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A developing body of theory and empirical evidence suggest that feeding behaviour as measured by the functional response (FR) can assist researchers in assessing the relative potential, ecological impacts and competitive abilities of native and introduced species. Here, we explored the FRs of two land snails that occur in south-western Ontario, one native (Mesodon thyroidus) and one non-indigenous (Cepaea nemoralis) to Canada. The non-indigenous species appears to have low ecological impact and inferior competitive abilities. Consistent with theory, while both species conformed to Type II functional responses, the native species had a significantly higher attack rate (5.30 vs 0.41, respectively) and slightly lower handling time (0.020 vs 0.023), and hence a higher maximum feeding rate (50.0 vs 43.5). The non-indigenous species exhibited a significantly longer time to contact for a variety of food types, and appeared less discriminating of paper that was offered as a non-food type. The non-indigenous species also ate significantly less food when in mixed species trials with the native snail. These feeding patterns match the known low ecological impact of the introduced snail and are consistent with the view that it is an inferior competitor relative to the native species. However, field experimentation is required to clarify whether the largely microallopatric distributions of the two species in south-western Ontario reflect competitive dominance by the native species or other factors such as habitat preference, feeding preferences or predator avoidance. The relative patterns of feeding behaviour and ecological impact are, however, fully in line with recent functional response theory and application. [ABSTRACT FROM AUTHOR]

Translocation and captivity are important tools for conservation biology and wildlife management. Understanding the movement ecology of animals following their release in novel terrain is critical to predicting the success of wildlife restoration efforts. Mountain caribou have high conservation value – efforts to restore their populations across western Canada involve hundreds of millions of dollars in science, monitoring, and management activity. Here, we examined the movements of adult female caribou (N = 36) following their translocation to, and release from, a maternity pen ('penned caribou') and compared these movements to animals that were not translocated ('unpenned caribou', N = 22). A maternity pen is a temporary holding facility, within the animals' existing range, that enables them to bear and raise their young in the absence of predators and with augmented resources. Penned and unpenned animals had similar home range sizes (1052.2 and 1314.6 km2, respectively, P = 0.46) though penned animals moved through the landscape in a faster yet less directed manner. We found some evidence that memory may improve the efficiency of space use. Home ranges with higher quality habitats tended to be smaller than home ranges with poorer quality habitats irrespective of penning status. Penned animals ranged at lower elevation (~150 m) than unpenned animals, particularly in spring and early winter. For penned animals, we did not detect evidence of homing back to the original capture site. The best predictor of how caribou will use the landscape appears to be proximity to the location of the release site. To maximize the fitness of released caribou, future plans for maternity pens and captive breeding programs need to consider the management of food, predators, and habitat across the 1000–2000 km2 that will form the home range near the release site. [ABSTRACT FROM AUTHOR]

Land modified for human use alters matrix shape and composition and is a leading contributor to global biodiversity loss. It can also play a key role in facilitating range expansion and ecosystem invasion by anthrophilic species, as it can alter food abundance and distribution while also influencing predation risk; the relative roles of these processes are key to habitat selection theory. We researched these relative influences by examining human footprint, natural habitat, and predator occurrence on seasonal habitat selection by range-expanding boreal white-tailed deer (Odocoileus virginianus) in the oil sands of western Canada. We hypothesized that polygonal industrial features (e.g. cutblocks, well sites) drive deer distributions as sources of early seral forage, while linear features (e.g. roads, trails, and seismic lines) and habitat associated with predators are avoided by deer. We developed seasonal 2nd -order resource selection models from three years of deer GPS-telemetry data, a camera-trap-based model of predator occurrence, and landscape spatial data to weigh evidence for six competing hypotheses. Deer habitat selection was best explained by the combination of polygonal and linear features, intact deciduous forest, and wolf (Canis lupus) occurrence. Deer strongly selected for linear features such as roads and trails, despite a potential increased risk of wolf encounters. Linear features may attract deer by providing high density forage opportunity in heavily exploited landscapes, facilitating expansion into the boreal north. [ABSTRACT FROM AUTHOR]

