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

A molecular approach to identifying the relationship between resource use and availability in Eurasian otters (Lutra lutra)
Canadian Journal of Zoology, e-First Articles. In South Korea, the Eurasian otter (Lutra lutra (Linnaeus, 1758)), a semi-aquatic carnivore, is found mainly in lower order streams that tend to have a low abundance of preferred prey fish species. To investigate the relationship between resource use and availability, we used DNA barcoding to identify otter diet items in 24 otter spraints (faeces) from 16 sites along the Nakdong River basin from 4 to 6 June 2014. At these sites fish availability was assessed using scoop nets and casting nets. Fish formed the bulk of otter diet, which included also frogs, mammals, and reptiles....
Source: Canadian Journal of Zoology - May 1, 2019 Category: Zoology Authors: Sungwon Hong Jeong-Soo Gim Hyo Gyeom Kim Phil E. Cowan Gea-Jae Joo Source Type: research

Effect of social environment on sexual differentiation in the highly gregarious red cherry shrimp (Neocaridina davidi)
Canadian Journal of Zoology, e-First Articles. Studies on social control of functional sex in crustaceans are scarce and focused on hermaphroditic species. Hence, the objective of this study was to determine whether adult sex ratio affects juvenile sexual differentiation in the gonochoristic red cherry shrimp (Neocaridina davidi (Bouvier, 1904)) (Decapoda, Caridea). We tested two alternative hypotheses: (1) that undifferentiated juveniles become males when reared in the presence of adult females and vice versa; (2) that the presence of adult males affects juvenile sexual differentiation through androgenic gland secretions....
Source: Canadian Journal of Zoology - April 30, 2019 Category: Zoology Authors: C. Tropea L.S. L ópez Greco Source Type: research

Food subsidies of raccoons (Procyon lotor) in anthropogenic landscapes
Canadian Journal of Zoology, e-First Articles. Food subsidies from human sources are often exploited by free-ranging vertebrates living in human-dominated landscapes. To explore the importance and attempt to estimate the reliance of raccoons (Procyon lotor (Linnaeus, 1758)) — common synanthropes in North America — on such food subsidies, we analyzed hair samples from 122 raccoons collected across four states in the Midwestern United States (Wisconsin, Minnesota, Iowa, and Illinois), including 9 raccoons that were livetrapped and sampled in Madison (Wisconsin). We f ound that raccoons inhabiting areas with more ...
Source: Canadian Journal of Zoology - April 30, 2019 Category: Zoology Authors: Kelsey Demeny Meredith McLoon Benjamin Winesett Jenna Fastner Eric Hammerer Jonathan N. Pauli Source Type: research

Environmental heterogeneity affects seasonal variation in thyroid hormone physiology of free-living arctic ground squirrels (Urocitellus parryii)
Canadian Journal of Zoology, e-First Articles. Thyroid hormones (TH) are key regulators of metabolism that could play an important role in altering physiology and energy allocation across life-history stages. Here, we examine seasonal TH dynamics from 345 plasma samples collected from 134 free-living arctic ground squirrels (Urocitellus parryii (Richardson, 1825)) across three consecutive years (2014 –2016). We also examine whether unbound levels of triiodothyronine (free T3) in plasma are correlated with total T3 levels and total thyroxine (T4) levels, and whether fecal T3 metabolite levels correlate with plasma TH ...
Source: Canadian Journal of Zoology - April 26, 2019 Category: Zoology Authors: Cory T. Williams Helen E. Chmura Victor Zhang Danielle Dillon Kathryn Wilsterman Brian M. Barnes C. Loren Buck Source Type: research

Latitudinal gradient in cortisol concentrations in Canada lynx (Lynx canadensis) is not explained by diet
Canadian Journal of Zoology, e-First Articles. Food limitation is an important stressor for most wildlife, and many specialist consumers will expand their dietary niche to contend with preferred prey limitation. How these dietary responses feed back into stress-axis regulation, however, is unknown. If alternative prey does not sufficiently fill the energetic requirements normally satisfied by preferred resources, then long-term glucocorticoid concentrations could be elevated in individuals consuming alternative prey. We measured cortisol concentrations and stable isotope ratios ( δ13C and δ15N) in hair of Canad...
Source: Canadian Journal of Zoology - April 26, 2019 Category: Zoology Authors: C.M. Burstahler C.V. Terwissen J.D. Roth Source Type: research

