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Mammal species have made the transition to the marine environment several times, and their lineages represent one of the classical examples of convergent evolution in morphological and physiological traits. Nevertheless, the genetic mechanisms of their phenotypic transition are poorly understood, and investigations into convergence at the molecular level have been inconclusive. While past studies have searched for convergent changes at specific amino acid sites, we propose an alternative strategy to identify those genes that experienced convergent changes in their selective pressures, visible as changes in evolutionary rate specifically in the marine lineages. We present evidence of widespread convergence at the gene level by identifying parallel shifts in evolutionary rate during three independent episodes of mammalian adaptation to the marine environment. Hundreds of genes accelerated their evolutionary rates in all three marine mammal lineages during their transition to aquatic life. These marine-accelerated genes are highly enriched for pathways that control recognized functional adaptations in marine mammals, including muscle physiology, lipid-metabolism, sensory systems, and skin and connective tissue. The accelerations resulted from both adaptive evolution as seen in skin and lung genes, and loss of function as in gustatory and olfactory genes. In regard to sensory systems, this finding provides further evidence that reduced senses of taste and smell are ubiquitous in marine mammals. Our analysis demonstrates the feasibility of identifying genes underlying convergent organism-level characteristics on a genome-wide scale and without prior knowledge of adaptations, and provides a powerful approach for investigating the physiological functions of mammalian genes.

International audience; In the last decade, specific attention has been paid to total mercury (HgT) stable isotopic composition, especially in natural samples such as aquatic organisms, due to its potential to track the cycle of this toxic element in the environment. Here, we investigated Hg Compound Specific stable Isotopic Composition (CSIC) of natural inorganic Hg (iHg) and methylmercury (MMHg) in various tissues of aquatic mammals (Beluga whale from the Arctic marine environment and seals from the freshwater lake Baikal, Russia). In seals' organs the variation in mass dependent fractionation (MDF, δ202Hg) for total Hg was significantly correlated to the respective fraction of iHg and MMHg compounds, with MMHg being enriched by ∼3‰ in heavier isotopes relative to iHg. On the other hand, we observe insignificant variation in Hg mass independent isotope fractionation (MIF, Δ199Hg) among iHg and MMHg in all organs for the same mammal species and MMHg in prey items. MIF signatures suggest that both MMHg and iHg in aquatic mammals have the same origin (i.e., MMHg from food), and are representative of Hg photochemistry in the water column of the mammal ecosystem. MDF signatures of Hg compounds indicate that MMHg is demethylated in vivo before being stored in the muscle, and the iHg formed is stored in the liver, and to a lesser extent in the kidney, before excretion. Thus, Hg CSIC analysis in mammals can be a powerful tool for tracing the metabolic response to Hg exposure

There are various interspecies differences in xenobiotic-metabolizing enzymes. It is known that cats show slow glucuronidation of drugs such as acetaminophen and strong side effects due to the UGT1A6 pseudogene. Recently, the UGT1A6 pseudogene was found in the Northern elephant seal and Otariidae was suggested to be UGT1A6-deficient. From the results of measurements of uridine diphosphate-glucuronosyltransferase (UGT) activity using liver microsomes, the Steller sea lion, Northern fur seal, and Caspian seal showed UGT activity toward 1-hydroxypyrene and acetaminophen as low as in cats, which was significantly lower than in rat and dog. Furthermore, UGT1A6 pseudogenes were found in Steller sea lion and Northern fur seal, and all Otariidae species were suggested to have the UGT1A6 pseudogene. The UGT1 family genes appear to have undergone birth-and-death evolution based on a phylogenetic and synteny analysis of the UGT1 family in mammals including Carnivora. UGT1A2-1A5 and UGT1A7-1A10 are paralogous genes to UGT1A1 and UGTA6, respectively, and their numbers were lower in cat, ferret and Pacific walrus than in human, rat, and dog. Felidae and Pinnipedia, which are less exposed to natural xenobiotics such as plant-derived toxins due to their carnivorous diet, have experienced fewer gene duplications of xenobiotic-metabolizing UGT genes, and even possess UGT1A6 pseudogenes. Artificial environmental pollutants and drugs conjugated by UGT are increasing dramatically, and their elimination to the environment can be of great consequence to cat and Pinnipedia species, whose low xenobiotic glucuronidation capacity makes them highly sensitive to these compounds.

Although black bears (Ursus americanus) were believed to be extirpated from the Interior Highlands of North America by the early 1900s, populations have recently recovered, aided in part by reintroductions in Arkansas. Today black bears can be found in the Ozark and Ouachita National Forests of northern and western Arkansas, the White River National Wildlife Refuge in eastern Arkansas, and the Ozark region of southern Missouri. Previous genetic studies have investigated the effects of translocating black bears from Minnesota and Manitoba, Canada, into the Ozark and Ouachita National Forests between 1958 and 1968, with differing results. We used nuclear microsatellite loci to infer the genetic structure of black bears across the Interior Highlands and to investigate the sources of bears found today in southern Missouri. Our results suggest that the Ozark population was strongly influenced by the reintroductions, whereas the Ouachita population was influenced to a lesser degree. Although the majority of bears in the Ozark region of Arkansas and Missouri represent a single genetic unit, bears in Webster County, Missouri, may represent a remnant of the historical population of the region. Our results confirm that the bear population in the White River National Wildlife Refuge is strongly differentiated genetically from other Arkansas populations and support previous reports that the Ouachita bear population may have resulted from an admixture of a remnant population and reintroduced bears.

Twinning is extremely rare in pinnipeds. Instances in which a female is observed simultaneously nursing 2 pups may represent alloparenting, or nonfilial nursing, a relatively common trait in pinnipeds. We explored the incidence of twinning in the Hawaiian monk seal (Monachus schauinslandi). We observed 7 sets of putative twins (i.e., an isolated female nursing 2 newborn pups) of 4,965 total births recorded between 1983 and 2008 (minimum twinning rate = 0.1%). Genetic specimens from the mother and both pups were available only for 5 of the 7 sets. Microsatellite genotyping revealed all of these to be dizygotic twins, with low probability of false assignment (P < 0.001). On average, Hawaiian monk seal twins were less likely to survive to weaning than singletons born in the same year and on the same island (P = 0.008). Those that weaned were smaller in size (i.e., axillary girths 1–4 SDs lower than singletons). In the critically endangered Hawaiian monk seal twinning appears to be a rare trait t...

