A re-examination of the relationship between Steller sea lion (Eumetopias jubatus) diet and population trend using data from the Aleutian Islands
Canadian Journal of Zoology, e-First Articles. Prey diversity and energy density have been linked to each other and to population trends in many studies of bird and mammal diets. We re-examined these relationships in Steller sea lions (Eumetopias jubatus (Schreber, 1776)) using data collected from the Aleutian Islands, where there has been a strong longitudinal gradient in population trend. Diet diversity and energy density metrics were similar in the western Aleutians, where sea lion counts declined consistently, and in the easternmost Aleutian area, where population trends improved significantly. We compared traditional ...
Source: Canadian Journal of Zoology - November 27, 2019 Category: Zoology Authors: L. Fritz B. Brost E. Laman K. Luxa K. Sweeney J. Thomason D. Tollit W. Walker T. Zeppelin Source Type: research

The life history and feeding ecology of velvet shell, Velutina velutina (Gastropoda: Velutinidae), a specialist predator of ascidians
This study outlines the life history and feeding ecology of V. velutina in eastern Canada based on laboratory work complemented by field observations. The life history of V. velutina is closely linked with ascidians, which serve as prey and protection for their egg capsules. Egg capsules were embedded within tunics of Aplidium glabrum (Verrill, 18 71) and Ascidia callosa Stimpson, 1852, with a preference for the latter. Seasonal behavioural shifts were consistent annually and corresponded with seawater temperature cycles. Feeding dominated during the coldest months (January–May), growth occurred as water temperature ...
Source: Canadian Journal of Zoology - November 26, 2019 Category: Zoology Authors: P.S. Sargent J.-F. Hamel A. Mercier Source Type: research

Seasonal differences in foraging and isotopic niche width related to body size in Gulf of Alaska harbor seals
Canadian Journal of Zoology, e-First Articles. Harbor seals (Phoca vitulina Linnaeus, 1758) use different foraging strategies based on body size and sex, but this difference can be difficult to evaluate across seasons. We used stable isotope analysis of harbor seal whiskers from 32 individuals to assess seasonal foraging of seals inhabiting tidewater glacial habitat in Southeast Alaska. We analyzed stable isotope ratios from serial sections of whiskers, estimated deposition date for each section, and used mixed models to determine if sex and body size influence stable isotope ratios. Seals were grouped by size (>1.4 m o...
Source: Canadian Journal of Zoology - November 26, 2019 Category: Zoology Authors: Justin Smith Shawna Karpovich Lara Horstmann Julie McIntyre Diane M. O ’Brien Source Type: research

Migration and disturbance: impact of fencing and development on Western Rattlesnake (Crotalus oreganus) spring movements in British Columbia
This study contributes significantly to our knowledge of how fencing barriers may impact normal behavioural patterns in smaller vertebrates. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - November 26, 2019 Category: Zoology Authors: Jared R. Maida Christine A. Bishop Karl W. Larsen Source Type: research

Keeping cool in the warming Arctic: thermoregulatory behaviour by Svalbard reindeer (Rangifer tarandus platyrhynchus)
In this study, we investigated if the cold-adapted Svalbard reindeer (Rangifer tarandus platyrhynchus (Vrolik, 1829)) used cool bed sites as a thermoregulatory behaviour in the summer. We recorded habitat variables and ground temperature at 371 bed sites with random “control” sites 10 and 100 m distant. Using case-control logistic regression, we found that reindeer selected bed sites on cool substrates (snow and mire), as well as cold, dry ground on days with warm ambient temperatures, while they avoided such sites on cold days. Selection of both cool subst rates and cool ground did not depend on age or sex. Th...
Source: Canadian Journal of Zoology - November 23, 2019 Category: Zoology Authors: Linda Williamsen Gabriel Pigeon Atle Mysterud Audun Stien Mads Forchhammer Leif Egil Loe Source Type: research

Male courtship behavior is triggered by female chemical cues in the scorpion Tityus pusillus (Scorpiones: Buthidae)
Canadian Journal of Zoology, e-First Articles. Recognizing conspecific individuals from other members of the community is important for many interactive behaviors, especially those involved in mate selection. We investigated whether male courtship behavior is triggered by chemical cues left by females on the substrate using the sedentary litter-dwelling scorpion Tityus pusillus Pocock, 1893, which is a small and common species distributed throughout the northeast Atlantic Forest in Brazil. In experiments using 50 pairs, we tested whether males recognize females by detecting sex-specific chemicals on the substrate. All male...
Source: Canadian Journal of Zoology - November 19, 2019 Category: Zoology Authors: L.M. Pordeus A.F.A. Lira C.M.R. Albuquerque Source Type: research

Experimentally derived incorporation rates and diet-to-tissue discrimination values for carbon and nitrogen stable isotopes in gray wolves (Canis lupus) fed a marine diet
Canadian Journal of Zoology, e-First Articles. Recent studies have noted the differential effects of marine versus terrestrial diets on the carbon and nitrogen stable isotope (13C and 15N, respectively) diet-to-tissue discrimination values and incorporation rates for omnivorous and carnivorous mammals. Inaccurate estimates of these parameters may result in misrepresentation of diet composition or in the timing of diet shifts. Here, we present the results of a diet-switch experiment designed to estimate diet-to-tissue discrimination values and incorporation rates for tissues of gray wolves (Canis lupus Linnaeus, 1758) fed a...
Source: Canadian Journal of Zoology - November 19, 2019 Category: Zoology Authors: A.E. Stanek N. Wolf J.M. Welker S. Jensen Source Type: research

