Large testes and brain sizes in odontocetes (order Cetacea, suborder Odontoceti): the influence of mating system on encephalization
Canadian Journal of Zoology, e-First Articles. Little is known about their mating systems, but odontocetes may utilize the same types of mating systems as terrestrial mammals. Species with relatively large testes are likely to be polygynandrous, while species with smaller testes and greater sexual size dimorphism (SSD) are predicted to be polygynous. The “Machiavellian intelligence or sexual conflict” hypothesis predicts that polygynadrous species also evolved larger brains both to coerce conspecifics to mate and to resist mating attempts by undesirable mates. The “costly tissue” hypothesis pr...
Source: Canadian Journal of Zoology - June 6, 2014 Category: Zoology Tags: article Source Type: research

Energy metabolism and cytochrome oxidase activity: linking metabolism to gene expression
Canadian Journal of Zoology, Volume 92, Issue 7, Page 557-568, July 2014. Modification of mitochondrial content demands the synthesis of hundreds of proteins encoded by nuclear and mitochondrial genomes. The responsibility for coordination of this process falls to nuclear-encoded master regulators of transcription. DNA-binding proteins and coactivators integrate information from energy-sensing pathways and hormones to alter mitochondrial gene expression. In mammals, the signaling cascade for mitochondrial biogenesis can be described as follows: hormonal signals and energetic information are sensed by protein-modifyin...
Source: Canadian Journal of Zoology - June 4, 2014 Category: Zoology Tags: article Source Type: research

Partial special issue on taxonomic diversity in the biology of migration / Numéro spécial partiel sur la diversité taxinomique dans la biologie de la migration
Canadian Journal of Zoology, Volume 92, Issue 6, Page iii-iii, June 2014. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - June 2, 2014 Category: Zoology Tags: article Source Type: research

Prevalence, transmission, and genetic diversity of blood parasites infecting tundra-nesting geese in Alaska
Canadian Journal of Zoology, e-First Articles. A total of 842 blood samples collected from five species of tundra-nesting geese in Alaska was screened for haemosporidian parasites using molecular techniques. Parasites of the genera Leucocytozoon Danilewsky, 1890, Haemoproteus Kruse, 1890, and Plasmodium Marchiafava and Celli, 1885 were detected in 169 (20%), 3 ( (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - May 26, 2014 Category: Zoology Tags: article Source Type: research

Consequences of experimental clutch enlargement in a High Arctic single-egg layer, the Little Auk (Alle alle)
Canadian Journal of Zoology, e-First Articles. Initial reproductive investments in birds are energy-demanding. Amount of energy allocated to egg production and incubation may have an important role in determining parental fitness and evolution of clutch size. Here, we investigated whether the Little Auk (Alle alle (L., 1758)), a small alcid with one-egg clutch but two brood patches (probably remnant of the original two-egg clutch), is capable of incubating two eggs and rearing two chicks. We performed an experiment with removing the egg from 20 nests and transferring it to 20 experimental nests (EN). In 25% of EN, bo...
Source: Canadian Journal of Zoology - May 26, 2014 Category: Zoology Tags: article Source Type: research

Inflammation in response to phytohemagglutinin injection in the Talas tuco-tuco (Ctenomys talarum): implications for the estimation of immunocompetence in natural populations of wild rodents
Canadian Journal of Zoology, e-First Articles. The immunological variation in wild populations and its relation to life-history traits has recently become a central topic in the field of evolutionary biology, considering the critical contribution of immunity to an individual’s fitness. A common technique used by ecologists to estimate immunocompetence in wild populations is the phytohemagglutinin (PHA) – skin test. In this test, the degree of local swelling triggered by PHA is usually considered an estimate of T-lymphocyte activity, although there is an ongoing debate regarding this interpretation. Here, ...
Source: Canadian Journal of Zoology - May 20, 2014 Category: Zoology Tags: article Source Type: research

