Light regime affects the seasonal cycle of Antarctic krill (Euphausia superba): impacts on growth, feeding, lipid metabolism, and maturity
Canadian Journal of Zoology, e-First Articles. Light regime is an important zeitgeber for Antarctic krill (Euphausia superba Dana, 1850), which seems to entrain an endogenous timing system that synchronizes its life cycle to the extreme light conditions in the Southern Ocean. To understand the flexibility of Antarctic krill ’s seasonal cycle, we investigated its physiological and behavioural responses to different light regimes and if an endogenous timing system was involved in the regulation of these seasonal processes. We analysed growth, feeding, lipid content, and maturity in a 2-year laboratory experiment simula...
Source: Canadian Journal of Zoology - July 13, 2018 Category: Zoology Authors: Flavia H öring Mathias Teschke Lavinia Suberg So Kawaguchi Bettina Meyer Source Type: research

How coexistence may influence life history: the reproductive strategies of sympatric congeneric terrestrial isopods (Crustacea, Oniscidea)
Canadian Journal of Zoology, e-First Articles. Patterns of allocation between reproduction, survival, and maintenance are what we call life history. By investigating the life-history strategy of sympatric species, we may understand how they are able to coexist, as different strategies are expected to evolve in species that occupy similar niche space. Terrestrial isopods are a group in which multiple species frequently inhabit the same area. Notably, they are usually infected by Wolbachia Hertig, 1936, a notorious manipulator of the hosts ’ reproductive processes. Thus, the aim of this study was to analyze the investm...
Source: Canadian Journal of Zoology - July 13, 2018 Category: Zoology Authors: Bianca La ís Zimmermann Alexandre Varaschin Palaoro Didier Bouchon Maur ício Pereira Almerão Paula Beatriz Araujo Source Type: research

Impacts of recolonizing gray wolves (Canis lupus) on survival and mortality in two sympatric ungulates
Canadian Journal of Zoology,Volume 96, Issue 7, Page 760-768, July 2018. There is growing recognition that humans may mediate the strength and nature of the ecological effects of large predators. We took advantage of ongoing gray wolf (Canis lupus Linnaeus, 1758) recolonization in Washington, USA, to contrast adult survival rates and sources of mortality for mule deer (Odocoileus hemionus (Rafinesque, 1817)) and white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) in areas with and without wolf packs in a managed landscape dominated by multiple human uses. We tested the hypothesis that the addition of wolves to th...
Source: Canadian Journal of Zoology - July 9, 2018 Category: Zoology Authors: J.A. Dellinger C.R. Shores M. Marsh M.R. Heithaus W.J. Ripple A.J. Wirsing Source Type: research

Large-scale changes in the littoral fish communities of lakes in southeastern Ontario, Canada
Canadian Journal of Zoology, e-First Articles. Biodiversity loss is a serious issue for freshwater fishes in temperate climates and there is a need for more information in this area. A study was conducted to assess fish community changes in the littoral zone of 22 lakes over a 45 year period (compared years 1969 –1979 and year 2014). To compare fish communities, historical seining records were compiled for 22 inland lakes and compared with contemporary data sampled using the same protocol. Fish abundance data analyzed using a multivariate approach identified a shift from cyprinid-dominated communities to centrarchid-...
Source: Canadian Journal of Zoology - July 3, 2018 Category: Zoology Authors: Paul A. Finigan Nicholas E. Mandrak Bruce L. Tufts Source Type: research

Arrayvolution: using microphone arrays to study bats in the field
Canadian Journal of Zoology, e-First Articles. Some parameters of echolocation signals can be studied using a single receiver. However, studying parameters such as source level, echolocation beam shape, and direction of signal emission require the use of multireceiver arrays. Acoustic localization allows for determination of the position of bats at the time of signal emission. When multiple animals are present, calls can be assigned to individuals based on their location. This combination makes large multireceiver arrays a powerful tool in bioacoustics research. Here, an overview of different array configurations used to r...
Source: Canadian Journal of Zoology - June 29, 2018 Category: Zoology Authors: Jens C. Koblitz Source Type: research

Urbanization as a driver of taxonomic, functional, and phylogenetic diversity losses in bird communities
Canadian Journal of Zoology, e-First Articles. Urbanization is one of the most important threats to biodiversity worldwide, as it drives declines in species diversity, functional diversity, and phylogenetic diversity and increases functional redundancy among species. We estimated taxonomic, functional, and phylogenetic diversities, as well as the abundance of several functional groups, in bird communities from a town in east-central Argentina in 1985 –1986 and 30 years after (2015–2016). In 1985–1986, we found that taxonomic diversity (abundance, species richness, and alpha diversity), functional richness...
Source: Canadian Journal of Zoology - June 15, 2018 Category: Zoology Authors: Facundo X. Palacio Luc ía M. Ibañez Ren é E. Maragliano Diego Montalti Source Type: research

