Behavioural response of larval sea lamprey (Petromyzon marinus) in a laboratory environment to potential damage-released chemical alarm cues
The objective of this study was to determine whether larval sea lamprey showed a behavioural response when exposed to damage-released chemical alarm cues by increasing their swimming time, rate of direction changes, or rate of escape attempts in an artificial stream channel experiment. Larval sea lampreys were exposed to conspecific larval sea lamprey extract, heterospecific swordtail (Xiphophorus hellerii Heckel, 1848) extract, or a distilled water control. The larvae increased their rate of escape attempts after exposure to both swordtail and larval lamprey extracts and their rate of direction changes after exposure to s...
Source: Canadian Journal of Zoology - March 19, 2014 Category: Zoology Tags: article Source Type: research

A generic target for species recovery
Canadian Journal of Zoology, Volume 0, Issue 0, Page 371-376, e-First articles. 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 exp...
Source: Canadian Journal of Zoology - March 19, 2014 Category: Zoology Tags: article Source Type: research

Behavioural response of larval sea lamprey (Petromyzon marinus) in a laboratory environment to potential damage-released chemical alarm cues
The objective of this study was to determine whether larval sea lamprey showed a behavioural response when exposed to damage-released chemical alarm cues by increasing their swimming time, rate of direction changes, or rate of escape attempts in an artificial stream channel experiment. Larval sea lampreys were exposed to conspecific larval sea lamprey extract, heterospecific swordtail (Xiphophorus hellerii Heckel, 1848) extract, or a distilled water control. The larvae increased their rate of escape attempts after exposure to both swordtail and larval lamprey extracts and their rate of direction changes after exposure to s...
Source: Canadian Journal of Zoology - March 19, 2014 Category: Zoology Tags: article Source Type: research

Body mass, age, and reproductive influences on liver mass of white-tailed deer (Odocoileus virginianus)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 273-278, e-First articles. Previous research into the liver has mainly examined liver function and liver response to energy restriction. There have been few investigations into how liver mass is coupled to body mass, body condition, age, and reproductive events like lactation. Therefore, we examined the scaling relationship between body mass and liver mass and the influences of age, sex, body condition (back fat), and lactation on liver mass to gain insight into liver-mass variation in white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)). Deer from two sit...
Source: Canadian Journal of Zoology - March 14, 2014 Category: Zoology Tags: article Source Type: research

Factors influencing mortality of Lesser Scaup (Aythya affinis) ducklings during a West Nile virus outbreak
Canadian Journal of Zoology, Volume 92, Issue 4, Page 365-370, April 2014. Temporal variation in exposure and (or) susceptibility to disease-causing agents may result in changing disease risks for offspring of seasonally reproducing organisms. Although increases in disease risk and disease-related mortality have been observed during the course of the breeding cycle in some systems, the extent to which this is a generalized ecological pattern remains uncertain. We obtained data during an outbreak of West Nile virus (WNV) associated mortality in 50 semicaptive Lesser Scaup (Aythya affinis (Eyton, 1838)) ducklings and u...
Source: Canadian Journal of Zoology - March 7, 2014 Category: Zoology Tags: article Source Type: research

Influence of climate and human land use on the distribution of white-tailed deer (Odocoileus virginianus) in the western boreal forest
Canadian Journal of Zoology, Volume 0, Issue 0, Page 353-363, e-First articles. Understanding the factors that drive species distributions is emerging as an important tool in wildlife management, under unprecedented changes in species ranges. While invasion ecologists have long studied the impact of human land use on species’ distributions, and models developed more recently to explain changes in species range boundaries have been largely parameterized by climate variables, few authors have considered climate and land-use factors together to explain species distribution. The purpose of this study was to test tw...
Source: Canadian Journal of Zoology - March 4, 2014 Category: Zoology Tags: article Source Type: research

Mitochondria: a multimodal hub of hypoxia tolerance
Canadian Journal of Zoology, Volume 0, Issue 0, Page 1-21, 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 apparen...
Source: Canadian Journal of Zoology - February 28, 2014 Category: Zoology Tags: article Source Type: research