Interspecific effects of forest fragmentation on bats
Canadian Journal of Zoology, e-First Articles. Wind-farm development may be an important contributor to forest fragmentation, but how such developments impact bats is poorly understood. We hypothesized that bat activity at a wind farm would be explained, at least in part, by attraction and avoidance behaviours caused by deforestation. We tested predictions of this hypothesis via a landscape-level acoustic, capture, and radiotelemetry survey of little brown bats (Myotis lucifugus (Le Conte, 1831)) and northern long-eared myotis (Myotis septentrionalis (Trouessart, 1897)). Acoustic and capture data indicated no signifi...
Source: Canadian Journal of Zoology - May 15, 2014 Category: Zoology Tags: article Source Type: research

Reproductive biology of the Amazon Lava Lizard (Tropidurus torquatus) from the Wet Chaco of Corrientes (Argentina): congeneric comparisons of ecotypic and interspecific variations
We describe the male and female reproductive cycles, minimum body size for adults, reproductive output, mean relative clutch mass, fat body cycles, and sexual dimorphism. Our results were compared with data on the reproductive biology of Brazilian populations of T. torquatus and congeneric species. In Corrientes, males of T. torquatus exhibited a continuous reproductive cycle, but with annual variation of testicular parameters associated with spermatogenic activity. In contrast, females were reproductive only from winter to summer (July–February), laying at least two clutches each of six eggs, on average, per reprodu...
Source: Canadian Journal of Zoology - May 14, 2014 Category: Zoology Tags: article Source Type: research

Reproductive biology of the Amazon Lava Lizard (Tropidurus torquatus) from the Wet Chaco of Corrientes (Argentina): congeneric comparisons of ecotypic and interspecific variations
We describe the male and female reproductive cycles, minimum body size for adults, reproductive output, mean relative clutch mass, fat body cycles, and sexual dimorphism. Our results were compared with data on the reproductive biology of Brazilian populations of T. torquatus and congeneric species. In Corrientes, males of T. torquatus exhibited a continuous reproductive cycle, but with annual variation of testicular parameters associated with spermatogenic activity. In contrast, females were reproductive only from winter to summer (July–February), laying at least two clutches each of six eggs, on average, per reprodu...
Source: Canadian Journal of Zoology - May 14, 2014 Category: Zoology Tags: article Source Type: research

Taxonomic diversity in the biology of migration
The objective of this partial series of the Canadian Journal of Zoology was to highlight taxonomic diversity in migration by featuring reviews of the current state of migration research in a range of taxa (freshwater fishes, mammals, and amphibians). This series provides an opportunity to compare and contrast the biology of migration among multiple taxa. The reviews include discussions of migration at both the individual and population levels, focusing on a range of topics including the evolution of migration, behavioural and physiological adaptations for migration, consequences of migration, and methods for modelling anim...
Source: Canadian Journal of Zoology - May 11, 2014 Category: Zoology Tags: article Source Type: research

Daytime declines in rumen–reticulum fill of male white-tailed deer (Odocoileus virginianus) from south Texas
We examined whether there were daytime declines in rumen–reticulum fill in response to high ambient temperatures in free-ranging white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) on a diurnal scale. We hypothesized that to reduce heat-producing digestive processes in the heat of the day, rumen–reticulum fill and digestion in the rumen–reticulum would decline throughout the day. We collected the rumina and reticula of adult males and females across 30 h in two autumns in south Texas, USA. We also measured dry digesta mass, organ mass, and crude protein and acid detergent fiber concentrations of...
Source: Canadian Journal of Zoology - May 9, 2014 Category: Zoology Tags: article Source Type: research

Mitochondria: a multimodal hub of hypoxia tolerance
Canadian Journal of Zoology, e-First Articles. Decreased oxygen availability impairs cellular energy production and, without a coordinated and matched decrease in energy consumption, cellular and whole organism death rapidly ensues. Of particular interest are mechanisms that protect brain from low oxygen injury, as this organ is not only the most sensitive to hypoxia, but must also remain active and functional during low oxygen stress. As a result of natural selective pressures, some species have evolved molecular and physiological mechanisms to tolerate prolonged hypoxia with no apparent detriment. Among these mecha...
Source: Canadian Journal of Zoology - May 6, 2014 Category: Zoology Tags: article Source Type: research