Investigating fish migration, mortality, and physiology to improve conservation planning of anadromous salmonids: a case study on the endangered North Sea houting (Coregonus oxyrinchus)
In this study, freshwater and marine migrations of the endangered salmonid North Sea houting (Coregonus oxyrinchus (Linnaeus, 1758)) were investigated using telemetry. Furthermore, physiological samples were collected from North Sea houting and from resident and anadromous populations of the closely related European whitefish (Coregonus lavaretus (Linnaeus, 1758)) to compare hypo-osmotic tolerances. On average, North Sea houting spent 193 days at sea where the mortality was 36%. Most fish returned from sea in the autumn, and river entry correlated inversely with river temperature and positively with discharge. Fish spent a...
Source: Canadian Journal of Zoology - November 19, 2019 Category: Zoology Authors: M. Hertz L.F. Jensen C. Pertoldi K. Aarestrup S.N. Thomsen A.K.O. Alstrup H. Asmus S.S. Madsen J.C. Svendsen Source Type: research

From abalone to zebra mussels: 90 years of the Canadian Journal of Zoology
Canadian Journal of Zoology, e-First Articles. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - November 6, 2019 Category: Zoology Authors: R. Mark Brigham Helga Guderley Tamer A. Elbokl Source Type: research

Relating the 4-year lemming (Lemmus spp. and Dicrostonyx spp.) population cycle to a 3.8-year lunar cycle and ENSO
Canadian Journal of Zoology, e-First Articles. Reported peak years of lemming (Lemmus spp. and Dicrostonyx spp.) and Arctic fox (Vulpes lagopus (Linnaeus, 1758)) abundance were compiled from the literature for 12 locations spanning 127 years. The mean period of the 34 reported lemming and Arctic fox cycles from 1868 to 1994 was 3.8 years, suggesting that the period of the 4-year cycle is actually 3.8 years. Peak population years were predicted using a simple model based on a 3.8-year lunar cycle. For nearly 130 years, reported years of peak abundance of lemmings and Arctic foxes were significantly correlated with and have ...
Source: Canadian Journal of Zoology - November 1, 2019 Category: Zoology Authors: H.L. Archibald Source Type: research

Testing theoretical metapopulation conditions with genotypic data from Boreal Chorus Frogs (Pseudacris maculata)
Canadian Journal of Zoology, e-First Articles. The metapopulation concept has far-reaching implications in ecology and conservation biology. Hanski ’s criteria operationally define metapopulations, yet testing them is hindered by logistical and financial constraints inherent to the collection of long-term demographic data. Hence, ecologists and conservationists often assume metapopulation existence for dispersal-limited species that occupy pa tchy habitats. To advance understanding of metapopulation theory and improve conservation of metapopulations, we used population and landscape genetic tools to develop a methodo...
Source: Canadian Journal of Zoology - October 25, 2019 Category: Zoology Authors: Shawn M. Billerman Brett R. Jesmer Alexander G. Watts Peter E. Schlichting Marie-Jos ée Fortin W. Chris Funk Paul Hapeman Erin Muths Melanie A. Murphy Source Type: research

Factors affecting space use by wild boars (Sus scrofa) in high-elevation tropical forests
Canadian Journal of Zoology, e-First Articles. The wild boar (Sus scrofa Linnaeus, 1758) is considered one of the 100 worst invasive species in the world and is present in the high-elevation forests in Brazil. Our objective was to understand how landscape and atmospheric conditions affect space use by wild boars. We hypothesized that wild boars would be more frequent at lower elevations, warmer and wetter forested areas, and away from human disturbances. After three years of data collection (2013 –2016) using 16 camera traps, 881 independent records were obtained with a mean of 4.44 ± 9.25 pigs per record. Wil...
Source: Canadian Journal of Zoology - October 16, 2019 Category: Zoology Authors: T.A. Morais C.A. Rosa C.S. Azevedo A.B. Viana-Junior P. Santos M. Passamani Source Type: research

Growth, developmental, and size structure responses in tadpole prey under increasing threat from gape-limited newts
Canadian Journal of Zoology, e-First Articles. Size variability within a cohort can have profound effects on community ecology and evolution. Although competition for resources generally increases size variability, the effect of (non-consumptive) predation on this demographic trait remains relatively poorly understood. Existing models suggest a positive correlation between growth rate (mediated by resource level) and expression of size variability (as measured by the coefficient of variation) in prey cohorts. We tested this prediction by exposing the tadpoles of the Japanese Forest Green Treefrog (Rhacophorus arboreus (Oka...
Source: Canadian Journal of Zoology - October 10, 2019 Category: Zoology Authors: Noelikanto Ramamonjisoa Akira Mori Source Type: research