Morphological characteristics of harbor seal (Phoca vitulina) whiskers and their use in dietary reconstruction using stable isotope ratios
Canadian Journal of Zoology,Volume 96, Issue 11, Page 1255-1263, November 2018. We investigated whether inferences about harbor seal (Phoca vitulina Linnaeus, 1758) whisker shed status and growth rates based on whisker morphology could improve dietary time series from whisker isotopic profiles. We identified morphometric characteristics of Alaskan harbor seal whiskers, including a smooth root section (SRS) and a bumpy section. The SRS was longer for spring versus fall-collected whiskers and matched the length of fully grown, shed whiskers. Thus, SRS length can differentiate whisker shed and growth status, and we used it to...
Source: Canadian Journal of Zoology - June 8, 2018 Category: Zoology Authors: Justin Smith Shawna Karpovich Greg A. Breed Diane M. O ’Brien Source Type: research

Fine- and coarse-scale movements and habitat use by Wood Turtles (Glyptemys insculpta) based on probabilistic modeling of radiotelemetry and GPS-telemetry data
We present results of a multiyear study on 48 adult Wood Turtles (Glyptemys insculpta (Le Conte, 1830)) from two different populations monitored with low-frequency radiotelemetry and high-frequency GPS telemetry. Results demonstrated the propensity for conventional radiotelemetry to underestimate cumulative distances moved and overestimate the amount of habitat used by Wood Turtles. Together the two data sets demonstrate the propensity for Wood Turtles to remain in close proximity to the river and that some differences in habitat use occur between the sexes; males tended to move parallel to the river, whereas females moved...
Source: Canadian Journal of Zoology - June 8, 2018 Category: Zoology Authors: D.G. Thompson T. Swystun J. Cross R. Cross D. Chartrand C.B. Edge Source Type: research

Blood parasite infection linked to condition of spring-migrating Lesser Scaup (Aythya affinis)
We examined w hether haemosporidian parasite infection status was linked to measures of size (mass, wing length, tarsus length, and keel length) and condition (body fat, size-corrected mass, wing-loading) in female spring-migrating scaup. Infection prevalence varied by year (21.7% in 2014; 47.1% in 2015) and perc ent body fat was negatively associated with the probability of infection. Body fat levels declined from 2014 to 2015, but at a similar rate for infected and uninfected birds. This pattern suggests that the increased prevalence in 2015 may have been related to the greater proportion of poor-condition birds being mo...
Source: Canadian Journal of Zoology - June 8, 2018 Category: Zoology Authors: L. Merrill J.M. Levengood J.C. England J.M. Osborn H.M. Hagy Source Type: research

Body condition of American Black Ducks (Anas rubripes) wintering in Atlantic Canada using carcass composition and a scaled mass index
Canadian Journal of Zoology, e-First Articles. Body condition is commonly used in ecology to assess the physiological health of an organism or population and can be used to predict individual survival or breeding success. Waterfowl have been the focus of much research on body condition, and we studied body condition via carcass composition and using a scaled mass index (SMI) in American Black Ducks (Anas rubripes Brewster, 1902) wintering in coastal, agricultural, and urban areas of Atlantic Canada. Carcass composition varied between sexes and body mass decreased through winter as fat reserves depleted. Carcass composition...
Source: Canadian Journal of Zoology - June 7, 2018 Category: Zoology Authors: Matthew D. English Gregory J. Robertson Liam E. Peck Donald Pirie-Hay Sheena Roul Mark L. Mallory Source Type: research

Environmental and spatial factors affect the composition and morphology of tadpole assemblages
This study has demonstrated how factors that control the assemblage composition of tadpoles also drive their morphological diversity. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - May 30, 2018 Category: Zoology Authors: N.C.S. Marques F. Nomura Source Type: research

Estimating densities for sympatric kit foxes (Vulpes macrotis) and coyotes (Canis latrans) using noninvasive genetic sampling
Canadian Journal of Zoology, e-First Articles. Kit fox (Vulpes macrotis Merriam, 1888) populations in the Great Basin Desert have declined and are of increasing concern for managers. Increasing coyote (Canis latrans Say, 1823) abundance and subsequent intraguild interactions may be one cause for this decline. Concurrent monitoring of carnivores is challenging and therefore rarely conducted. One possible solution for monitoring elusive carnivores is using noninvasive genetic sampling. We used noninvasive genetic sampling to collect fecal DNA from kit foxes and coyotes and estimate their densities from 2013 –2014 in Ut...
Source: Canadian Journal of Zoology - May 30, 2018 Category: Zoology Authors: R.C. Lonsinger P.M. Lukacs E.M. Gese R.N. Knight L.P. Waits Source Type: research