Diet and isotopic niche of eastern sand darter (Ammocrypta pellucida) near the northern edge of its range: a test of niche specificity
Canadian Journal of Zoology, e-First Articles. Niche specificity can predispose species to population declines during periods of resource limitation, yet trophic niche specificity is poorly known for many small-bodied freshwater fishes. Applying a two-tiered approach involving stomach content and stable isotope analyses, we examined the diet and trophic niche of the threatened eastern sand darter (Ammocrypta pellucida (Putnam, 1863)) and co-occurring fishes in the Thames River, Ontario, Canada. As with previous studies, stomach content analysis revealed that eastern sand darter consumed a variety of benthic organisms inclu...
Source: Canadian Journal of Zoology - April 17, 2019 Category: Zoology Authors: Jacob Burbank Mary Finch D. Andrew R. Drake Michael Power Source Type: research

Cisco diversity in a historical drainage of glacial Lake Algonquin
Canadian Journal of Zoology, e-First Articles. Cisco (Coregonus artedi (sensu lato) Lesueur, 1818) forms matching in appearance to Blackfin Cisco from the Laurentian Great Lakes occur in four lakes in Algonquin Park, Ontario, Canada, a historical drainage of glacial Lake Algonquin (precursor of lakes Michigan and Huron). Their occurrence may represent colonization from glacial Lake Algonquin drainage patterns 13  000 calibrated years BP or independent evolution within each lake. Gill-raker numbers, temperature at capture depth during lake stratification, and hurdle models of habitat distribution are summarized. Blac...
Source: Canadian Journal of Zoology - April 17, 2019 Category: Zoology Authors: Allan H. Bell Gabriel Piette-Lauzi ère Julie Turgeon Mark S. Ridgway Source Type: research

Sexual differentiation in juvenile American lobster (Homarus americanus)
Canadian Journal of Zoology, e-First Articles. American lobsters (Homarus americanus H. Milne Edwards, 1837) settling to the bottom after their pelagic larval stage are sexually undifferentiated. Based on stereomicroscope observations, the female ’s gonopore first appeared for lobsters about 13 mm carapace length (CL) and the dimorphism of the first pair of male pleopods was first observed at about 15 mm CL. Based on histological observations, the internal reproductive system for both males and females began differentiating at sizes ≥20 mm CL. The vasa deferentia were observed for males>30 mm CL indicating that...
Source: Canadian Journal of Zoology - April 17, 2019 Category: Zoology Authors: Michel Comeau Kadra Benhalima Source Type: research

The lizard abides: cold hardiness and winter refuges of Liolaemus pictus argentinus in Patagonia, Argentina
Canadian Journal of Zoology, e-First Articles. In environments where the temperature periodically drops below zero, it is remarkable that some lizards can survive. Behaviorally, lizards can find microsites for overwintering where temperatures do not drop as much as the air temperature. Physiologically, they can alter their biochemical balance to tolerate freezing or avoid it by supercooling. We evaluated the cold hardiness of a population of Liolaemus pictus argentinus M üller and Hellmich, 1939 in the mountains of Esquel (Patagonia, Argentina) during autumn. Additionally, we assessed the thermal quality (in degree-da...
Source: Canadian Journal of Zoology - April 7, 2019 Category: Zoology Authors: N.R. Cecchetto S.M. Medina S. Taussig N.R. Ibarg üengoytía Source Type: research

Spatiotemporal habitat use by a multitrophic Alaska alpine mammal community
Canadian Journal of Zoology, e-First Articles. Evaluating sympatric habitat use of a mammal community can help determine intra- and inter-guild interactions and identify important habitats, potentially improving the management of these communities with a changing climate. Increasingly variable climatic patterns in Alaska, USA, are raising concerns of mismatched phenologies and altered ecosystem structures. We studied the occupancy of 10 mammal species over 15 months, via camera traps, occupying alpine areas of the Alaska Range in interior Alaska, from 2013 to 2014. We tested hypotheses about how habitat use of these specie...
Source: Canadian Journal of Zoology - April 5, 2019 Category: Zoology Authors: Jeremy S. Dertien Calvin F. Bagley John A. Haddix Aleya R. Brinkman Elizabeth S. Neipert Kim A. Jochum Paul F. Doherty Source Type: research