Novel “omega muscle units” in superficial body-wall myotomes during metamorphosis in the northern brook lamprey (Ichthyomyzon fossor)
Canadian Journal of Zoology, e-First Articles. Lampreys transform from sedentary filter feeders to more mobile adults through a dramatic metamorphosis that includes remodeling of head muscle and skeletal systems. Metamorphic modifications of body-wall myotomes that could support changes in swimming behavior from larvae to adults have not been previously reported. Thus, transverse sections of northern brook lamprey (Ichthyomyzon fossor Reighard and Cummins, 1916) in larval (n = 4), metamorphosing (n = 3), and adult (n = 2) stages were used to investigate the architecture of body-wall muscle and to detect whether Pax7 and My...
Source: Canadian Journal of Zoology - October 9, 2019 Category: Zoology Authors: J.E. Anderson A. Cunha M.F. Docker Source Type: research

Rapid adoption of nest boxes by Prothonotary Warblers (Protonotaria citrea) in mesic deciduous forest
Canadian Journal of Zoology, e-First Articles. Breeding territory selection in Prothonotary Warblers (Protonotaria citrea (Boddaert, 1783)) is thought to hinge on standing water, with a strong preference for low-lying areas prone to seasonal flooding. However, we have observed this species nesting in much drier areas than previously reported. We recently initiated a study of the Carolina Wren (Thryothorus ludovicianus (Latham, 1790)) using wooden nest boxes, and nearly 60% of all nests produced in these boxes during the initial study year were produced by Prothonotary Warblers, despite this species being absent from our fi...
Source: Canadian Journal of Zoology - September 4, 2019 Category: Zoology Authors: A.J. Mueller D.J. Twedt E.K. Bowers Source Type: research

Effects of industrial disturbance on abundance and activity of small mammals
Canadian Journal of Zoology, e-First Articles. Anthropogenic disturbance can negatively impact animal populations and alter the behaviour of individuals. Disturbance associated with the energy sector has been increasing in the boreal forest of northern Alberta. Disturbances associated with the oil and gas industry vary in the infrastructure present and sensory stimuli generated. Two common types are compressor stations and roads. It is important to assess population consequences of disturbance on small mammals because they serve as prey, predators, and seed –spore dispersers in the terrestrial ecosystems that they in...
Source: Canadian Journal of Zoology - September 4, 2019 Category: Zoology Authors: J. Shonfield E.M. Bayne Source Type: research

Seasonal variability and individual consistency in gray seal (Halichoerus grypus) isotopic niches
We examined skin, fur, and blood components to investigate seasonal variability and individual consistency in foraging niches, and serially sampled vibrissae to quantify the degree of individual foraging specialization in this population. Our results suggest that seals shift from coastal foraging habitats before molt to offshore habitats after molt, with a coincident shift from higher to lower trophic-level prey. Adult gray seals also exhibited individual consistency in foraging niches independent of population-level shifts and reflect a generalist population composed of individual foraging specialists. These findings serv...
Source: Canadian Journal of Zoology - August 24, 2019 Category: Zoology Authors: K.M. Hernandez A.L. Bogomolni J.H. Moxley G.T. Waring R.A. DiGiovanni M.O. Hammill D.W. Johnston L. Sette M.J. Polito Source Type: research

Influence of field technique, density, and sex on home range and overlap of the southern red-backed vole (Myodes gapperi)
We examined the effect of density, sex, and field method on home range of southern re d-backed voles (Myodes gapperi (Vigors, 1830)) inhabiting eastern hemlock (Tsuga canadensis (L.) Carrière) forests. Twelve mark–recapture grids were used to census M. gapperi from 2014 to 2017. In 2017, individuals were radio-collared. Home-range size, core-area size, and shared space were calcul ated using kernel density estimators from both mark–recapture and radiotelemetry data. Density effects on home range and core area were analyzed and differences between sex and field method were compared. We found (i) density d...
Source: Canadian Journal of Zoology - August 17, 2019 Category: Zoology Authors: Honora B. Tisell Allyson L. Degrassi Ryan B. Stephens Rebecca J. Rowe Source Type: research

Variation in anti-predator behaviors of white-tailed deer (Odocoileus virginianus) in a multi-predator system
Canadian Journal of Zoology, e-First Articles. Anti-predator responses to perceived predation risk can influence population demography. Understanding the relative effect of predator exposure and intraspecific interactions across a variety of anti-predator behaviors provides important insight into inter- and intra-specific drivers of species-specific behaviors. We merged classical behavioral observation methods with camera trapping techniques to examine anti-predator behaviors of white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) relative to variation in predator exposure and interspecific interactions. We coded ...
Source: Canadian Journal of Zoology - August 17, 2019 Category: Zoology Authors: E.R. Olson T.R. Van Deelen S.J. Ventura Source Type: research

