When organisms select habitat, they may lessen the environmental variance they experience relative to their surroundings. Such discrepancies in variance could reveal organisms' habitat preferences and perceptual ranges, particularly when examined across spatial and temporal scales. To test whether habitat variance might provide such understanding, we applied geostatistics to the variance in availability and use of habitat by GPS-collared adult female white-tailed deer (Odocoileus virginianus) in central Ontario, Canada. First, to quantify use and availability, we measured vegetation at the locations used by deer during May-June 2022, as well as in the general environment, then applied principal components analysis (PCA) to capture the major gradients in vegetation conditions. Second, to identify habitat selection, we tested for differences between use and availability in both the means and variance of vegetation characteristics. Finally, to depict how variance changed across scales, we constructed spatial and temporal variograms. Based on the first two axes of the PCA, we found that deer selected greater abundance in forage and lower variation in canopy closure. Across space, the selection for reduced variance in canopy appeared largely independent of scale (50-1000 m), implying that the perception capacity of deer may exceed this range. Across time, deer exhibited rising variance in forage abundance at short lags (4-12 h), resembling the periods (6-10 h) when movements were more linear. Deer thus selected for lower variance of habitat without selecting for disproportionate levels of habitat. We propose that selection for diminished variance is a fundamental property of habitat selection, whose scale-dependence might be uncovered with geostatistics.

In many regions of Canada, knowledge of the distribution of insect species is far from complete. This knowledge gap, known as the Wallacean Shortfall, is often manifest by species records separated by large, often remote areas with no records. Paradoxically, these difficult-to-access areas offer the best opportunity to study unaltered native community assemblages. Such gaps in knowledge are exemplified by ground beetles, a well-known group, yet with record gaps in many unstudied areas of Canada, including Akimiski Island, Nunavut. This postglacial rebound island, located in James Bay, has no permanently occupied human dwellings and almost no human-altered habitat. Using a combination of pitfall-malaise traps, pitfall traps, and hand captures during 2008-2014, we collected 1368 ground beetles (Coleoptera: Carabidae) as part of a larger biodiversity survey. We identified 31 species, 29 of which were first territorial records for Nunavut. Our results almost double the number of Carabidae known from Nunavut and extend the known range of eight other species. Seventeen of the species that we caught cannot fly, evidence for colonists arriving on Akimiski on floating debris. Our study fills substantial range gaps and serves as baseline information to detect future change.

Sea ice loss, disturbance, and habitat modification by humans can alter functional landscape connectivity, with negative impacts on wildlife. Connectivity facilitates movement and gene flow, and contributes to genetic diversity, metapopulation dynamics, and species range-shifts under climate change. For Arctic ungulates, which disperse over large areas including sea ice, environmental change threatens further isolation. Protecting habitat and its linkages is critical and depends on identifying such areas at commensurate, broad scales. Using caribou, the world's most vagile species, we modelled and mapped the drivers of connectivity across ca. 2 million km2 of the Canadian Arctic Archipelago - where the pace of climate change is among the fastest and caribou are threatened with extinction. First, we quantified hierarchical genetic structure and identified two discrete groups. Next, using circuit theory and simultaneous multi-surface optimization, we tested whether land- and sea-scape heterogeneity or geographic distance better accounted for movement and gene flow within each group. We show that anthropogenic interference is far-reaching. High Arctic Peary caribou displayed isolation-byresistance, where glacier cover, low sea-ice concentrations during fall, and human trails impeded connectivity. In contrast, more southerly barren-ground caribou displayed largely unrestricted gene flow. These divergent outcomes underscore that organism-landscape relationships can vary across space and highlight the importance of intra-specific structure and responses. By leveraging genetic data, our study demonstrates how critical movement pathways can be identified, even for remote and imperilled species. Such knowledge supports broadscale conservation planning, in particular, by accounting for complex organism-landscape relationships, across vast, heterogeneous ecosystems.