Effect of habitat use and diet on the gastrointestinal parasite community of an avian omnivore from an urbanized environment
We examined the effect of habitat use and diet on gastrointestinal parasite assemblages of Ring-billed Gulls (Larus delawarensis Ord, 1815) breeding in an urbanized region (Montréal, Quebec, Canada) using three approaches depicting different temporal scales. Birds were fitted with global positioning system data loggers to determine habitat-use patterns during a 2–3 day period. Stomach contents were examined, providing dietary information during the preceding hours. Liver carbon (δ13C) and nitrogen (δ15N) stable isotope signatures served as proxy of nutrient assimilation during the preceding 10 days...
Source: Canadian Journal of Zoology - May 5, 2014 Category: Zoology Tags: article Source Type: research

Plasticity in secondary sexual characteristics in male freshwater blennies (Salaria fluviatilis)
Canadian Journal of Zoology, e-First Articles. Alternative reproductive tactics (ARTs) driven by environmental factors are common among fish. However, the flexibility of fish to adopt distinct tactics in response to the characteristics of their environment has received little attention. The aim of the present work was to study phenotypic plasticity in the adoption of dominant behaviour (“bourgeois tactic”) by male freshwater blennies (Salaria fluviatilis (Asso, 1801)). For this purpose, two simultaneous experiments in aquaria were performed to examine the effect of social cues and nest abundance on the ac...
Source: Canadian Journal of Zoology - May 5, 2014 Category: Zoology Tags: article Source Type: research

Diel patterns of baseline glucocorticoids and stress responsiveness in a teleost fish (bluegill, Lepomis macrochirus)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 417-421, e-First articles. Little is known about whether glucocorticoids (GC) and GC responsiveness vary on a diel basis in the wild, especially for fish. Using bluegill (Lepomis macrochirus Rafinesque, 1819) as a model freshwater teleost fish, we tested whether baseline concentration and stress responsiveness of GCs (i.e., plasma glucose and cortisol) varied over a 24 h period. Blood samples from lake-dwelling wild bluegill were obtained across six periods representing a complete circadian cycle to determine GC levels in newly captured fish (i.e., within 3 min of ...
Source: Canadian Journal of Zoology - April 27, 2014 Category: Zoology Tags: article Source Type: research

Ghost of land-use past in the context of current land cover: evidence from salamander communities in streams of Blue Ridge and Piedmont ecoregions
Canadian Journal of Zoology, e-First Articles. The Blue Ridge and Piedmont of the southeastern United States are rich in biodiversity and have undergone centuries of extensive deforestation and subsequent urbanization resulting in geomorphic landscape changes. To investigate the impacts of past and present land uses on stream salamander communities across both ecoregions, we surveyed streams associated with different land uses at the riparian zone and watershed. Using the USGS land-cover data set (2006) and aerial photographs (1940), we assessed the current and historical percent land cover (urban, agriculture, and f...
Source: Canadian Journal of Zoology - April 24, 2014 Category: Zoology Tags: article Source Type: research

Assessing the relative culpability of Simulium (Diptera: Simuliidae) species in recent black fly outbreaks along the middle Orange River, South Africa
Canadian Journal of Zoology, e-First Articles. Black fly along the Orange River are major pests of livestock and labour-intensive agriculture, causing annual estimated industry losses in excess of US$30 million. The problem is attributed to winter high flows, with the main pest species being Simulium chutteri Lewis, 1965, although Simulium damnosum Theobald, 1903 and Simulium impukane de Meillon, 1936 may also be periodically problematic. During 2011, black fly outbreaks along the middle Orange River were perceived by farmers to have worsened and attributed to S. impukane. Here, we investigate the likelihood of this ...
Source: Canadian Journal of Zoology - April 23, 2014 Category: Zoology Tags: article Source Type: research

