Winter habitat use by ptarmigan, snowshoe hares, red foxes, and river otters in the boreal forest – tundra transition zone of western Quebec

1995 ◽  
Vol 73 (4) ◽  
pp. 755-764 ◽  
Author(s):  
Mario St-Georges ◽  
Simon Nadeau ◽  
Daniel Lambert ◽  
Robert Décarie
Keyword(s):  
Boreal Forest ◽  
Transition Zone ◽  
Species Abundance ◽  
Habitat Type ◽  
Riparian Habitat ◽  
Red Foxes ◽  
Winter Habitat ◽  
Forest Tundra ◽  
River Otters ◽  
Snowshoe Hares

We investigated species–habitat relationships of the midsized fauna inhabiting the transition zone between the boreal forest and forest tundra of subarctic Quebec. Data were collected during a winter aerial track survey of 46 randomly selected 25-km2 plots. The presence of species tracks and habitat variables were recorded for each 1-km section of riparian edge habitat within a plot. Sections of non-riparian habitat were also surveyed. Logistic regression was used to construct habitat models for ptarmigan (Lagopus spp.), snowshoe hares (Lepus americanus), red foxes (Vulpes vulpes), and river otters (Lutra canadensis). Species' habitat type selection was studied by comparing use and availability. Kendall's correlation coefficients were computed to analyze interrelations between variables. Significant logistic regressions were obtained for each species. The index of rank correlation between the observed responses and predicted probabilities for all pairs of observations ranged from 0.67 for ptarmigan to 0.84 for river otters. Species abundance was negatively associated with latitude except for that of snowshoe hare, which showed a stronger negative link with open habitat. For all species, distribution was not proportional to the frequency of occurrence of habitat types. Non-riparian habitat was either avoided or not significantly preferred by all species. Herbivorous species and river otter selected edge habitats along watercourses. Our study suggests that differences presented by the forest tundra and boreal forest are of importance for wildlife.

Transformation of abandoned farm fields into coniferous plantations: Is there enough vegetation structure left to maintain winter habitat of snowshoe hares?

2010 ◽  
Vol 88 (6) ◽  
pp. 579-588 ◽  
Author(s):  
C. Roy ◽  
L. Imbeau ◽  
M. J. Mazerolle
Keyword(s):  
Habitat Use ◽  
Habitat Type ◽  
Critical Threshold ◽  
Natural Forests ◽  
Wood Fibers ◽  
Alternative Source ◽  
Winter Habitat ◽  
Snowshoe Hares ◽  
Pellet Counts ◽  
Intensively Managed

Natural forests will likely be unable to sustainably fulfill society needs for wood fibers and intensively managed plantations could be an alternative source of timber in the future. Abandoned farm fields are often targeted for conversion, as they are already disturbed sites; however, they also represent high-quality habitat for species such as snowshoe hares ( Lepus americanus Erxleben 1777), a keystone mammal in the boreal forest. We evaluated the effect of converting abandoned farm fields (n = 22) to conifer plantations (n = 19) on habitat use by snowshoe hares, using pellet counts and snow-tracking surveys. Both survey techniques yielded similar results: winter habitat use by hares is mostly affected by vegetation cover rather than habitat type. In the short term, plantations do not offer less protective cover than the one found in abandoned farm fields. However, upon reaching a certain height (≥7 m), plantations are mechanically pruned and lose their protective quality. Promoting silvicultural techniques that maintain lateral cover beyond a critical threshold (70%) could preserve the quality of hare habitat for an extended proportion of rotation time of the plantation.