Nutritional implications of increased shrub cover for caribou (Rangifer tarandus) in the Arctic
Canadian Journal of Zoology, Volume 0, Issue 0, Page 339-351, e-First articles. Shrubs are increasing in the annual range of arctic caribou (Rangifer tarandus (L., 1758)), but it is unknown how much summer browse caribou could consume. We measured instantaneous intakes of resin birch (Betula glandulosa Michx.) and feltleaf willow (Salix alaxensis (Andersson) Coville) by caribou during summer. Daily intake of a formulated diet without toxins was measured during the same period to monitor appetite. Caribou appetite increased from 64.1 to 86.7 g DM·kg–0.75·day−1 as animals gained body mass from...
Source: Canadian Journal of Zoology - February 27, 2014 Category: Zoology Tags: article Source Type: research

Seasonal variation in foraging behaviour of plains zebra (Equus quagga) may alter contact with the anthrax bacterium (Bacillus anthracis)
This study investigated seasonal changes in bite density and diet of plains zebras (Equus quagga Boddaert, 1785) in relation to anthrax seasonality in Etosha National Park, Namibia, where most zebra anthrax cases are observed in wet seasons. The diet of zebras shifted from more short grasses during the wet season to more tall grasses in the dry season, suggesting a greater potential for soil ingestion in wet seasons. Zebras also foraged most intensively in the wet season with the number of bites/step declining through the dry season. This higher bite density in wet seasons may lead individuals to ingest greater concentrati...
Source: Canadian Journal of Zoology - February 27, 2014 Category: Zoology Tags: article Source Type: research

Greater Sage-Grouse (Centrocercus urophasianus) hen survival: effects of raptors, anthropogenic and landscape features, and hen behavior
Canadian Journal of Zoology, Volume 0, Issue 0, Page 319-330, e-First articles. Survival of breeding-age hens has been identified as the demographic rate with the greatest potential to influence population growth of Greater Sage-Grouse (Centrocercus urophasianus (Bonaparte, 1827); hereafter “Sage-Grouse”). During 2008–2011, we collected summer survival data from 427 Sage-Grouse hens in southern Wyoming, USA. We assessed the effects of raptor densities, anthropogenic features, landscape features, and Sage-Grouse hen behavior on Sage-Grouse hen survival. Survival of Sage-Grouse hens was positively ass...
Source: Canadian Journal of Zoology - February 26, 2014 Category: Zoology Tags: article Source Type: research

A comparison of locomotor performance of the semiarboreal Pacific marten (Martes caurina) and semiaquatic mustelids
Canadian Journal of Zoology, Volume 0, Issue 0, Page 259-266, e-First articles. The relatively long body and short limbs of mustelids allow them to exploit resources from a diversity of habitat types. This body plan also has important implications for energetics because of increased heat loss from a high surface to volume ratio and muscular support of an elongated spine. Past research suggests that dorsal flexion of the spine enables semiaquatic mustelids to be relatively economical runners at faster speeds. We evaluated locomotor performance in a semiarboreal mustelid, the Pacific marten (Martes caurina (Merriam, 18...
Source: Canadian Journal of Zoology - February 13, 2014 Category: Zoology Tags: article Source Type: research

Facultative nocturnal behaviour in snakes: experimental examination of why and how with Ratsnakes (Elaphe obsoleta) and Racers (Coluber constrictor)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 229-237, e-First articles. Diel activity patterns are often fixed within species such that most animals can be classified as diurnal, crepuscular, or nocturnal, and have sensory abilities that reflect when they are active. However, many snake species appear capable of switching between diurnal and nocturnal activity. Here, we evaluate the hypothesis that some species are constrained in their activity by the sensory cues used for foraging. We experimentally assessed differences between two sympatric snake species in their ability to alter diel activity patterns, to ...
Source: Canadian Journal of Zoology - February 12, 2014 Category: Zoology Tags: article Source Type: research

Morphological and genetic analyses identify a new record of a glacial relict: pygmy whitefish (Prosopium coulterii) from northwestern Ontario
Canadian Journal of Zoology, Volume 0, Issue 0, Page 1-5, e-First articles. The pygmy whitefish (Prosopium coulterii (Eigenmann and Eigenmann, 1892)) is a glacial relict species with a disjunct North American distribution that, apart from its most easterly known location in Lake Superior, is predominantly found in northern and western regions of Canada. Here we report on a new finding of pygmy whitefish from Winnange Lake in northwestern Ontario that extends the range of this species ∼320 km from its most easterly distribution in Lake Superior and almost 1500 km east of the closest previously known western locali...
Source: Canadian Journal of Zoology - February 7, 2014 Category: Zoology Tags: article Source Type: research