Alarm calls of the same individual vary during a response to the same predator in Gunnison ’s prairie dogs (Cynomys gunnisoni)
Canadian Journal of Zoology,Volume 97, Issue 11, Page 1092-1100, November 2019. Many animals emit vocalizations in a repetitive series, but are all the calls within a series structurally the same? To answer this question, we recorded the barks of adult female Gunnison ’s prairie dogs (Cynomys gunnisoni (Baird, 1855)) during 5 min experimental presentations of several terrestrial stimuli. We measured eight variables (primarily pitch and duration measures) of the first, middle, and last barks in each bout of barking produced by each of 24 females, as well as the duration of inter-bout intervals, the number of barks per...
Source: Canadian Journal of Zoology - August 16, 2019 Category: Zoology Authors: W.J. Loughry M. Oeser J.L. Hoogland Source Type: research

Modeling allometric variation: lessons from the metabolic allometry of black carp (Mylopharyngodon piceus)
Canadian Journal of Zoology, e-First Articles. I used linear and nonlinear regression to re-examine published data on the scaling of metabolic rate vs. body mass in an ontogenetic series of black carp (Mylopharyngodon piceus (Richardson, 1846)). My objective was to expose shortcomings of the conventional procedure for fitting statistical models to bivariate observations (i.e., the procedure that is widely attributed to J.S. Huxley) and simultaneously to outline a more general and utilitarian protocol for analyzing bivariate data in studies of allometry. Authors of the original study on carp reported exponents of 0.83 and 0...
Source: Canadian Journal of Zoology - August 15, 2019 Category: Zoology Authors: G.C. Packard Source Type: research

Changes in underground roosting patterns to optimize energy conservation in hibernating bats
Canadian Journal of Zoology, e-First Articles. Non-migratory bats in colder climates use hibernation to survive winter. By reducing metabolic rate (i.e., using torpor), bats can survive winter on stored fat reserves. During hibernation, bats arouse from torpor and may move within the hibernaculum, a process called “internal migration”. We hypothesized that internal migration occurs to optimize hibernation energetics in that bats move to select a microclimate to minimize energy expenditure both by seeking cooler areas of the hibernacula and avoiding those with large temperature fluctuations. Early in the w inter...
Source: Canadian Journal of Zoology - August 15, 2019 Category: Zoology Authors: Caleb C. Ryan Lynne E. Burns Hugh G. Broders Source Type: research

Trace element and stable isotope analysis elucidate stock structure in a narwhal (Monodon monoceros) population with no genetic substructure
Canadian Journal of Zoology, e-First Articles. Chemical composition of tissues can act as a biological tag to discriminate among groups of animals that inhabit different areas. In Canada, subsistence hunting of the Baffin Bay narwhal (Monodon monoceros Linnaeus, 1758) population is managed as stocks represented by summer aggregations. However, narwhals are highly mobile and are hunted during the migration while stocks mix. Thus, information that can help managers decipher the stock origin of hunted individuals to prevent overexploitation of animals adapted to particular summering grounds is needed. Stable isotope and trace...
Source: Canadian Journal of Zoology - August 8, 2019 Category: Zoology Authors: Cortney A. Watt Claire Hornby Steven H. Ferguson Source Type: research

Spatial, sexual, and rapid temporal differentiation in neuromast expression on lateral plates of Haida Gwaii threespine stickleback (Gasterosteus aculeatus)
We examined numbers of superficial neuromasts on the buttressing lateral plates (LP) of 1910 threespine stickleback (Gasterosteus aculeatus Linnaeus, 1758) from 26 ecologically and morphologically diverse populations on the Haida Gwaii archipelago, western Canada. Extending from previous studies, we predicted that (i) highly stained dystrophic localities would have threespine stickleback with elevated numbers of neuromasts per plate due to a greater reliance on non-visual sensory modalities and (ii) that LP count and neuromast numbers per plate would functionally covary with predatory assemblage. We found that there were n...
Source: Canadian Journal of Zoology - August 1, 2019 Category: Zoology Authors: N.P. Planidin T.E. Reimchen Source Type: research

Host resistance and tolerance to parasitism: development-dependent fitness consequences in Common Hourglass Tree Frog (Polypedates cruciger) tadpoles exposed to two larval trematodes
Canadian Journal of Zoology, e-First Articles. Tolerance and resistance to parasites are defense strategies of host organisms. Here, we tested the development-dependent tolerance and resistance of Polypedates cruciger Blyth, 1852 tadpoles to trematode infection. We exposed the tadpoles at Gosner stages 27, 28 –29, and 30–31 to two types of cercariae (furcocercous and pleurolophocercous cercariae of Acanthostomum burminis (Bhalerao, 1926)) under laboratory conditions. To determine tolerance (the ability of a host to limit health effects of a given parasite load), we exposed the tadpoles until all cerc ariae pene...
Source: Canadian Journal of Zoology - July 30, 2019 Category: Zoology Authors: N.U.K. Pathirana M. Meegaskumbura R.S. Rajakaruna Source Type: research

Does prey availability affect the reproductive performance of Barn Swallows (Hirundo rustica) breeding in Ontario, Canada?
Canadian Journal of Zoology, e-First Articles. Animal populations are often limited by food availability, particularly during the breeding season. In birds, food limitation can impact several components of the reproductive cycle, including the timing of reproduction and reproductive output. Barn Swallows (Hirundo rustica Linnaeus, 1758) have experienced a population decline over the past 40 years in North America that is thought to be related to changes in prey availability. We monitored Barn Swallow reproductive behaviour and prey availability throughout two breeding seasons at 10 sites in Ontario, Canada, to test the hyp...
Source: Canadian Journal of Zoology - July 27, 2019 Category: Zoology Authors: Beverly McClenaghan Kevin C.R. Kerr Erica Nol Source Type: research