Extreme operative temperatures in exposed microsites used by roosting Rufous-cheeked Nightjars (Caprimulgus rufigena): implications for water balance under current and future climate conditions
Canadian Journal of Zoology, e-First Articles. Nocturnally active birds roosting in exposed microsites can experience operative temperatures (Te) that markedly differ from air temperature (Ta). Thus, quantifying Te becomes important for accurately modeling energy and water balance. We measured Te at roost and nest sites used by Rufous-cheeked Nightjars (Caprimulgus rufigena A. Smith, 1845) (mean body mass = 57.1 g) with three-dimensionally printed models covered with the plumage of a bird. Additionally, we estimated site-specific diurnal water requirements for evaporative cooling by integrating Te and Ta profiles with evap...
Source: Canadian Journal of Zoology - May 29, 2018 Category: Zoology Authors: R.S. O ’Connor R.M. Brigham A.E. McKechnie Source Type: research

European Starling (Sturnus vulgaris) reproduction undeterred by predator scent inside nest boxes
Canadian Journal of Zoology, e-First Articles. Indirect predator cues near nests have been shown to enhance perceived predation risk and associated antipredator behaviours in breeding animals across taxa and particularly with birds. We hypothesized that scent from the raccoon (Procyon lotor (Linnaeus, 1758)) inside nest boxes would, despite being an evolutionarily unique predator, enhance perceived risk to the European Starling (Sturnus vulgaris (Linnaeus, 1758)), thus reducing use of treated sites and reproduction. During early spring, starlings selected from nest boxes treated with equal volumes of predator scent, a nove...
Source: Canadian Journal of Zoology - May 18, 2018 Category: Zoology Authors: Bradley F. Blackwell Thomas W. Seamans Morgan B. Pfeiffer Bruce N. Buckingham Source Type: research

Factors affecting gray wolf (Canis lupus) encounter rate with elk (Cervus elaphus) in Yellowstone National Park
Canadian Journal of Zoology, e-First Articles. Despite encounter rates being a key component of kill rate, few studies of large carnivore predation have quantified encounter rates with prey, the factors that influence them, and the relationship between encounter rate and kill rate. The study ’s primary motivation was to determine the relationship between prey density and encounter rate in understanding the mechanism behind the functional response. Elk (Cervus elaphus Linnaeus, 1758) population decline and variable weather in northern Yellowstone National Park provided an opportunity t o examine how these factors infl...
Source: Canadian Journal of Zoology - May 14, 2018 Category: Zoology Authors: H.W. Martin L.D. Mech J. Fieberg M.C. Metz D.R. MacNulty D.R. Stahler D.W. Smith Source Type: research

Integrative taxonomy reveals a new genus and new species of Philosciidae (Crustacea: Isopoda: Oniscidea) from the Neotropical region
This study highlights the importance of multiple and complementary perspectives as a way to improve the quality of species hypothesis and associated descriptions. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - May 8, 2018 Category: Zoology Authors: Bianca L. Zimmermann Ivanklin S. Campos-Filho Paula B. Araujo Source Type: research

Integrative taxonomy reveals a new genus and new species of Philosciidae (Crustacea: Isopoda: Oniscidea) from the Neotropical region
This study highlights the importance of multiple and complementary perspectives as a way to improve the quality of species hypothesis and associated descriptions. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - May 8, 2018 Category: Zoology Authors: Bianca L. Zimmermann Ivanklin S. Campos-Filho Paula B. Araujo Source Type: research

Dental enamel hypoplasias in Holocene bighorn sheep (Ovis canadensis) in eastern Washington state, USA
Canadian Journal of Zoology,Volume 96, Issue 5, Page 460-465, May 2018. Dental enamel hypoplasias have been documented in extant and fossil mammal species and attributed to several kinds of physiological stress. They have not previously been reported among bighorn sheep (Ovis canadensis Shaw, 1804). Forty-six (36.8%) of 125 mandibular molars (m1, m2, m3) of bighorn recovered from disturbed Holocene archaeological deposits in eastern Washington state display several kinds of hypoplasias. The exact ontogenetic age of the individual animals when hypoplasias formed cannot be determined. The majority of the hypoplasias occur ne...
Source: Canadian Journal of Zoology - May 4, 2018 Category: Zoology Authors: R. Lee Lyman Source Type: research

Dental enamel hypoplasias in Holocene bighorn sheep (Ovis canadensis) in eastern Washington state, USA
Canadian Journal of Zoology, e-First Articles. Dental enamel hypoplasias have been documented in extant and fossil mammal species and attributed to several kinds of physiological stress. They have not previously been reported among bighorn sheep (Ovis canadensis Shaw, 1804). Forty-six (36.8%) of 125 mandibular molars (m1, m2, m3) of bighorn recovered from disturbed Holocene archaeological deposits in eastern Washington state display several kinds of hypoplasias. The exact ontogenetic age of the individual animals when hypoplasias formed cannot be determined. The majority of the hypoplasias occur near the root –enamel...
Source: Canadian Journal of Zoology - May 4, 2018 Category: Zoology Authors: R. Lee Lyman Source Type: research