Relatedness within and among northern long-eared bat (Myotis septentrionalis) colonies at a local scale
Canadian Journal of Zoology, e-First Articles. We assessed parentage within and among maternity colonies of northern long-eared bats (Myotis septentrionalis (Trouessart, 1897)) in north-central Kentucky, USA, from 2011 to 2013 to examine colony social structure, formation, and membership dynamics. We intensively sampled colonies in close and remote (>10 km) proximity before and after targeted day-roost removal. Colonies were not necessarily composed of closely related individuals, although natal philopatry was common. Adjacent colonies often contained maternally related individuals, indicating that some pups did dispers...
Source: Canadian Journal of Zoology - March 21, 2019 Category: Zoology Authors: Miluska Olivera-Hyde Alexander Silvis Eric M. Hallerman W. Mark Ford Eric R. Britzke Source Type: research

Food caching by a marine apex predator, the leopard seal (Hydrurga leptonyx)
Canadian Journal of Zoology, e-First Articles. The foraging behaviors of apex predators can fundamentally alter ecosystems through cascading predator –prey interactions. Food caching is a widely studied, taxonomically diverse behavior that can modify competitive relationships and affect population viability. We address predictions that food caching would not be observed in the marine environment by summarizing recent caching reports from two ma rine mammal and one marine reptile species. We also provide multiple caching observations from disparate locations for a fourth marine predator, the leopard seal (Hydrurga lep...
Source: Canadian Journal of Zoology - March 21, 2019 Category: Zoology Authors: Douglas J. Krause Tracey L. Rogers Source Type: research

Prevalence and consequences of ants and other arthropods in active nests of Midwestern birds
Canadian Journal of Zoology, e-First Articles. Many organisms build nests which create unique microhabitats that are exploited by other animals. In turn, these nest colonizers may positively or negatively influence nest owners. Bird nests are known to harbor communities that include both harmful and possibly beneficial species. We quantified the nest arthropod communities of 10 bird species in Illinois, USA, along a land-use gradient, focusing on ant prevalence. We found eight ant species in nests, and for three species, at least part of their colonies inhabited nests. The odorous house ant (Tapinoma sessile (Say, 1836)) w...
Source: Canadian Journal of Zoology - March 20, 2019 Category: Zoology Authors: J.C. Gibson A.V. Suarez D. Qazi T.J. Benson S.J. Chiavacci L. Merrill Source Type: research

The spatial distribution and fecundity of sympatric species of Diplostomum (subclass Digenea) in single-species and mixed-species infections in the intestine of the Ring-billed Gull (Larus delawarensis)
Canadian Journal of Zoology, e-First Articles. Interactions between parasite species may influence their distribution and abundance within communities. Experimental single-species infections of Diplostomum spp. in the gut of the definitive host, the Ringed-billed Gull (Larus delawarensis Ord, 1815), were compared with mixed-species infections to explore interactions among parasites. Three species of Diplostomum von Nordmann, 1832 (Digenea), designated as Diplostomum sp. 1, Diplostomum sp. 4, and Diplostomum baeri Dubois, 1937, were examined for intestinal distribution and fecundity in single and mixed infections. In single...
Source: Canadian Journal of Zoology - March 13, 2019 Category: Zoology Authors: Angela Rose Lapierre Marilyn E. Scott J. Daniel McLaughlin David J. Marcogliese Source Type: research

Seasonal and annual variations in egg mass and clutch size for Loggerhead Sea Turtles (Caretta caretta): experienced females lay heavier eggs
Canadian Journal of Zoology,Volume 97, Issue 7, Page 644-649, July 2019. Organisms modify reproductive traits adaptively or non-adaptively in response to temporal environmental variation. Long-lived iteroparous sea turtles are ideal animals to examine such temporal shifts in resource allocation. We analyzed seasonal shifts in egg mass and clutch size for Loggerhead Sea Turtles (Caretta caretta (Linnaeus, 1758)) nesting at a temperate rookery (Yakushima Island, Japan) over a 2-year period, as well as annual variation in egg mass and clutch size over a 5-year period. Egg mass and clutch size, adjusted for female body size, d...
Source: Canadian Journal of Zoology - March 13, 2019 Category: Zoology Authors: Hideo Hatase Kazuyoshi Omuta Source Type: research

