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You searched for: Journal Canadian journal of zoology Remove constraint Journal: Canadian journal of zoology Publication Year 2011 Remove constraint Publication Year: 2011 Source 2011 v.89 no.12 Remove constraint Source: 2011 v.89 no.12
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1. Costs of multiple parasitism for an avian brood parasite, the Brown-headed Cowbird (Molothrus ater)

Author:
Goguen, C.B.; Curson, D.R.; Mathews, N.E.
Source:
Canadian journal of zoology 2011 v.89 no.12 pp. 1237-1248
ISSN:
1480-3283
Subject:
Molothrus ater; Piranga; Polioptila; birds; eggs; fecundity; females; hosts; intraspecific competition; mortality; multiparasitism; nesting; nestlings; nests; parasites; predation; New Mexico
Abstract:
... The Brown-headed Cowbird (Molothrus ater (Boddaert, 1783)) is a generalist brood parasite that often lays into nests that contain conspecific eggs. Although it has often been assumed that this multiple parasitism reduces Cowbird survival, this has rarely been evaluated. We measured Cowbird survival in nests of the Blue-gray Gnatcatcher (Polioptila caerulea (L., 1766)), Plumbeous Vireo (Vireo plumb ...
DOI:
10.1139/z11-104

2. Effects of predator exposure on Hsp70 expression and survival in tadpoles of the Common Frog (Rana temporaria)

Author:
Sørensen, Jesper Givskov; Loeschcke, Volker; Merilä, Juha; Laurila, Anssi
Source:
Canadian journal of zoology 2011 v.89 no.12 pp. 1249-1255
ISSN:
1480-3283
Subject:
Aeshna; Rana temporaria; frogs; heat; heat-shock protein 70; predation; predator-prey relationships; predators; protein synthesis; risk; stress response; tadpoles
Abstract:
... Predator-induced changes in prey behavior and morphology are widespread, but little is known about physiological and cellular-level responses in prey in response to predation risk. We investigated whether predator (larvae of the dragonfly Aeshna Fabricius, 1775) presence elevated the expression level of heat-shock protein 70 (Hsp70)—a commonly found response to stress—in tadpoles of the Common Fro ...
DOI:
10.1139/z11-105

3. Habitat heterogeneity and climatic seasonality structure the avifauna trophic guilds in the Brazilian Pantanal wetland

Author:
Figueira, J.E.C.; Mourão, F.A.; Coelho, A.S.
Source:
Canadian journal of zoology 2011 v.89 no.12 pp. 1206-1213
ISSN:
1480-3283
Subject:
aquatic habitat; aquatic invertebrates; drying; floodplains; landscapes; multidimensional scaling; nectar; rain; swamps; temporal variation; water birds; woodlands; Pantanal; South America
Abstract:
... Landscape heterogeneity and annual flood pulses characterize the Brazilian Pantanal, the largest floodplain in South America. The objective of this work was to explain spatial and temporal variations in the trophic structure of a bird assemblage consisting of 316 species of terrestrial and aquatic birds, out of which 88 are visitors. The food items potentially consumed by these species were combin ...
DOI:
10.1139/z11-099

4. Is sperm viability independent of ejaculate size in the house cricket (Acheta domesticus)?

Author:
Gress, Brian E.; Kelly, Clint D.
Source:
Canadian journal of zoology 2011 v.89 no.12 pp. 1231-1236
ISSN:
1480-3283
Subject:
Acheta domesticus; fertilizers; males; mortality; spermatophores; spermatozoa; statistical analysis; viability
Abstract:
... Assessing sperm viability is a popular means of testing hypotheses related to ejaculate quality. This technique has produced interesting results; however, the sperm viability assay itself may kill sperm. This is a serious pitfall, as assay-related mortality could confound results and produce artificially low estimates of viability. To avoid spurious results, it has been recommended that investigat ...
DOI:
10.1139/z11-103

