Canadian Journal of Zoology 

About: Canadian Journal of Zoology is an academic journal published by NRC Research Press. The journal publishes majorly in the area(s): Population & Predation. It has an ISSN identifier of 0008-4301. Over the lifetime, 14830 publications have been published receiving 460612 citations. The journal is also known as: Journal canadien de zoologie & Revue canadienne de zoologie.

Behavioral decisions made under the risk of predation: a review and prospectus

Abstract: Predation has long been implicated as a major selective force in the evolution of several morphological and behavioral characteristics of animals. The importance of predation during evolutionary ti...

Preservation of avian blood and tissue samples for DNA analyses

Abstract: A problem frequently faced by researchers involved in collecting tissues for DNA isolation is the preservation of samples in the field prior to and during their transportation to the laboratory. Prevention of DNA degradation is usually achieved through freezing. As this is not always practical, we have tested the efficiency of chemical solutions containing high concentrations of salts (e.g., NaCl, EDTA, and diaminocyclohexanetetraacetate) and detergent at preserving DNA in bird tissue and blood samples stored at ambient temperature for extended periods of time. For blood samples, we recommend the use of a buffer that lyses the cells and nuclei and contains 0.01 M Tris, 0.01 M NaCl, 0.01 M EDTA, and 1% n-lauroylsarcosine, Ph 7.5. Tissue samples are best preserved as small pieces in a saline solution made of 20% dimethyl sulfoxyde, 0.25 M EDTA, saturated with NaCl, pH 8.0. DNA extracted from samples preserved in these solutions for up to 24 weeks was compared with DNA recovered from tissue samples stored at...

Stable isotopes of carbon and nitrogen in the study of avian and mammalian trophic ecology

Abstract: Differential fractionation of stable isotopes of carbon during photosynthesis causes C 4 plants and C3 plants to have distinct carbon-isotope signatures. In addition, marine C 3 plants have stable-isotope ratios of carbon that are intermediate between C4 and terrestrial C3 plants. The direct incorporation of the carbon-isotope ratio ( 13 C/ 12 C) of plants into consumers' tissues makes this ratio useful in studies of animal ecology. The heavy isotope of nitrogen ( 15 N) is preferentially incorporated into the tissues of the consumer from the diet, which results in a systematic enrichment in nitrogen-isotope ratio ( 15 N/ 14 N) with each trophic level. Consequently, stable isotopes of nitrogen have been used pri- marily to assess position in food chains. The literature pertaining to the use of stable isotopes of carbon and nitrogen in animal trophic ecology was reviewed. Data from 102 studies that reported stable-isotope ratios of carbon and (or) nitrogen of wild birds and (or) mammals were compiled and analyzed relative to diet, latitude, body size, and habitat moisture. These analyses supported the predicted relationships among trophic groups. Carbon-isotope ratios differed among species that relied on C3 ,C 4, and marine food chains. Likewise, nitrogen-isotope ratios were enriched in terres- trial carnivorous mammals relative to terrestrial herbivorous mammals. Also, marine carnivores that ate vertebrates had nitrogen-isotope ratios that were enriched over the ratios of those that ate invertebrates. Data from the literature also indicated that (i) the carbon-isotope ratio of carnivore bone collagen was inversely related to latitude, which was likely the result of an inverse relationship between the proportion of carbon in the food chain that was fixed by C 4 plants and latitude; (ii) seabirds and marine mammals from northern oceans had higher nitrogen-isotope ratios than those from southern oceans; (iii) the nitrogen-isotope ratios of terrestrial mammals that used xeric habitats were higher than the ratios of those that used mesic habitats, indicating that water stress can have important effects on the nitrogen-isotope ratio; (iv) there was no relationship between body mass and nitrogen-isotope ratio for either bone collagen or muscle of carnivores; and (v) there was linear covariation between stable-isotope ratios of carbon and nitrogen in marine food chains (but not in terrestrial C 3 or C4 food chains), which is likely a product of increases in carbon-isotope ratio with trophic level in marine food chains. Differences in stable-isotope composition among trophic groups were detected despite variation attributable to geographic location, climate, and analytical techniques, indicating that these effects are large and pervasive. Consequently, as knowledge of the distribution of stable isotopes of carbon and nitrogen increases, they will probably become an increasingly important tool in the study of avian and mammalian trophic ecology. 27 Resume : Le fractionnement differentiel des isotopes stables de carbone durant la photosynthese fait que les plantes C 4 et les plantes C3 ont des signatures d'isotopes de carbone differentes. En outre, chez les plantes C 3 marines, le rapport entre les isotopes stables de carbone est intermediaire entre celui des plantes C 4 et celui des plantes C3 terrestres.

Wolves, elk, and bison: reestablishing the "landscape of fear" in Yellowstone National Park, U.S.A.

Abstract: The elk or wapiti (Cervus elaphus) and bison (Bison bison) of Yellowstone National Park have lived in an environment free of wolves (Canis lupus) for the last 50 years. In the winter of 1994-1995, wolves were reintroduced into parts of Yellowstone National Park. Foraging theory predicts that elk and bison would respond to this threat by increasing their vigilance levels. We tested this prediction by comparing vigilance levels of elk and bison in areas with wolves with those of elk still in "wolf-free" zones of the Park. Male elk and bison showed no response to the reintroduction of wolves, maintaining the lowest levels of vigilance throughout the study (12 and 7% of the time was spent vigilant, respectively). Female elk and bison showed significantly higher vigilance levels in areas with wolves than in areas without wolves. The highest vigilance level (47.5 ± 4.1%; mean ± SE) was seen by the second year for female elk with calves in the areas with wolves and was maintained during the subsequent 3 years of...

Profitable stream positions for salmonids: relating specific growth rate to net energy gain

Abstract: A model is developed to predict potential net energy gain for salmonids in streams from characteristics of water velocity and invertebrate drift. Potential net energy gain, or potential profit, is ...