Phenotypic plasticity under desert environment constraints: mandible variation in the dwarf fat-tailed jerboa, Pygeretmus pumilio (Rodentia: Dipodidae)
Canadian Journal of Zoology,Volume 97, Issue 10, Page 940-951, October 2019. Arid areas have a comparatively narrow range of habitat types, with restricted variation in environmental parameters, leaving narrow boundaries for phenotypic variation to correlate with ecological variables. To test this presumption, we explored variation in size and shape of the mandible in the dwarf fat-tailed jerboa (Pygeretmus pumilio (Kerr, 1792)) under the constraints of a rigorous desert environment. Size varied significantly and predictably with geographic position and demonstrated a strong, nonlinear longitudinal pattern. Moreover, size ...
Source: Canadian Journal of Zoology - July 26, 2019 Category: Zoology Authors: B. Kry štufek F. Jan žekovič G. Shenbrot D. Ivajn šič T. Klenov šek Source Type: research

Beta diversity and factors that drive land-snail patterns in Jiangxi Province, People ’s Republic of China
Canadian Journal of Zoology, e-First Articles. Jiangxi Province is a biodiversity hotspot in the People ’s Republic of China and has abundant land-snail species (247). Beta diversity is a key concept for understanding the functioning of ecosystems, the conservation of biodiversity, and the management of ecosystems. Here, the pattern of beta diversity for land snails in Jiangxi Province was analyzed. The results showed that the spatial turnover component was the main contributor to beta diversity, indicating that additional conservation efforts must target an increase in the number of protected areas, which should be ...
Source: Canadian Journal of Zoology - July 26, 2019 Category: Zoology Authors: Yang Xu Xiongjun Liu Guanglong Xie Jiajun Qin Xiaoping Wu Shan Ouyang Source Type: research

The impact of ectoparasitism on thermoregulation in Yarrow ’s Spiny Lizards (Sceloporus jarrovii)
Canadian Journal of Zoology, e-First Articles. Parasites are ubiquitous and can have large impacts on the fitness of their hosts. The effects of ectoparasites on physiology, behaviour, and immune function suggest that they could be part of the factors which impact thermoregulation. We tested the hypothesis that ectoparasites impact thermoregulation in Yarrow ’s Spiny Lizards (Sceloporus jarrovii Cope in Yarrow, 1875) living along an elevational gradient. We predicted a positive association between ectoparasite load and body temperature (Tb), and a negative association between ectoparasite load and effectiveness of th...
Source: Canadian Journal of Zoology - July 8, 2019 Category: Zoology Authors: N. Johnson A.H. Lymburner G. Blouin-Demers Source Type: research

Evidence for spring stopover refuelling in migrating silver-haired bats (Lasionycteris noctivagans)
Canadian Journal of Zoology, e-First Articles. Migrating animals must acquire sufficient fuel to sustain migratory movement, but how time is allocated to achieve this can vary greatly. The fuel strategies used by migrating bats are not well understood and have not been investigated during the spring when insectivorous bats face low food abundance. Migrating silver-haired bats (Lasionycteris noctivagans (Le Conte, 1831)) were captured at a stopover site in Long Point, Ontario, Canada, in April and May of 2012 –2014. We followed the movements of 40 bats outfitted with radio transmitters using an automated telemetry arr...
Source: Canadian Journal of Zoology - June 27, 2019 Category: Zoology Authors: Kristin A. Jonasson Christopher G. Guglielmo Source Type: research

Occupancy, detectability, and density of crab-eating fox (Cerdocyon thous) in two protected areas of restinga habitats in Brazil
Canadian Journal of Zoology,Volume 97, Issue 10, Page 952-959, October 2019. Crab-eating foxes (Cerdocyon thous (Linnaeus, 1766)) are frequently recorded in lists of mammal communities. However, studies quantifying aspects of the ecology of the species are uncommon in the literature. Thus, we aimed to quantify the density, activity, habitat use, and potential threats of C. thous in two protected areas (PAs) in the State of Esp írito Santo, Brazil. We used data derived from camera traps and sand plots to model occupancy, detectability, activity; we also used random encounter models (REMs) to model density and abundan...
Source: Canadian Journal of Zoology - June 27, 2019 Category: Zoology Authors: Priscila St éfani Monteiro-Alves D ébora Molino Helmer Atilla Colombo Ferreguetti Juliane Pereira-Ribeiro Carlos Frederico Duarte Rocha Helena Godoy Bergallo Source Type: research

