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The energetic consequences of body size, behaviour, and fine-scale environmental variation remain understudied, particularly among free-ranging carnivores, due to logistical and methodological challenges of studying them in the field. Here, we present novel activity, heart rate, and metabolic data on free-ranging Canada lynx (Lynx canadensis Kerr, 1792) to (i) investigate intraspecific patterns of energy expenditure, particularly how they relate to body size, environmental conditions, and activity variation, and (ii) position lynx - a cold-climate, mesocarnivore - within interspecific allometries of carnivore energetics. Lynx demonstrated limited behavioural and metabolic responses to environmental conditions, despite extreme cold and moderate snow depths during our study, but marked body size patterns with larger lynx having higher activity and lower resting heart rate than smaller lynx. Compared with similar-sized carnivores, lynx were less active and had lower heart rate, likely due to their ambush hunting style, but higher energy expenditure, likely due to their coldclimate existence and access to abundant prey. Overall, lynx were more similar to other ambush hunters than to sympatric cold-climate species and mesocarnivores. Our data provide insight into the relative importance of abiotic and biotic drivers of carnivore energetics and the ways in which predators maintain energy balance in variable environments. Key words: activity, allometry, biologger, boreal ecology, energy expenditure, heart rate, Canada lynx, Lynx canadensis, mesocarnivore, winter. Les consequences energetiques de la taille du corps, du comportement et de variations environnementales a petite echelle demeurent sous-etudiees, particulierement chez les carnivores en liberte en raison de defis logistiques et methodologiques associes a leur etude sur le terrain. Nous presentons de nouvelles donnees sur l'activite, le rythme cardiaque et le metabolisme pour des lynx du Canada (Lynx canadensis Kerr, 1792) en liberte afin (i) d'examiner les motifs intraspecifiques de depense d'energie, plus particulierement leurs relations a la taille du corps, aux conditions ambiantes et aux variations de l'activite, et (ii) de positionner le lynx, un mesocarnivore de climat froid, au sein d'allometries interspecifiques d'energetique des carnivores. Les lynx presentent des reactions comportementales et metaboliques limitees aux conditions ambiantes, malgre des froids extremes et des epaisseurs de neige moderees durant l'etude, mais des motifs de taille du corps marques, les plus grands lynx presentant une plus grande activite et un rythme cardiaque au repos plus faible que les lynx plus petits. Comparativement a d'autres carnivores de taille semblable, les lynx etaient moins actifs et leur rythme cardiaque etait plus faible, probablement en raison de leur mode de chasse par embuscade, mais de plus grandes depenses energetiques, vraisemblablement en raison de leur vie en climat froid et leur acces a une abondance de proies. Globalement, les lynx sont plus semblables a d'autres chasseurs par embuscade qu'a des especes sympatriques et des mesocarnivores de climat froid. Nos donnees permettent de mieux comprendre l'importance relative de facteurs abiotiques et biotiques qui influencent l'energetique des carnivores et les moyens qu'emploient les predateurs pour maintenir leur equilibre energetique dans des milieux variables. [Traduit par la Redaction] Mots-cles : activite, allometrie, capteur de parametres biologiques, ecologie boreale, depense energetique, rythme cardiaque, lynx du Canada, Lynx canadensis, mesocarnivore, hiver., Introduction Predators occupying high trophic positions tend to have high energy requirements due to their large body size (Kleiber 1932; Schmidt-Nielsen 1984; Peters 1986; White et al. 2019); elevated resting [...]

There is limited information available on wolverine (Gulo gulo) population density and trends in the boreal forest of North America. We estimated wolverine density using spatial capture‐recapture methods across 2 boreal forest study areas in Red Lake, Ontario (26,568 km2) and Rainbow Lake, Alberta (19,084 km2), Canada. We also used radio‐telemetry data to estimate annual survival of adult and sub‐adult wolverines and evaluated population trends with a stage‐based matrix model. We used an array of run poles and live traps to detect wolverines. In Red Lake over 3 winter field seasons (2019–2022), we detected 56 individual wolverines (17 females, 32 males, and 7 unknown sex), and in Rainbow Lake over 2 field seasons (2014–2016), we detected 48 individuals (19 females, 18 males, and 11 of unknown sex). Average densities in Red Lake and Rainbow Lake were 3.64 and 6.74 wolverines/1,000 km2, respectively. Adults and sub‐adults occurred at equal abundance. Spring snow cover, roads, and industrial developments were not associated with spatial patterns of wolverine density. Most deaths occurred near roads; wolverines were killed in fur traps set along roads, by wolves using roads to travel, and by vehicles. The largest source of death was from incidental (n = 6 in Red Lake) or licensed fur trapping (n = 8 in Rainbow Lake) and we report 8 injuries from fur trapping sets. Red Lake survival estimates for adults (0.87) and sub‐adults (0.86) contributed to a stable population trend. Rainbow Lake survival estimates for adults (0.66) and sub‐adults (0.50) contributed to a declining population trend based on a relatively low sample of radio‐days. Red Lake and Rainbow Lake combined survival estimates for adults (0.77) and sub‐adults (0.73) also contributed to a declining population trend. Our survival and population modeling suggests that human‐caused mortality is a significant risk to these populations. Our results can be applied to wolverine status assessments and used as benchmarks for future monitoring. Wolverine population stability or growth might be achieved by reducing incidental trapping deaths or injury and hindering human access to wolverine habitats through decommissioning or limiting development of industrial roads or other anthropogenic linear features. [ABSTRACT FROM AUTHOR]