Ultra-high resolution assessment of potential impacts of vegetation shadows on satellite-derived spectral signals from small thermokarst lakes in the boreal forest-tundra transition zone (subarctic Canada)

2021 ◽  
Author(s):  
Pedro Freitas ◽  
Gonçalo Vieira ◽  
Carla Mora ◽  
João Canário ◽  
Diogo Folhas ◽  
...  
Keyword(s):  
High Resolution ◽  
Boreal Forest ◽  
Transition Zone ◽  
Satellite Data ◽  
Thermokarst Lakes ◽  
Forest Tundra ◽  
Permafrost Thaw ◽  
Spectral Signal ◽  
Tree Communities ◽  
Additional Support

<p>Warming of the circumpolar north is accelerating permafrost thaw, with implications for landscapes, hydrology, ecosystems and the global carbon cycle. In subarctic Canada, abrupt permafrost thaw is creating widespread thermokarst lakes. Little attention has been given to small waterbodies with area less than 10,000 m<sup>2</sup>, yet these are biogeochemically more active than larger lakes. Additionally, the landscapes where they develop show intense shrubification and terrestrialization processes, with increases in area and height of shrub and tree communities. Tall vegetation that is colonizing waterbody margins can cast shadows that impact productivity, thermal regime and the water spectral signal, which in satellite data generates pixels with mixed signatures between sunlit and shaded surfaces. We undertook UAV surveys using optical and multispectral sensors at long-term monitoring sites of the Center for Northern Studies (CEN) in subarctic Canada, from the sporadic (SAS/KWAK) to the discontinuous (BGR) permafrost zones in the boreal forest-tundra transition zone. This ultra-high spatial resolution data enabled spectral characterization and 3D reconstruction of the study areas. Ultra-high resolution digital surface models were produced to model shadowing at satellite overpass time (WorldView, PlanetScope and Sentinel-2). We then analyzed the impacts of surrounding vegetation and cast shadows on lake surface spectral reflectance derived from satellite imagery. Ultra-high resolution UAV data allows generating accurate shadow models and can be used to improve the assessment of errors and accuracy of satellite data analysis. Particularly, we identify different spectral signal impacts of cast shadows according to lake color, which highlight the need for special attention of this issue onto lakes with more turbidity.</p><p>This research is funded by the Portuguese Foundation for Science and Technology (FCT) under the project THAWPOND (PROPOLAR), by the Centre of Geographical Studies (FCT I.P. UIDB/00295/2020 and UIDP/00295/2020), with additional support from ArcticNet (NCE), Sentinel North (CFREF) and CEN and is a contribution to T-MOSAiC. PF is funded by FCT (SFRH/BD/145278/2019).</p>

Song pitch – habitat relationships in white-throated sparrows: cracks in acoustic windows?

1988 ◽  
Vol 66 (11) ◽  
pp. 2578-2581 ◽  
Author(s):  
Joseph R. Waas
Keyword(s):  
Boreal Forest ◽  
Inverse Relationship ◽  
Habitat Type ◽  
Zonotrichia Albicollis ◽  
Acoustic Window ◽  
Wrong Reason ◽  
Foliage Density ◽  
The Right ◽  
Forest Habitats

I compared the hypothesis that birds singing from song posts above 1–2 m should sing in as low a pitch as possible regardless of habitat type, with the traditional "acoustic window" hypothesis which argues that selection favours an inverse relationship between song pitch and foliage density. Songs of white-throated sparrows, Zonotrichia albicollis, were obtained from four habitats which could be arranged in a gradient of foliage density. The pitch of these songs was found to be inversely related to the density of foliage in the habitat occupied, consistent with the acoustic window hypothesis. Significant pitch variation occurred not only between open and forest habitats, but also between mixed and boreal forest habitats. I distinguish between hypotheses that could explain support for the traditional hypothesis despite recent data suggesting that low pitched sound travels best regardless of habitat at song post heights used by white-throated sparrows (5–10 m). I conclude that the acoustic window model may make the right prediction for the wrong reason in white-throated sparrows. I emphasize the need to define and test the assumptions of models before the models themselves are accepted on the basis of support for their predictions.

