Investigating patterns and extent of predation of hatchery-reared juvenile Nechako white sturgeon (Acipenser transmontanus) by North American river otter (Lontra canadensis) in the Nechako River, British Columbia, Canada
Canadian Journal of Zoology, Ahead of Print. Predation of fish released as part of conservation aquaculture programs may undermine conservation goals. Identification of factors influencing predation, therefore, can inform management decisions that minimize predation losses. For the endangered Nechako white sturgeon (Acipenser transmontanus Richardson, 1836), the survival of individuals released as part of a conservation aquaculture program is threatened by river otter (Lontra canadensis (Schreber, 1777)) predation. Through the recovery of sturgeon passive integrated transponder (PIT) tags from otter latrines, we set out to...
Source: Canadian Journal of Zoology - May 23, 2023 Category: Zoology Authors: Cale N. Babey Nikolaus Gantner J. Mark Shrimpton Source Type: research
Dietary thiaminase impairs cardiac function and increases heart size in lake trout (Salvelinus namaycush (Walbaum in Artedi, 1792))
Canadian Journal of Zoology, Ahead of Print. The consumption of invasive, high-thiaminase prey fishes can cause thiamine deficiency, which has been hypothesized to be a major barrier for lake trout (Salvelinus namaycush (Walbaum in Artedi, 1792)) restoration in the Great Lakes. In fishes, an understudied aspect of thiamine deficiency is its effect on cardiac function, despite evidence of this effect in mammals. Here, parr of two strains of lake trout (Seneca and Slate) were raised on either a control or high-thiaminase diet for nine months. We then measured cardiac function and morphology, particularly as it relates to the...
Source: Canadian Journal of Zoology - May 23, 2023 Category: Zoology Authors: Peter M. Baker Christian A. Therrien Carlie A. Muir Shawn R. Garner Bryan D. Neff Source Type: research
Microhabitat of Myotis leibii summer roosts at the southwestern periphery of their range
Canadian Journal of Zoology, Ahead of Print. Understanding microhabitat use is needed to make sound conservation decisions for at-risk, patchy-habitat specialists, such as rock-habitat specialists. Rock habitats offer unique microclimatic refugia for reptiles and mammals. Eastern small-footed bats (Myotis leibii (Audubon and Bachman, 1842)) use rock roosts during the summer, but data on these summer roosts are lacking for this species classified as (critically) imperiled in several US states and Canadian provinces and globally endangered. Our goal was to characterize the structure and microclimate of Myotis leibii roosts a...
Source: Canadian Journal of Zoology - May 23, 2023 Category: Zoology Authors: Valerie M. Kearny Roger W. Perry Thomas S. Risch Virginie Rolland Source Type: research
Behavioral adaptations of scatterhoarders to seasonal flooding
We examined how eastern gray squirrels (Sciurus carolinensis, Gmelin 1778) have adapted to a seasonally flooded ecosystem in Alabama. Our study area was dry September –November and flooded the rest of the year. We predicted squirrels would respond to flooding by storing food in areas that stay dry during winter, seasonally shifting to dry habitat, or decreasing the amount of hard mast in their winter diet. We also examined previously reported survival differenc es between the dry and flooded seasons. During the dry season, 72% of acorns were buried in areas that later flooded. Habitat use did not change significantly dur...
Source: Canadian Journal of Zoology - May 23, 2023 Category: Zoology Authors: Sarah B. Wilson Robert A. Gitzen Stephen S. Ditchkoff Todd D. Steury Source Type: research
Behavioral observations of Molossus nigricans in a Neotropical city: a contribution toward understanding its urban tolerance
In this study, we described some aspects of the roosting, social, vocal, and foraging behavior of one of these species, Molossus nigricans Miller, 1902, in the tropical city of Villahermosa, in southeastern Mexico. We described roosting attributes and colony size in 54 roosts of M. nigricans between 2016 and 2018. In a subsample of roosts, we registered emergence and return times throughout the night, described colony composition, and recorded vocalizations using a full-spectrum ultrasonic detector. We found that M. nigricans exhibits high plasticity in its roosting behavior, occupying both natural and anthropogenic struct...