Maternal attendance patterns in free-ranging wildlife can provide insight into basic biology, foraging behavior, and population dynamics. We collected detailed visual observations of attendance patterns by adult lactating Steller sea lions (Eumetopias jubatus) from 2005 to 2007 on 6 major rookeries in the Russian Far East, including those with an increasing population trend (Sea of Okhotsk), severely depleted populations that were recovering (Kuril Islands), or those that were stable (Commander Islands). Individually identifiable females were observed during the postpartum period, with special attention paid to presence and absence during the day and to departure and arrival times. Within Russia females on several Kuril Islands rookeries exhibited extremely short foraging trip durations (median 6.5–8.0 h) and spent higher proportions of time on the rookery (75–82%), whereas females in the Sea of Okhotsk population had the longest trips (median 19.8 h) and spent the least amount of time on the roo...

Endothermic mammals in cold environments have a range of adaptations enabling them to maintain a constant core body temperature. Of critical importance to many is a thick hair coat that retains air and so acts as a barrier to minimize heat exchange between the skin and ambient environment. Disruption to the pelage can increase costs of maintaining body temperature and compromise survival of the individual. Fur seals rely on a pelage of dense, dry underfur protected by guard hairs for insulation in the aquatic environment. Since 1989 a potentially serious alopecia (hair loss) syndrome has been recognized in Australian fur seals. Between September 2007 and February 2010 we investigated the prevalence and potential impacts of the condition. The syndrome manifests as bilaterally symmetrical alopecia, which occurs predominantly in juveniles and has a strong sex bias (51 of 55 juveniles captured for examination were female). It also occurs in adult females but has never been seen on postpubescent males. Prevalence of alopecia was highest at the large Lady Julia Percy Island colony (approximately 30,000 seals) in northwestern Bass Strait where it has a distinct seasonal pattern of prevalence, peaking in spring and summer with up to 50% of juvenile females affected. Thermal images indicated that alopecic and nonalopecic areas of the dorsal thorax had a mean difference of 6.6°C, and affected animals were in significantly (P < 0.001) poorer body condition than unaffected animals.

Wolves (Canis lupus), as both opportunistic and specialist predators, can limit and regulate ungulate dynamics. As part of understanding predator–prey interactions in the largely undisturbed system of the Besa-Prophet area in northern British Columbia, we used stable isotopes of carbon and nitrogen to infer seasonal diets of 5 wolf packs. We selected the hair, tissue, or blood sample of each prey species that could best index within-season diet composition. Seasonal isotopic differences for a given sample type were as much as 0.28% d 13 C and 0.97% d 15 N. The large biomass species of moose (Alces americanus) and elk (Cervus elaphus) dominated the diets of wolves, but caribou (Rangifer tarandus) and Stone’s sheep (Ovis dalli stonei) also were locally or seasonally important to some packs. Mean isotopic determinations of summer food habits were correlated positively (P , 0.001) with proportions of prey by species determined from scat samples. This general agreement lends support for the tissue to diet discrimination values used in the Bayesian modeling and indicates that the longer-term dietary estimates from stable isotopes were reflective of shorter-term recent ingestion. Although moose have been assumed to be the most important prey item for wolves throughout the year in northern British Columbia, our results indicate that dietary dynamics of wolves in the Besa-Prophet area are more complex than previously reported.

Movements away from the natal or home territory are important to many ecological processes, including gene flow, population regulation, and disease epidemiology, yet quantitative data on these behaviors are lacking. Red foxes exhibit 2 periods of extraterritorial movements: when an individual disperses and when males search neighboring territories for extrapair copulations during the breeding season. Using radiotracking data collected at 5-min interfix intervals, we compared movement parameters, including distance moved, speed of movement, and turning angles, of dispersal and reproductive movements to those made during normal territorial movements; the instantaneous separation distances of dispersing and extraterritorial movements to the movements of resident adults; and the frequency of locations of 95%, 60%, and 30% harmonic mean isopleths of adult fox home territories to randomly generated fox movements. Foxes making reproductive movements traveled farther than when undertaking other types of movement, and dispersal movements were straighter. Reproductive and dispersal movements were faster than territorial movements and also differed in intensity of search and thoroughness. Foxes making dispersal movements avoided direct contact with territorial adults and moved through peripheral areas of territories. The converse was true for reproductive movements. Although similar in some basic characteristics, dispersal and reproductive movements are fundamentally different both behaviorally and spatially and are likely to have different ultimate purposes and contrasting effects on spatial processes such as disease transmission.

Temporal partitioning in foraging patterns of syntopic Virginia opossums (Didelphis virginiana) and raccoons (Procyon lotor) was investigated at 3 sites in western Tennessee through the use of timers attached to live traps on trapping grids and through time-stamped remote photography using infrared-triggered cameras at bait stations. Data were analyzed using Watson’s U 2 -test, chi-square analyses, and probability tests. Results revealed no intraspecific differences in time of foraging for either species and a lack of interspecific differentiation. A high degree of overlap in foraging times of the species was observed. Virginia opossums and raccoons apparently did not partition their times of foraging. Foraging patterns of each species seem to be independent of the other (neutral association).

The monophyletic group Caniformia (dog-like carnivores) in the order Carnivora comprises 9 families. Except for the general consensus for the earliest divergence of Canidae and the grouping of Procyonidae and Mustelidae, conflict- ing phylogenetic hypotheses exist for the other caniformian families. In the present study, a data set comprising >22 kb of 22 nuclear intron loci from 16 caniformian species is used to investigate the phylogenetic utility of nuclear introns in resolving the interfamilial relationships of Caniformia. Our phylogenetic analyses support Ailuridae as the sister taxon to a clade containing Procyonidae and Mustelidae, with Mephitinae being the sister taxon to all of them. The unresolved placements of Ursidae and Pinnipeds here emphasize a need to add more data and include more taxa to resolve this prob- lem. The present study not only resolves some of the ambiguous relationships in Caniformia phylogeny but also shows that the noncoding nuclear markers can offer powerful complementary data for estimating the species tree. None of the newly developed introns here have previously been used for phylogeny reconstruction, thus increasing the spectrum of molecular markers available to mammalian systematics. Interestingly, all the newly developed intron data partitions ex- hibit intraindividual allele heterozygotes (IIAHs). There are 115 cases of IIAHs in total. The incorporation of IIAHs into phylogenetic analysis not only provides insights into the interfamilial relationships of Caniformia but also identifies two potential hybridization events occurred within Ursidae and Otariidae, respectively. Finally, the powers and pitfalls of phy- logenetics using nuclear introns as markers are discussed in the context of Caniformia phylogeny. (Caniformia; intron; intraindividual allele heterozygotes; phylogeny; transposable elements.)