Movement-based methods to infer parturition events in migratory ungulates
Canadian Journal of Zoology, e-First Articles. Long-distance migrations by ungulate species are a globally imperiled natural phenomenon and conservation of them requires monitoring population vital rates. Satellite telemetry tracking is widely used for understanding the spatial distribution and movement of animals, especially migratory animals in remote environments. Recently, analytical methods have been developed to infer parturition events from movement data in multiple species that calve in isolation, but to date such methods have not been tested on animals that both migrate and spatially aggregate during calving. We a...
Source: Canadian Journal of Zoology - April 25, 2018 Category: Zoology Authors: Matthew D. Cameron Kyle Joly Greg A. Breed Lincoln S. Parrett Knut Kielland Source Type: research

Experimental setup influences the cardiovascular responses of decapod crustaceans to environmental change
Canadian Journal of Zoology, e-First Articles. The effects of different holding methods on heart rate (HR) changes in the green crab, Carcinus maenas (Linnaeus, 1758), were investigated. Green crabs were held in perforated plastic boxes (with or without a layer of sand) suspended above the bottom of the tank or strapped to a weighted plastic grate. The HR of green crabs classified as unrestrained (plastic box with or without sand) dropped more rapidly compared with restrained (hanging from band, strapped to grate) green crabs. Within 1 h, unrestrained green crabs exhibited periods of cardiac pausing accounting for between ...
Source: Canadian Journal of Zoology - April 25, 2018 Category: Zoology Authors: I.J. McGaw S.J. Nancollas Source Type: research

Large mothers, but not large fathers, influence offspring number in a caridean shrimp
Canadian Journal of Zoology, e-First Articles. The relationship between parental mass and female reproductive output, as well as offspring quality, was studied in the red cherry shrimp (Neocaridina davidi (Bouvier, 1904)) under controlled laboratory conditions. Adult males and females of the same age were paired combining different shrimp masses. The number of hatched juveniles from large females was higher than that from small ones, but no influence of paternal mass was detected on this variable. Both the mass of newly hatched juveniles and their growth increment during a 60-day period were similar for all parental masses...
Source: Canadian Journal of Zoology - April 20, 2018 Category: Zoology Authors: D.E. Sganga C. Tropea M. Valdora M.F. Statti L.S. L ópez Greco Source Type: research

Thermal acclimation of fast-growing Japanese Quails (Coturnix japonica) exhibit decreased oxidative stress and increased muscle fiber diameters after acute heat challenges
We examined whether developing in warmer temperatures would physiologically benefit adult Japanese Quails (Coturnix japonica Temminck and Schlegel, 1849) by exploring changes in oxidative stress and muscle structure in two quail lines — one selected for control growth and another for fast growth and after acute heat challenges. We used a factorial design to administer four treatment combinations to each line: an initial period of either heat-stress acclimation (3 h every other day to 37 °C) or no acclimation, and after 5 weeks , either an acute heat-stress challenge (8 h at 39 °C) or no challenge. We found th...
Source: Canadian Journal of Zoology - April 20, 2018 Category: Zoology Authors: Ana Gabriela Jimenez Jennifer Dias Tram Nguyen Brigid Reilly Nicholas Anthony Source Type: research

Corticosteroid-binding globulin levels in North American sciurids: implications for the flying squirrel stress axis
Canadian Journal of Zoology, e-First Articles. Corticosteroid-binding globulin (CBG) helps to regulate tissue bioavailability of circulating glucocorticoids (GCs), and in most vertebrates, ≥80%–90% of GCs bind to this protein. New World flying squirrels have higher plasma total cortisol levels (the primary corticosteroid in sciurids) than most vertebrates. Recent research suggests that flying squirrels have either low amounts of CBG or CBG molecules that have a low binding affinit y for cortisol, as this taxon appears to exhibit very low proportions of cortisol bound to CBG. To test whether CBG levels have been ad...
Source: Canadian Journal of Zoology - April 19, 2018 Category: Zoology Authors: Lanna M. Desantis Jeff Bowman Erin Faught Rudy Boonstra Mathilakath M. Vijayan Gary Burness Source Type: research

Spineless tales: development and evolution of invertebrates
Canadian Journal of Zoology,Volume 96, Issue 5, Page iii-iii, May 2018. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - April 17, 2018 Category: Zoology Authors: Hillary C. Maddin A. Richard Palmer Source Type: research

Spineless tales: development and evolution of invertebrates
Canadian Journal of Zoology, e-First Articles. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - April 17, 2018 Category: Zoology Authors: Hillary C. Maddin A. Richard Palmer Source Type: research