Source: Canadian Journal of Zoology - May 23, 2023 Category: Zoology Authors: Rafael Avila-Flores Rafael Le ón-Madrazo Lucio Perez-Perez Alba Z. Rodas-Mart ínez Source Type: research
Contractile function of fasting and digesting broad-snouted caiman (Caiman latirostris)
Canadian Journal of Zoology, Ahead of Print. Feeding regimes are a critical process to ensure survival and reproduction, which modulate several behavioral and physiological patterns of ectotherms, especially cardiovascular adjustments. However, crocodilian myocardial contractile function after food intake remains understudied. We investigated the importance of ventricular myocardial contractility during digestion in the broad-snouted caiman, Caiman latirostris Daudin, 1801. Isometric ventricle preparations and Ca2+-handling protein expression were used to investigate the effects of prolonged fasting (30 days) and feeding (...
Source: Canadian Journal of Zoology - May 17, 2023 Category: Zoology Authors: Andr é Guelli Lopes Diana Amaral Monteiro Eliton da Silva Vasconcelos Ana L úcia Kalinin Source Type: research
Effects of anthropogenic noise on haul-out numbers of harbor seals (Phoca vitulina)
Canadian Journal of Zoology, Ahead of Print. Haul-out sites of harbor seals, Phoca vitulina Linnaeus, 1758, include areas with high levels of anthropogenic noise. In some cases, seals haul out at night when there are lower in-air noise levels. However, it is unclear whether there are additional responses to noise pollution. To determine potential impacts of anthropogenic noise on haul-out behavior, we compared numbers of hauled-out harbor seals relative to in-air noise levels at two sites in Washington state, USA —one close to human activities (Bellingham waterfront) and one more distant (Semiahmoo marina)—between July...
Source: Canadian Journal of Zoology - May 11, 2023 Category: Zoology Authors: Kyra Bankhead Grace Freeman Wyatt Heimbichner Goebel Alejandro Acevedo-Guti érrez Source Type: research
Nutrient allocation to eggs in female Argentine shortfin squid, Illex argentinus using fatty acids as nutrient indicator
Canadian Journal of Zoology, Ahead of Print. Fatty acids play a critical role in embryonic development of cephalopods. However, little information is available on the allocation of fatty acids to eggs during oogenesis, limiting our understanding regarding how these animals maximize reproductive performance in terms of energy and nutrient use. We explored the nutrients for egg production during maturation for Argentine shortfin squid (Illex argentinus (Castellanos, 1960)) by comparing the fatty acid profiles between the ovary and eggs in the oviducts. We detected 30 fatty acids in the ovary and eggs, of which 19 constituted...
Source: Canadian Journal of Zoology - May 11, 2023 Category: Zoology Authors: Na Zang Dongming Lin Andr é E. Punt Xinjun Chen Source Type: research
Premium food for offspring? Black-backed Woodpecker (Picoides arcticus) diet during breeding season in eastern Canada
Canadian Journal of Zoology, Ahead of Print. Knowledge on the diet of the Black-backed Woodpecker (Picoides arcticus Swainson, 1832) is fragmentary and relies on a limited number of studies. Gaps remain in our understanding of the plasticity of its diet, particularly in the eastern part of its range. The main objective of this study was to assess the diet of Black-backed Woodpeckers in burned and unburned habitats and among sexes and ages in Qu ébec. We collected feces and fecal bags from unburned and burned habitats in the Central Laurentians ecoregion of the eastern boreal shield ecozone and assessed diets based on iden...
Source: Canadian Journal of Zoology - May 11, 2023 Category: Zoology Authors: Junior A. Tremblay Gabriel L. Fontaine Jean-Pierre L. Savard Jean-Michel B éland Christian H ébert Jacques Ibarzabal Source Type: research
Influence of the invasive bivalve Isognomon bicolor on the native community found in northeast Brazilian coast
This study provides data on the relationship between I. bicolor and the native community of sandstone reefs, which could be applied to monitor the expansion of I. bicolor to the Northeast region of Brazil. (Source: Canadian Journal of Zoology)
Source: Canadian Journal of Zoology - May 11, 2023 Category: Zoology Authors: Romilda Narciza Mendon ça de Queiroz Graciele de Barros Linaldo Luiz de Oliveira Camile Dias Avelino Thelma L úcia Pereira Dias Source Type: research
Human hosts recruit more host-seeking deer flies (Diptera: Tabanidae) while walking than sitting
Canadian Journal of Zoology, Ahead of Print. Biting flies can strongly influence the behaviour of their hosts, for example, there is evidence that some species may avoid harassment by reducing their locomotory activity. We tested the hypothesis that potential hosts can reduce their attraction to deer flies by remaining stationary —that reducing locomotory movement reduces exposure to new deer flies compared to remaining still. During early summer in central Ontario, Canada, we conducted 20-min trials where a human host either walked or sat quietly; tabanids were captured and counted each minute using a hat outfitted with...