High-mountain altitudinal gradient influences thermal ecology of the Mesquite Lizard (Sceloporus grammicus)
Canadian Journal of Zoology, e-First Articles. The thermal requirements of ectotherms may vary among species due to adaptation to different thermal environments. Nevertheless, some of these requirements are evolutionarily conserved, leading organisms to compensate behaviorally for harsh environmental conditions. High-mountain systems provide temperature gradients that allow for studies of evolutionary and plastic variation in thermal ecology under natural conditions. We evaluated the thermoregulation strategies of Sceloporus grammicus Wiegmann, 1828 at three points (2600, 3100, and 4150 m above sea level) along an altitudi...
Source: Canadian Journal of Zoology - March 8, 2019 Category: Zoology Authors: A.H. D íaz de la Vega-Pérez R. Barrios-Montiel V.H. Jim énez-Arcos A. Bautista E. Bastiaans Source Type: research

Effects of livestock grazing on flocks of seed-eating birds in the central Monte desert, Argentina
Canadian Journal of Zoology, e-First Articles. Animal populations often decline due to habitat disturbance, but the initial response of organisms to human-induced environmental change is usually behavioral. Intra- and inter-specific interactions can restrict or facilitate access to resources, resulting in changes to individual fitness, and resource depletion may affect the frequency and strength of interactions. In birds, it is often assumed that feeding in groups increases foraging efficiency. We assessed how the reduction of seed resources provoked by cattle grazing affected different properties of seed-eating bird flock...
Source: Canadian Journal of Zoology - March 8, 2019 Category: Zoology Authors: A. Zarco V.R. Cueto M.C. Sagario L. Marone Source Type: research

Historical signatures in the alpha and beta diversity patterns of Atlantic Forest harvestman communities (Arachnida: Opiliones)
Canadian Journal of Zoology, e-First Articles. The integration of ecology and historical biogeography is fostering the investigation of diversity patterns. We studied alpha and beta diversity patterns of Brazilian Atlantic Forest harvestman (Arachnida: Opiliones) communities and related them to environmental and historical factors. Our data bank contains 508 species from 63 sites, encompassing almost the entire latitudinal range of Atlantic Forest. Alpha diversity was higher in coastal sites in the south and southeast regions and decreased in sites inland, as well as in sites in the coastal northeast region, especially in ...
Source: Canadian Journal of Zoology - March 7, 2019 Category: Zoology Authors: A.A. Nogueira C. Bragagnolo M.B. DaSilva T.K. Martins E.P. Lorenzo G. Perbiche-Neves R. Pinto-da-Rocha Source Type: research

Tree Swallow (Tachycineta bicolor) nest success and nestling growth near oil sands mining operations in northeastern Alberta, Canada
Canadian Journal of Zoology, e-First Articles. Industrial development and contaminant exposure may affect reproductive success and food quality for birds. Tree Swallows (Tachycineta bicolor (Vieillot, 1808)) nesting near oil sands development in northern Alberta (Canada) potentially experience elevated environmental stressors that could influence reproduction. We measured reproductive and growth endpoints in Tree Swallows, predicting reduced reproductive success and nestling growth near oil sands operations compared with reference sites. We also identified the invertebrate prey in the stomach contents of nestlings to under...
Source: Canadian Journal of Zoology - March 6, 2019 Category: Zoology Authors: Christine M. Godwin Robert M.R. Barclay Judit E.G. Smits Source Type: research

Vertical distribution and aggregation patterns of krill (Crustacea: Euphausiacea) in the Bay of Biscay: interannual and seasonal variability
Canadian Journal of Zoology, e-First Articles. Studies of krill (Crustacea: Euphausiacea) in oceanic waters of the Bay of Biscay are scarce and restricted to the epipelagic zone, overlooking vertical dynamics such as diurnal vertical migration (DVM). There is a growing interest in acoustically evaluating the biomass of krill in this area, but this requires a good knowledge of its vertical dynamics and aggregation patterns. In this work we employed acoustic data and net samples from two consecutive annual surveys covering a wide off-shelf area of the Bay of Biscay (JUVENA surveys of 2013 and 2014) and four seasonal surveys ...
Source: Canadian Journal of Zoology - February 14, 2019 Category: Zoology Authors: M. Pe ña R. Gonz ález-Quirós I. Munuera-Fern ández F. Gonz ález S. Romero-Romero E. Nogueira Source Type: research

