Flexibility of nuptial colouration in a unique ecotype of threespine stickleback (Gasterosteus aculeatus)
Canadian Journal of Zoology, Ahead of Print. Nuptial colouration in animals may serve as a signal of competitor and (or) mate quality during breeding. In many temperate fishes, nuptial colouration develops during discrete breeding seasons and is a target of sexual selection. We examine nuptial colouration and behaviour of a unique ecotype of threespine stickleback (Gasterosteus aculeatus Linnaeus, 1758), wherein males turn from dull brown-grey to pearlescent white during the breeding season. The main goal of this work was to determine the relative role of white colouration in intersexual competition and mate choice. In a c...
Source: Canadian Journal of Zoology - April 29, 2021 Category: Zoology Authors: Rachel H. Corney Anne L. Haley Laura K. Weir Source Type: research
Long-term stability in the volume of Atlantic Puffin (Fratercula arctica) eggs in the western North Atlantic
In this study, we investigate Atlantic Puffin egg volume in the western North Atlantic. We compiled 140 years (1877–2016) of egg volume measurements (n = 1805) and used general additive mixed-effects models to investigate temporal trends and regional variation. Our findings indicate that Atlantic Puffin egg volume differs regionally but has remained unchanged temporally in the western North Atlan tic since at least the 1980s. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - April 29, 2021 Category: Zoology Authors: Kyle J. Lefort Heather L. Major Alexander L. Bond Antony W. Diamond Ian L. Jones William A. Montevecchi Jennifer F. Provencher Gregory J. Robertson Source Type: research
Population dynamics of muskrats (Ondatra zibethicus) and American mink (Neovison vison): investigating contemporary patterns in a classic predator –prey system
Canadian Journal of Zoology, Ahead of Print. A well-studied predator –prey relationship between American mink (Neovison vison (Schreber, 1777); formerly known as Mustela vison Schreber, 1777) and muskrats (Ondatra zibethicus (Linnaeus, 1766)) in Canada has advanced our understanding of population cycles including the influence of density dependence and lagged respo nses of predators to prey abundances. However, it is unclear if patterns observed in Canada extend across the southern half of their native range. We used data from the United States to create a 41-year time series of mink and muskrat harvest reports (1970–2...
Source: Canadian Journal of Zoology - April 28, 2021 Category: Zoology Authors: Adam A. Ahlers Timothy P. Lyons Edward J. Heske Source Type: research
Effects of landscape composition on wetland occupancy by Blanding ’s Turtles (Emydoidea blandingii) as determined by environmental DNA and visual surveys
Canadian Journal of Zoology, Ahead of Print. Habitat loss and degradation have led to the extinction of many species worldwide. The endangered Blanding ’s Turtle (Emydoidea blandingii (Holbrook, 1838)), a semi-aquatic freshwater turtle, occupies a wide range of wetlands and landscapes primarily in southeastern Canada and the Great Lakes region of the United States. We explored whether the probability of wetland occupancy by Blanding’s Turtles i s affected by the surrounding landscape. We used visual surveys, environmental DNA, and Atlas data to document the presence of Blanding’s Turtles in wetlands in Ottawa, Ontari...
Source: Canadian Journal of Zoology - April 28, 2021 Category: Zoology Authors: Vincent K. Fyson Gabriel Blouin-Demers Source Type: research
Short-term capture stress and its effects on corticosterone levels and heat shock proteins in captive American Alligators (Alligator mississippiensis)
Canadian Journal of Zoology, Ahead of Print. Heat shock proteins (HSPs) are important mediators of the normal cellular function and the cellular stress response. As such, HSPs are often utilized to measure the effects of stressors on organisms in vivo. However, multiple variables can influence their expression, including time or season, confounding results. To investigate the utility of HSPs in measuring effects of stressors in a top-trophic carnivore, we captured 20 American Alligators (Alligator mississippiensis (Daudin, 1802)), placed them in burlap sacks for 2 h and collected blood samples over four time points (baseli...