Coccidial dispersion across trans- and cis-Andean antbirds (Passeriformes: Thamnophilidae): Isospora sagittulae (Apicomplexa: Eimeriidae) from nonsympatric hosts
Canadian Journal of Zoology, Volume 0, Issue 0, Page 383-388, e-First articles. Isospora sagittulae McQuistion and Capparella, 1992 (Protozoa: Apicomplexa: Eimeriidae) is reported from White-throated Antbirds (Gymnopithys salvini (Berlepsch, 1901)) and from Common Scale-backed Antbirds (Willisornis poecilinotus (Cabanis, 1847)), which are thamnophilid birds from the Brazilian Amazon. Its oocysts are ovoidal to ellipsoidal, 28.4 μm × 22.4 μm, with smooth, bilayered wall, 1.1 μm. Micropyle and oocyst residuum are absent, but one to three polar granules are present. Sporocysts are subspherical to ovoidal,...
Source: Canadian Journal of Zoology - April 19, 2014 Category: Zoology Tags: article Source Type: research

Sex-specific differences in the physiological basis of water conservation in the fruit fly Drosophila hydei from the western Himalayas
Canadian Journal of Zoology, Volume 92, Issue 6, Page 545-555, June 2014. In the cosmopolitan fruit fly Drosophila hydei Sturtevant, 1921 (Diptera: Drosophilidae), the relative abundance of males is significantly higher than females, but the physiological basis of such sex-specific differences are largely unknown. For wild populations of D. hydei, we found seasonal changes (summer versus autumn) in desiccation-related traits, but the desiccation tolerance of males was higher than that of females in all seasons. For desiccation-related traits, we tested whether thermal developmental acclimation at three temperatures (...
Source: Canadian Journal of Zoology - April 18, 2014 Category: Zoology Tags: article Source Type: research

Lack of genetic divergence in capelin (Mallotus villosus) spawning at beach versus subtidal habitats in coastal embayments of Newfoundland
Canadian Journal of Zoology, Volume 0, Issue 0, Page 377-382, e-First articles. Capelin (Mallotus villosus (Müller, 1776)), a focal forage fish in the north Atlantic, spawn on both beach and demersal (deep-water) sites throughout their circumpolar distribution. Although these habitats rarely occur in close proximity, demersal spawning sites within 4 km of beach spawning sites (subtidal) have recently been discovered in two coastal embayments in Newfoundland, Canada. The physical environment differs considerably between beach and subtidal spawning sites, creating the potential for local adaptation and genetic div...
Source: Canadian Journal of Zoology - April 16, 2014 Category: Zoology Tags: article Source Type: research

Movement ecology of amphibians: from individual migratory behaviour to spatially structured populations in heterogeneous landscapes,
Canadian Journal of Zoology, e-First Articles. Both genetic cohesion among local populations of animals and range expansion depend on the frequency of dispersers moving at an interpatch scale. Animal movement has an individual component that reflects behaviour and an ecological component that reflects the spatial organization of populations. The total movement capacity of an individual describes maximum movement distance theoretically achievable during a lifetime, whereas its variation among the members of a local population determines the magnitude of interpatch movements and thus of gene flow between neighbouring p...
Source: Canadian Journal of Zoology - April 15, 2014 Category: Zoology Tags: article Source Type: research

Milk composition, milk consumption, and growth rate of a captive spotted seal (Phoca largha) pup from Liaodong Bay, China
In this study, we investigated variation in the pattern of energy transfer and allocation during lactation in the spotted seal (Phoca largha Pallas, 1811). Temporal changes in milk composition, milk consumption, and pup mass gain were analyzed from birth to weaning in a spotted seal pup that was hand-reared on a donor-female’s milk. In addition, growth rates were measured in six pups raised in captivity but nursed naturally. We found that milk fat content increased and water content decreased during lactation. We calculated that spotted seal pup ingest a mean (±SD) daily energy of 39.5 ± 8.6 MJ/day, whi...
Source: Canadian Journal of Zoology - April 12, 2014 Category: Zoology Tags: article Source Type: research