Climate change portends serious implications for Arctic vegetation. Understanding these effects is likely to be enhanced with long-term observations from permanent plots. I evaluated three decades of change in tundra vegetation from 80 permanent plots on south-eastern Victoria Island, Nunavut, Canada. I compared baseline (1991 and 1992) and contemporary (2019 and 2022) periods in the cover and frequency of graminoids, mosses and common species of forbs, shrubs and lichens. I found substantial shifts in cover of several species and growth forms—an increase in graminoids, decreases in Dryas integrifolia, Polygonum viviparum and Saxifraga oppositifolia, and marginally significant declines in mosses and Cassiope tetragona, but no detectable changes in other groups. The decline in Dryas integrifolia was more pronounced at lower elevations and was noticeable as patches of apparent mortality, inside the plots and elsewhere. The shifts in species abundance were not significantly correlated with each other, nor with changes in soil depth. These changes, manifest as communities with more abundant graminoids, are consistent with expected climate change effects in colder regions of the Arctic. Repeated observations of permanent plots can aid in detecting and understanding long-term ecological change.

Horse flies and deer flies are important components of habitat for many species, but how logging may alter the communities of biting flies in the boreal forest is largely unexplored. Such knowledge is important to conservation, because biting flies can shape the behaviour and sometimes even the demography of vertebrates in the boreal forest. We compared the abundance and distribution of Tabanidae species in managed boreal forest stands in northwestern Ontario with three harvest histories. Using sweep nets during 2 summers, we collected specimens from forest stands that were young (harvested 20-35 years ago), intermediate (harvested 36-69 years ago), and old (unharvested or harvested & GE; 70 years ago). We tested the hypothesis that greater harassment potential in young stands was due not only to more abundant tabanids, but more abundant obligate blood-feeding (anautogenous) tabanids, which are more persistent in host seeking. We caught 8,895 specimens from 44 species. The oldest stands had the highest species richness, but the lowest abundance of individuals, whereas young stands had the highest relative abundance and the most anautogenous specimens, potentially causing more stress to hosts in young stands. These results demonstrate that forest harvesting may reduce habitat suitability for many large mammals due to an altered tabanid community.

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 a sticky trap. During 10 trials in each treatment, we captured a total of 868 deer flies, all in the genus Chrysops; the total capture while walking was nearly five-fold greater than while sitting. During trials, the change in catch rate also differed with host activity. While the host was sitting, the mean rate of capture declined rapidly (−16% per min) to nearly zero by 20 min. In contrast, while the host was walking, this decline was much more gradual (−5% per min); after 20 min, the catch rate remained nearly constant, at roughly half the initial rate. These results are consistent with the hypothesis.

Abstract The distribution and diversity of fauna of remote regions, including much of the boreal forest, are incompletely known. We took part in extensive biodiversity surveys in the Far North of Ontario (north of 51° N), Canada from 2009 to 2015. In the family Carabidae Latreille (Coleoptera), we report new records and range extensions for 600 specimens representing 99 species. We documented the first record for Canada of one species, the first records for Ontario of 11 species, and range extensions (> 100 km from the known range) for 70 species. The range extensions were largely in a northwards direction, with a median distance of 650 km and a positive skew in the distribution of these distances. These new records fill an important gap in knowledge of the distribution of this family.

Landscapes can influence the distribution of harvesting by influencing animal distribution and hunter access. For species like caribou, Rangifer tarandus, decades-long shifts in abundance and distribution might alter such relationships, but few studies have been conducted at such scales. We examined relationships between landscape features and 21,380 harvest records of migratory caribou in Newfoundland during caribou population growth (1980s), cessation of growth (1990s), and decline (2000s). We focused on features hypothesized to influence the distributions of caribou and hunters: lichen landcover, roads, cutblocks, outfitter camps, power lines, and towns. We uncovered larger harvests by resident hunters of male and female caribou among lichen landcover, likely providing preferred caribou forage, and larger harvests by non-resident hunters of male caribou away from towns, reflecting the locations of outfitter camps. Only during later decades, resident harvests occurred nearer power lines and cutblocks, likely providing hunter access and reflecting risk-prone foraging by caribou. We surmise that the harvest was facilitated by open habitats, preferred by caribou, and anthropogenic features leading to hunter access, especially as the caribou population declined. Such knowledge at broad scales is increasingly important in an era of widespread disruption to landscapes.