Rudiment resorption as a response to starvation during larval development in the sea urchin Strongylocentrotus droebachiensis
We report for the first time on rudiment regression and complete resorption as a response to starvation during larval development in the sea urchin Strongylocentrotus droebachiensis (O.F. M üller, 1776) and identify a developmental “window of opportunity” within which this can occur. Based on our observations and previous suggestions, we speculate that sea urchin rudiments might provide means of buffering development during unfavorable conditions. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - April 15, 2018 Category: Zoology Authors: A. Singh L. Pinto C. Martin N. Rutherford A. Ragunathan U. Upadhyay P. Kapoor M. McRae A. Siddiqui D. Cantelmi A. Heyland G. Wray J.R. Stone Source Type: research

Taxonomy and biogeography of Hemphillia (Gastropoda: Pulmonata: Arionidae) in North American rainforests, with description of a new species (Skade ’s jumping-slug, Hemphillia skadei sp. nov.)
Canadian Journal of Zoology, e-First Articles. Species diversity of the genus Hemphillia Bland and W.G. Binney, 1872 (jumping-slugs) was studied across its range in western North America ’s inland temperate rainforests. The taxonomic relationships among jumping-slug populations were clarified by integrating morphological, molecular, and biogeographic approaches. A new species, Skade’s jumping-slug (Hemphillia skadei sp. nov.), was discovered in this process and is described here in. We base this taxonomic decision on molecular comparison of representatives from other Hemphillia species and four morphological ch...
Source: Canadian Journal of Zoology - March 30, 2018 Category: Zoology Authors: M.K. Lucid A. Rankin A. Esp índola L. Chichester S. Ehlers L. Robinson J. Sullivan Source Type: research

Influence of agricultural intensification on prey availability and nestling diet in Tree Swallows (Tachycineta bicolor)
Canadian Journal of Zoology, e-First Articles. Over the last decades, aerial insectivorous birds have been declining in both North America and Europe. Those declines have been hypothetically attributed to a decrease in prey availability caused by agricultural intensification, but empirical evidence remains scarce. Here, we quantify the effect of landscape composition on the abundance and diversity of potential prey of Tree Swallows (Tachycineta bicolor (Vieillot, 1808)) and on nestling diet in southern Quebec, Canada. We collected food boluses from nestlings and compared their composition with spatiotemporally correspondin...
Source: Canadian Journal of Zoology - March 28, 2018 Category: Zoology Authors: V. Bellavance M. B élisle J. Savage F. Pelletier D. Garant Source Type: research

Larval salamanders are as effective at short-term mosquito predation as mosquitofish
Canadian Journal of Zoology, e-First Articles. Biological control of mosquitoes can have unintended ecological consequences. One example is the introduction of the genus Gambusia Poey, 1854 into ponds and wetlands. Gambusia spp. are invasive in many parts of the world and have the potential to alter ecosystems by changing trophic interactions and extirpating amphibians. We sought to determine whether larval amphibians are capable of consuming larval mosquitoes as effectively as Gambusia spp. We tested the predation ability of larval Spotted Salamanders (Ambystoma maculatum (Shaw, 1802); n = 13), Southern Leopard Frog (Rana...
Source: Canadian Journal of Zoology - March 27, 2018 Category: Zoology Authors: Amanda M. Watters Freya E. Rowland Raymond D. Semlitsch Source Type: research

Identifying resilient Eastern Massasauga Rattlesnake (Sistrurus catenatus) peatland hummock hibernacula
Canadian Journal of Zoology, e-First Articles. At the northern limit of the Eastern Massasauga Rattlesnake ’s (Sistrurus catenatus (Rafinesque, 1818)) range, individuals spend up to half the year overwintering. In hummock hibernacula found in peatlands, it is likely that subsurface temperature and water table position are contributing factors dictating habitat suitability. As a step towards assessing t he vulnerability of hibernacula to anthropogenic changes, we combined subsurface temperature and water table dynamics to assess the likelihood that unflooded and unfrozen conditions were present in hummock hibernacula....
Source: Canadian Journal of Zoology - March 27, 2018 Category: Zoology Authors: A.G. Smolarz P.A. Moore C.E. Markle J.M. Waddington Source Type: research

Incubation temperature influences sex ratio and offspring ’s body composition in Zebra Finches (Taeniopygia guttata)
Canadian Journal of Zoology, e-First Articles. Incubation temperature has the potential to influence offspring sex, phenotype, and survival, particularly in species with temperature-dependent sex determination. However, relatively little is known about how incubation temperature affects sex ratio and offspring condition in other animals. Incubating birds allocate varying time for egg incubation depending on the parents ’ condition and ambient temperature, likely altering nest microclimate. To understand how incubation temperature impacts offspring phenotype in birds, we artificially incubated Zebra Finch (Taeniopygia...
Source: Canadian Journal of Zoology - March 27, 2018 Category: Zoology Authors: Haruka Wada Buddhamas P. Kriengwatana Todd D. Steury Scott A. MacDougall-Shackleton Source Type: research