Guidelines for MSAT and SNP panels that lead to high-quality data for genetic mark–recapture studies
We present a case study on Pacific walrus, Odobenus rosmarus divergens (Illiger, 1815), using simulation results to inform genetic marker choices. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - April 1, 2014 Category: Zoology Tags: article Source Type: research

Testing predictions of optimal diving theory using animal-borne video from harbour seals (Phoca vitulina concolor)
We examined the temporal pattern of prey encounters within a dive from concurrently collected dive data and animal-borne video from a free-ranging pinniped to test predictions of optimal diving theory. Crittercams were deployed on 32 adult male harbour seals (Phoca vitulina concolor De Kay, 1842) at Sable Island, Nova Scotia, Canada, for 3 days each. Deployments resulted in approximately 3 h of video per seal and a total of 2275 capture attempts for 1474 prey encounter events recorded. We found support for seven of the nine selected predictions of optimal diving theory. As predicted, prey encounters increased with bottom d...
Source: Canadian Journal of Zoology - March 30, 2014 Category: Zoology Tags: article Source Type: research

Diel patterns of baseline glucocorticoids and stress responsiveness in a teleost fish (bluegill, Lepomis macrochirus)
Canadian Journal of Zoology, Volume 92, Issue 5, Page 417-421, May 2014. Little is known about whether glucocorticoids (GC) and GC responsiveness vary on a diel basis in the wild, especially for fish. Using bluegill (Lepomis macrochirus Rafinesque, 1819) as a model freshwater teleost fish, we tested whether baseline concentration and stress responsiveness of GCs (i.e., plasma glucose and cortisol) varied over a 24 h period. Blood samples from lake-dwelling wild bluegill were obtained across six periods representing a complete circadian cycle to determine GC levels in newly captured fish (i.e., within 3 min of capture...
Source: Canadian Journal of Zoology - March 28, 2014 Category: Zoology Tags: article Source Type: research

β-Keratin composition of the specialized spectacle scale of snakes and geckos
Canadian Journal of Zoology, Volume 0, Issue 0, Page 299-307, e-First articles. The eyes of snakes and most geckos are shielded beneath a layer of transparent skin (the “spectacle”), of which the outermost layer consists of an optically transparent scale. The characteristics of the spectacle scale that contribute to its transparency are not well understood but may conceivably be related to its biochemical composition. The composition of the spectacle scales of numerous snakes and two geckos was analyzed with particular focus on β-keratins, the hard proteins that form the outermost layer of squamate s...
Source: Canadian Journal of Zoology - March 27, 2014 Category: Zoology Tags: article Source Type: research

Coccidial dispersion across trans- and cis-Andean antbirds (Passeriformes: Thamnophilidae): Isospora sagittulae (Apicomplexa: Eimeriidae) from nonsympatric hosts
Canadian Journal of Zoology, Volume 92, Issue 5, Page 383-388, May 2014. Isospora sagittulae McQuistion and Capparella, 1992 (Protozoa: Apicomplexa: Eimeriidae) is reported from White-throated Antbirds (Gymnopithys salvini (Berlepsch, 1901)) and from Common Scale-backed Antbirds (Willisornis poecilinotus (Cabanis, 1847)), which are thamnophilid birds from the Brazilian Amazon. Its oocysts are ovoidal to ellipsoidal, 28.4 μm × 22.4 μm, with smooth, bilayered wall, 1.1 μm. Micropyle and oocyst residuum are absent, but one to three polar granules are present. Sporocysts are subspherical to ovoidal, 15.0 &...
Source: Canadian Journal of Zoology - March 27, 2014 Category: Zoology Tags: article Source Type: research

Temporal change in body mass of two sympatric hamster species and implications for population dynamics
Canadian Journal of Zoology, Volume 92, Issue 5, Page 389-395, May 2014. Shifting of body size distributions of animals has been a long-time focus in population ecology, but the underlying mechanism of density-dependent changes in body size and its implications for population dynamics of animals are largely unknown. In this 26-year study, we investigated intrinsic and extrinsic factors affecting body mass of the Chinese striped hamster (Cricetulus barabensis Pallas, 1773) and the greater long-tailed hamster (Tscherskia triton de Winton, 1899) in the Northern China Plain. We proposed three hypotheses to explain body m...
Source: Canadian Journal of Zoology - March 27, 2014 Category: Zoology Tags: article Source Type: research

