ABSTRACT
Interspecific interactions can mediate site occupancy of sympatric species and can be a key factor in habitat use patterns. American martens (Martes americana) and Fishers (Pekania pennanti) are two sympatric mesocarnivores in eastern North American forests. Due to their larger size, fishers have a competitive advantage over martens. We investigated site occupancy of martens and fishers in temperate deciduous forests of Québec, an environment modified by forest management and climate change. We formulated hypotheses on the spatial distribution of the studied species based on the knowledge of local trappers and on the scientific literature regarding forest cover composition, habitat fragmentation, and competitive relationships. We used a network of 49 camera traps monitored over two fall seasons to document site occupancy by both species. We used two-species site occupancy models to assess habitat use and the influence of fishers on martens at spatial grains of different sizes. None of the habitat variables that we considered explained site occupancy by fishers. Availability of dense old coniferous stands explained the spatial distribution of martens both at the home range grain size and at the landscape grain size. We identified the characteristics of habitat hotspots based on the knowledge of trappers, which highlighted the importance of stand composition, height, age, and canopy closure. The characteristics of habitat hotspots for martens in temperate deciduous forests refine the habitat suitability model for American martens that was originally developed for boreal forests of Québec.
Les interactions interspécifiques peuvent affecter l'occupation de sites par des espèces sympatriques et jouer un rôle clé dans leur utilisation des habitats. La martre d'Amerique (Martes americana) et le pékan (Pekania pennanti) sont deux mésocarnivores sympatriques des forêts de l'est de l'Amérique du Nord. En raison de sa grande taille, le pékan est un compétiteur dominant de la martre. Nous avons étudié l'occupation des sites par la martre et le pékan dans la forêt tempérée feuillue du Québec, un environnement modifié par l'aménagement forestier et les changements climatiques. Nous avons formulé des hypothèses sur la répartition spatiale des espèces étudiées en nous basant sur les connaissances des trappeurs locaux et sur la littérature scientifique en ce qui a trait à la composition du couvert forestier, à la fragmentation de l'habitat, et aux relations de compétition. Nous avons utilisé un réseau de 49 appareils photo à déclenchement automatique pendant deux automnes pour documenter l'occupation des sites par les deux espèces. Nous avons utilisé des modèles d'occupation de sites à deux espèces afin d'évaluer l'effet de la présence du pékan sur l'utilisation de l'habitat par la martre à des échelles spatiales de résolutions variables. Aucune des variables d'habitat que nous avons prises en compte n'explique l'occupation des sites par les pékans. La disponibilité de vieux peuplements denses de conifères explique la répartition spatiale de la martre aux échelles spatiales du domaine vital et du paysage. Nous avons développé un indice d'habitat potentiel basé sur les connaissances des trappeurs, qui a mis en évidence l'importance de la composition, de la hauteur, de l'âge et de la densité des peuplements. Cet indice affine, pour les forêts tempérées feuillues du Québec, le modèle de qualité de l'habitat de la martre d'Amérique originellement élaboré pour la forêt boréale.
ABSTRACT
Citizen science (CS) currently refers to the participation of non-scientist volunteers in any discipline of conventional scientific research. Over the last two decades, nature-based CS has flourished due to innovative technology, novel devices, and widespread digital platforms used to collect and classify species occurrence data. For scientists, CS offers a low-cost approach of collecting species occurrence information at large spatial scales that otherwise would be prohibitively expensive. We examined the trends and gaps linked to the use of CS as a source of data for species distribution models (SDMs), in order to propose guidelines and highlight solutions. We conducted a quantitative literature review of 207 peer-reviewed articles to measure how the representation of different taxa, regions, and data types have changed in SDM publications since the 2010s. Our review shows that the number of papers using CS for SDMs has increased at approximately double the rate of the overall number of SDM papers. However, disparities in taxonomic and geographic coverage remain in studies using CS. Western Europe and North America were the regions with the most coverage (73%). Papers on birds (49%) and mammals (19.3%) outnumbered other taxa. Among invertebrates, flying insects including Lepidoptera, Odonata and Hymenoptera received the most attention. Discrepancies between research interest and availability of data were as especially important for amphibians, reptiles and fishes. Compared to studies on animal taxa, papers on plants using CS data remain rare. Although the aims and scope of papers are diverse, species conservation remained the central theme of SDM using CS data. We present examples of the use of CS and highlight recommendations to motivate further research, such as combining multiple data sources and promoting local and traditional knowledge. We hope our findings will strengthen citizen-researchers partnerships to better inform SDMs, especially for less-studied taxa and regions. Researchers stand to benefit from the large quantity of data available from CS sources to improve global predictions of species distributions.