Individual vigilance profiles in flocks of House Sparrows (Passer domesticus)
Canadian Journal of Zoology, e-First Articles. Individual vigilance against threats typically decreases with group size. However, group size often explains a small amount of variation in vigilance, suggesting that other factors such as individual differences might contribute. For instance, individuals could maintain different vigilance levels overall and also respond differently to variation in group size. We investigated individual variation in vigilance and its patterns of plasticity in flocks of House Sparrows (Passer domesticus (Linnaeus, 1758)). We carried out observations at one provisioned site and used multiple obs...
Source: Canadian Journal of Zoology - March 27, 2018 Category: Zoology Authors: Hakima Boujja-Miljour Patrick A. Leighton Guy Beauchamp Source Type: research

The frequency of leg autotomy and its influence on survival in natural populations of the wolf spider Pardosa valens
We examined frequency of autotomy in two riparian zone populations of the wolf spider Pardosa valens Barnes, 1959 and then used both mark –recapture work at these sites and laboratory predation trials to determine whether autotomy affected survival. Autotomy occurred in 31% of spiders; males were more likely than females to have a missing leg, but female reproductive status (carrying an egg sac or not) was unrelated to leg loss stat us. At both sites, survival over 1 week in the field was significantly higher for intact spiders than for spiders missing a leg, for both sexes and both female reproductive states. Additi...
Source: Canadian Journal of Zoology - March 27, 2018 Category: Zoology Authors: Christopher A. Brown Carlos C. Amaya Daniel R. Formanowicz Source Type: research

Environmental variation and seasonal changes as determinants of the spatial distribution of scorpions (Arachnida: Scorpiones) in Neotropical forests
Canadian Journal of Zoology, e-First Articles. Habitat selection and seasonal changes are key drivers of the population dynamics of many species. We analyzed how the environmental structure influences species establishment in an area by comparing microhabitat preference and functional richness of scorpions (Arachnida: Scorpiones) in wet (Atlantic forest) and semiarid (Caatinga) areas. Variations in superficial foraging activity and microhabitat colonization during dry and rainy seasons were evaluated as an indication of the climatic impact on population dynamics. We collected 12 scorpion species using ultraviolet light lam...
Source: Canadian Journal of Zoology - March 26, 2018 Category: Zoology Authors: A.F.A. Lira A.M. DeSouza C.M.R. Albuquerque Source Type: research

Nutrition and ontogeny influence weapon development in a long-lived mammal
Canadian Journal of Zoology, e-First Articles. Selection in male cervids should optimize allocation of nutritional resources to the competing demands of body growth versus weapon development. We investigated allocation decisions of growing and mature male white-tailed deer (Odocoileus virginianus (Zimmerman, 1780)) from three regions of low, moderate, and high diet quality. We tested (i) if deer under greater nutritional limitations would allocate proportionally less to antler growth, (ii) if antler and body mass became less variable with age, and (iii) if antler size consistently exhibited positive allometry with body mas...
Source: Canadian Journal of Zoology - March 26, 2018 Category: Zoology Authors: P.D. Jones B.K. Strickland S. Demarais G. Wang C.M. Dacus Source Type: research

Identifying the critical habitat of Canadian vertebrate species at risk
Canadian Journal of Zoology, e-First Articles. Identification of critical habitat is central to major conservation laws protecting endangered species in North America and around the world. Yet the actual ecological research that is required to identify which habitats are critical to the survival or recovery of species is rarely discussed and poorly documented. Here we quantitatively assess the information and methods used to identify critical habitat in the recovery strategies of 53 vertebrates at risk in Canada. Of the critical habitat identifications assessed, 17% were based on habitat occupancy information, 28% on habit...
Source: Canadian Journal of Zoology - March 26, 2018 Category: Zoology Authors: S. Lemieux Lefebvre M. Landry-Cuerrier M.M. Humphries Source Type: research

Don ’t believe the mike: behavioural, directional, and environmental impacts on recorded bat echolocation call measures
Canadian Journal of Zoology, e-First Articles. Echolocation calls produced by bats in their larynges allow these flying, nocturnal mammals to orient and find food at night. The acoustic signals are not like bird song, and even individual bats exhibit great flexibility in call design and between-species overlap is common. As a result, identifying bats to species by their echolocation calls even in communities with few bat species can be difficult. Unfortunately, the situation is worse still. As a result of several factors — some to do with microphones, some with environment, some with bats, and the calls themselves &m...
Source: Canadian Journal of Zoology - March 20, 2018 Category: Zoology Authors: J.M. Ratcliffe L. Jakobsen Source Type: research