Conservation genetics of the endangered Spotted Turtle (Clemmys guttata) illustrate the risks of “bottleneck tests”
Canadian Journal of Zoology, Volume 0, Issue 0, Page 149-162, e-First articles. Studies of population genetics in turtles have suggested that turtles do not experience genetic impacts of bottlenecks as strongly as expected. However, recent studies cast doubt on two commonly used tests implemented in the program BOTTLENECK, suggesting that these findings should be re-evaluated. The Spotted Turtle (Clemmys guttata (Schneider, 1792)) is endangered both globally and within Canada, but genetic data required to develop effective recovery strategies are unavailable. Here, we conducted the first study of population genetic s...
Source: Canadian Journal of Zoology - January 31, 2014 Category: Zoology Tags: article Source Type: research

Flight muscle carnitine palmitoyl transferase activity varies with substrate chain length and unsaturation in the hoary bat (Lasiurus cinereus)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 1-4, e-First articles. Fat is an important fuel for bats to support high metabolic rates in extended periods of flight. The fatty acid composition of adipose stores could affect whole animal exercise performance, as fatty acids vary in rates of mobilization and oxidation. A key step in the fatty acid oxidation pathway is transporting fatty acids from the cytosol into mitochondria, mediated by the enzyme carnitine palmitoyl transferase (CPT). Therefore, understanding the substrate preference patterns of CPT in bats is important for interpreting the consequences of a...
Source: Canadian Journal of Zoology - January 25, 2014 Category: Zoology Tags: article Source Type: research

Effects of age and experience on reproductive performance of captive red wolves (Canis rufus)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 251-258, e-First articles. Propagation programs contribute to the conservation of a species by preserving genetic and demographic stock that may be used to reinforce or re-establish wild populations. Identifying traits that affect reproductive success is essential to achieve this goal. Longitudinal reproductive events of the captive population of endangered red wolves (Canis rufus Audubon and Bachman, 1851) were investigated to determine whether parental age, breeding experience, and rearing type were factors in reproduction, litter size, and sex ratio, as well as ...
Source: Canadian Journal of Zoology - January 24, 2014 Category: Zoology Tags: article Source Type: research

Critical thermal maximum (CTmax) and hematology of shortnose sturgeons (Acipenser brevirostrum) acclimated to three temperatures
Canadian Journal of Zoology, Volume 92, Issue 3, Page 215-221, March 2014. Quantifying a species thermal tolerance is critical to assessing biological impacts of anticipated increases in temperature (e.g., climate change). Although many studies have documented the critical thermal maximum (CTmax) of fish, there is a paucity of research on thermal biology of sturgeon. The shortnose sturgeon (Acipenser brevirostrum LeSueur, 1818) is a threatened species that exists along the eastern coast of North America. They can be exposed to temperatures ranging from freezing to above 25 °C. Using a heating rate of 6 °C/h, ...
Source: Canadian Journal of Zoology - January 18, 2014 Category: Zoology Tags: article Source Type: research

Do social mating systems limit maternal immune investment in shorebirds?
We examined how the amount of maternal immune investment, measured as immunoglobulin Y and lysozyme activity in eggs, was influenced by female role across three social mating systems (polyandry, polygyny, and monogamy) in shorebirds. We predicted that polyandry should impose the greatest costs on the ability to provision eggs and monogamy, where females receive benefits from biparentality, the least. Contrary to our predictions, levels of maternally derived egg immune constituents were consistently high across measures in the polyandrous species and low in the monogamous species. Our results may support a link with pace-of...
Source: Canadian Journal of Zoology - January 18, 2014 Category: Zoology Tags: article Source Type: research

Using spoor and prey counts to determine temporal and spatial variation in lion (Panthera leo) density
Canadian Journal of Zoology, Volume 0, Issue 0, Page 97-104, e-First articles. In many African countries, large carnivores such as lions (Panthera leo (L., 1758)) are under serious threat through conflict with people, declining prey abundance, and exposure to disease. Spoor and prey count surveys were used to determine temporal and spatial variation in lion density in Khutse Game Reserve (KGR), Botswana, and the adjacent communal grazing area. Estimated lion density in KGR for the period September 2008 – June 2010 was 41% lower than for the period June 2007 – August 2008 (1.02 vs. 1.72 lions/100 km2). Pri...
Source: Canadian Journal of Zoology - January 16, 2014 Category: Zoology Tags: article Source Type: research

