Aselliscus was estimated at 22 million years ago.

Five microsatellite loci were used to develop multilocus genotypes for Neotoma macrotis (n = 128) and N. fuscipes (n = 29). Several statistical analyses were used to estimate genetic structure, levels of genetic variability, and degree of relatedness within groups of these 2 species. Samples of N. macrotis represented 2 groups and 4 population clusters throughout southern California. Samples of N. fuscipes represented 2 regions in northern and southern California. Genetic structure was detected among samples of N. macrotis and N. fuscipes at a regional level. Both species displayed moderate to high genetic diversity in terms of mean expected heterozygosity (0.939 and 0.804 for N. macrotis and N. fuscipes, respectively) and mean polymorphic information content (0.930 and 0.761 for N. macrotis and N. fuscipes, respectively). Mean relatedness values within regions and populations of N. macrotis indicated 4th-order levels of relatedness within groups (e.g., distant-cousin relationships). Mean relatedness values within regions of N. fuscipes indicated 2nd-order (e.g., half-sibling) relationships within the northern region and 3rd-order (e.g., cousin) relationships in the southern region. One locus in particular (Nma04) was determined to be diagnostic in distinguishing between these 2 species.

Sequence data from a 597–base pair region of the mitochondrial DNA control region and data for 19 presumed allozyme loci were used to examine genetic structure and to detect gene flow among populations of southern red-backed voles (Myodes gapperi, formerly known as Clethrionomys gapperi) inhabiting spruce–fir “sky-islands” in the southern Appalachians. Allozyme data showed a significant heterozygote deficiency for most populations. Average individual heterozygosity varied among populations from 1.75% to 16.78% (X̄ ± SE = 8.63% ± 2.03%). F_ST values between any 2 sites ranged from 0.100 to 0.517 (X̄ ± SE = 0.296 ± 0.026), with a significant metapopulation F_ST value = 0.599. Nei's genetic distances (based on allozyme data) among spruce–fir habitats ranged from 0.037 to 0.310 (X̄ ± SE = 0.139 ± 0.079). Analysis of molecular variance permitted determination of the extent of geographic subdivision of mitochondrial haplotypes for 3 hierarchically organized sampling regimes: 14 high-altitude sample sites; 7 spruce–fir islands within which the sample sites are located; and whether sample sites were located south or north of the dominant, low-altitude barrier, the French Broad River. Genetic variation among groups and Φ_ST values were highly significant for all sampling regimes, indicating significant population structure at all hierarchical levels tested. Mantel's general regression test indicated that gene flow and genetic relationships fit an isolation-by-distance model. Since the Pleistocene, gene flow within the metapopulation of M. gapperi appears to have declined as a result of increasing distances between habitat islands and because of population bottlenecks.

Calomys Waterhouse, 1837, is one of the most speciose genera of the Phyllotini tribe of the South American sigmodontine rodents. Distributed predominately in southern South America, the genus has been proposed to have originated in the central Andes with further differentiation as subsequent occupations of the lowlands of the continent occurred. In this study, 30 newly obtained sequences of the cytochrome-b gene from specimens collected in Brazil were analyzed in conjunction with data available in GenBank in an attempt to discern the dispersion patterns of this genus in the South American lowlands. The analyses support a scenario where a phyllotine lineage appeared in the Andes and later separated into 2 larger clades. Members of 1 clade remained in the highlands (C. musculinus, C. lepidus, and C. sorellus), experiencing some local differentiation. Members of the 2nd clade invaded the lowlands of South America, especially nonforested biomes, where they underwent intense differentiation resulting in species with wide distributions in the continent. In the lowland clade, the “callosus–venustus” group is more derived, is characterized by a larger body size, and has a broad distribution; differentiation of this group was probably accompanied by some reduction in chromosomal diploid numbers.