Structure, variation, and systematic implications of the hemipenes of liolaemid lizards (Reptilia: Liolaemidae)
We reported 42 characters, the majority not published previously. We constructed a metatree based on previously proposed phylogenetic studies and optimized the hemipenial characters in this topology. Among the most informative characters are presence or absence of flounces or calyces on the sulcate face, ornamentation of the apex, presence or absence of an asulcate face prominence, and presence of a thickening on the proximal region of the asulcate face. Furthermore, we performed a phylogenetic analysis exclusively with the hemipenial characters, not with the intention of making a phylogeny based on this single set of char...
Source: Canadian Journal of Zoology - March 9, 2018 Category: Zoology Authors: M. Quipildor A.S. Quinteros F. Lobo Source Type: research

Critical snow density threshold for Dall ’s sheep (Ovis dalli dalli)
We examined the effect of snow density, snow depth, and snow hardness on sinking depths of Dall’s sheep tracks encountered in Wrangell–St. Elias National Park and Preserve, Alaska. Snow depth was a poor predictor of sinking depths of sheep tracks (R2 = 0.02, p = 0.38), as was mean weighted hardness (R2 = 0.09, p = 0.07). Across competing models, top layer snow density (0–10 cm) and sheep age class were the best predictors of track sink depths (R2 = 0.58). Track sink depth decreased with increasin g snow density, and the snowpack supported the mass of a sheep above a density threshold of 329 ± 18 kg...
Source: Canadian Journal of Zoology - March 5, 2018 Category: Zoology Authors: Kelly J. Sivy Anne W. Nolin Christopher L. Cosgrove Laura R. Prugh Source Type: research

Climate and habitat influences on bee community structure in Western Canada
Canadian Journal of Zoology, e-First Articles. The persistence of pollinators in a given habitat is determined in part by traits that affect their response to environmental variables. Here, we show that climate and habitat features are the main drivers of trait distribution in bees across spatially separated habitats. We determined that trait and clade filtering results in bee assemblages in Western Canada exhibiting clustering that is correlated with differences in temperature, humidity, and rainfall. Phylogenetic signals were detected in all traits associated with pollinator life-history strategies, including phenology. ...
Source: Canadian Journal of Zoology - March 5, 2018 Category: Zoology Authors: Soraya Villalobos Jana C. Vamosi Source Type: research

Elk (Cervus elaphus) railway mortality in Ontario
This study gathered important information about an under-studied aspect of wildl ife–human conflicts and provides a basis for the investigation of other species that may be affected by railways. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - March 4, 2018 Category: Zoology Authors: J.N. Popp J. Hamr C. Chan F.F. Mallory Source Type: research

Effect of forager density on feeding rates in spring-staging Semipalmated Sandpipers (Calidris pusilla) using different foraging modes
We examined the influence of the density of foragers on feeding rates of Semipalmated Sandpipers (Calidris pusilla (Linnaeus, 1766)) while using different foraging modes at a spring stopover site in Delaware Bay, USA. Using dynamic estimates of interindividual distances obtained at short intervals of time, we explored how forager density affected feeding rates when Semipalmated Sandpipers used visual pecking or tactile probing. Pecking rate significantly increased with interindividual distances, whereas probe rate was not affected by density. Our study also showed that in fast-moving foragers, such as Semipalmated Sandpipe...
Source: Canadian Journal of Zoology - March 4, 2018 Category: Zoology Authors: Ivana Novcic Guy Beauchamp Source Type: research

Fatty acids in an iteroparous fish: variable complexity, identity, and phenotypic correlates
Canadian Journal of Zoology, e-First Articles. Ecologists often focus on summarized composition when assessing complex, multivariate phenotypes such as fatty acids. Increasing complexity in fatty acid composition may offer benefits to individuals that may not be recognized by assessing mean fatty acid identity. We quantified fatty acid identity and complexity in the egg and muscle of spawning female yellow perch (Perca flavescens (Mitchill, 1814)) exposed to three overwinter thermal regimes (4, 8, and 13 °C) to evaluate (i) thermal regulation of fatty acid complexity, (ii) fatty acid complexity and identity differences...
Source: Canadian Journal of Zoology - March 4, 2018 Category: Zoology Authors: Zachary S. Feiner Robert K. Swihart David P. Coulter Tomas O. H öök Source Type: research

Contrasts in body size and growth suggest that high population density results in faster pace of life in Damaraland mole-rats (Fukomys damarensis)
Canadian Journal of Zoology, e-First Articles. We studied the correlates of population density and body size, growth rates, litter size, and group size in Damaraland mole-rats (Fukomys damarensis (Ogilby, 1838)) at two study sites with contrasting population densities. Group size, litter size, and the probability of recapture were independent of study site. However, body size differed between the two study sites, suggesting that population density may affect life-history traits in social mole-rats. At the low-density site (0.13 groups/ha), individuals were significantly larger and subordinate males showed higher growth rat...
Source: Canadian Journal of Zoology - March 3, 2018 Category: Zoology Authors: K.T. Finn D.M. Parker N.C. Bennett M. Z öttl Source Type: research