Responses of the mussel Brachidontes rodriguezii to aerial exposure: implications on growth and physiological condition
Canadian Journal of Zoology, e-First Articles. The length of aerial exposure (i.e., environmental conditions) of an organism, due to daily tides, induces physiological responses. A mark –recapture field experiment was conducted in two intertidal zones (low tide and high tide) using the stain calcein AM to determine growth, as measured by shell length, of the mussel Brachidontes rodriguezii (d’Orbigny, 1842) along its vertical distribution off the north Argentinean coast. In the high intertidal zone, B. rodriguezii exhibited slower growth in shell length because of the physiological stress resulting from aerial ...
Source: Canadian Journal of Zoology - February 6, 2019 Category: Zoology Authors: Mar ía Eugenia Torroglosa Juliana Gim énez Source Type: research

Disc starts: the pectoral disc of stingrays promotes omnidirectional fast starts across the substrate
Canadian Journal of Zoology, e-First Articles. We explored how the flattened and rounded pectoral disc of the ocellate river stingray (Potamotrygon motoro (M üller and Henle, 1841)) enables them to use the benthic plane during fast-start escape. Escape responses were elicited via prodding different locations around the pectoral disc and were recorded using video. Modulation of pectoral-fin movements that power swimming enabled omnidirectional escape acr oss the substrate, with similar performance in all directions of escape. Hence, translation of the body did not necessarily have to follow the orientation of the head,...
Source: Canadian Journal of Zoology - February 1, 2019 Category: Zoology Authors: S.G. Seamone T.M. McCaffrey D.A. Syme Source Type: research

Non-digestible proteins and protease inhibitors: implications for defense of the colored eggs of the freshwater apple snail Pomacea canaliculata
Canadian Journal of Zoology,Volume 97, Issue 6, Page 558-566, June 2019. Apple snails (Pomacea Perry, 1810) are successful invaders that cause ecological perturbations, economic losses, and medical issues. A peculiar trait of this snail is a high biological potential, related to the absence of predators of their eggs. Eggs show protease inhibitor (PI) activity, originally ascribed to PcOvo perivitellin in the apple snail Pomacea canaliculata (Lamarck, 1822) but absent in PmPV1, the orthologoue of PcOvo, in eggs of the apple snail Pomacea maculata Perry, 1810. As egg fluid diminishes rat growth rate, an antidigestive effect...
Source: Canadian Journal of Zoology - February 1, 2019 Category: Zoology Authors: Santiago Ituarte Tabata Romina Brola Marcos Sebasti án Dreon Jin Sun Jian-Wen Qiu Horacio Heras Source Type: research

Oxidative stress does not differ in primary dermal fibroblasts isolated from fast-growing and control-growing Japanese Quail (Coturnix japonica)
Canadian Journal of Zoology, e-First Articles. Growth rate is a key life-history trait that influences fitness and shapes the physiology of organisms. Additionally, faster growing individuals of the same species seem to be burdened with higher whole-animal metabolism and higher cellular turnover rates, which may lead to increases in oxidative stress, though this fact remains controversial within the literature. Aerobic organisms are subjected to metabolic by-products known as reactive oxygen species (ROS), which can wreak havoc on macromolecules, such as structurally altering proteins and inducing mutations in DNA, among o...
Source: Canadian Journal of Zoology - February 1, 2019 Category: Zoology Authors: Ursula Konstantin Beattie Ana Gabriela Jimenez Source Type: research