Trophic interactions between the Kelp Gull (Larus dominicanus) and Royal and Cayenne terns (Thalasseus maximus maximus and Thalasseus sandvicensis eurygnathus, respectively) in a human-modified environment
Canadian Journal of Zoology, e-First Articles. Many closely related seabirds nest in mixed colonies, and this association may result in interspecific interactions such as competition for common resources and kleptoparasitism. Trophic interactions were evaluated between the Kelp Gull (Larus dominicanus Lichtenstein, 1823) and Royal and Cayenne terns (Thalasseus maximus maximus (Boddaert, 1783) and Thalasseus sandvicensis eurygnathus (Saunders, 1876), respectively) nesting at a mixed-species colony in an area with high availability of recreational fishery waste for the opportunistic Kelp Gull. Diet analyses were based on gul...
Source: Canadian Journal of Zoology - June 26, 2019 Category: Zoology Authors: Cristian Marinao Nicol ás Suárez Pablo Yorio Source Type: research

Seasonal variation in the foraging activity of desert argali (Ovis ammon) in Mongolia
Canadian Journal of Zoology,Volume 97, Issue 10, Page 931-939, October 2019. Debate remains whether energy maximization or time minimization strategies best explain foraging in ungulates. It has also been hypothesized that the capacity of an animal to dissipate body heat regulates animal activity. We investigated these hypotheses while measuring the daily activity of desert argali (Ovis ammon (Linnaeus,1758)) for 12 months and relating the activity pattern to environmental seasonality. We found significant seasonal cycles in argali activity, with the greatest proportion of daytime in winter spent foraging and the greatest ...
Source: Canadian Journal of Zoology - June 21, 2019 Category: Zoology Authors: Barry Rosenbaum Richard P. Reading Garam Tsogtjargal Sukh Amgalanbaatar Sebastien Comte Source Type: research

Parasites of Prussian carp (Carassius gibelio): an invasive species in Alberta, Canada
We examined 22 fish (20 female, 2 male) ranging from 3 to 5 years of age and recorded morphological features, stomach contents, and performed standard necropsy examinations for parasites. One parasite species, the acanthocephalan Pomphorhynchus bulbocolli Linkins in Van Cleave, 1919, was found in three fish (14%), with a mean intensity of 1.0. This is a new host record and the first report of any acanthocephalan parasite in Prussian carp. We conclude that Prussian carp are not introducing any novel parasites into native fish and that they are resistant to most infections by native parasites. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - June 21, 2019 Category: Zoology Authors: Hasanna Kucher T.M. Stock Mrinal K. Das Source Type: research

Winter movement behavior by swift foxes (Vulpes velox) at the northern edge of their range
Canadian Journal of Zoology, e-First Articles. Winter can be a limiting time of year for many temperate species, who must access depressed prey resources to meet energetic demands. The swift fox (Vulpes velox (Say, 1823)) was extirpated from Canada and Montana (USA) by 1969, but was reintroduced in the 1980s to Canada, and subsequently spread into northern Montana. Swift foxes in this region are at the current northern range edge where winter conditions are harsher and persist longer than in their southern range (i.e., Colorado (USA) to Texas (USA)). We collected fine-scale locational data from swift foxes fitted with glob...
Source: Canadian Journal of Zoology - June 9, 2019 Category: Zoology Authors: Andrew R. Butler Kristy L.S. Bly Heather Harris Robert M. Inman Axel Moehrenschlager Donelle Schwalm David S. Jachowski Source Type: research

Macroecological approach for scorpions (Arachnida, Scorpiones): β-diversity in Brazilian montane forests
Canadian Journal of Zoology, e-First Articles. The montane forests of northeastern Brazil are patches of rainforests, surrounded by xeric vegetation, that originated during the expansion of rainforests in the Pleistocene epoch. Their historical processes make these areas ideal for biogeographical investigations of organisms, particularly in groups with low dispersion and habitat specificity, such as scorpions. We perform a macroecological investigation of the community assembly process of scorpions, disentangling the pattern of β-diversity to test the hypothesis that the similarity in the composition of scorpion fauna...
Source: Canadian Journal of Zoology - June 7, 2019 Category: Zoology Authors: S.I.A. Foerster A.M. DeSouza A.F.A. Lira Source Type: research

Moose, caribou, and fire: have we got it right yet?
Canadian Journal of Zoology, e-First Articles. Natural disturbance plays a key role in shaping community dynamics. Within Canadian boreal forests, the dominant form of natural disturbance is fire, and its effects are thought to influence the dynamics between moose (Alces alces (Linnaeus, 1758)) and the boreal ecotype of woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)). Boreal caribou are considered “threatened” and population declines are attributed, at least in part, to disturbance-mediated apparent competition (DMAC) with moose. Here, we tested a primary prediction of the DMAC hypothesis: that moos...
Source: Canadian Journal of Zoology - June 7, 2019 Category: Zoology Authors: C.A. DeMars R. Serrouya M.A. Mumma M.P. Gillingham R.S. McNay S. Boutin Source Type: research

Recent advances in understanding the environmental footprint of trawling on the seabed
Canadian Journal of Zoology, e-First Articles. Bottom trawling accounts for nearly a quarter of wild-capture seafood production, but it is associated with physical disturbance of the seabed leading to changes in benthic abundance, habitat structure, and biogeochemical processes. Understanding the processes of benthic depletion and recovery in relation to different types of fishing gears, and in different seabed types, is an important pre-requisite to inform appropriate management measures to limit or reduce the effects of trawling on the seabed. The combined approaches of meta-analysis and modelling that link fishing-gear ...
Source: Canadian Journal of Zoology - May 27, 2019 Category: Zoology Authors: Michel J. Kaiser Source Type: research