Source: Canadian Journal of Zoology - April 28, 2021 Category: Zoology Authors: John W. Finger Meghan D. Kelley Yufeng Zhang Matthew T. Hamilton Ruth M. Elsey Mary T. Mendonca Andreas Kavazis Source Type: research
A new miniature Pristella (Actinopterygii: Characiformes: Characidae) with reversed sexual dimorphism from the rio Tocantins and rio S ão Francisco basins, Brazil
Canadian Journal of Zoology, Ahead of Print. A new species of the genus Pristella Eigenmann, 1908 (Pristella crinogi sp. nov.) is described from the middle rio Tocantins and middle rio São Francisco basins, Brazil. The new species can be diagnosed from its two congeners, Pristella ariporo Conde-Saldaña, Albornoz-Garzón, García-Melo, Villa-Navarro, Mirande, and Lima, 2019 and Pristella maxillaris (Ulrey, 1894), b y a combination of color pattern and teeth morphology characters. A phylogenetic analysis of the genus recovered P. crinogi as the sister taxa of P. ariporo. Pristella crinogi, along with P. ariporo, are the...
Source: Canadian Journal of Zoology - April 26, 2021 Category: Zoology Authors: F.C.T. Lima R.A. Caires C.C. Conde-Salda ña J.M. Mirande F.R. Carvalho Source Type: research
Recent findings suggest adding red fox (Vulpes vulpes) to climate-threatened whitebark pine (Pinus albicaulis) trophic system
Canadian Journal of Zoology, Ahead of Print. Mountain ecosystems are sensitive to climate change, and climate-driven declines in primary producers can impact food webs. Whitebark pine (Pinus albicaulis Engelm.) seed, a valuable food resource for montane wildlife species, is threatened by climate change. Whitebark pine exhibit masting, and during a snow-tracking study of Rocky Mountain red foxes (Vulpes vulpes macroura Baird, 1852) in the Greater Yellowstone Ecosystem that happened to coincide with masting, we unexpectedly observed red foxes consuming whitebark pine seeds from red squirrel (Tamiasciurus hudsonicus (Erxleben...
Source: Canadian Journal of Zoology - April 25, 2021 Category: Zoology Authors: Patrick R. Cross Robert L. Crabtree Source Type: research
The neuromuscular system in flatworms: serotonin and FMRFamide immunoreactivities and musculature in Prodistomum alaskense (Digenea: Lepocreadiidae), an endemic fish parasite of the northwestern Pacific
Canadian Journal of Zoology, Ahead of Print. Using the immunocytochemical method and confocal scanning laser microscopy, we obtained pioneering data on the muscle system organization and presence and localization of biogenic amine serotonin and FMRFamide-related peptides in the nervous system of the trematode Prodistomum alaskense (Ward and Fillingham, 1934) Bray and Merrett 1998 (family Lepocreadiidae). This flatworm is an intestinal parasite of endemic representatives of the marine fauna of the northwestern Pacific Ocean — the prowfish (Zaprora silenus Jordan, 1896) and the lumpfish (Aptocyclus ventricosus (Pallas, 1...
Source: Canadian Journal of Zoology - April 15, 2021 Category: Zoology Authors: D.A. Nefedova N.B. Terenina N.V. Mochalova L.G. Poddubnaya S.O. Movsesyan I.I. Gordeev A.V. Kuchin N.D. Kreshchenko Source Type: research
Ontogenetic shifts in natural diet, chelae, and mandibles of the omnivorous freshwater crab Aegla uruguayana: linking morphology and function
Canadian Journal of Zoology, Ahead of Print. We analyze whether ontogenetic diet change in Aegla uruguayana Schmitt, 1942 is related to the morphological changes in chelae and mandibles. We use a combination of scanning electron microscope (SEM) observation, dietary composition analysis (stomach observation, trophic niche amplitude, trophic overlap, and feeding strategy), and geometric morphometric tools (discriminant analysis and two-block partial least squares analysis). The two structures analyzed by SEM show differences between juvenile and adult specimens, both in their cuticle and morphology specializations. In juven...
Source: Canadian Journal of Zoology - April 14, 2021 Category: Zoology Authors: M. Florencia Viozzi Juan M. Cabrera Federico Giri D ébora de Azevedo Carvalho Ver ónica Williner Source Type: research
Next generation sequencing, insect microbiomes, and the confounding effect of Wolbachia: a case study using spotted-wing drosophila (Drosophila suzukii) (Diptera: Drosophilidae)
Canadian Journal of Zoology, Ahead of Print. Next generation sequencing (NGS) increasingly is being used to characterize the gut microbiome of insects to provide insights into the ecology and biology of the host, but results may be confounded by co-occurring infections of bacteria genus Wolbachia Hertig, 1936 in the cells of the host. We illustrate this issue using spotted-wing drosophila, Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae), as an example. With an assay based on polymerase chain reactions, we detected Wolbachia in 20% of flies collected from sites in British Columbia, Alberta, and Newfoundland an...