Erratum: Erratum — Re-evaluating niche conservatism versus divergence in the Woodland Salamander genus Plethodon: a case study of the parapatric members of the Plethodon glutinosus species complex
Canadian Journal of Zoology, Volume 0, Issue 0, Page 1, e-First articles. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - January 15, 2014 Category: Zoology Tags: article Source Type: research

Resource selection in a high-altitude rangeland equid, the kiang (Equus kiang): influence of forage abundance and quality at multiple spatial scales
Canadian Journal of Zoology, Volume 0, Issue 0, Page 239-249, e-First articles. Herbivores foraging in arid and seasonal environments often face choices between plant patches varying in abundance and nutritional quality at several spatial and temporal scales. Because of their noncompartmented digestive system, equids typically rely on abundant forage to meet their nutrient requirements. In forage-limited environments, therefore, scarcity of food resources represents a challenge for wild equids. We investigated hierarchical resource-selection patterns of kiangs (Equus kiang Moorcroft, 1841), a wild equid inhabiting th...
Source: Canadian Journal of Zoology - January 15, 2014 Category: Zoology Tags: article Source Type: research

Evolution of shell apertural barriers in viviparous land snails (Gastropoda: Pulmonata: Clausiliidae)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 205-213, e-First articles. Apertural barriers in the snail shell were frequently associated with adaptation against predators or with reducing water loss. Yet formation of teeth occluding the aperture is costly and potentially precludes life-bearing reproduction. In viviparous species, a trade-off between the shell aperture size and the embryo shell size at birth is expected. This hypothesis was tested in clausiliids, land snails with strong apertural barriers, that displayed a range of reproductive strategies (oviparity, egg retention, viviparity). We assessed the...
Source: Canadian Journal of Zoology - January 13, 2014 Category: Zoology Tags: article Source Type: research

Variations of estradiol-17β and testosterone levels correlated with gametogenesis in the gonad of Zhikong scallop (Chlamys farreri) during annual reproductive cycle
Canadian Journal of Zoology, Volume 0, Issue 0, Page 195-204, e-First articles. To assess the potential roles of sex steroids in modulating reproductive processes in the Zhikong scallop (Chlamys farreri (Jones and Preston, 1904)), variations in estradiol-17β (E2) and testosterone (T) levels in gonads were examined monthly from January to December 2012 by enzyme-linked immunosorbent assay (ELISA). The mean concentrations of E2 and T in gonads ranged from 75.07 to 666.24 pg/g and from 91.09 to 506.28 pg/g, respectively. Concentrations of E2 were significantly higher in ovaries than in testes, while T concentration...
Source: Canadian Journal of Zoology - January 13, 2014 Category: Zoology Tags: article Source Type: research

Wing wear, but not asymmetry in wear, affects load-lifting capability in bumble bees Bombus impatiens
Canadian Journal of Zoology, Volume 0, Issue 0, Page 179-184, e-First articles. Wing wear is widespread in flying insects, but its effects on flight are controversial. In this research, we examine the separate and combined effects of wing area and wing area asymmetry on maximum load-lifting capability in bumble bees Bombus impatiens Cresson, 1863. Individual bees with experimentally induced forewing wear (0%–24% forewing area loss, 0%–38% forewing area asymmetry) were harnessed with a string to which small bead groups were attached and tested in a flight chamber to measure the maximum weight that they cou...
Source: Canadian Journal of Zoology - January 13, 2014 Category: Zoology Tags: article Source Type: research

Effects of anthropogenic and environmental stress on the corticosterone levels of wintering Northern Pintails (Anas acuta)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 185-193, e-First articles. Winter-specific survival rates for female Northern Pintails (Anas acuta L., 1758; hereafter “Pintails”) at the Bosque del Apache National Wildlife Refuge were found in a previous study to be low relative to other wintering areas, raising concerns that tourism could be impacting the health of the population. Measurements of corticosterone levels enable the assessment and quantification of human-induced stressors that can ultimately affect fitness. We analyzed corticosterone concentrations and the relationship between body condi...
Source: Canadian Journal of Zoology - January 9, 2014 Category: Zoology Tags: article Source Type: research