Canada's federal recovery strategy for boreal woodland caribou (Rangifer tarandus caribou) classifies areas burned by forest fire as disturbed habitat. This assignment of fire as a disturbance has potential economic and social implications across Canada, and influences plans and actions to achieve caribou conservation and recovery. Previous researchers have reported caribou avoid burned habitat, but these studies did not typically consider unburned residual patches within fire perimeters. Additionally, the implications of burned habitat on individual caribou survival is unclear. We examined resource selection by boreal woodland caribou of burns, and unburned residual patches, using global positioning system (GPS) locations for 201 caribou across 6 caribou populations in Alberta, Canada. We also examined if burned habitat affected the survival of adult female caribou. Caribou avoided burns and unburned residual patches. Increased use of burned habitats, however, did not lower the survival of adult caribou. Collectively, these results provide evidence to support current assertions that burns, and the embedded unburned residual patches are not preferred caribou habitat and increase our understanding of the implications of forest fire for caribou vital rates. Our investigation offers important information about the role of forest fire in caribou ecology and enhances the identification of disturbed habitat under recovery strategy guidelines to effectively address caribou population declines. © 2021 The Wildlife Society. : Woodland caribou in Alberta, Canada avoid burned habitat including unburned residual patches; however, there was no relationship between burned habitat use and adult female survival. This suggests fire disturbance is not a key influence of caribou population persistence, and we recommend reevaluation of the current approach listed in the federal boreal caribou recovery strategy that includes anthropogenic and fire disturbance in a cumulative assessment of disturbed habitat. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Fisheries & Aquatic Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bank Swallows (Riparia riparia) are designated as Threatened in Canada, in part due to loss of natural breeding habitat along lakeshores and rivers. Excavation in sand and gravel pits (aka aggregate pits) has increased availability of potential nesting habitat away from lakes and rivers, and these substitute habitats may be important to stabilize the decline experienced by some Bank Swallow populations. Over 2 yr, we collected data on Bank Swallow reproductive success from 2 natural lakeshore habitat sites along bluffs of the north shore of Lake Ontario and 7 aggregate pits in southern Ontario, within 100 km of the lakeshore. Nests at the lakeshore habitat were initiated earlier than in aggregate pits, 8 days earlier in 2014 and 13 days earlier in 2015. Neither clutch size nor number of nestlings were different between the 2 habitat types. There were differences in the number of fledglings produced between the habitat types, with Bank Swallows nesting in aggregate pits raising more fledglings per successful nest. However, birds nesting in aggregate pits also had significantly more nests that raised no fledglings, even though eggs in those nests hatched. Breeding adults from aggregate pits were initially heavier than those from the lakeshore habitat, but their mass decreased significantly over the nesting season. Fledgling masses were not significantly different between habitat types. Parasite loads on fledgling Bank Swallows from aggregate pits were significantly lower than on fledglings from the lakeshore. These indicators suggest that aggregate pits can provide at least equivalent habitat for Bank Swallows to that provided by natural lakeshore habitat, making them potentially key for the recovery of this species in Ontario. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Structurally complex cobble seafloor protects against predators, and is generally assumed to be the only meaningful habitat for settlement and benthic recruitment of American lobsters (Homarus americanus H. Milne Edwards, 1837). Accordingly, historical surveys on featureless substrates such as mud have found few and only older juveniles. Mud, however, is far more common than cobble across the lobster's range, and may be of increasing importance in regions where the lobster population has been growing over the past few decades. As a first step to determining whether mud seafloor serves as meaningful recruitment habitat for juvenile lobsters, we deployed artificial habitats (bio-collectors) at five locations varying from 100% mud to mostly cobble, in Maces Bay, Bay of Fundy, NB, Canada, to capture young lobsters. A broad size range of lobsters, from new settlers up to adolescents, colonized bio-collectors in all locations, suggesting that lobsters settle and spend at least some of their juvenile life on mud. Differences in body condition (length-standardized mass) of lobsters sampled from the different locations suggest that some individuals must reside on mud for at least months to years, long enough to show differential growth between habitats. The greater relative abundance of adolescents in bio-collectors on mud also suggests their net movement from densely populated cobble beds into mud habitat. We propose that mud seafloor may be a more important habitat for settlement and early survival of American lobsters than is currently appreciated, especially given the current potential saturation of scarce cobble nursery habitat by growing lobster populations and, in some regions, reduced predation on mud seafloor due to overfishing of groundfish. [ABSTRACT FROM AUTHOR]