The rodent Calomys musculinus is the reservoir of the Junin virus, which causes Argentine hemorrhagic fever. A phylogeographic approach was used for the analysis of 6 populations from central Argentina based on cytochrome-b sequences from 27 individuals. Thirteen haplotypes were detected, each closely linked in the phylogenetic network; 2 of the most frequent haplotypes were internal, whereas the majority were unique to single populations and presented distal positions in the network. Most of the variance was explained by within-population genetic diversity. Results of a mismatch distribution analysis and the deviation from neutrality confirmed that C. musculinus has experienced a recent range expansion; genetic drift has apparently been the main force acting at present, with low to moderate current gene flow. These results are in agreement with previous studies based on polymerase chain reaction–restriction fragment length polymorphism data of the mitochondrial D-loop region, and they support the reliability of both types of techniques.

Mountain hares (Lepus timidus hibernicus Bell) are extremely vagile and commute up to 3 km daily within their home ranges. However, observational and mark–recapture evidence suggests that they do not disperse far in their lifetime. Whether behavioral factors such as philopatry are promoting genetic structuring in this largely solitary species is not known. We examined genetic structure in the mountain hare using microsatellite markers from 321 mountain hares from across southern Ireland. Genetic differentiation ranged from low to moderate (pairwise F_ST = 0–0.116), and across distances of 200 km, F_ST was not correlated with geographic distance, suggesting possible population fragmentation. Home ranges of males in this species are significantly larger than those of females during the breeding season, suggesting that dispersal may be male-biased. Mean corrected assignment index (mAI_C) was lower in males (−0.280) than in females (0.403). F_ST was lower among male cohorts of population samples (0.040) than among female cohorts (0.051), but the difference was not significant. These results are consistent with natal dispersal of nonresident males into the sampling areas.

Dispersal of individuals can be defined as movement and settling outside the natal home range. Such dispersal is often sex-biased among vertebrates, and is generally expected to be male-biased in polygynous mammals. We used microsatellite markers scored on harvested wolverines (Gulo gulo) to test the prediction of male-biased dispersal in a population in the western Brooks Range, Alaska. Our analyses suggested a high rate of dispersal within the population, but provided no support for sex differences in dispersal tendencies across the sampled spatial scale. Previous studies have implied male-biased dispersal among wolverine populations on an interpopulation scale. We suggest 3, not exclusive, explanations to reconcile these differences: low power to detect sex biases in dispersal tendencies in this panmictic population; a scale-dependent component in dispersal tendencies, where males are overrepresented among interpopulation migrants; and lower reproductive success for dispersing females compared to more philopatric ones.

A total of 676 elk (Cervus elaphus) were genotyped at 16 tetranucleotide microsatellite loci to evaluate genetic differences among 3 subspecies of elk in California: tule (C. e. nannodes), Roosevelt (C. e. roosevelti), and Rocky Mountain (C. e. nelsoni) elk. Of the 13 populations analyzed, 5 represented tule elk herds, 3 were Roosevelt elk, 2 were Rocky Mountain elk, and 3 were of uncertain taxonomic status. Overall, populations averaged between 7 and 8 alleles per locus, with observed heterozygosity values ranging from 0.33 to 0.58 per population. Tule elk, which experienced a severe bottleneck in the 1870s, had consistently less genetic diversity than the other subspecies. All 3 subspecies were significantly differentiated, with the greatest genetic distance seen between the tule and Roosevelt subspecies. Assignment of individuals to subspecies using microsatellite data was nearly 100% accurate. Despite the past population bottleneck, significant differences were found among the tule elk herds. Assignment testing of elk from Modoc, Siskiyou, and Shasta counties to determine subspecific status of individuals suggested that these populations contained both Roosevelt and Rocky Mountain elk and their hybrids, indicating that these elk subspecies interbreed where subspecies coexist.

General guidelines for use of wild mammal species are updated from the 1998 version approved by the American Society of Mammalogists (ASM) and expanded to include additional resources. Included are details on marking, housing, trapping, and collecting mammals. These guidelines cover current professional techniques and regulations involving mammals used in research. Institutional animal care and use committees, regulatory agencies, and investigators should review and approve procedures concerning use of vertebrates at any particular institution. These guidelines were prepared and approved by the ASM, whose collective expertise provides a broad and comprehensive understanding of the biology of nondomesticated mammals in their natural environments.