Postglacial population genetic differentiation potentially facilitated by a flexible migratory strategy in Golden-crowned Kinglets (Regulus satrapa)
We report significant gene flow between Haida Gwaii and the western North American mainland from mitochondrial markers, but significant population genetic differentiation at nuclear markers. We also report genetic divergence between eastern and western Golden-crowned Kinglets, as well as higher genetic diversity and population substructuring within the western population than within the eastern population. The east–west differentiation probably arose due to isolation in separate Pleistocene refugia south of the ice sheets. However, population differences within the west are likely caused by more recent processes; con...
Source: Canadian Journal of Zoology - January 9, 2014 Category: Zoology Tags: article Source Type: research

Wing morphology of Neotropical bats: a quantitative and qualitative analysis with implications for habitat use
Canadian Journal of Zoology, Volume 0, Issue 0, Page 141-147, e-First articles. Wing morphology has a direct influence on the flight manoeuvrability, agility, and speed of bats. Studies addressing the relationship between bat wing morphology and ecology are biased towards Old World species and few of them have addressed the ecologically rich Amazonian bat fauna. We quantitatively and qualitatively characterized the wing shape of 51 bat species found in the Brazilian Amazonia by measuring their aspect ratio (AR) and relative wing load (RWL). We found a high variability in wing shape: AR varied from 5.0862 (pygmy round...
Source: Canadian Journal of Zoology - January 8, 2014 Category: Zoology Tags: article Source Type: research

Atrazine exposure increases time until cannibalistic response in the widow skimmer dragonfly (Libellula luctuosa)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 113-117, e-First articles. Agricultural runoff containing herbicide is known to have adverse effects on freshwater organisms. Aquatic insects are particularly susceptible, and herbicide runoff has the potential to affect behavior in this group. Here we examine the effects of short-term exposure to the herbicide atrazine on cannibalistic behavior in larvae of the widow skimmer dragonfly (Libellula luctuosa Burmeister, 1839). Large larvae (>12 mm length) were exposed to concentrations of 0, 1, 10, or 100 μg/L atrazine for 96 h. A smaller ( (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - January 7, 2014 Category: Zoology Tags: article Source Type: research

Do nest exclosures affect the behaviour of Piping Plovers (Charadrius melodus melodus) and their predators?
We examined the effects of nest exclosures on the behaviour of incubating Piping Plovers (Charadrius melodus melodus Ord, 1824) and their predators on nesting beaches in eastern Canada. Using a combination of field observations, video monitoring, and an artificial nest experiment, we found that adult incubation behaviour did not differ between exclosed and unexclosed nests. Predators, however, visited exclosed nests more often than unexclosed nests and spent more time in the vicinity of exclosed nests than unexclosed nests at one of our sites. These findings suggest that concerns over increased adult mortality and nest aba...
Source: Canadian Journal of Zoology - January 3, 2014 Category: Zoology Tags: article Source Type: research

Social learning within and across species: information transfer in mouse-eared bats
Canadian Journal of Zoology, Volume 0, Issue 0, Page 129-139, e-First articles. Social learning describes information transfer between individuals through observation or direct interaction. Bats can live and forage in large groups, sometimes comprising several species, and are thus well suited for investigations of both intraspecific and interspecific information transfer. Although social learning has been documented within several bat species, it has not been shown to occur between species. Furthermore, it is not fully understood what level of interaction between individuals is necessary for social learning in bats....
Source: Canadian Journal of Zoology - January 3, 2014 Category: Zoology Tags: article Source Type: research

Habitat selection by a generalist mesopredator near its historical range boundary
We examined the influence of anthropogenic (agricultural areas, developed land, roads), disturbed (corridor, forest edge, grassland, water), and native (forest, shrub land) habitats on habitat selection at the second- and third-order scales across three seasons. At the second-order scale, areas proximate to agricultural fields and developed land were selected in the breeding and postbreeding seasons, respectively. Areas proximate to roads were selected at both spatial scales during all seasons except winter at the third-order scale. Areas near forest with high forest-edge density were selected throughout the year at both s...
Source: Canadian Journal of Zoology - December 20, 2013 Category: Zoology Tags: article Source Type: research