Copyright of Condor: Ornithological Applications is the property of Oxford University Press / USA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Variation in food abundance and distribution influences animal foraging behavior, but response is contingent on the amount of resource heterogeneity detected, which is consistent with environmental 'grain' size. Large mammals presumably perceive their surroundings at broad spatial scales, but the importance of landscape‐level food resource properties for habitat use is generally less understood. We evaluated the role of heterogeneity of Canada buffaloberry Shepherdiacanadensis, defined by fruit distribution and variability in patch quality (fruit density), in grizzly bear Ursus arctos habitat selection by comparing patch‐ and landscape‐level foraging strategies (resource use). Our objectives were to: 1) identify the spatial scale at which grizzly bears select buffaloberry fruit resources; 2) determine whether patch‐ or landscape‐level foraging strategies explain resource use; and 3) assess the importance of resource heterogeneity in structuring habitat selection. Buffaloberry patch and landscape variables were combined with GPS radio‐telemetry data from eight collared grizzly bears in west‐central Alberta, Canada, to fit resource selection functions (RSFs). We found that a spatial scale of 1887 m, corresponding to an average travel distance for bears over 5.5 h, was the most supported scale for buffaloberry use. Landscape‐level foraging strategies generally had more support than those of the patch‐level, with spatial heterogeneity of buffaloberry patches best explaining grizzly bear selection for fruit resources. Bears selected for areas with a wider distribution of buffaloberry fruit and greater variability in patch quality, thus providing both a higher probability of shrub encounter and greater contrast between resource patches. A negative interaction between distribution and variability, however, indicated a tradeoff where use of areas with a more widespread fruit distribution decreased when variability in resource quality was high. These results demonstrate the influence of food resource heterogeneity on animal habitat use and emphasize the value in considering spatial scale in studies of animal—resource interactions. [ABSTRACT FROM AUTHOR]

Habitat loss and fragmentation result in landscapes where high quality habitat patches are surrounded by matrix habitats of low and variable quality. For mobile species to persist in such landscapes, individual animals often rely on the high quality habitats but also use matrix habitats for supplemental resources or while moving between higher quality patches. Determining what habitat features animals select when in these matrix areas is important, as retaining desirable features in lower quality habitats may enable species persistence. We examine a population of US federally threatened Canada lynx ( Lynx canadensis) in northcentral Washington, near the southwestern range limit, where lynx habitat is fragmented by topography, wildfires, and human impacts. We used Global Positioning System radio-collar data from 17 lynx in the North Cascade Mountains during 2007-2013 to explore lynx habitat use. We used Random Forest models to analyze core hunting, resting, and denning habitat, and the habitats lynx select while between patches of core habitat. While selecting core habitat, lynx used spruce ( Picea engelmannii)-fir ( Abies lasiocarpa), lodgepole pine ( Pinus contorta), and mixed sub-boreal-Douglas fir ( Pseudotsuga menziesii) forests, and avoided dry forests and forest openings including new burns. When not in core habitat, lynx used a wider range of habitats, including new burns where fire skips and residual trees offered cover. Our results show clearly that Canada lynx tolerate a wider range of habitats where they occupy fragmented landscapes. Consequently, maintaining animals in fragmented landscapes requires that we identify and conserve not only the core habitats a particular species selects, but also the habitat features animals use while in less suitable environments. [ABSTRACT FROM AUTHOR]

According to density-dependent habitat selection theory, areas of high density can be indicative of high population productivity and have positive individual fitness consequences. Here, we explore six groundfish populations on the Scotian Shelf, Canada, where a decline in areas of high density beyond a certain threshold is associated with disproportionately large declines in Spawning Stock Biomass (SSB). This is evidenced by empirical, concave, positive relationships between high-density areas (HDAs) and SSB. We introduce a methodology to estimate the threshold below which SSB declines increasingly faster per unit of HDA decline. The spatial threshold among these six stocks was remarkably consistent; when stocks lose 70-80% of HDAs, disproportionately large SSB declines are likely to occur. We propose that spatial thresholds could serve as spatial reference points to complement existing SSB limit reference points (LRPs). For some stocks we identify spatial thresholds which correspond to SSB levels that exceed those associated with the designated SSB LRP, suggesting that a review of these SSB LRPs warrants merit. For other stocks, spatial reference points can be used in concert with SSB reference points, strengthening efforts to incorporate a precautionary approach to fisheries management. Our results warrant further research into the general application of HDA as spatial limit and target reference points for fisheries management in addition to other population status indicators within a broad recovery framework. [ABSTRACT FROM AUTHOR]