Male Juan Fernandez fur seals (Arctocephalus philippii) are significantly larger than females at birth and show extreme dimorphism as adults. We investigated morphological differences among male and female pups using a cross-sectional sampling design to evaluate whether pup growth rates were sex-specific during the breeding season. We characterized growth rates using mass, length, and girth and found that length was the least variable measure of body growth (based on the coefficients of variation for the 3 measures of body size). Male pups were heavier on average than female pups on any given day of sampling but did not grow faster than females. No significant differences were noted in the body conditions of male and female pups. These findings suggest that the sexual differences among pups of A. philippii originate before birth and are not accentuated while suckling during the breeding season.

Migration can enhance survival and recruitment of mammals by increasing access to higher-quality forage or reducing predation risk, or both. We used telemetry locations collected from 140 adult female elk during 2000– 2003 and 2007–2008 to identify factors influencing the migration of northern Yellowstone elk. Elk wintered in 2 semidistinct herd segments and migrated 10–140 km to at least 12 summer areas in Yellowstone National Park (YNP) and nearby areas of Montana. Spring migrations were delayed after winters with increased snow pack, with earlier migration in years with earlier vegetation green-up. Elk wintering at lower elevations outside YNP migrated an average of 13 days earlier than elk at higher elevations. The timing of autumn migrations varied annually, but elk left their summer ranges at about the same time regardless of elevation, wolf numbers, or distance to their wintering areas. Elk monitored for multiple years typically returned to the same summer (96% fidelity, n 5 52) and winter (61% fidelity, n 5 41) ranges. Elk that wintered at lower elevations in or near the northwestern portion of the park tended to summer in the western part of YNP (56%), and elk that wintered at higher elevations spent summer primarily in the eastern and northern parts of the park (82%). Elk did not grossly modify their migration timing, routes, or use areas after wolf restoration. Elk mortality was low during summer and migration (8 of 225 elk-summers). However, spatial segregation and differential mortality and recruitment between herd segments on the northern winter range apparently contributed to a higher proportion of the elk population wintering outside the northwestern portion of YNP and summering in the western portion of the park. This change could shift wolf spatial dynamics more outside YNP and increase the risk of transmission of brucellosis from elk to cattle north of the park. DOI: 10.1644/08-MAMM-A-252.1.

Mitigation of predation risk promotes high-elevation dispersion prior to birthing in many ungulate populations. Coyotes (Canis latrans) account for nearly 80% of pronghorn (Antilocapra americana) fawn mortality in Yellowstone National Park, but reintroduced gray wolves (Canis lupus) and factors associated with mountainous terrain can strongly influence space use by predators during summer and are likely to underlie significant spatial variation in survival rates of pronghorn fawns. We used generalized logit models paneled by maternal identity to assess the relative and interactive influences of summer wolf density, winter snow depth, and terrain slope on survival of pronghorn fawns in Yellowstone during 1999–2001 and 2004–2006. In this partially migratory population only migrant pronghorn accessed areas where wolves were numerous and winter snow depths were high. Survival of migrant fawns was higher in areas that experienced deep winter snow and had steeper slope. The influence of wolves on fawn survival was positive only in areas of low winter snowfall where coyotes were abundant, supporting predictions of a coyote-mediated effect of wolves and winter snowfall on pronghorn reproductive success. Our results suggest that deep winter snow, coupled with constraints on mobility imposed by reproduction in populations of social carnivores, can lead to the formation of highelevation refugia for migrant ungulates. This research offers novel insights into the indirect effects of wolf restoration and climatic factors on the Yellowstone predator–prey complex and a conceptual framework for examining the ecological effects in other mountain communities of restoration of, and seasonal space use by, large carnivores. DOI: 10.1644/09-MAMM-A-057.1.

The estimation of life-history parameters for a threatened species is important for understanding its biology and helping to determine management options. This research investigates age- and sex-related survival estimates incorporating tag loss for New Zealand (NZ) sea lions (Phocarctos hookeri) from Sandy Bay, Enderby Island, Auckland Islands, New Zealand, using multistate mark–recapture data from known-age individuals over 8 years (1997–1998 to 2005–2006). Survival estimates and tag loss rates differed significantly by sex and age class, with adult males having the lowest tag retention of any age or sex class and females � 3 years old having lower survival estimates than their male counterparts. The variability and lower female survival relative to males is a critical problem for NZ sea lions, because even small changes in adult female survival significantly affect population trends for such large, long-lived mammals. DOI: 10.1644/09-MAMM-A-285.1.

Investigations into mechanisms of resource partitioning are particularly suited to systems where nascent interactive behaviors are observable. Wolf (Canis lupus) recolonization of the Greater Yellowstone Ecosystem provided such a system, and we were able to identify behaviors influencing the partitioning of resources by coyotes (Canis latrans) and wolves. We observed coyote-wolf interactions immediately after wolf recolonization, when reemergent behaviors mediating the outcome of competitive interactions were detectable and mechanisms of spatial avoidance were identifiable. Although coyotes used the same space as wolves, they likely minimized risk of encounter by making adaptive changes in resource selection based on perception of wolf activity and potential scavenging opportunities. When exploiting carrion subsidies (i.e., wolf-killed ungulates), coyotes relied on social behaviors (i.e., numerical advantage in concert with heightened aggression) to mitigate escalating risk from wolves and increase resource-holding potential. By adapting behaviors to fluctuating risk, coyotes might reduce the amplitude of competitive asymmetries. We concluded coyotes do not perceive wolves as a threat requiring generalized spatial avoidance. Rather, the threat of aggressive interactions with wolves is spatially discrete and primarily contained to areas adjacent to carrion resources.

Glacial cycles in the late Pleistocene played a dominant role in sculpting the evolutionary histories of many high-latitude organisms. The refugial hypothesis argues that populations retracted during glacial maxima and were isolated in separate refugia. One prediction of this hypothesis is that populations inhabiting different refugia diverged and then, during interglacial periods, rapidly expanded into deglaciated regions. The range of the gray wolf (Canis lupus) was modified by these expansion and contraction cycles in the late Pleistocene. Our analyses of variation of mitochondrial control region sequences corroborate previous microsatellite analyses supporting independent evolutionary histories for Coastal and Continental wolves in North America. Coastal wolves represent the remnants of a formerly widespread and diverse southern clade that expanded into coastal Southeast Alaska, likely in the early Holocene. In contrast, extant northern Continental populations appear to be admixed, composed of lineages independently arising from ancestors that persisted in either southern or northern (Beringia) refugia. This pattern of diversification suggests the possibility of 3 temporally independent colonizations of North America by wolves from Asia. Coastal wolves are the last vestige of a formerly widespread phylogroup that largely was extirpated in North America by humans during the last century. The independent phylogeographic history of these Coastal wolves has yet to be characterized. Their distinctiveness among North American wolf populations may warrant a reevaluation of their conservation status and management. DOI: 10.1644/09-MAMM-A-036.1.