Source: Canadian Journal of Zoology - April 13, 2021 Category: Zoology Authors: Diana M. Wilches Paul C. Coghlin Kevin D. Floate Source Type: research
Not only big bulls — Correlation between morphometry, reproductive success, and testosterone level in a flooded savannah population of the Spectacled Caiman (Caiman crocodilus)
Canadian Journal of Zoology, Ahead of Print. Testosterone is a steroid hormone involved in the expression of many morphological, physiological, and behavioral traits that arguably affect reproductive success. The evidence for that link is, however, incomplete or absent in the research on crocodilian species. Testosterone levels are also known to change throughout the breeding season, often on an hourly basis, which may further complicate studying their relationship with breeding success. We tested here whether baseline testosterone levels, measured out of the breeding season, are correlated with morphometry and reproductiv...
Source: Canadian Journal of Zoology - April 10, 2021 Category: Zoology Authors: L.A. Barrag án-Contreras R. Antelo A. Am ézquita Source Type: research
The degree of embryonic development influenced some eggshell characteristics of wild Red-tailed Hawks (Buteo jamaicensis borealis)
Canadian Journal of Zoology, Ahead of Print. The influence of embryonic development on eggshell characteristics of wild birds, particularly raptors, is not well studied. Red-tailed Hawk (Buteo jamaicensis borealis (Gmelin, 1788)) eggs (n = 66) collected in central New York State (USA) during the late 1800s and early 1900s were examined to determine if eggshell mass, eggshell thickness, and a thickness index corrected for egg shape and blowhole size were influenced by the degree of embryonic development at the time of collection. C hanges in these characteristics were examined with linear mixed models with year of collect...
Source: Canadian Journal of Zoology - April 8, 2021 Category: Zoology Authors: William P. Brown Source Type: research
Stable isotope analysis reveals that humpback whales (Megaptera novaeangliae) primarily consume capelin (Mallotus villosus) in coastal Newfoundland, Canada
Canadian Journal of Zoology, Ahead of Print. On the Newfoundland (Canada) foraging ground, humpback whales (Megaptera novaeangliae (Borowski, 1781)) are found associated with a dominant forage fish species, capelin (Mallotus villosus (M üller, 1776)), that experienced a population collapse in the early 1990s and has not recovered. Our primary goal was to reconstruct dietary proportions of humpback whales on their summer foraging grounds off the northeast coast of Newfoundland during July–August 2016 and 2017 using a Bayesian sta ble isotope mixing model (MixSiar). Modelled dietary proportions were similar in both years,...
Source: Canadian Journal of Zoology - April 6, 2021 Category: Zoology Authors: Kelsey F. Johnson Gail K. Davoren Source Type: research
Forest edges negatively influence daily nest survival rates of a grassland Tinamou, the Spotted Nothura (Nothura maculosa)
Canadian Journal of Zoology, Ahead of Print. Grassland degradation and fragmentation produced by land use have globally impacted biodiversity. In the Neotropics, the Pampas Grasslands have been greatly altered by agriculture and the introduction of exotic trees. To evaluate the effects of changing habitat features on indigenous grassland fauna, we studied a breeding population of a ground-nesting bird, the Spotted Nothura (Nothura maculosa (Temminck, 1815)), in a natural grassland under cattle grazing in central-east Argentina. We estimated daily nest survival rate (DSR) and modeled it as a function of habitat (distance to...
Source: Canadian Journal of Zoology - April 6, 2021 Category: Zoology Authors: M.A. Colombo L.N. Segura Source Type: research
A quantitative analysis of gilthead seabream (Sparus aurata) juvenile dentition as a tool to assess the effect of diet
Canadian Journal of Zoology, Ahead of Print. Gilthead seabream (Sparus aurata Linnaeus, 1758 (Perciformes, Sparidae)) is an important aquaculture species in the Mediterranean Sea basin. Yet, quantitative data on its dentition under standard farming conditions are currently lacking. Furthermore, it is unknown if the dentition can adapt to food of different sizes. Here, we describe the lower jaw dentition of juvenile S. aurata fed a standard pellet size (4 mm) and present a detailed analysis of 11 representative teeth. Overall, the number of teeth showed large individual variation, but it was not significantly related to ...
Source: Canadian Journal of Zoology - April 3, 2021 Category: Zoology Authors: A.M. de Azevedo R. Fontanillas M.A.G. Owen S. Busti L. Parma A. Bonaldo P.E. Witten A. Huysseune Source Type: research