5. Movement of small mammals across divided highways with vegetated medians

Author:
McLaren, Ashley A.D.; Fahrig, Lenore; Waltho, Nigel
Source:
Canadian journal of zoology 2011 v.89 no.12 pp. 1214-1222
ISSN:
0008-4301
Subject:
canopy gaps; highways; probability; small mammals; vegetation cover; vegetation types
Abstract:
... Previous studies suggest the gap in forest cover generated by roads contributes to the barrier effect of roads on movement of forest-dwelling small mammals. However, it is not known if vegetated medians of divided highways affect movement of small mammals by reducing the effective highway width. The purpose of our study was to determine whether the type of vegetation cover in the median (treed or ...
DOI:
10.1139/z11-100

6. Roosts and home ranges of spotted bats (Euderma maculatum) in northern Arizona

Author:
Chambers, Carol L.; Herder, Michael J.; Yasuda, Kei; Mikesic, David G.; Dewhurst, Stephen M.; Masters, W. Mitchell; Vleck, David
Source:
Canadian journal of zoology 2011 v.89 no.12 pp. 1256-1267
ISSN:
0008-4301
Subject:
Chiroptera; conservation areas; drinking; females; flight; foraging; forests; home range; insectivores; males; ponds; public lands; radio transmitters; roosting behavior; shrublands; water stress; woodlands; Arizona
Abstract:
... Roosting ecology and foraging behavior of spotted bats (Euderma maculatum (J.A. Allen, 1891)) are poorly known. We captured 47 spotted bats at three locations in northern Arizona and attached radio transmitters to 16 bats to identify roosts and home ranges. We identified 14 roosts for 12 bats. Female roosts faced south; males did not select a roost aspect. Bats used a mean of 1.4 roosts during 10  ...
DOI:
10.1139/z11-106

7. An experimental test of facilitation between non-native earthworms

Author:
Cameron, Erin K.; Bayne, Erin M.
Source:
Canadian journal of zoology 2011 v.89 no.12 pp. 1223-1230
ISSN:
1480-3283
Subject:
Dendrobaena; Lumbricus terrestris; additive effect; biomass; boreal forests; cocoons; earthworms; forest litter; forest soils; introduced species; organic horizons; soil structure; synergism
Abstract:
... Invasional meltdowns, in which facilitation between species causes an accelerating increase in the number of introduced species or impacts, can cause large impacts in invaded systems. Earthworm invasion of northern forests has been suggested as a meltdown, with litter-dwelling species altering soil structure and facilitating mineral-soil or deep-burrowing earthworms that may be less capable of inv ...
DOI:
10.1139/z11-102

8. Diet and energetic constraints of an earthworm specialist, the Mesa Central Blotched Garter Snake (Thamnophis scaliger)

Author:
Reguera, S.; Santos, X.; Feriche, M.; Mociño-Deloya, E.; Setser, K.; Pleguezuelos, J.M.
Source:
Canadian journal of zoology 2011 v.89 no.12 pp. 1178-1187
ISSN:
1480-3283
Subject:
Thamnophis; arthropods; body size; diet; earthworms; energy intake; females; forage; foraging; lizards; meta-analysis; optimal nutrition; predators; reproduction; small mammals; snakes; water content
Abstract:
... Optimal diet theory predicts that predators optimize energy intake by balancing costs and benefits of foraging. One extreme strategy of snake foraging ecology is shown by specialist species that forage on low-energy prey, such as Thamnophis scaliger (Jan, 1863) which feeds almost exclusively on earthworms. Compared with other prey types such as small mammals, lizards, or arthropods, earthworms are ...
DOI:
10.1139/z11-096

9. In the shallow end: diving behaviour of recolonising female New Zealand sea lions (Phocarctos hookeri) around the Otago Peninsula