Relatively little is known about the mating behavior, and factors that influence the mating behavior, of socially monogamous mammals. We used a combination of behavioral and genetic data to examine the mating tactics of a socially monogamous population of bat-eared foxes (Otocyon megalotis). In contrast to some other canid species, we found no evidence that either sex increased range size or traveling distance during the mating season, demonstrating that neither sex roams widely in pursuit of extrapair copulations. Mated partners maintained close proximity during, and sometimes outside, the mating season, suggesting that females looking to engage with extrapair mates might find it difficult to do so. Consistent with these findings, microsatellite analyses revealed lower levels of extrapair paternity (EPP) than have been reported in other canid species, with only 9.8% of cubs produced outside of the pair-bond. We suggest that the relatively low level of EPP in the bat-eared fox may be influenced partly by diet and foraging behavior, which makes it easy for males to maintain close proximity to partners and costly for either sex to roam in search of extrapair mates.

During 1994–2007 a total of 156,416 raccoons was live-captured in Ontario, Canada, as part of mark–recapture studies to estimate raccoon density during rabies-control operations. Mean density in southern Ontario ranged between 3.4 and 13.6 raccoons/km2 when density in northern Ontario was

A sample of 834 female New Zealand sea lions (Phocarctos hookeri), which were aged and measured, was obtained between 1998 and 2001. In addition, the reproductive histories of 505 marked females from the Auckland Islands were recorded from 1998 to 2005. These data sets were used to investigate growth and reproductive rates. Length and weight ranged from 134 to 197 cm and 49 to 156 kg, respectively. A Gompertz growth model best described growth and predicted that females attained 90% of asymptotic length (161.7 cm) and weight (112.0) at ages 4 and 11 years, respectively. No significant differences were found in growth rates among years, nor between the 2 major breeding colonies in the Auckland Islands. Females reproduced between the ages of 3 and 26 years, with evidence of reproductive senescence starting at age 23 years. Although females up to age 28 years were observed, no females over 26 years were recorded as reproductive. Age-specific reproductive rate p(x) increased rapidly between ages 3 an...

Analyses of feces, stomach contents, and regurgitated pellets are common techniques for assessing diets of vertebrates and typically contain more than 1 food item per sampling unit. When analyzed, these individual food items have traditionally been treated as independent, which represents pseudoreplication. When food types are recorded as present or absent, these samples can be treated as multinomial vectors of food items, with each vector representing 1 realization of a possible diet. We suggest such data have a similar structure to capture histories for closed-capture, capture–mark–recapture data. To assess the effects of landscapes and presence of a potential competitor, we used closed-capture models implemented in program MARK into analyze diet data generated from feces of swift foxes (Vulpes velox) and coyotes (Canis latrans) in northwestern Texas. The best models of diet contained season and location for both swift foxes and coyotes, but year accounted for less variation, suggesting that landscape type is an important predictor of diets of both species. Models containing the effect of coyote reduction were not competitive (DQAICc 5 53.6685), consistent with the hypothesis that presence of coyotes did not influence diet of swift foxes. Our findings suggest that landscape type may have important influences on diets of both species. We believe that multinomial models represent an effective approach to assess hypotheses when diet studies have a data structure similar to ours. DOI: 10.1644/07-MAMM-A-291R1.1.

I examined dispersal, home-range establishment, and home-range fidelity in American black bears (Ursus americanus) using radiotelemetry data for individuals whose natal ranges were known (n = 43), individuals whose natal ranges were identified using microsatellite DNA (n = 13), and individuals whose natal ranges were unknown (n = 86). Dispersal was highly male-biased. Nearly all males emigrated 22–62 km from their natal ranges between the ages of 1 and 3 years. Some males continued to float, moving their ranges 15–68 km between successive years. Most males settled into a permanent home range by age 4 years, and all males settled by age 7 years. One 8-year-old male apparently did not disperse and resided only 7 km from his natal range. Females were more philopatric and settled 0–7 km from their natal ranges. Only 1 female moved her range >20 km at the age of 5 years. The adaptive significance of male-biased natal dispersal is discussed.

Patterns of space use can provide valuable insights into patterns of activity and social structure of poorly known mammal species. From April 2005 to November 2006 we radiotracked a low-density population of ferret badgers (Melogale moschata) in central China. Fourteen males and 8 females were caught. Nine of these individuals (6 males and 3 females) were followed; mean (± SD) 100% minimum convex polygon (MCP100) home range was 128.3 ± 131.9 ha, with no difference between sexes. For MCP100, neither nightly movement distances nor daily activity patterns revealed significant variation due to sex or season. Core areas (50% minimum convex polygon [MCP50]) were typically located centrally within overall home ranges. Two distinct groups of animals were evident in the radiotracked subpopulation, one consisting of 7 adults and the other composed of at least the 2 remaining collared badgers with field signs of additional badgers from the periphery of our study area. Within each group, home ranges of radiocollared individuals overlapped extensively (62.1% ± 26.5% for MCP100; 59.6% ± 23.0% for MCP95; 37.1% ± 24.5% for MCP50), and up to 4 adults per group shared the same burrow (sett). We consider the implications of our data for understanding of mustelid sociospatial behavior.

Spatial or temporal isotopic variation, or both, in primary producers must be controlled for when investigating the foraging and trophic ecology of top consumers using isotopic data. Populations of the sister species Zalophus californianus and Z. wollebaeki are separated by approximately 3,350 km in the eastern tropical Pacific Ocean, which prevents contact and mixing between the 2 populations. To explore differences in trophic ecology between these species, as well as the impact of differences in baseline food-web isotope values between the 2 regions, we compared conventional dietary data derived from analyses of scat contents to isotopic values of hair collected from pups at 13 rookeries in the Gulf of California (Z. californianus) and 11 rookeries on the Galápagos Islands (Z. wollebaeki). Mean ± 1 SD δ13C and δ15N values were −15.9‰ ± 0.5‰ and 21.8 ± 0.7‰ in the Gulf of California, whereas for the Galápagos they were −14.5‰ ± 0.5‰ and 13.1‰ ± 0.5‰. Examination of scat data suggested overlap in 6 of the 10 most common prey consumed by sea lions. Trophic level (TL) derived from scat analysis was positively related with δ15N values for the Gulf of California rookeries, but estimates of TL for each region were similar (4.4 for Galápagos and 4.1 for Gulf of California), suggesting that foraging behavior makes a limited contribution to the large difference in δ15N value between the 2 populations. Particulate organic matter δ15N values near the Galápagos Islands are 5.3‰ lower than values in the Gulf of California, suggesting that the baseline food-web values account for approximately two-thirds of the observed difference in pup hair δ15N values. This study may provide clues to better understand isotopic values of marine top predators migrating across the eastern Pacific Ocean.