Perceived predation risk alters prey behaviour and physiology, but few studies have examined downstream consequences on prey demography in wild populations. Perceived predation risk could alter adult reproductive performance via reduced investment in offspring quality and post-birth care. We manipulated perceived predation risk in snowshoe hare (Lepus americanus Erxleben, 1777) by exposing pregnant mothers to chases by a domestic dog (Canis familiaris Linnaeus, 1758). Litter size was comparable between risk-augmented and control groups, but treated females had more stillbirths and gave birth to leverets of lower body condition. Leverets from risk-augmented females had 88% higher 40-day mortality rate. Maternally preventable causes of death like starvation or predation by red squirrel (Tamiasciurus hudsonicus (Erxleben, 1777)) caused this difference, particularly during the nursing period. Risk-augmented mothers were always more active than controls, but the difference was greatest during the nursing period. We found that perceived predation risk reduces maternal productivity pre- and post-partum, implying downstream consequences to populations. Because our treatment ended before parturition, we can link offspring performance such as survival and behaviour specifically to maternal life-history trade-offs, which has not been shown in a wild mammal. [ABSTRACT FROM AUTHOR]

Context: Capture–recapture sampling is one of the most commonly used methods for monitoring population demographics and is needed in a wide variety of studies where repeat sampling of individuals is desired. Although studies employing capture–recapture methods often assume unbiased sampling, it is well established that inherent capture biases can occur with these methods, including those related to baits. Reducing sources of sampling bias and augmenting recapture reliability is necessary for capture-dependent studies. However, few studies have examined the efficacy of baits on individuals with variable capture experience. Aims: To investigate the use of an attractant-augmented bait in enhancing capture–recapture probabilities for snowshoe hares (Lepus americanus). Methods: To examine the efficacy of different attractant-augmented bait types, a variety of baits were created, with bait preference tested on a captive hare. Because a strawberry jam-based bait was preferentially consumed (in comparison with other tested baits), the effectiveness of this attractant in enhancing capture–recapture rates was subsequently examined in wild hares, using paired live-trapping field trials (n = 6 trials). Results: Live-trapping trials showed that although overall hare capture rates were not affected by the use of a jam-based bait, recaptures were 33.1% higher in capture-naïve individuals exposed to our attractant. This was not the case for hares with prior capture experience; such hares had an equal likelihood of being recaptured regardless of the bait type used. Conclusions: The tested attractant improved recapture rates of capture-naïve hares. Implications: Studies relying on high recapture rates should use methods that maximise recapture rates wherever possible, including the use of baits that may augment recaptures in capture-naïve animals. Capture–recapture sampling is commonly used for monitoring population demographics, and needed for repeat measurements of individuals. Bait types used can lead to capture bias or influence recapture reliability. We investigated an attractant-augmented bait in enhancing recapture probabilities in snowshoe hares. The attractant increased recapture rates in previously uncaptured individuals. Studies relying on high recapture rates should (1) test for bait effectiveness before studies are conducted, and (2) employ effective attractants when high capture–recapture rates are desired. Photograph by Melanie R. Boudreau. [ABSTRACT FROM AUTHOR]

ABSTRACT Peer review is pivotal to science and academia, as it represents a widely accepted strategy for ensuring quality control in scientific research. Yet, the peer-review system is poorly adapted to recent changes in the discipline and current societal needs. We provide historical context for the cultural lag that governs peer review that has eventually led to the system's current structural weaknesses (voluntary review, unstandardized review criteria, decentralized process). We argue that some current attempts to upgrade or otherwise modify the peer-review system are merely sticking-plaster solutions to these fundamental flaws, and therefore are unlikely to resolve them in the long term. We claim that for peer review to be relevant, effective, and contemporary with today's publishing demands across scientific disciplines, its main components need to be redesigned. We propose directional changes that are likely to improve the quality, rigour, and timeliness of peer review, and thereby ensure that this critical process serves the community it was created for. [ABSTRACT FROM AUTHOR]

On 3 May 2016, we observed two Merlins (Falco columbarius) copulating near Hungry Lake in southwestern Yukon. We recorded Merlins frequently from May until the beginning of July and observed them defending the area from Common Ravens (Corvus corax) on two occasions, an activity indicative of a nesting pair. This is the first breeding record for Merlins in southern Yukon, as previous records have documented the breeding range only in central and northern parts of the territory. Here, we summarize historical sightings and breeding reports throughout southern Yukon since 1975 and fill a gap in the breeding range of this species. [ABSTRACT FROM AUTHOR]