Temporal change in body mass of two sympatric hamster species and implications for population dynamics
Canadian Journal of Zoology, Volume 0, Issue 0, Page 389-395, e-First articles. Shifting of body size distributions of animals has been a long-time focus in population ecology, but the underlying mechanism of density-dependent changes in body size and its implications for population dynamics of animals are largely unknown. In this 26-year study, we investigated intrinsic and extrinsic factors affecting body mass of the Chinese striped hamster (Cricetulus barabensis Pallas, 1773) and the greater long-tailed hamster (Tscherskia triton de Winton, 1899) in the Northern China Plain. We proposed three hypotheses to explain...
Source: Canadian Journal of Zoology - March 27, 2014 Category: Zoology Tags: article Source Type: research

Assessing prehistoric genetic structure and diversity of North American elk (Cervus elaphus) populations in Alberta, Canada
This study targeted 551 bp of mitochondrial D-loop DNA from 50 elk remains recovered from 16 archaeological sites (2260 BCE (before common era) to 1920 CE (common era)) to examine the former genetic diversity and population structure of Alberta’s historic elk populations. Comparisons of ancient and modern haplotype and nucleotide diversity suggest that historic population declines reduced the mitochondrial diversity of Manitoban elk, while translocation of animals from Yellowstone National Park in the early 20th century served to maintain the diversity of Rocky Mountain populations. Gene flow between the two subspeci...
Source: Canadian Journal of Zoology - March 26, 2014 Category: Zoology Tags: article Source Type: research

Egg yolk fatty acids as a proxy to quantify diets of female Spectacled Eiders (Somateria fischeri)
Canadian Journal of Zoology, Volume 92, Issue 5, Page 453-461, May 2014. Determining the diets of threatened Spectacled Eiders (Somateria fischeri (Brandt, 1847)) in relation to life-history stages will provide information to help identify and characterize their critical habitats. Quantitative fatty acid signature analysis (QFASA) is a novel tool that estimates the proportion of diet items in consumers from their fat depots. We conducted feeding experiments to validate the use of QFASA to estimate the mixed diets of captive female Spectacled Eiders using egg yolk fatty acids (FA) collected in 2008 and 2009. Calibrati...
Source: Canadian Journal of Zoology - March 26, 2014 Category: Zoology Tags: article Source Type: research

Egg yolk fatty acids as a proxy to quantify diets of female Spectacled Eiders (Somateria fischeri)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 1-9, e-First articles. Determining the diets of threatened Spectacled Eiders (Somateria fischeri (Brandt, 1847)) in relation to life-history stages will provide information to help identify and characterize their critical habitats. Quantitative fatty acid signature analysis (QFASA) is a novel tool that estimates the proportion of diet items in consumers from their fat depots. We conducted feeding experiments to validate the use of QFASA to estimate the mixed diets of captive female Spectacled Eiders using egg yolk fatty acids (FA) collected in 2008 and 2009. Calibr...
Source: Canadian Journal of Zoology - March 26, 2014 Category: Zoology Tags: article Source Type: research

Patterns of host and flea communities along an elevational gradient in Colorado
Canadian Journal of Zoology, Volume 92, Issue 5, Page 433-442, May 2014. Patterns in community composition across a landscape are the result of mechanistic responses and species interactions. Interactions between hosts and parasites have additional complexity because of the contingency of host presence and interactions among parasites. To assess the role of environmental changes within host and parasite communities, we surveyed small mammals and their fleas over a dynamic elevational gradient in the Front Range in Colorado, USA. Communities were characterized using several richness and diversity metrics and these wer...
Source: Canadian Journal of Zoology - March 25, 2014 Category: Zoology Tags: article Source Type: research