The impact of variable predation risk on stress in snowshoe hares over the cycle in North America’s boreal forest: adjusting to change

Oecologia ◽  
2021 ◽  
Author(s):  
Sophia G. Lavergne ◽  
Charles J. Krebs ◽  
Alice J. Kenney ◽  
Stan Boutin ◽  
Dennis Murray ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Predation Risk ◽  
Snowshoe Hares ◽  
The Impact

scholarly journals Population Structure of Harvested Red Foxes (Vulpes vulpes) and Coyotes (Canis latrans) on Prince Edward Island, Canada

2013 ◽  
Vol 126 (4) ◽  
pp. 288 ◽  
Author(s):  
Wendela Wapenaar ◽  
Fiep De Bie ◽  
David Johnston ◽  
Ryan M. O'Handley ◽  
Herman W. Barkema
Keyword(s):  
Population Dynamics ◽  
Wildlife Management ◽  
Urban Areas ◽  
Vulpes Vulpes ◽  
Prince Edward Island ◽  
Canis Latrans ◽  
Habitat Type ◽  
Red Foxes ◽  
Wild Canids ◽  
Agricultural Areas

An understanding of the population dynamics and habitat of wild Red Foxes (Vulpes vulpes) and Coyotes (Canis latrans) is a prerequisite to wildlife management. This information is also important in assessing the risk these wild canids pose to the public and domestic animals. On Prince Edward Island, information on age, sex, reproductive activity, and habitat use of 271 Red Foxes and 201 Coyotes was collected in the hunting and trapping season of 2004–2005. The estimated age of Red Foxes and Coyotes ranged from 0.5 to 13.5 years. A large proportion of harvested Red Foxes and Coyotes (58% and 48%, respectively) consisted of juveniles. The sex ratio was not significantly different from 1:1 for either species. Average litter size was 5.0 and 5.2 for Red Foxes and Coyotes, respectively. Number of placental scars ranged from 0 to 7 in Red Foxes and from 0 to 11 in Coyotes. Agricultural areas were the main habitat type (52%) of harvested Red Foxes. For harvested Coyotes, forest was the main habitat (44%), followed closely by agricultural areas (43%). Urban areas were a significant part (13%) of the habitat of Red Foxes. These data can be used to monitor population dynamics over time, provide information for wildlife management, and provide information on potential risk areas for disease transmission by wild canids.

Epibenthic community structure in Port Phillip Bay, Victoria, Australia

2000 ◽  
Vol 51 (7) ◽  
pp. 689 ◽  
Author(s):  
Brian F. Cohen ◽  
David R. Currie ◽  
Matthew A. McArthur
Keyword(s):  
Community Structure ◽  
Species Abundance ◽  
Habitat Type ◽  
Demersal Fish ◽  
Asterias Amurensis ◽  
Styela Plicata ◽  
Strong Trend ◽  
Epifaunal Community ◽  
Inshore Waters ◽  
Total Species

Epibenthic community structure in Port Phillip Bay was examined from quantitative diver samples collected at 30 depth-stratified stations during 1998. Analysis of variance showed a strong trend of decreasing epibenthic abundance, biomass and species diversity with depth. Reductions in these three parameters were most pronounced over shallow inshore waters and could be attributed largely to decreases in the abundance of the heavy, mat-forming ascidian Pyura stolonifera with depth. Four epifaunal community groupings, closely reflecting differences in sediment and habitat type within the bay, were identified from ordinations of species abundance and biomass data. The four epifaunal groupings also closely matched distributional patterns observed in other studies in both demersal fish and infaunal communities. Epifaunal communities in the bay were dominated by filter-feeding organisms which accounted for nearly 95% of the total species abundance and 98% of the total species biomass. Seven of the 63 epibenthic organisms collected during the survey are exotic introductions to the bay (Sabella spallanzanii, Ascidiella aspersa, Styela clava, Styela plicata, Ciona intestinalis, Pyromaia tuberculata and Asterias amurensis). As many of these species are widespread and abundant (35% of all individuals), their effects on the ecology of Port Phillip Bay are likely to be significant.

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