Passive transport has likely contributed to the post-glacial dispersal of species in temperate regions. However, identifying such processes from patterns can be obscured by confounding environmental conditions. We studied the distribution of ground beetles in Ontario's Far North, a vast (450,000 km(2)) and largely intact region, to identify mechanisms that aid in species dispersal when confounding factors, such as temperature, are controlled. We tested a model of passive, riverine dispersal using recent records of flightless and flighted ground beetles from 34 sites across the region. The number of species declined with distance from main watershed rivers, as predicted from our model at the site level. Contrary to expectations, this pattern was evident with flighted species but not flightless species. The opposite pattern, with flightless species displaying a decrease with increasing distance from river, was evident at a regional level. These patterns are consistent with ground beetles carried along rivers since glacial retreat. We surmise that northward dispersal of these invertebrates into the boreal forest has been aided by vegetation and other debris flowing down rivers, including soil from eroded banks in which larvae and pupae reside. Biogeographic inferences, although often subtle, can be supported by broad-scale studies of intact landscapes.

Syrphids (Diptera: Syrphidae) are a diverse and widespread family of pollinating flies. Their diverse life history traits not only allow them to thrive in a wide range of habitats but also make them potential bioindicators of environmental change. Here, we report on their distributions from a previously understudied and undeveloped part of northern Ontario that is a large part of the third-largest wetland in the world. Samples were collected from across the region between 2009 and 2016, using numerous sampling methods. Of the 122 species identified from 1514 specimens, six are new provincial records to Ontario. Five species were collected over 800 km from their previously known ranges, some of which were west of the Rocky Mountains. Of all the trapping methods employed in the study, Malaise traps were found to be the most effective at catching syrphid species. This work updates known range and provincial records for more than 100 species of syrphids, bringing into clearer focus their distribution throughout this region.

Climate change and biodiversity loss underscore the need for conservation planning, even in remote areas. Species distribution models (SDMs) can help identify critical habitat for reserve design and selection, and have quickly advanced to the fore of ecological inquiry. Such models are typically dominated by abiotic factors, following the Eltonian Noise Hypothesis (ENH) that physical features set the limits of species distributions. Nevertheless, recent studies challenge this notion and highlight the importance of biotic interactions. Resolving this discrepancy could have significant implications for conservation and ecological understanding. To test these ideas, we built distribution models for two large herbivores, muskoxen (Ovibos muschatus) and Peary caribou (Rangifer tarandus pearyi), systematically observed across a vast spatial extent – 65 islands spanning 800,000 km2 in the Canadian High Arctic. To test the ENH we fit SDMs with two sets of predictors: (1) abiotic only (i.e. topographic, climatic) and (2) abiotic + biotic (i.e. vegetation communities, distance-to-heterospecifics). We evaluated these models and spatially estimated habitat suitability for each species. We found both sets of models had good predictive ability, although biotic variables (i.e. proportion of grass-lichen-moss) improved model performance and substantially narrowed areas of high habitat suitability. Niche overlap between caribou and muskoxen was moderate and highly suitable areas were spatially disjunct between species and largely outside protected areas. These results fail to support the ENH. Our study implies that biotic features, although often overlooked, may be important to the performance of SDMs and vital in identifying priority areas for conservation. For these large herbivores, reflecting trophic interactions in SDMs was essential when estimating areas of conservation value. Our approach helps prepare the way for improved projections regarding the prospects for wildlife while laying the foundation for biologically relevant protected areas.

Flower flies (Diptera: Syrphidae) are a diverse group of pollinators found almost worldwide. Species surveys of these flies provide unique challenges as they can be difficult to collect due to different trapping biases. Here, we test the efficacy of the Nzi trap for use in the collection of syrphids by comparing the richness and abundance of syrphids caught in a Malaise trap and Nzi trap, July, 2012-2017 on Akimiski Island, Nunavut. We found that the Nzi trap caught many of the same species and in similar abundances as the Malaise trap, except for Platycheirus kelloggi (Snow), of which more were caught in the Nzi than the Malaise. The high capture rate of P. kelloggi using Nzi traps could be due to the flies’ unique shelter- or mate-seeking behaviours related to structure or colour. Using collections from 2008-2017, we also provide new territory records for 55 species and range extensions for 19 species. Two of these, Platycheirus kelloggi and Platycheirus latitarsis Vockeroth, had previously been reported only west of the Rocky Mountains.