Holding our breath in our modern world: will mitochondria keep the pace with climate changes?
Canadian Journal of Zoology, e-First Articles. Changes in environmental temperature can pose considerable challenges to animals and shifts in thermal habitat have been shown to be a major force driving species’ adaptation. These adaptations have been the focus of major research efforts to determine the physiological or metabolic constraints related to temperature and to reveal the phenotypic characters that can or should adjust. Considering the current consensus on climate change, the focus of research will likely shift to questioning whether ectothermic organisms will be able to survive future modifications of...
Source: Canadian Journal of Zoology - December 20, 2013 Category: Zoology Tags: article Source Type: research

Holding our breath in our modern world: will mitochondria keep the pace with climate changes?
Canadian Journal of Zoology, Volume 0, Issue 0, Page 1-11, e-First articles. Changes in environmental temperature can pose considerable challenges to animals and shifts in thermal habitat have been shown to be a major force driving species’ adaptation. These adaptations have been the focus of major research efforts to determine the physiological or metabolic constraints related to temperature and to reveal the phenotypic characters that can or should adjust. Considering the current consensus on climate change, the focus of research will likely shift to questioning whether ectothermic organisms will be able to s...
Source: Canadian Journal of Zoology - December 20, 2013 Category: Zoology Tags: article Source Type: research

Mitochondrial reactive oxygen species (ROS) in animal cells: relevance to aging and normal physiology
Canadian Journal of Zoology, e-First Articles. In animal mitochondria, the four electron reduction of molecular oxygen to produce water at respiratory complex IV is the terminal step in substrate oxidation. However, respiratory complexes I, II, and III can participate in the single electron reduction of oxygen to produce the radical species superoxide. This progenitor reactive oxygen species (ROS) participates in a number of reactions that generate other ROS. These molecules may react with, and damage, intracellular macromolecules, leading to cellular dysfunction. Mitochondrial ROS production is often considered from...
Source: Canadian Journal of Zoology - December 18, 2013 Category: Zoology Tags: article Source Type: research

Mitochondrial reactive oxygen species (ROS) in animal cells: relevance to aging and normal physiology
Canadian Journal of Zoology, Volume 0, Issue 0, Page 1-11, e-First articles. In animal mitochondria, the four electron reduction of molecular oxygen to produce water at respiratory complex IV is the terminal step in substrate oxidation. However, respiratory complexes I, II, and III can participate in the single electron reduction of oxygen to produce the radical species superoxide. This progenitor reactive oxygen species (ROS) participates in a number of reactions that generate other ROS. These molecules may react with, and damage, intracellular macromolecules, leading to cellular dysfunction. Mitochondrial ROS produ...
Source: Canadian Journal of Zoology - December 18, 2013 Category: Zoology Tags: article Source Type: research

Role of temperature in determining relative abundance in cave twilight zones by two species of lungless salamander (family Plethodontidae)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 119-127, e-First articles. Lungless salamanders of the family Plethodontidae have historically been considered to be passive conformers to their surrounding thermal environment because there is no evidence that they thermoregulate behaviourally in the field. In contrast, plethodontids readily choose optimal temperatures when placed on experimental thermal gradients. It has been hypothesized that restriction to moist habitats prevents these salamanders from exploiting thermally diverse microhabitats in nature. We tested this hypothesis, as well as the hypothesis tha...
Source: Canadian Journal of Zoology - December 17, 2013 Category: Zoology Tags: article Source Type: research

Note of appreciation / note de reconnaissance
Canadian Journal of Zoology, Volume 0, Issue 0, Page iii-iv, e-First articles. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - December 11, 2013 Category: Zoology Tags: article Source Type: research

Sex-biased parasitism in Richardson’s ground squirrels (Urocitellus richardsonii) depends on the parasite examined
We examined sex-biased parasitism in Richardson’s ground squirrels (Urocitellus richardsonii (Sabine, 1822)) and hypothesized that males would be more heavily parasitized than females, as they are larger, have larger home ranges, and display high aggression and fighting during the short mating season, suggesting that they may trade off investment in immunity for higher investment in reproduction. Squirrels were caught during the mating season and examined for endoparasites and ectoparasites. Body mass, condition, and immune measures were recorded. Males had higher nematode prevalence and abundance, whereas females ha...
Source: Canadian Journal of Zoology - December 4, 2013 Category: Zoology Tags: article Source Type: research