Source: Canadian Journal of Zoology - April 26, 2023 Category: Zoology Authors: April C. DeJong James A. Schaefer David V. Beresford Source Type: research
Ascertaining the life history and thermal preferences and tolerances of the hot spring snail Physella wrighti Te and Clarke (Gastropoda: Physidae)
Canadian Journal of Zoology, Ahead of Print. Physella wrighti Te and Clarke, 1985 is an Endangered freshwater snail endemic to the Liard Hot Springs. The thermal characteristics of its environment suggest that water temperature (WT) is essential for the snail ’s survival. Initially, Physella wrighti’s preferred WT was assessed, with 23 °C preferred. To determine if WT influenced the snail, the activity level, behaviour, survivability, number of egg masses (EMs) produced, number of eggs per mass (EPM), egg volume, EM viability, and incubation period (IP) were examined in 13 °C, 23 °C (preferred WT), and 33 °C water....
Source: Canadian Journal of Zoology - April 26, 2023 Category: Zoology Authors: Erika Helmond Kerri Finlay Cory Sheffield Mel Hart Jennifer Heron Source Type: research
From color to shape: ontogenetic shifts in traits of the freshwater crab Dilocarcinus pagei (Brachyura: Trichodactylidae)
Canadian Journal of Zoology, Ahead of Print. Crustaceans usually undergo a series of changes after the puberty molt. These changes are often associated with size increases in the body and in structures such as the abdomen and claws so that they can achieve higher reproductive fitness. These morphological changes allow the animal to fight, court, and signal for its conspecific with better performance. To compare ontogenetic changes, we used the freshwater crab Dilocarcinus pagei Stimpson, 1851 as a model. We analyzed differences in carapace and claw shape, force generation (via the apodeme area), morphological integration o...
Source: Canadian Journal of Zoology - April 25, 2023 Category: Zoology Authors: Alexandre R. da Silva Caio S. Nogueira Source Type: research
The phylogenetic position of Maritrema afanassjewi Belopol'skaya, 1952 (Digenea, Plagiorchiida: Microphallidae), a parasite of the Ussuri brown bear, Ursus arctos lasiotus Gray, 1867 (Carnivora, Ursidae)
Canadian Journal of Zoology, Ahead of Print. Adult digeneans of Maritrema afanassjewi Belopol'skaya, 1952 parasitize birds and mammals along the North Pacific coasts and were previously studied in terms of morphology. However, morphological features not supported by molecular characterization are considered an insufficient tool for the identification of evolutionary lineages of microphallid digeneans. Here we provide the first data on the phylogenetic position of this species inferred from sequences of the 28S rRNA gene and the ITS2 locus of the nuclear DNA, as well as additional morphometric data. The trematodes were isol...
Source: Canadian Journal of Zoology - April 23, 2023 Category: Zoology Authors: Sergey G. Sokolov Sergei V. Shchenkov Fuat K. Khasanov Ilya I. Gordeev Source Type: research
Abundance and occupancy of the western yellow-billed cuckoo (Coccyzus americanus) in Sonora, Mexico
Canadian Journal of Zoology, Ahead of Print. Unveiling factors that determine abundance and distribution of endangered wildlife species has important implications for their conservation across international boundaries. For instance, the Western Distinct Population (as defined by the U.S. Fish and Wildlife Service) of the yellow-billed cuckoo Coccyzus americanus (Linnaeus, 1758) has disappeared in most of the species ’ range across western United States and southwestern Canada but little is known about the conservation status at the southern edge of its breeding distribution in Mexico. To fill this information gap, we est...
Source: Canadian Journal of Zoology - April 20, 2023 Category: Zoology Authors: Alberto Mac ías-Duarte Edwin Ju árez Eduardo S ánchez Murrieta E. Leonel Perales-Hoeffer Carmen I. Ortega Rosas Source Type: research