Subject(s)
Citizen Science/trends , Animals , Biodiversity , Databases, Factual , Linear Models , Peer Review, ResearchABSTRACT
In North America, the greatest and most sudden threat to hibernating bats is white-nose syndrome (WNS), which has caused massive declines in populations since 2006. Other determinants of bat dynamics, such as the climate, and the effect of reduction in the number of individuals sharing foraging space and summer roosting habitat may have an effect on population dynamics. We analyzed transect acoustic bat surveys conducted with ultrasonic detectors in 16 regions in Quebec, Canada, between 2000 and 2015. We used piecewise regression to describe changes in activity over time for each species and a meta-analytic approach to measure its association with the North Atlantic Oscillation (NAO). As expected, mouse-eared bat (Myotis spp.) activity sharply declined after the onset of WNS, down by 79% after 3 years. In contrast, big brown/silver-haired bat activity increased over the same period, possibly due to a release of competition. Hoary bats and red bats remained present, although their activity did not increase. Myotis activity was positively correlated with a one-year lag to the NAO index, associated with cold conditions in winter, but warm autumns. Big brown/silver-haired and hoary bats were also more active during NAO-positive years but without a lag. We conclude that combinations of threats may create rapid shifts in community compositions and that a more balanced research agenda that integrates a wider range of threats would help better understand and manage those changes.
ABSTRACT
Habitat loss and degradation induced by human development are among the major threats to biodiversity worldwide. In this study, we tested our ability to predict the response of bird communities (128 species) to land-use changes in southern Quebec (~483,100 km2 ) over the last 30 yr (between 1984-1989 and 2010-2014) by using species distribution models (299,302 occurrences in 30,408 locations) from a hindcasting perspective. Results were grouped by functional guilds to infer potential impacts on ecosystem services, and to relate model transferability (i.e., ability of our models to be generalized to other times and scales) to specific functional and life-history traits. Overall, our models were able to accurately predict, both in space and time, habitat suitability for 69% of species, especially for granivorous, nonmigrant, tree-nesting species, and species that are tied to agricultural areas under intensive use. These findings indicate that model transferability depends upon specific functional and life-history traits, providing further evidence that species' ecologies affect the ability of models to accurately predict bird distributions. Declining bird species were mostly short-distance migrants that were associated with open habitats (agricultural and nonproductive forest) with aerial insectivorous or granivorous diets, which may be related to agricultural intensification and land abandonment. Land-use changes were positive for some forest bird species that were mainly associated with mixed and deciduous forests, generalist diets and tree-nesting strategies. Yet cavity-nesting birds have suffered substantial reductions in their distributions, suggesting that cumulative effects of intensive logging and wildfires on mature forests pose a threat for forest-specialist species. Habitat suitability changes predicted by our coarse-scale species distribution models partially agreed with the long-term trends reported by the North American Breeding Bird Survey. Our findings confirm land-use change as a key driving force for shaping bird communities in southern Quebec, together with the need to explicitly incorporate it into global change scenarios that better inform decision-makers on conservation and management.
Subject(s)
Agriculture , Animal Distribution , Birds , Forests , Animals , Ecosystem , Models, Biological , QuebecABSTRACT
BACKGROUND: Monitoring of fur-bearing species populations is relatively rare due to their low densities. In addition to catch data, trappers' experience provides information on the ecology and status of the harvested species. Fisher (Pekania pennanti) and American marten (Martes americana) are mustelids that are sensitive to forest management and therefore considered to be ecological indicators of forest health. Fisher populations have increased in eastern North America since the early 2000s and this could have resulted in a northeastern extension of the species' range and increased overlap with marten's range. Moreover, habitats of both species are subject to natural and anthropogenic disturbances. The objective of this study was to document the knowledge held by local trappers in the northern area of sympatry between fisher and marten to identify factors that could explain variation in populations of the two species and interactions between them. METHOD: Forty-one semi-directed interviews with Indigenous and non-Indigenous trappers in the Abitibi-Témiscamingue region of western Quebec (Canada), at the northern limit of the overlapping ranges of the two mustelid species. RESULTS: Trappers highlighted the lack of exclusivity of marten and fisher to coniferous forests, although marten is more closely associated with them than is fisher. Fisher apparently also takes advantage of open environments, including agroforestry systems. Moreover, climate change increases the frequency of freeze-thaw events that cause the formation of an ice crust on the snow surface, which favors fisher movements. CONCLUSION: The fisher was identified as a competitor and even a predator of the marten. Furthermore, the fisher is less affected than the marten by forest management, and it also seems to benefit from climate change to a greater extent.