Science is an underpinning of the North American Model. As such, it is the basis for informed decision-making in wildlife management in Canada and the United States. While the history of wildlife management is deeply rooted in the writings of Aldo Leopold, it is often the communication of this knowledge to wildlife "users" that garners the most support for conservation and sustainable use of wildlife resources. This chapter discusses the historical development of scientific management of wildlife and examines how the relatively new field of "human dimensions" has evolved the theory and application of scientific management to include the influence of humans in the understanding of wildlife and habitats. This chapter also comments on hunters' contributions to the scientific management of wildlife species and provides recommendations for scientific advocacy, emphasizing the need for scholarship in transferring science to wildlife conservation and management policy.

Citizens' observations of wildlife offer a wealth of information. Such data, however, may be prone to biases or inaccuracies - in particular, the over-reporting of novel species and under-reporting of common or mundane species. Few studies have assessed the relationship between unstructured and structured observations using long-term data. We compared 69 years of voluntary bird sightings, recorded in the regular publication of Peterborough Field Naturalists (PFN), 1948-2016, to systematic Christmas Bird Counts (CBC; during winter) and Breeding Bird Surveys (BBS; during spring) in central Ontario, Canada. We focused on seven species that had expanded their ranges into the area: Northern Cardinal (Cardinalis cardinalis), House Finch (Haemorhous mexicanus), Purple Finch (Haemorhous purpureus), Red-bellied Woodpecker (Melanerpes carolinus), Wild Turkey (Meleagris gallopavo), Canada Goose (Branta canadensis), and American Robin (Turdus migratorius). For each species, we compared the first record, the annual number of sightings, and the annual relative abundance from the PFN to the first record and annual relative abundance in the CBC and BBS. We anticipated that naturalists' accounts would be more sensitive to the arrival of novel species but would underestimate abundance as the species became common. In general, our results agreed with these predictions. In 11 of 12 cases, the naturalists detected a species well in advance of the CBC and BBS - on average by 1 1/2 decades (range: 5-33 years). The correlations in bird abundance between unstructured (PFN) and structured (CBC and BBS) data were variable; most were weak and negative. We found significant negative correlations for the two most common species, Northern Cardinal (winter) and House Finch (spring), as well as for Wild Turkey (winter), and a positive correlation for the rarest species, the Red-bellied Woodpecker (spring). We surmise that novelty underlies these results - that rarity increases the likelihood of reporting by non-professionals. We conclude that unstructured observations are valuable in detecting novel species, but they may be inconsistent, even inverse, indicators of the abundance of expanding species, once established.

Aim Population-limiting factors represent the core of conservation biology. Because animal space use is affected by ecological constraints that can vary among populations, limiting factors might be revealed from intraspecific variation in home range size. We evaluated biogeographic variation in the home range size of woodland caribou (Rangifer tarandus caribou), a threatened species inhabiting the boreal forest, in relation to land cover, topography, snowcover and disturbance across the species' range. Location Twenty-five populations in Canada, spanning the contiguous boreal forest (an east-west extent of 4,400 km), including the southern fringe of the species' range, adjacent to a broad region of extirpation. Methods We compiled the average annual home range size of adult female caribou (5-68 home ranges per population) and 18 putative predictor variables in each population range. We uncovered major gradients using principal components analysis and then evaluated models of home range size using multiple regression, with orthogonal variables representing vegetation, human disturbance and snowcover. Results Average home range size varied 28-fold among populations (range: 312-8,838 km(2)). Home range area was most strongly and negatively correlated with anthropogenic disturbance in the population range (R-2 = 0.391), a variable in all seven top models (Delta AIC(c) <= 5.99). Among populations, where human disturbance in the population range was low (<= 10%), mean home range sizes consistently exceeded 1,400 km(2). Conversely, where human disturbance was high (>55%), especially at the species' southern range margin, mean home range sizes did not exceed 1,500 km(2). Main Conclusions In the boreal forest, female caribou may constrict their home ranges amid human-caused disturbances. We speculate that smaller home ranges may lower the risk of encounter by predators, a key limiting factor. Among populations, smaller home ranges may serve as a signal of anthropogenic habitat loss.