Condition-dependent sex difference in nestling House Wren (Troglodytes aedon) response to phytohaemagglutinin injection
Canadian Journal of Zoology, Volume 0, Issue 0, Page 1-7, e-First articles. Adult male and female birds typically respond differently to immunological challenges, but whether this difference is present in altricial nestlings is not well-documented. Furthermore, the timing of the development of different axes of the immune system might vary in nestlings and also be affected by differences in condition and health state. We tested for sex-related differences in the immune response of nestling House Wrens (Troglodytes aedon Vieillot, 1809) to the injection of phytohaemagglutinin (PHA) and in the bacteria-killing capacity...
Source: Canadian Journal of Zoology - November 27, 2013 Category: Zoology Tags: article Source Type: research

Effects of ectoparasites on seasonal variation in quality of nestling Tree Swallows (Tachycineta bicolor)
We examined the effect of ectoparasites on seasonal variation in indices of nestling quality and survival in Tree Swallows (Tachycineta bicolor (Vieillot, 1808)) at breeding sites in British Columbia (PG) and Saskatchewan (SDNRA). In a parasite removal experiment, we detected no seasonal trend in flea abundance and, contrary to expectation, there were fewer blow flies in nests of late breeders. Negative effects of parasites on nestlings were documented at PG, where lengths of primary feather and head–bill were affected. Parental, rather than environmental, quality had the greatest effect on reproductive success at PG...
Source: Canadian Journal of Zoology - November 27, 2013 Category: Zoology Tags: article Source Type: research

Microclimate preferences correlate with contrasted evaporative water loss in parapatric vipers at their contact zone
Canadian Journal of Zoology, Volume 0, Issue 0, Page 81-86, e-First articles. Terrestrial ectotherms predominantly use behavioural means to thermoregulate and thereby optimize performances. However, thermoregulation can impart physiological challenges to other critical processes such as water balance by increasing evaporative water loss (EWL). Like thermoregulation, water balance is influenced by both external factors (e.g., microhabitat and environmental constraints) and endogenous traits (e.g., evaporative water loss rates, dehydration tolerance). Although thermoregulation and water balance are tightly linked, the ...
Source: Canadian Journal of Zoology - November 27, 2013 Category: Zoology Tags: article Source Type: research

Species composition and abundance of ants and other invertebrates in stands of crested wheatgrass (Agropyron cristatum) and native grasslands in the northern Great Plains
Canadian Journal of Zoology, Volume 0, Issue 0, Page 49-55, e-First articles. Habitat alteration by exotic plant species can have profound effects on vertebrates, but its effects on invertebrates are less well-known. Crested wheatgrass (Agropyron cristatum (L.) Gaertn.) is a perennial grass that has been planted on>106 ha of the Great Plains. We tested the hypothesis that invertebrate communities (especially ants) differed between native grasslands and A. cristatum stands, using pitfall traps in Saskatchewan and Montana. Ant species composition differed significantly between native grasslands and A. cristatum stan...
Source: Canadian Journal of Zoology - November 25, 2013 Category: Zoology Tags: article Source Type: research

Sprint speed is related to blood parasites, but not to ectoparasites, in an insular population of lacertid lizards
In this study, we examine the relationship between parasitism and burst speed in an insular population of Lilford’s Wall Lizard (Podarcis lilfordi (Günther, 1874)). Podarcis lilfordi is normally infected with haemogregarine blood parasites and mites in our study location, Aire Island (Balearic Islands, Spain). Unlike the results from other studies on lizards, we found a significant negative correlation between intensity of infection by haemogregarines and burst speed. Body condition is also significantly related to burst speed. Thus, lizards with a lower blood parasite load and better body condition show a faste...
Source: Canadian Journal of Zoology - November 25, 2013 Category: Zoology Tags: article Source Type: research

Group size and dispersal ploys: an analysis of commuting behaviour of the pond bat (Myotis dasycneme)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 57-65, e-First articles. Like most bat species, the pond bat (Myotis dasycneme (Boie, 1825)) lives in roosts more or less in the centre of their foraging habitat and are considered central-place foragers. Commuting routes, or flyways, between roosts and hunting areas have an essential ecological function for bats. We summarize the results of research performed on the commuting routes of pond bats between 2002 and 2009. We give, among others, a description on how bats disperse, how to recognize a commuting route, and details about the effort needed to make a complet...
Source: Canadian Journal of Zoology - November 25, 2013 Category: Zoology Tags: article Source Type: research