We investigated potential ecological attributes of the striking coat colour polymorphism in the black bear (Ursus americanus kermodei Hornaday) occurring on several small islands off the mid-coast of British Columbia, where a white morph (Kermode), fully recessive to the black morph, reaches 10–25% of the population. During three autumn field seasons (2000–2002; 697 h of observation time), we monitored salmon capture behaviour of individual bears (black, N = 37; white, N = 4). Both colour morphs foraged on salmon throughout daylight and darkness but with twice the rate during darkness. Log-linear analysis of capture efficiency (success/attempts) and average capture success per bout of the white morph was marginally lower than the black morph during darkness (22.8%, N = 158 versus 25.8%, N = 279 respectively; P 0.4) in response to either the white or black models; however, during daylight, salmon were twice as evasive to the black compared to the white model (P < 0.001). The persistence of this coat colour polymorphism may be facilitated by increased salmon accessibility to the Kermode bear and diel foraging differences between morphs. These results are consistent with multi-niche models of adaptive variability. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 479–488.

Mammalian reproductive biology is modified consistently across pinnipeds to achieve a synchronous and seasonal reproductive pattern. This synchrony relies on an embryonic diapause and ensures optimal conditions for offspring survival. Behavioral observations on Galapagos sea lions (Zalophus wollebaeki) indicate little synchrony and variable breeding seasons, making this species unique among otariids. We studied the reproductive physiology of wild female Galapagos sea lions in 2 months in contrasting seasons, March 2005 (n = 11) and August 2006 (n = 12) by examining progesterone and estrogen concentrations in serum and plasma. We provide physiological evidence for remarkably low synchrony and minor seasonality in the breeding cycle of Galapagos sea lions. Specifically, we found females in intermediate or advanced pregnancy during both seasons, as determined by high progesterone concentrations coupled with physical examination. Possible causes for this low synchrony are absence of strong photop...

Life-history theory predicts that within a species, reproduction and survival rates will differ among populations that differ in resource availability or predation rates through phenotypic plasticity. When populations are near carrying capacity (K) or when they are declining due to reduced prey resources, the average age at 1st reproduction (average AFR) is predicted to be older than in populations below K. Differences between the trajectories of northern sea otter (Enhydra lutris kenyoni) populations in Alaska provides an opportunity to examine phenotypic plasticity. Using premolar teeth or reproductive tracts, we estimated average AFR from demographically distinct populations of sea otters in Alaska. We obtained samples from 2 populations near K, Prince William Sound (PWS) and the Aleutian Archipelago (archived samples), and from 2 populations below K, the Kodiak Archipelago and Sitka. The average AFR was lower in populations below K (3.60 years 6 0.16 SD) compared to those near K (4.21 6 0.13 years, P , 0.001), and differed among all populations, with the Aleutian population possessing the oldest average AFR (4.29 6 0.09 years) followed by PWS (4.05 6 0.24 years), Sitka (3.80 6 0.21 years), and Kodiak (3.19 6 0.37 years). The difference in average AFR among populations supports life-history theory and provides evidence of phenotypic plasticity in sea otters. Our findings highlight the value of using average AFR as a tool for monitoring mammalian populations.

Black bears (Ursus americanus) forage selectively in natural environments. To determine if bears also forage selectively for anthropogenic resources we analyzed data on vehicles broken into by bears from Yosemite National Park, California. We classified vehicles into 9 categories based on their make and model and collected data on use (2001–2007) and availability (2004–2005). From 2001 to 2007 bears broke into 908 vehicles at the following rates: minivan (26.0%), sport–utility vehicle (22.5%), small car (17.1%), sedan (13.7%), truck (11.9%), van (4.2%), sports car (1.7%), coupe (1.7%), and station wagon (1.4%). Only use of minivans (29%) during 2004–2005 was significantly higher than expected (7%). We discuss several competing hypotheses about why bears selected minivans.

The competitive dynamics between domestic and native carnivores are poorly studied. We examined competition for food between sympatric populations of free-ranging dogs (Canis familiaris) and Indian foxes (Vulpes bengalensis) through dietary analysis in a protected, dry grassland habitat in central India. We expected significant dietary overlap between dogs and foxes because of clear evidence of interference competition between dogs and foxes in this area. However, dogs subsisted largely on human-derived foods (HDFs) from direct feeding, and scavenging on garbage, crop residue, and livestock carcasses (83% relative occurrence [RO]). Wild-caught foods constituted only 11% RO of the diet of dogs. The majority of the diet of Indian foxes consisted of invertebrates (33% RO), rodents (20% RO), and fruits of Zizyphus (18.5% RO). Indian foxes did not consume HDF, nor did they scavenge from large-mammal carcasses, and included only a small portion of agricultural produce in their diet. The low contribution of HDF and agricultural food sources to the diet of Indian foxes was surprising because this species is a generalist omnivore. Dogs may be preventing foxes from accessing agricultural lands and human-associated foods by interference competition.

The American black bear (Ursus americanus) experienced a significant range contraction during the 19th and 20th centuries due to a variety of anthropogenic factors. Although previous molecular studies of black bears provided insight into historic and contemporary forces shaping phylogeographic patterns, none included black bears from the central part of the species distribution. Understanding the historical aspects of the connectivity and genetic differentiation of black bears in this region is important for proper management and conservation programs, but this understanding is confounded by poorly documented translocation efforts and population expansion. To address these issues, we generated mitochondrial DNA sequence data for 409 black bears from 15 populations in North America. Two sampling localities (Manitoba, Canada, and Minnesota) were source populations for translocation into western Arkansas and Louisiana. Major conclusions from our study include: black bears in western Arkansas were affected genetically by the translocation program; eastern Oklahoma has been repopulated by westward expansion of bears from Arkansas with a mixture of translocated bears and remnant individuals; black bears in Louisiana were not affected genetically by the translocation program; black bears in western Texas and northern Mexico dispersed there from the southeastern United States; and bears in White River National Wildlife Refuge (eastern Arkansas) share closer genetic affinities with U. a. luteolus than they do with the widespread U. a. americanus.