Author:
Augé, Amélie A.; Chilvers, B. Louise; Davis, Lloyd S.; Moore, Antoni B.
Source:
Canadian journal of zoology 2011 v.89 no.12 pp. 1195-1205
ISSN:
1480-3283
Subject:
Phocarctos hookeri; adults; animals; females; habitats; islands
Abstract:
... Female New Zealand sea lions (Phocarctos hookeri (Gray, 1844)) at the Auckland Islands (remnant populations) are the deepest and longest diving otariids. These remnant populations are found at the margin of the historical range of the species. We hypothesized that diving behaviours of animals in the core of their historical range is less extreme owing to a better marine habitat. All female New Zea ...
DOI:
10.1139/z11-098

10. Use of cranial characters in taxonomy of the Minnesota wolf (Canis sp.)

Author:
Mech, L. David; Nowak, Ronald M.; Weisberg, Sanford
Source:
Canadian journal of zoology 2011 v.89 no.12 pp. 1188-1194
ISSN:
1480-3283
Subject:
Canis lupus; Canis lycaon; endangered species; hybridization; skull; taxonomy; wolves; Minnesota; Ontario
Abstract:
... Minnesota wolves (Canis sp.) sometimes are reported to have affinity to a small, narrow-skulled eastern form (Canis lupus lycaon Schreber, 1775) and sometimes to a larger, broader western form (Canis lupus nubilus Say, 1823). We found that pre-1950 Minnesota wolf skulls were similar in size to those of wolves from southeastern Ontario and smaller than those of western wolves. However, Minnesota wo ...
DOI:
10.1139/z11-097

11. Differences in plasma testosterone levels related to social status are more pronounced during mating than nonmating season in the tropical bat Saccopteryx bilineata (greater sac-winged bat)

Author:
Greiner, Sabine; Dehnhard, Martin; Voigt, Christian C.
Source:
Canadian journal of zoology 2011 v.89 no.12 pp. 1157-1163
ISSN:
1480-3283
Subject:
parasites; parasitoses; males; Chiroptera; socioeconomic status; seasonal variation; mammals; testosterone; females; breeding season; territoriality
Abstract:
... Testosterone (T) concentrations often covary strongly with mating activities in temperate-zone vertebrates. Recent studies suggest that males of tropical species experience lower and year-round constant T levels. Here we studied plasma T concentrations in a tropical mammal with a seasonally invariant social system, the greater sac-winged bat (Saccopteryx bilineata (Temminck, 1838)). Colony composi ...
DOI:
10.1139/z11-092

12. Is the risk of nest predation heterospecifically density-dependent in precocial species belonging to different nesting guilds?

Author:
Elmberg, Johan; Pöysä, Hannu
Source:
Canadian journal of zoology 2011 v.89 no.12 pp. 1164-1171
ISSN:
1480-3283
Subject:
Anas platyrhynchos; Bucephala; Martes martes; immigration; mortality; nesting; nests; predation; risk
Abstract:
... Nest predation is a key source of mortality and variation in fitness, but the effect co-occurring species belonging to different nesting guilds have on each other’s nest success is poorly understood. By using artificial nests, we tested if predation on cavity nests of Common Goldeneyes (Bucephala clangula (L., 1758)) is increased in the presence of ground nests of Mallards (Anas platyrhynchos L., ...
DOI:
10.1139/z11-093

13. Nest-site selection in the Canada Warbler (Wilsonia canadensis) in central New Hampshire

Author:
Goodnow, M.L.; Reitsma, L.R.
Source:
Canadian journal of zoology 2011 v.89 no.12 pp. 1172-1177
ISSN:
1480-3283
Subject:
Cardellina canadensis; birds; forests; nesting sites; nests; predators; reproductive success; risk reduction; tropics; woody plants; New Hampshire
Abstract:
... Reproductive success in birds is largely influenced by nest-site selection. Nest predators are the greatest source of nest failure for most species of birds. Species that nest on the ground may be particularly adapted to maximally conceal nests to reduce the risk of loss to predators. Little is known about nest-site selection in the Canada Warbler (Wilsonia canadensis (L., 1766)), a small ground-n ...
DOI:
10.1139/z11-094