Effect of habitat loss and fragmentation on fruit-feeding butterflies in the Brazilian Atlantic Forest
Canadian Journal of Zoology, e-First Articles. Habitat loss and fragmentation have drastically altered the availability and quality of tropical forest habitats, but information on how such changes influence local biodiversity is still insufficient. Here, we examine the effects of both patch and landscape metrics on fruit-feeding butterfly assemblages in a fragmented landscape of the Brazilian Atlantic Forest. Our study was carried out in three habitat types: eight fragments (ranging from 8 to 126 ha), eight areas of forest edge (50 m from forest border), and eight areas of forest interior (>200 m from forest border) of ...
Source: Canadian Journal of Zoology - January 18, 2019 Category: Zoology Authors: D.H.A. Melo B.K.C. Filgueiras C.A. Iserhard L. Iannuzzi A.V.L. Freitas I.R. Leal Source Type: research

A reexamination of the metabolic response of the genus Peromyscus to a climatic gradient
Canadian Journal of Zoology, e-First Articles. An earlier analysis demonstrated that the mass-independent energy expenditure of five species of the genus Peromyscus Gloger, 1841 decreased with increasing aridity along a mesic –xeric climatic gradient. Each species was represented by two populations that were located along the gradient. These data are reexamined with new analytical techniques. A mass analysis accounted for the basal rates of six populations within 10% of the measured rates. The analysis accounted for th e rates of all eight populations within 10% when it included the gradient. An apparent limit to thi...
Source: Canadian Journal of Zoology - January 18, 2019 Category: Zoology Authors: Brian K. McNab Source Type: research

The effects of repeat acute thermal stress on the critical thermal maximum (CTmax) and physiology of juvenile shortnose sturgeon (Acipenser brevirostrum)
Canadian Journal of Zoology,Volume 97, Issue 6, Page 567-572, June 2019. The shortnose sturgeon (Acipenser brevirostrum Lesueur, 1818) is a species of special concern in Canada, but little is known about their thermal biology. Information on the upper thermal tolerance of shortnose sturgeon becomes valuable for predicting future survival particularly with climate change and improving species management. Using a modified critical thermal maximum (CTmax) methodology, the objective is to determine whether previous thermal stress affects the thermal tolerance of juvenile shortnose sturgeon when exposed to a second thermal stre...
Source: Canadian Journal of Zoology - January 17, 2019 Category: Zoology Authors: Brittany Bard James D. Kieffer Source Type: research

Successive matings produce opposite patterns on ejaculate volume and spermatozoa number in an ancient arthropod model with indirect sperm transfer
Canadian Journal of Zoology, e-First Articles. The production of spermatophore and ejaculate is energetically expensive for males. High mating rates may accelerate sperm depletion and progressively decrease the size of the ejaculates. Sperm competition can shape spermatozoon numbers according to different signals and cues such as number of potential rivals or female mating status. Factors influencing patterns of sperm allocation have been neglected in terrestrial arthropods that transfer sperm indirectly using a complex sclerotized spermatophore deposited on the soil. We used the Neotropical scorpion Bothriurus bonariensis...
Source: Canadian Journal of Zoology - January 15, 2019 Category: Zoology Authors: D.E. Vrech M.A. Oviedo-Diego P.A. Olivero A.V. Peretti Source Type: research

Understanding habitat co-occurrence and the potential for competition between native mammals and invasive wild pigs (Sus scrofa) at the northern edge of their range
We examined habitat factors that we predicted would affect co-occurrence of wild pigs with native mammals. We randomly placed 17 camera traps in four stratified habitat types (deciduous forest, grassland, cropland, and wetland) for 2 years to examine species co-occurrence in these habitats. We analyzed camera-trap data using nonmetric multidimensional scaling. Wild pig detection during winter was greatest in wetland and cropland and positively associated with occurrence of moose (Alces alces (Linnaeus, 1758)) and coyote (Canis latrans Say, 1823) and negatively associated with the presence of white-tailed deer (Odocoileus v...
Source: Canadian Journal of Zoology - January 15, 2019 Category: Zoology Authors: Paul O ’Brien Eric Vander Wal Erin L. Koen Carissa D. Brown Jenn Guy Floris M. van Beest Ryan K. Brook Source Type: research