Density, snow, and seasonality lead to variation in muskox (Ovibos moschatus) habitat selection during summer
Canadian Journal of Zoology, e-First Articles. Understanding how environmental conditions influence habitat selection and suitability of free-ranging animals is critical, as the outcome may have implications for individual fitness and population dynamics. Density and snow are among the most influential environmental conditions driving habitat-selection patterns of northern ungulates. We used two decades of census data from high Arctic Greenland to quantify inter- and intra-annual variations in muskox (Ovibos moschatus (Zimmermann, 1780)) habitat selection and suitability during the Arctic summer (July through October). Acr...
Source: Canadian Journal of Zoology - May 17, 2019 Category: Zoology Authors: Orlando Tomassini Floris M. van Beest Niels M. Schmidt Source Type: research

Lower reproductive output of Mountain Bluebirds (Sialia currucoides) in clearcut versus grassland habitat is consistent with a passive ecological trap
Canadian Journal of Zoology, e-First Articles. Clearcutting of forests results in habitats that structurally resemble grasslands and so may act as ecological traps for grassland birds. Several studies have implicated predation as the factor that decreases the number of offspring, but few have examined performance at other breeding stages. Consistent with a passive ecological trap, Mountain Bluebirds (Sialia currucoides (Bechstein, 1798)) that settled in clearcuts in central British Columbia did not differ in age or quality from adults in grasslands. Nest building and laying date of the first egg did not differ between habi...
Source: Canadian Journal of Zoology - May 17, 2019 Category: Zoology Authors: J.A. Stalwick K.L. Wiebe Source Type: research

Neonatal line may develop after birth in the Indo-Pacific bottlenose dolphin (Tursiops aduncus)
This study of Indo-Pacific bottlenose dolphins (Tursiops aduncus (Ehrenberg, 1833)) is the first to investigate when the NNL appears in odontocete dentine. Two to four teeth were prepared by decalcification, thin-sectioning, and staining for 103 dolphins, including 7 dolphins of known age. Tooth length, prenatal and postnatal dentine and NNL widths were measured. Developmental class (foetus, young neonate, older neonate,
Source: Canadian Journal of Zoology - May 17, 2019 Category: Zoology Authors: C.M. Kemper S. Milano A.C. Ciraolo Source Type: research

Small-mammal abundance differs between pipelines, edges, and interior boreal forest habitat
Canadian Journal of Zoology, e-First Articles. Oil and gas development alters boreal forests by creating early-successional habitat and an increased amount of edge. We evaluated which small-mammal species used pipeline rights of way, the influence of vegetation recovery on pipelines, and edge effects in the adjacent forest. Meadow voles (Microtus pennsylvanicus (Ord, 1815)) were the most common species on pipelines, whereas adjacent forest was dominated by southern red-backed voles (Myodes gapperi (Vigors, 1830)), northern red-backed voles (Myodes rutilus (Pallas, 1779)), and North American deer mice (Peromyscus maniculatu...
Source: Canadian Journal of Zoology - May 16, 2019 Category: Zoology Authors: A.F. Darling L. Leston E.M. Bayne Source Type: research

Found, forgotten, and found again: systematics and distribution of Cooper ’s Rocky Mountain snail (Oreohelix cooperi) on a sky island in the Canadian Prairies
Canadian Journal of Zoology, e-First Articles. The results of phylogeographic and biogeographic studies of organisms residing in isolated habitats provide key insights into processes of population differentiation, speciation, and endemicity. Several of the approximately 70 species of land snail in the genus Oreohelix Pilsbry, 1904 occur only on isolated sky islands on the North American Great Plains. The restricted distributions of these snails have led to concerns regarding their conservation status, particularly in western Canada where their systematics and distributions are poorly known. Cooper ’s Rocky Mountain s...
Source: Canadian Journal of Zoology - May 16, 2019 Category: Zoology Authors: Z.W. Dempsey T.M. Burg C.P. Goater Source Type: research

Tools to understand seasonality in health: quantification of microbe loads and analyses of compositional ecoimmunological data reveal complex patterns in Mojave Desert Tortoise (Gopherus agassizii) populations
Canadian Journal of Zoology,Volume 97, Issue 9, Page 841-848, September 2019. Using data from six wild Mojave Desert Tortoise (Gopherus agassizii (Cooper, 1861)) populations, we quantified seasonal differences in immune system measurements and microbial load in the respiratory tract, pertinent to this species ’ susceptibility to upper respiratory tract disease. We quantified bacteria-killing activity of blood plasma and differential leukocyte counts to detect trends in temporal variation in immune function. We used centered log-ratio (clr) transformations of leukocyte counts and stress that such transf ormations are ...
Source: Canadian Journal of Zoology - May 15, 2019 Category: Zoology Authors: F.C. Sandmeier K.L. Leonard C.R. Tracy K.K. Drake T.E. Esque K. Nussear J.M. Germano Source Type: research