The contemporary genetic structure of animal populations is sculpted by past events, including demographic bottlenecks and expansions and movement of animals by humans. In an analysis of microsatellite DNA of black bears (Ursus americanus; n 5 540) across California, we discovered distinct population structure and genetic evidence of 2 historic colonization events. First, genotypes of bears sampled in southern California are most related to those from the Yosemite National Park region and not with spatially intervening populations. Historical records recount the translocation of 28 black bears from the Yosemite National Park area of the central Sierra Nevada to the San Bernardino Mountains in southern California in the 1930s. Second, before colonization of California by Europeans, the Central Coast region was inhabited by the now extinct California grizzly bear (Ursus arctos californiensis), but not black bears. Following an apparent competitive release and range expansion during the past century, black bears now inhabit the Central Coast region of California. Black bears in California’s Central Coast display lower genetic diversity (founder effect) and a genetic signature most closely allied with black bears from the southern Sierra Nevada. In both these cases, molecular genetic techniques allowed historical reconstruction of anthropogenic events leading to changes in animal distributions.

Patterns of geographic variation of the canid Cerdocyon thous have historically been obscured by its remarkable intraspecific morphological variability. The observed distribution is highly associated with phytophysiognomy, a feature considered highly dynamic along geological time. In the present study, we tested whether vegetation distribution during the Holocene Glacial Maximum of South America (HGM) explains the patterns of morphological variation within Cerdocyon thous. The species was divided in groups according to paleohabitats that could support their presence during the HGM, and then tested for differences in skull morphometrics. The results obtained demonstrate that the climatic changes during the HGM influenced the population structure of this species, resulting in the establishment of geographical groups with different degrees of morphological cohesion. Higher morphological cohesion found in the Northern group might be explained by the marked discontinuity between its geographical range and the rest of the species’distribution. The Eastern and Southern morphological divergence is less striking and, although this could be related to past vegetation distribution, the disappearance of those barriers leads to a population structure that could be slowly breaking down. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 77‐84.

Historic fur returns from Hudson’s Bay Company posts in northwestern Canada reveal periodic oscillations in mink (Neovision vision) harvests lagging 2–3 years behind oscillations in muskrat (Ondatra zibethicus) harvests, as would be expected in a predator–prey interaction. Toward central and eastern Canada, the strength of the interaction between time series of harvests of minks and muskrats weakens and the lag between fluctuations of these 2 species decreases to 1 and 0 years, respectively. We tested the hypothesis that this gradient in mink– muskrat interactions is the result of decreased dependency of minks on muskrats in areas where minks have access to more alternate prey. We tested 2 predictions: species richness of mink prey is greatest in eastern Canada and decreases to the west, and percent muskrats in the diets of minks decreases as species richness of mink prey increases. Contrary to the 1st prediction, we found that species richness of mink prey in Canada is highest in southcentral Canada. Consistent with the 2nd prediction, percent occurrence of muskrats in the diets of minks was much lower in areas with greater species richness of mink prey. Local species richness of mink prey therefore could influence the degree of specialization of minks on muskrats, but may be insufficient to explain the geographic pattern in the lag between muskrat and mink harvests in eastern Canada.

Polar bears (Ursus maritimus) are faced with potential drastic changes to their ice habitat in the near future. Climate models predict that the ice-covered period during which bears use the sea ice to hunt seals is getting shorter, and that the ice-free season will become extended. Bears will not have enough ice time to accumulate the necessary body fat reserves they need to live off when stranded on land during summers. However, polar bears have been observed making use of several food sources while on land, although the energetic contributions of these diets to the bears’ energy budget were considered to be minor. We examine mathematically whether observed diets (i.e., arctic charr [Salvelinus alpinus], ringed seal [Pusa hispida] blubber, and berry diets) can contribute sufficient energy to offset the daily body mass loss. We then estimate the amount or mass of the diet that must be consumed to achieve a balanced daily energy loss, and whether this is possible, given specific constraints on feeding. The analysis indicated that it is possible for polar bears to maintain their body mass while on shore by feeding on arctic charr and seal blubber. Polar bears of body masses up to 280 kg could gain sufficient energy from blueberries to match the daily energy loss. The question that arises is how many bears of a population would resort to such strategies? To better understand how polar bears will adapt to a warming climate, we recommend continued examination of polar bear diets in the field, and controlled feeding trials with captive polar bears.

We investigated the effects of fluctuating prey numbers on the foraging strategies and potential mechanisms for coexistence of 2 sympatric predators, coyotes (Canis latrans) and red foxes (Vulpes vulpes), in a heterogeneous environment in northeastern Illinois. We quantified the availability of mammalian and avian prey across different habitats, analyzed scats collected along standardized routes for occurrence of prey items, and estimated the number and biomass of vertebrate prey consumed. Abundances of the most frequently consumed prey (voles, rabbits, and mice) differed significantly over time, especially in relation to an ice storm that occurred during the study. Coyotes and red foxes tended to select voles and rabbits in number, rabbits in biomass, and incorporated greater numbers and biomass of other prey such as deer, pheasants, and sciurids after the ice storm. Log-linear analyses indicated that both coyotes and red foxes exhibited switching behavior, with differential shifts among the number and biomass of alternative prey they consumed. Hence, foraging strategies of coyotes and red foxes appeared to be a combination of prey selectivity and switching behavior. Our study suggests that competition between coyotes and red foxes for similar primary prey species and limited environments to exploit at the urban–rural interface may contribute to displacement of red foxes by coyotes.

Aims: This study sought to evaluate the distribution of the enterococcal surface protein (esp) gene in Enterococcus faecium in the Pacific coast environment as well as the distribution and diversity of the gene in Northern California animal hosts. Methods and Results: Over 150 environmental samples from the Pacific coast environment (sand, surf zone, fresh/estuarine, groundwater, and storm drain) were screened for the esp gene marker in E. faecium, and the marker was found in 37% of the environmental samples. We examined the host specificity of the gene by screening various avian and mammalian faecal samples, and found the esp gene to be widespread in nonhuman animal faeces. DNA sequence analysis performed on esp polymerase chain reaction amplicons revealed that esp gene sequences were not divergent between hosts. Conclusions: Our data confirm recent findings that the E. faecium variant of the esp gene is not human-specific. Significance and Impact of the Study: Our results suggest that the use of the esp gene for microbial source tracking applications may not be appropriate at all recreational beaches.