Seasonal variation in the feeding ecology of pumas (Puma concolor) in northern California
Canadian Journal of Zoology, Volume 92, Issue 5, Page 397-403, May 2014. Direct effects of predators depend upon factors that can vary across seasons, including variations in the abundance and vulnerability of migrating prey. Past studies show conflicting results of whether puma (Puma concolor (L., 1771)) feeding ecology varies among seasons. We employed GPS collars to study puma feeding ecology in a single-prey system with migratory black-tailed deer (Odocoileus hemionus columbianus (Richardson, 1829)). We hypothesized that puma feeding ecology would vary based on changes in prey abundance and spatial distribution, ...
Source: Canadian Journal of Zoology - March 25, 2014 Category: Zoology Tags: article Source Type: research

Patterns of host and flea communities along an elevational gradient in Colorado
Canadian Journal of Zoology, Volume 0, Issue 0, Page 433-442, e-First articles. Patterns in community composition across a landscape are the result of mechanistic responses and species interactions. Interactions between hosts and parasites have additional complexity because of the contingency of host presence and interactions among parasites. To assess the role of environmental changes within host and parasite communities, we surveyed small mammals and their fleas over a dynamic elevational gradient in the Front Range in Colorado, USA. Communities were characterized using several richness and diversity metrics and th...
Source: Canadian Journal of Zoology - March 25, 2014 Category: Zoology Tags: article Source Type: research

Seasonal variation in the feeding ecology of pumas (Puma concolor) in northern California
Canadian Journal of Zoology, Volume 0, Issue 0, Page 397-403, e-First articles. Direct effects of predators depend upon factors that can vary across seasons, including variations in the abundance and vulnerability of migrating prey. Past studies show conflicting results of whether puma (Puma concolor (L., 1771)) feeding ecology varies among seasons. We employed GPS collars to study puma feeding ecology in a single-prey system with migratory black-tailed deer (Odocoileus hemionus columbianus (Richardson, 1829)). We hypothesized that puma feeding ecology would vary based on changes in prey abundance and spatial distrib...
Source: Canadian Journal of Zoology - March 25, 2014 Category: Zoology Tags: article Source Type: research

Eastern Newt (Notophthalmus viridescens) larvae alter morphological but not chemical defenses in response to predator cues
Canadian Journal of Zoology, Volume 0, Issue 0, Page 279-283, e-First articles. Prey traits are often modified in response to exposure to predators, a phenomenon known as predator-induced phenotypic plasticity. Morphological plasticity in response to predator cues is well documented in amphibians; however, predator-induced chemical defenses have received relatively little attention. The Eastern Newt (Notophthalmus viridescens (Rafinesque, 1820)), which possesses tetrodotoxin—a toxin for chemical defense, is most vulnerable to predation during its larval stage. We assessed whether exposing Eastern Newt larvae to...
Source: Canadian Journal of Zoology - March 20, 2014 Category: Zoology Tags: article Source Type: research

Neuronal classes and their specialization in the corticoid complex of a food-storing bird, the Indian House Crow (Corvus splendens)
Canadian Journal of Zoology, Volume 92, Issue 5, Page 423-432, May 2014. Neuronal classes and their specialization in the corticoid complex of a food-storing bird (the Indian House Crow, Corvus splendens Vieillot, 1817) have been investigated using Golgi and Cresyl-violet methods. The aim of present study is to observe the neuronal characteristics of corticoid complex of the House Crow (food-storing bird) and to compare them with that of a nonfood-storing bird (the Strawberry Finch, Estrilda amandava = Amandava amandava (L., 1758)). Three main neuronal classes, viz. projection neurons, local circuit neurons, and stel...
Source: Canadian Journal of Zoology - March 20, 2014 Category: Zoology Tags: article Source Type: research