Subject(s)
Climate Change , Forestry/methods , Mustelidae , Animals , Animals, Wild , Ecosystem , Environment , Female , Food Chain , Male , Population Density , QuebecABSTRACT
Food insecurity is a growing concern for indigenous communities worldwide. While the risk of heavy metal contamination associated to wild food consumption has been extensively studied in the Arctic, data are scarce for the Boreal zone. This study addressed the concerns over possible heavy metal exposure through consumption of traditional food in four Anishnaabeg communities living in the Eastern North American boreal forest. Liver and meat samples were obtained from 196 snowshoe hares (Lepus americanus) trapped during winter 2012 across the traditional lands of the participating communities and within 56-156km of a copper smelter. Interviews were conducted with 78 household heads to assess traditional food habits, focusing on snowshoe hare consumption. Concentrations in most meat and liver samples were below the detection limit for As, Co, Cr, Ni and Pb. Very few meat samples had detectable Cd and Hg concentrations, but liver samples had mean dry weight concentrations of 3.79mg/kg and 0.15mg/kg respectively. Distance and orientation from the smelter did not explain the variability between samples, but percent deciduous and mixed forest cover had a marginal negative effect on liver Cd, Cu and Zn concentrations. The estimated exposition risk from snowshoe hare consumption was low, although heavy consumers could slightly exceed recommended Hg doses. In accordance with the holistic perspective commonly adopted by indigenous people, the nutritional and sociocultural importance of traditional food must be considered in risk assessment. Traditional food plays a significant role in reducing and preventing serious health issues disproportionately affecting First Nations, such as obesity, diabetes, and cardiovascular diseases.
Subject(s)
Hares , Meat , Metals, Heavy/analysis , Animals , Culture , Food Safety , Food Supply , Hazard Analysis and Critical Control Points , Liver/chemistry , Nutritive Value , Quebec , Risk AssessmentABSTRACT
Dynamic N-mixture models have been recently developed to estimate demographic parameters of unmarked individuals while accounting for imperfect detection. We propose an application of the Dail and Madsen (2011: Biometrics, 67, 577-587) dynamic N-mixture model in a manipulative experiment using a before-after control-impact design (BACI). Specifically, we tested the hypothesis of cavity limitation of a cavity specialist species, the northern flying squirrel, using nest box supplementation on half of 56 trapping sites. Our main purpose was to evaluate the impact of an increase in cavity availability on flying squirrel population dynamics in deciduous stands in northwestern Québec with the dynamic N-mixture model. We compared abundance estimates from this recent approach with those from classic capture-mark-recapture models and generalized linear models. We compared apparent survival estimates with those from Cormack-Jolly-Seber (CJS) models. Average recruitment rate was 6 individuals per site after 4 years. Nevertheless, we found no effect of cavity supplementation on apparent survival and recruitment rates of flying squirrels. Contrary to our expectations, initial abundance was not affected by conifer basal area (food availability) and was negatively affected by snag basal area (cavity availability). Northern flying squirrel population dynamics are not influenced by cavity availability at our deciduous sites. Consequently, we suggest that this species should not be considered an indicator of old forest attributes in our study area, especially in view of apparent wide population fluctuations across years. Abundance estimates from N-mixture models were similar to those from capture-mark-recapture models, although the latter had greater precision. Generalized linear mixed models produced lower abundance estimates, but revealed the same relationship between abundance and snag basal area. Apparent survival estimates from N-mixture models were higher and less precise than those from CJS models. However, N-mixture models can be particularly useful to evaluate management effects on animal populations, especially for species that are difficult to detect in situations where individuals cannot be uniquely identified. They also allow investigating the effects of covariates at the site level, when low recapture rates would require restricting classic CMR analyses to a subset of sites with the most captures.
ABSTRACT
We evaluated the effectiveness and practicality of using isoflurane as an inhalation anesthetic with oxygen as a gas carrier for American martens (Martes americana) in a field setting. Sixty-eight martens were trapped in the Waswanipi Cree Model Forest (Québec, Canada) from October to November 2005 and anesthetized with isoflurane in 100% oxygen (1 l/min) using a face mask. Induction setting of isoflurane was 3% for all animals. Mean (+/-SD) length of induction was 1.8+/-1.2 min. Maintenance isoflurane settings ranged from 1% to 4%. Procedures lasted an average of 16.4+/-7.1 min and were uneventful. Length of recovery, defined as the interval between the end of the procedure and animal release, was short (6.3+/-2.8 min), and well below reported lengths of recovery using injectable anesthetics (>/=70 min). As compared to open drop administration of isoflurane described in previous studies, the use of an anesthesia machine prevents the risk of potential fatal anesthetic overdose. We conclude that among anesthesia techniques currently available, isoflurane with oxygen as a gas carrier is a safe and useful field anesthetic in martens, when issues with equipment portability can be overcome.