Patterns of sperm use in two populations of Red-sided Garter Snake (Thamnophis sirtalis parietalis) with long-term female sperm storage
Canadian Journal of Zoology, Volume 0, Issue 0, Page 33-40, e-First articles. Long-term sperm storage may contribute to postcopulatory sexual selection because it enhances the commingling of sperm from different males within the female reproductive tract, which is the prerequisite for sperm competition. Long-term sperm storage and multiple paternity has been documented in snakes, but the identity of the last potential father is usually unknown in studies demonstrating multiple paternity. Here we present the first study in Red-sided Garter Snakes (Thamnophis sirtalis parietalis (Say in James, 1832)) to use experimenta...
Source: Canadian Journal of Zoology - November 19, 2013 Category: Zoology Tags: article Source Type: research

Skull allometry and sexual dimorphism in the ontogeny of the southern elephant seal (Mirounga leonina)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 19-31, e-First articles. The southern elephant seal (Mirounga leonina (L., 1758)) is one of the most dimorphic mammals, but sexual dimorphism in its skull ontogeny is poorly known. We study ontogeny of sexual dimorphism by the allometric relationships between 21 measurements and its geometric mean. Based on 66 specimens (36 females, 30 males), the bivariate and multivariate analyses indicated that both approaches were congruent in most variables. We detected that sexual dimorphism was reached mostly by sexual shape differences in the ontogenetic trajectories of mal...
Source: Canadian Journal of Zoology - November 19, 2013 Category: Zoology Tags: article Source Type: research

Warm-season heat stress in moose (Alces alces)
Canadian Journal of Zoology, Volume 0, Issue 0, Page 893-898, e-First articles. Understanding how moose (Alces alces (L., 1758)) are affected by temperature is critical for determining why populations have recently declined at the southern extent of their North American range. Warm-season heat-stress thresholds of 14 and 20 °C are commonly used to study moose, but the variable response of free-ranging moose to temperatures above these thresholds suggests that moose may be more tolerant to heat. We studied zoo-managed cow and bull moose to identify factors that influence warm-season heat stress. We found clear beh...
Source: Canadian Journal of Zoology - November 15, 2013 Category: Zoology Tags: article Source Type: research

The effects of two fish predators on Wood Frog (Lithobates sylvaticus) tadpoles in a subarctic wetland: Hudson Bay Lowlands, Canada
Canadian Journal of Zoology, Volume 0, Issue 0, Page 866-871, e-First articles. Fish can have strong predatory impacts on aquatic food webs. Indeed, fish are known to have strong effects on amphibians, with some species being excluded from communities where fish are present. Most research with amphibians and fish has focused on lower latitudes and very little is known of amphibian–fish interactions at higher latitudes. Therefore, we conducted an enclosure experiment in a subarctic natural wetland to examine the predatory effects of two species of fish, brook sticklebacks (Culaea inconstans (Cuvier, 1829)) and n...
Source: Canadian Journal of Zoology - November 5, 2013 Category: Zoology Tags: article Source Type: research

Environmental factors influencing immigration behaviour of the invasive earthworm Lumbricus terrestris
This study investigated how environmental conditions influence the immigration behaviour of L. terrestris. Experimental mesocosms were used to test for differences in burrow establishment depending on leaf-litter type (sugar maple (Acer saccharum Marsh.) or white pine (Pinus strobus L.)) or the background population density of conspecifics (0, 25, or 100 m−2). Choice chambers were used to test for selection between habitat conditions. Video recording was used to measure the latency between introduction and establishment. A significantly greater proportion of individuals established burrows in the presence of maple ov...
Source: Canadian Journal of Zoology - October 31, 2013 Category: Zoology Tags: article Source Type: research

Affinities of the alleged earliest Cambrian gastropod Aldanella
Canadian Journal of Zoology, Volume 91, Issue 12, Page 914-923, December 2013. Unlike true Palaeozoic gastropods, but similar to some coeval hyoliths, the cup-like hemispherical embryonic shell of Aldanella attleborensis (Shaler and Foerste, 1888) from the earliest Cambrian (early Tommotian) Erkeket Formation of northern Siberia bears a mucro. Also, the pattern of mortality, with right-skewed distribution and a peak at about 1.0 mm diameter, is not similar to that of early Palaeozoic gastropods; there is no evidence of metamorphosis that would end the pelagic larval stage of ontogeny. Specimens of larger size are rar...
Source: Canadian Journal of Zoology - October 30, 2013 Category: Zoology Tags: article Source Type: research