Aim: Archipelagos provide ideal natural systems for testing the effects of isolation and fragmentation of habitats on the genetic makeup of populationsan important consideration, given that many insular species are of conservation concern. Two theories predominate: Island Biogeography Theory (IBT) posits that proximity to the mainland drives the potential for migrants and gene flow. The Central Marginal Hypothesis (CMH) predicts that island populations at the periphery of a species range may experience low gene flow, small population size and high rates of genetic drift. We investigated population genetic structure, genetic diversity and key drivers of diversity for Arctic island-dwelling caribou (Rangifer tarandus). Our aim was to inform intraspecific units for conservation and decipher how IBT and CMH could act in an archipelago where isolation is highly variable due to sea ice and open water. Location: Canadian Arctic Archipelago, Canada (Latitude, 55-82 degrees N; Longitude, 61-123 degrees W). Methods: We genotyped 447 caribou at 16 microsatellite loci; these caribou represented two subspecies (R.t.groenlandicus, R.t.pearyi) and three designatable units. We used hierarchical Bayesian clustering and ordination to determine genetic groups. We evaluated the influence of ecological and geographic variables on genetic diversity using linear mixed-effects models and compared diversity among mainland and island herds. Results: Bayesian clustering revealed nine genetic clusters with differentiation among and within caribou subspecies. Genetic differentiation was explained predominantly by isolation-by-distance across all caribou, even at the scale of subspecies. Island caribou were less genetically diverse than mainland herds; individual heterozygosity was negatively correlated with distance-to-mainland and the extent of autumn ice-free coastline and positively correlated with unglaciated island size. Main conclusions: Our findings underscore the importance of hierarchical analysis when investigating genetic population structure. Genetic diversity and its key drivers lend support to both IBT and CMH and highlight the pending threat of climate change for Arctic island caribou.

Movement influences a myriad of ecological processes operating at multiple spatial and temporal scales. Yet our understanding of animal movement is limited by the resolution of data that can be obtained from individuals. Traditional approaches implicitly assume that movement decisions are made at the spatial and temporal scales of observation, although this scale is typically an artifact of data‐gathering technology rather than biological realism. To address this limitation, we used telemetry‐based movement data for caribou Rangifer tarandus in Newfoundland, Canada, and compared movement decisions estimated at the temporal resolution of GPS relocations (2 h) to a novel model describing directional movement to areas reachable over an extended period. We showed that this newer model is a better predictor of movement decisions by caribou, with decisions made at the scale of ∼2 km, including the strong avoidance of dense coniferous forest, an outcome not detectable at the scale of GPS relocations. These results illustrate the complexity of factors affecting animal movement decisions and the analytical challenges associated with their interpretation. Our novel modelling framework will help support increased accuracy in predictive models of animal space‐use, and thereby aid in determining biologically meaningful scales for collecting movement and habitat data.

ABSTRACTHabitat loss has been implicated in the decline of forest‐dwelling caribou (Rangifer tarandus caribou), but it is unknown how biting insects, potentially important components of boreal forest habitat for caribou, influence the activity of this threatened species. During summers in 2011 and 2012 in northern Ontario, Canada, we quantified the relative abundance of black flies, mosquitoes, and tabanids in boreal forest stands of different ages and related their abundance to caribou activity. We counted insects in young (25–35 yrs since forest harvesting), intermediate (36–69 yrs), and old (≥70 yrs) stands using sweep nets and counts on human subjects. We related the daily variation in abundance of these insect families, along with daily maximum temperature, to the activity of female caribou, determined by accelerometers in global positioning system collars. We found higher insect abundance in young versus old stands. During the first 5 minutes in a forest stand, the rate of accumulation of mosquitoes and black flies on human subjects increased, but at a decelerating rate, whereas tabanid abundance declined over time. On days when tabanids were more numerous, female caribou were less active, possibly a response to reduce exposure and harassment. To a lesser extent, mosquitoes and black flies also tended to elicit lower activity of caribou. Our study reveals that biting flies can alter the behavior of female caribou in the boreal forest. Loss of old stands may accentuate the potential for insect harassment. © 2018 The Wildlife Society.