Lack of genetic divergence in capelin (Mallotus villosus) spawning at beach versus subtidal habitats in coastal embayments of Newfoundland
Canadian Journal of Zoology, Volume 92, Issue 5, Page 377-382, May 2014. Capelin (Mallotus villosus (Müller, 1776)), a focal forage fish in the north Atlantic, spawn on both beach and demersal (deep-water) sites throughout their circumpolar distribution. Although these habitats rarely occur in close proximity, demersal spawning sites within 4 km of beach spawning sites (subtidal) have recently been discovered in two coastal embayments in Newfoundland, Canada. The physical environment differs considerably between beach and subtidal spawning sites, creating the potential for local adaptation and genetic divergence...
Source: Canadian Journal of Zoology - March 20, 2014 Category: Zoology Tags: article Source Type: research

Milk composition, milk consumption, and growth rate of a captive spotted seal (Phoca largha) pup from Liaodong Bay, China
In this study, we investigated variation in the pattern of energy transfer and allocation during lactation in the spotted seal (Phoca largha Pallas, 1811). Temporal changes in milk composition, milk consumption, and pup mass gain were analyzed from birth to weaning in a spotted seal pup that was hand-reared on a donor-female’s milk. In addition, growth rates were measured in six pups raised in captivity but nursed naturally. We found that milk fat content increased and water content decreased during lactation. We calculated that spotted seal pup ingest a mean (±SD) daily energy of 39.5 ± 8.6 MJ/day, whi...
Source: Canadian Journal of Zoology - March 20, 2014 Category: Zoology Tags: article Source Type: research

A long-term study reveals multiple reproductive behavior strategies among territorial adult male Steller sea lions (Eumetopias jubatus)
Canadian Journal of Zoology, Volume 92, Issue 5, Page 405-415, May 2014. We conducted a long-term study to assess how tenure and territorial behaviors influence reproductive success among male Steller sea lions (Eumetopias jubatus (Schreber, 1776)). Copulations by males (n = 44) that maintained territories on a rookery in the Gulf of Alaska from 2001 to 2009 were observed using a remote video system. Approximately half of postpartum females copulated with a male in a different territory from where they gave birth. Nearly two-thirds of territorial males with known tenure were unsuccessful in copulating during their fi...
Source: Canadian Journal of Zoology - March 20, 2014 Category: Zoology Tags: article Source Type: research

Neuronal classes and their specialization in the corticoid complex of a food-storing bird, the Indian House Crow (Corvus splendens)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 423-432, e-First articles. Neuronal classes and their specialization in the corticoid complex of a food-storing bird (the Indian House Crow, Corvus splendens Vieillot, 1817) have been investigated using Golgi and Cresyl-violet methods. The aim of present study is to observe the neuronal characteristics of corticoid complex of the House Crow (food-storing bird) and to compare them with that of a nonfood-storing bird (the Strawberry Finch, Estrilda amandava = Amandava amandava (L., 1758)). Three main neuronal classes, viz. projection neurons, local circuit neurons, a...
Source: Canadian Journal of Zoology - March 20, 2014 Category: Zoology Tags: article Source Type: research

A long-term study reveals multiple reproductive behavior strategies among territorial adult male Steller sea lions (Eumetopias jubatus)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 405-415, e-First articles. We conducted a long-term study to assess how tenure and territorial behaviors influence reproductive success among male Steller sea lions (Eumetopias jubatus (Schreber, 1776)). Copulations by males (n = 44) that maintained territories on a rookery in the Gulf of Alaska from 2001 to 2009 were observed using a remote video system. Approximately half of postpartum females copulated with a male in a different territory from where they gave birth. Nearly two-thirds of territorial males with known tenure were unsuccessful in copulating during t...
Source: Canadian Journal of Zoology - March 20, 2014 Category: Zoology Tags: article Source Type: research

A generic target for species recovery
Canadian Journal of Zoology, Volume 92, Issue 5, Page 371-376, May 2014. Recovery targets for threatened species are typically developed on a species- or population-specific basis. Such narrow taxonomic specificity stands in contrast with widely applied species-independent metrics of conservation status. Here, we propose a generic protocol that can be used to specify broadly applicable targets intended to recover the ecological and evolutionary functionality of threatened species. The method is based on basic density-dependent population dynamics, draws on first principles related to population growth, and explicitly...
Source: Canadian Journal of Zoology - March 19, 2014 Category: Zoology Tags: article Source Type: research