The impact of acute salinity exposure and temperature on the survival, osmoregulation, and hematology of juvenile shortnose sturgeon (Acipenser brevirostrum)
Canadian Journal of Zoology, e-First Articles. Juvenile shortnose sturgeon (Acipenser brevirostrum Lesueur, 1818) were exposed to seawater and freshwater for 24 h to evaluate the osmoregulatory capabilities over a seasonal temperature gradient (5, 10, 15, 20 °C). Additionally, juveniles were exposed to 5 °C seawater and freshwater over 72 h to evaluate survival and osmoregulatory capacity under cold water conditions. Osmoregulatory capability was evaluated using standard metrics: survival rate, mass loss, plasma chloride ion (Cl–) concentrations, os molality, oxygen-carrying variables, and energy metabolites....
Source: Canadian Journal of Zoology - March 3, 2018 Category: Zoology Authors: Adam T. Downie Hannah Wallace Samantha Taylor James D. Kieffer Source Type: research

First full annual cycle tracking of a declining aerial insectivorous bird, the Common Nighthawk (Chordeiles minor), identifies migration routes, nonbreeding habitat, and breeding site fidelity
Canadian Journal of Zoology, e-First Articles. Over one third of North American bird species are in decline, and for many species, we still lack fundamental biogeographic information such as migration routes and nonbreeding areas. Identifying causes of declines is limited because tracking many species throughout their annual cycle with high precision and accuracy is challenging. Common Nighthawks (Chordeiles minor (J.R. Forster, 1771)) have declined throughout much of their range and have yet to have their migratory and nonbreeding areas identified and characterized. We tracked Common Nighthawks by deploying a new 3.5 g Pi...
Source: Canadian Journal of Zoology - March 3, 2018 Category: Zoology Authors: J.W. Ng E.C. Knight A.L. Scarpignato A.-L. Harrison E.M. Bayne P.P. Marra Source Type: research

Primary study of seroprevalence to virus pathogens in wild felids of South Primorie, Russia
Canadian Journal of Zoology, e-First Articles. Seroprevalence to nine different virus pathogens was estimated for Russian big cats (Amur tiger (Panthera tigris altaica Temminck, 1844) and far-eastern leopard (Panthera pardus orientalis (Schiegel, 1857))) in Southern Primorie, Russia (n = 25), in 2008 –2016. Serum samples from smaller cats (Eurasian lynx (Lynx lynx (Linnaeus, 1758)) and far-eastern wildcat (leopard cat) (Prionailurus bengalensis euptilurus (Elliot, 1871))) were also tested for these pathogens (n = 19) during the same period. Felids of Russian Southern Primorie showed seropreval ence to eight out of ni...
Source: Canadian Journal of Zoology - March 3, 2018 Category: Zoology Authors: S.V. Naidenko J.A. Hernandez-Blanco E.V. Pavlova M.N. Erofeeva P.A. Sorokin M.N. Litvinov A.K. Kotlyar N.S. Sulikhan V.V. Rozhnov Source Type: research

First study on lipid dynamics during the female reproductive cycle of Polybetes pythagoricus (Araneae: Sparassidae)
Canadian Journal of Zoology, e-First Articles. Spiders are valuable to humans, not only for their role in health but also as biologic pest controllers. In oviparous species, lipids are the main energy source for embryo development and the growth and survival of larvae. Using the spider Polybetes pythagoricus (Holmberg, 1875) as an experimental model, we studied the fluctuations in lipids and fatty acids occurring in tissues related to vitellogenesis. Different reproductive stages (previtellogenesis, early vitellogenesis, vitellogenesis, and postvitellogenesis) were determined histologically. Gonadosomatic and hepatosomatic...
Source: Canadian Journal of Zoology - March 3, 2018 Category: Zoology Authors: S. Romero A. Laino F. Arrighetti M. Cunningham C.F. Garcia Source Type: research

Fragmentation alters home range and movements of the Dunes Sagebrush Lizard (Sceloporus arenicolus)
Canadian Journal of Zoology, e-First Articles. Habitat fragmentation is a major driver of biodiversity loss and among reptiles has been attributed as a cause of species decline. The negative effect of habitat fragmentation has also been shown to be worse for species that are habitat specialists. The Dunes Sagebrush Lizard (Sceloporus arenicolus Degenhardt and Jones, 1972) is a species that specializes on the shinnery oak (Quercus havardii Rydb.) sand-dune landform of the Mescalero –Monahans Sandhills ecosystem in western Texas and eastern New Mexico, USA. This landform has been fragmented by roads and well pads used ...
Source: Canadian Journal of Zoology - February 22, 2018 Category: Zoology Authors: Megan E. Young Wade A. Ryberg Lee A. Fitzgerald Toby J. Hibbitts Source Type: research