We investigated molar-crown–size variation, sexual dimorphism, and allometry in the black bear (Ursus americanus), using hunter-shot specimens (n ¼ 429) from the island of Newfoundland, and museum specimens from elsewhere in Canada and the continental United States (n ¼ 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 (¼ 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 mass 1/3 (21%). Sexes did not differ in relative molar size. Molar size was mainly isometric

We examine foraging behavior of coastal black bears (Ursus americanus kermodei) during different light regimes on a salmon stream in British Columbia, Canada (2000–2002). Bears (maximum 7 simultaneously) were primarily active during daylight near the onset of the salmon spawning run and shifted to twilight and darkness as the spawning run progressed. Overall time budget included search and pursuit (58%), handling and ingestion (38%), and agonistic interactions with other bears (4%). Scavenging was greatest during daylight (19%) and lowest during darkness (3%). Bears were most efficient at capturing live salmon when standing (35.4% success) followed by running (20.5%) and walking (15.2%). Highest capture efficiency occurred during twilight (33.6%) compared with daylight (26.5%) and darkness (24.7%). Capture rate ranged from 1 to 3 salmon per hour per bear. Our results suggest that bears increased their total salmon intake by alternate use of visual and auditory cues during daylight and darkness.

Determinants of sex ratios in animal populations have been of general interest to ecologists for decades. We tested the hypothesis that offspring sex ratio in a population of northern elephant seals (Mirounga angustirostris) was related to large-scale environmental indices reflecting ocean climate and productivity that affected the condition of reproductive females over 31 years (1976‐2006). More males were produced during years of weaker pressure differences and warmer sea surface temperature anomalies in the northeastern Pacific, conditions that reduce or disperse prey resources for gestating females in the North Pacific Ocean. For this species, sexually distinct forage resources exist, so competition for food resources occurs predominately within sex. These results are consistent with the resource competition model for facultative adjustments of offspring sex ratio. Anthropogenic global warming is predicted to warm the North Pacific. This could result in altered basin-scale ocean productivity, increased nutritional stress, and an overabundance of males that may adversely affect this and other similarly regulated mammalian populations.

The cause of extinction of the noble marten (Martes americana nobilis), as well as its taxonomic position, has been the subject of debate in recent years. This extinct marten, a close relative of the extant American marten (Martes americana), is known from 18 sites in western North America, most dating to the late Pleistocene. Because boreal fauna were associated with the late-Pleistocene noble marten, researchers generally believed that it inhabited boreal forests like the American marten, and competition between the 2 may have caused its extinction. Recent discoveries of noble martens associated with xeric fauna from Holocene contexts have called these assumptions into question. I explore the adaptation and habitat of the noble marten with an analysis of its faunal associations and find-site locations. The analysis suggests that the noble marten was adapted to open, mesic grasslands in montane foothills, and was likely not sympatric with the American marten. I also introduce a new Holocene noble marten specimen, a right mandible dating to 6,400 years ago, from Mummy Cave, an archaeological site in northwestern Wyoming.

The hog-nosed skunk, Conepatus Gray, 1837, is one of the most widespread carnivorans in the New World, and one of the first to arrive in South America during the Great American Biotic Interchange (GABI). We report a basal hog-nosed skunk, Conepatus sanmiguelensis sp. nov., from the early Pliocene San Miguel de Allende Basin, Guanajuato State, central Mexico. The Mexican species greatly extends the first appearance of Conepatus from Irvingtonian to early Blancan in North America, more than doubling the time period of previously known appearances. The new species of Conepatus is also geographically closer to the Panamanian land bridge than previous records from the United States and northern Mexico, and permits a better sense of the faunal exchange during the early phase of the GABI. The new species is represented by two individuals, including a nearly complete skull and a partial mandible with most of the cheek teeth, as well as a large portion of the skeleton. Such a nearly complete representation of cranial, dental and skeletal materials enables us to conduct a species-level phylogenetic analysis. C. sanmiguelensis is characterized by its large size, condyloid foramen confluent with posterior lacerate foramen, presence of a P2, an M1 not very elongated and long trigonid on m1. This combination of primitive and derived characters suggests a phylogenetic position basal to a North American clade [C. sanmiguelensis (C. robustus, C. leuconotus)]. The new phylogenetic reconstruction suggests that Central and South American Conepatus form a sister group to the North American clade, and as such, must have equally ancient divergence time that dates back to at least 4–5 Ma. As a result, C. altiramus from coastal marine cliffs of Argentina should be seriously reconsidered to be from the Chapadmalal Formation in the early Pliocene, a notion dismissed by some recent authors. If this is correct, South American Conepatus represents the first known carnivoran immigrant during the first wave of the GABI. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 154, 386–407.

Chromosome painting was used to investigate the conservation of high-resolution longitudinal 4',6-diamidino-2-phenylindole (DAPI)/G bands in Carnivore chromosomes. Cat (Felis catus) and raccoon dog (Nyctereutes procyonoides) painting probes were hybridized to the ringtail (Bassaricus astutus), dwarf mongoose (Helogale parvula) , and Malagasy civet (Fossa fossa) to identify homologous chromosome elements. The patterns of chromosome segment homology among Carnivore species allowed us to reconstruct and propose the disposition of a high-resolution banded ancestral carnivore karyotype (ACK). Three bi-armed chromosomes consistently found among Caniformia species are represented as 6 homologous acrocentric chromosomes among Feliformia species of Carnivora. However, reexamination of the most basal of Feliformia species, the African palm civet Nandinia, revealed the presence of the 3 heretofore Caniformia bi-armed chromosomes. Because these 3 bi-armed chromosomes are found in both Caniformia and Feliformia lineages, they are presumed ancestral for all Carnivora, suggesting that the ACK chromosome number would be 38, rather than the previously supposed 42. Banded chromosomes of the ACK are used to evaluate the consistency between recently determined molecular phylogenetic relationships and postulated cytogenetic dynamics in the same Carnivore species.

International audience; Since the 1990s, Brucella strains not matching the characteristics of any of the six conventional species have been isolated worldwide from marine mammals. In this study, 31 Brucella strains isolated from various marine mammals were examined for their oxidative metabolic pattern on 12 amino-acid and carbohydrate substrates. Three main oxidative profiles different from those of the Brucella terrestrial mammal strains were identified for the marine mammal strains: one gathering strains isolated from pinnipeds and two gathering strains from cetaceans. Thus, both oxidative metabolism results and previous molecular studies are in agreement with the proposal of two new Brucella species, Brucella pinnipediae and Brucella cetaceae, to classify the Brucella strains isolated from marine mammals, and are also in accordance with a classification of species of the Brucella genus based on host preference.