Use of visual and olfactory sensory cues by an apex predator in deciduous forests
Canadian Journal of Zoology, e-First Articles. Predator –prey interactions influence behaviors and life-history evolution for both predator and prey species and also have implications for biodiversity conservation. A fundamental goal of ecology is to clarify mechanisms underlying predator–prey interactions and dynamics. To investigate the role of pre dator sensory mechanisms in predator–prey interactions, specifically in predator detection of prey, we experimentally evaluated importance of visual and olfactory cues for an apex predator, the coyote (Canis latrans Say, 1823). Unlike similar studies, we exam...
Source: Canadian Journal of Zoology - January 15, 2019 Category: Zoology Authors: Riley R. Lawson Dillon T. Fogarty Scott R. Loss Source Type: research

Experimental assessments of marine species sensitivities to ocean acidification and co-stressors: how far have we come?
Canadian Journal of Zoology, e-First Articles. Experimental studies assessing the potential impacts of ocean acidification on marine organisms have rapidly expanded and produced a wealth of empirical data over the past decade. This perspective examines four key areas of transformative developments in experimental approaches: (1) methodological advances; (2) advances in elucidating physiological and molecular mechanisms behind observed CO2 effects; (3) recognition of short-term CO2 variability as a likely modifier of species sensitivities (Ocean Variability Hypothesis); and (4) consensus on the multistressor nature of marin...
Source: Canadian Journal of Zoology - January 15, 2019 Category: Zoology Authors: Hannes Baumann Source Type: research

Determinants of home-range size of imperiled New England cottontails (Sylvilagus transitionalis) and introduced eastern cottontails (Sylvilagus floridanus)
Canadian Journal of Zoology, e-First Articles. In fragmented habitat, population persistence depends in part on patch quality and patch size relative to home-range size. The imperiled New England cottontail (Sylvilagus transitionalis (Bangs, 1895)) is an obligate user of shrublands in the northeastern United States, a highly fragmented and declining ecosystem. New England cottontail conservation efforts have targeted habitat creation; however, efforts are hindered by a limited knowledge of seasonal space use and its relationship to habitat quality, which could help inform minimum patch-size requirements and implications of...
Source: Canadian Journal of Zoology - January 11, 2019 Category: Zoology Authors: Amanda E. Cheeseman Jonathan B. Cohen Sadie J. Ryan Christopher M. Whipps Source Type: research

Sexual dimorphism of the cuticle and body-wall muscle in free-living mycophagous nematodes
We examined the motility-related components in four species: Bursaphelenchus conicaudatus Kanzaki, Tsuda and Futai, 2000; Bursaphelenchus rainulfi Braasch and Burgermeister, 2002; Bursaphelenchus doui Braasch, Gu, Burgermeister and Zhang, 2005; Parasitaphelenchus costati Kanzaki, Ekino, Ide, Masuya and Degawa, 2018. We measured the structure and amount of cuticle and body-wall muscles and estimated their relationship to body diameter or total cross-sectional area. Although no structural differences were observed in muscle, the relevant muscle area of B. doui and P. costati was significantly smaller in females than in males...
Source: Canadian Journal of Zoology - January 11, 2019 Category: Zoology Authors: T. Ekino T. Yoshiga Y. Takeuchi-Kaneko Y. Ichihara N. Kanzaki Source Type: research

The effect of predator kairomones on caudal regeneration by Allegheny Mountain Dusky Salamanders (Desmognathus ochrophaeus)
Canadian Journal of Zoology, e-First Articles. Many prey use autotomy as an antipredator mechanism. Rapid regeneration of autotomized appendages is beneficial because forfeited tissues may serve as organs for energy storage, accessories for locomotion, or indicators of social status. We monitored levels of caudal regeneration by Allegheny Mountain Dusky Salamanders (Desmognathus ochrophaeus Cope, 1859) exposed to kairomones from predatory Eastern Garter Snakes (Thamnophis sirtalis (Linnaeus, 1758)). After the induction of autotomy, salamanders were exposed to one of three treatment regimens: blank (water), or acute (30 min...
Source: Canadian Journal of Zoology - January 10, 2019 Category: Zoology Authors: W.I. Payette A.M. Sullivan Source Type: research

Local habitat features explain the distribution of the imperiled grass pickerel (Esox americanus vermiculatus)
This study identifies habitat elements important to grass pickerel and offers insights into management implications. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - January 10, 2019 Category: Zoology Authors: J.E. Colm N.E. Mandrak B.L. Tufts Source Type: research