How do embryonic turtles process yolk? Evidence from the Snapping Turtle, Chelydra serpentina (Chelydridae)
In this study, we used scanning electron microscopy to determine which of these developmental patterns (if either) occurs in a representative chelonian, the North American Snapping Turtle (Chelydra serpentina (Linnaeus, 1758)). Our observations reveal that yolk-filled endodermal cells progressively fill the yolk sac cavity. These cells become organized around anastomosing blood vessels, forming elongated strands that are morphologically well suited for yolk digestion and vascular transport of nutrients. This developmental pattern shares features with that of squamates, but it differs markedly from that of birds. These obse...
Source: Canadian Journal of Zoology - May 13, 2019 Category: Zoology Authors: Daniel G. Blackburn Luisa Lestz Madeline S. Barnes Kathryn G. Powers Source Type: research

The first assessment of social organisation of the Indian Ocean humpback dolphin (Sousa plumbea) along the south coast of South Africa
Canadian Journal of Zoology, e-First Articles. The Indian Ocean humpback dolphin (Sousa plumbea (G. Cuvier, 1829)) is the most endangered marine mammal species in South Africa, and the overall decline of its abundance and group size may affect the social organisation of the species, potentially accentuating its vulnerability. Understanding the social organisation is therefore particularly relevant to conservation efforts. From photo-identification surveys along the south coast of South Africa from March 2014 to June 2015, we quantified association patterns and investigated the social organisation of Indian Ocean humpback d...
Source: Canadian Journal of Zoology - May 9, 2019 Category: Zoology Authors: Thibaut Bouveroux Stephen P. Kirkman Danielle Conry O. Alejandra Vargas-Fonseca Pierre A. Pistorius Source Type: research

The role of sex and temperature in melanin-based immune function
Canadian Journal of Zoology, e-First Articles. Sex differences in immunity have been observed across a wide range of species. Still, it remains unclear how sex-specific interactions with the environment are linked to sex differences in immunity. We studied the plasticity of immunological sex differences by focusing on melanin-based traits in the Pacific field cricket (Teleogryllus oceanicus (Le Guillou, 1841)). Insects rely on the pigment melanin for both immune function and coloration of the cuticle; therefore, changes in melanin production for one of these traits may indirectly affect the other. Male crickets use melaniz...
Source: Canadian Journal of Zoology - May 9, 2019 Category: Zoology Authors: Rebecca L. Ehrlich Marlene Zuk Source Type: research

Goats adjust their feeding behaviour to avoid the ingestion of different insect species
Canadian Journal of Zoology, e-First Articles. Ungulates feed on plants that are often inhabited by insects. Goats (Capra hircus Linnaeus, 1758) can efficiently avoid the ingestion of setae-covered noxious, caterpillars while feeding, but it is unknown how they respond to non-toxic insects. We filmed and analysed the behavioural responses of goats to smooth, innocuous silkworms (Bombyx mori (Linnaeus, 1758)) while feeding. The goats successfully sorted the silkworms apart from the food despite their tendency to cling to the leaves. Although the goats exhibited behaviours similar to those displayed with noxious caterpillars...
Source: Canadian Journal of Zoology - May 7, 2019 Category: Zoology Authors: T.S. Berman T.A. Glasser M. Inbar Source Type: research

Calcium signalling in early divergence of Metazoa: mechanisms involved in the control of muscle-like cell contraction in Hydra plagiodesmica
Canadian Journal of Zoology, e-First Articles. Our laboratory has previously examined the effect of neuropeptides on the activity of the hypostome of the hydra Hydra plagiodesmica Dioni, 1968 (Cnidaria: Hydrozoa). These results showed that the hypostome, a structure extruded during feeding, responds to myoregulatory peptides and that this mechanism might be regulated by changes in the cytosolic levels of calcium (Ca2+). We analyse now the ways in which Ca2+ modulates hypostome activity during feeding. The use of calcium chelators confirms that Ca2+ is relevant in inducing hypostome extrusion. The assay of compounds that mo...
Source: Canadian Journal of Zoology - May 6, 2019 Category: Zoology Authors: Mar ía Eugenia Alzugaray Mar ía Victoria Gavazzi Jorge Rafael Ronderos Source Type: research

Supplemental feeding may reduce responsiveness of Black-capped Chickadees (Poecile atricapillus) to avian mobbing calls during gap-crossing experiments
Canadian Journal of Zoology, e-First Articles. Deforestation creates gaps in forest habitat, which can limit the movements of many avian species. Increased predation risk associated with crossing open habitats is often considered the primary impediment to crossing gaps. However, other factors such as energetic reserves may also influence these decisions. We conducted playback experiments before and after supplemental feeding of Black-capped Chickadees (Poecile atricapillus (Linnaeus, 1766)) to investigate how energetic reserves influenced gap-crossing decisions. Black-capped Chickadees were less likely to respond to playba...
Source: Canadian Journal of Zoology - May 2, 2019 Category: Zoology Authors: Jacob M. Bailey Matthew W. Reudink Ken A. Otter Source Type: research