We developed and tested a protocol for determining the sex of individual pinnipeds using the sex-chromosome-specific genes ZFX and ZFY. We screened a total of 368 seals (168 crabeater, Lobodon carcinophaga; 159 Weddell, Leptonychotes weddellii; and 41 Ross, Ommatophoca rossii) of known or unknown sex and compared the molecular sex to the sex assigned at the time of biopsy sample collection in the Ross and Amundsen seas, Antarctica. We also screened 6 captive northern elephant seals (Mirounga angustirostris) and 2 captive California sea lions (Zalophus californianus) of known sex. The assigned sex and genetic sex agreed for virtually all seals. Indeed, discrepancies ranged from 0.0% to 6.7% among species. It is not clear, however, if the few mis-assignments of sex occurred in situ or in the laboratory. The assigned morphological and molecular sex might both be correct with the discrepancies owing perhaps to developmental effects of environmental pollution. A subset of individuals sequenced at both loci revealed no intraspecific sequence variation. There was, however, sequence variation among species at both loci, which allowed them to be uniquely identified with as few as 2 and as many as 31 nucleotides.

Variation was investigated at exon 2 (including part of the putative peptide-binding region) of the class II major histocompatibility complex (MHC) DQB locus for two congeneric phocid seal species and two congeneric otariid seal species. Polymorphism in one phocid species, the southern elephant seal (Mirounga leonina), was comparable to that seen in human populations, while the other phocid, the northern elephant seal (Mirounga angustirostris), has been through a severe population bottleneck and exhibited much less variation at this locus. A phylogenetic comparison of the four species was consistent with the trans-specific pattern of evolution described for other taxa at this locus, and relative nonsynonymous and synonymous substitution rates suggest the maintenance of polymorphisms by natural selection. A comparison of sequence patterns also suggested that some variation could have been generated through recombinational events, primarily within genera. These results suggest a pattern of evolution of the immune response in pinnipeds similar to that in terrestrial mammal species.

Phylogenetic analyses of closely related species should use information from multiple, independent genes with relatively high rates of sequence evolution. To investigate species for which there are few prior sequence data for single-copy nuclear (scnDNA) genes, primers for gene amplification can be designed to highly conserved regions of exons in order to amplify both coding (exons) and noncoding (introns) sequences. We have explored this approach in a phylogenetic analysis of six species of pinnipeds that, together with terrestrial carnivore outgroups, encompass divergence times < or = 40-50 Mya. We sequenced one intron from each of the aldolase A (ALD-A), aldolase C (ALD-C), and histone H2AF genes; one exon from the major-histocompatibility-complex DQA gene; a H2AF processed pseudogene (psi H2AF); and, for comparison with the nuclear genes, the 5' portion of the mitochondrial DNA (mtDNA) control region. The pinniped psi H2AF genes were found to be of limited use because they were paralogous with the gene in the outgroup. The rate of silent substitution in scnDNA (primarily introns) was 5-10-fold lower than that for mtDNA control region I, and scnDNA sequence divergence increased linearly with time < or = 40-50 Mya. Alleles at three polymorphic scnDNA loci (ALD-A, H2AF, and DQA) in the southern elephant seal were paraphyletic with respect to the allele from the closely related northern elephant seal, while the more numerous mtDNA alleles were monophyletic. This we attribute to the consequences of a higher mutation rate rather than to a lower effective population size of mtDNA compared with scnDNA. Within the short (i.e., < 500-bp) sequences of individual scnDNA sequences, phylogenetically informative variation was insufficient to obtain robust phylogenies. However, the combined scnDNA sequences produced a well-supported phylogeny congruent with that derived from mtDNA. This analysis illustrates the high resolution of mtDNA sequences compared with a similar length of scnDNA sequence, but it also demonstrates the utility of combining information from multiple short scnDNA sequences obtained using broadly applicable primers.

Ultrafiltered fur seal muscle hydrolysate was divided into eleven fractions by gel filtration on Sephadex G-15. One of the fractions (Fraction G9) accelerated the ATPase activity of carp myosin B to a rate about two-fold faster than that of the control. Fraction G9 showed a single ninhydrin spot in its silica gel thin layer chromatograph, and gave a positive test for tryptophan by the p-dimethylaminobenzaldehyde method, while tests for tyrosine, and for arginine were negative. The ion exchange amino acid analysis of its acid hydrolysate showed a predominant content of lysine, nearly equivalent to the amount of tryptophan determined from its UV absorbancy and the p-dimethylaminobenzaldehyde method. The N-terminal amino acid analysis gave di-DNP-Lys as the sole DNP-amino acid. The structure of the ATPase accelerating peptide fraction, Fraction G9, was deduced to be Lys-Trp.

Pregnant and non-pregnant Weddell seals and foetuses were found to have very high plasma concentrations of corticosteroids (1–7 μmol/l) that were unaffected by stress. Cortisol comprised most of the corticosteroid in the adult but only 50 % of that in the foetus. The affinity constant (4.30–5.53 × 107 l/mol) and specificity of CBG and the MCR (4.5 l/d/kg lean body mass) in adult seals were similar to those of Man. The binding capacity of CBG (1.48–1.86 μmol/l) which is approximately three times that of Man contributed to the high plasma corticosteroid concentrations but the main factor was the cortisol turnover rate of 3670 μmol/d (1.3 g/d) which is the highest value reported in any species.

Grey seal skeletal muscle containing high levels of myoglobin was used to prepare poly(A)+ RNA. In vitro translation of this RNA produced a range of polypeptides including myoglobin. cDNA was prepared by reverse transcription of muscle poly(A)+ RNA and cloned into the plasmid pAT 153. 4% of cDNA recombinants were shown to contain myoglobin cDNA inserts. DNA sequence analysis of one clone (pSM 178) which contained a relatively large myoglobin cDNA insert showed an incomplete cDNA comprising the terminal 293 nucleotides of 3' non-translated mRNA sequences. Hybridization experiments using this myoglobin cDNA indicated that seal myoglobin is coded by a single gene which is transcribed to give a 1400 nucleotide mRNA considerably longer than related haemoglobin mRNAs.

SUMMARY The stratum corneum of the guinea-pig back and of human upper arm epidermis, in formalin fixed tissue, is divisible under the light microscope into conjunctum and disjunctum sub-layers. The former is without discernible intracellular or intercellular spaces. It is stained uniformly with eosin and is rich in both bound phospholipids and bound sulphydryl groups. The disjunctum sub-layer shows dorso-ventral intercellular spaces and large intra-cellular spaces due to removal of unfixed soluble constituents of the keratinocytes by water, ethanol and xylene during histological processing. Osmium tetroxide precipitates many soluble chemical constituents so that the horny cells stain uniformly black. Large intracellular spaces in the disjunctum cells were shown by osmium staining in the guinea-pig horny layer, which has been previously leached experimentally in petroleum ether, ethanol and water. The stratum corneum of the common seal resembles the abnormal human parakeratotic layer in not showing intracellular spaces in eosin-stained sections. It is suggested that the thick phospholipid-rich horny layer in the seal may improve the waterproofing ability of the epidermis.