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The article focuses on the rich contributions of Professor M. Brock Fenton to the field of bat biology in Canada, tracing his early experiences, academic journey, and impactful career, including his role in mentoring students and his continued influence after retirement. Topics include Fenton's bat encounters, academic achievements, research contributions, mentoring legacy, and post-retirement activities, highlighting his multidimensional impact on the field.

Bats are hosts to a range of pathogens, which include zoonotic pathogens and pathogens of conservation concern. Brock Fenton's research on bat ecology has always balanced clear communication of potential health risks associated with bats and the need to communicate these risks precisely to avoid unnecessary persecution of bats. Here, we integrate Brock's work in the field of disease ecology with that of his students and collaborators and consider the potential advantages of studying disease ecology of bats within the Canadian context. The broad distribution of a few common species across the vast landscape of present-day Canada provides an opportunity to untangle the impacts of environmental variation on host–pathogen interactions and disease severity, particularly in the context of climate change. The varying migratory strategies and social structure of the bat species found in Canada could also facilitate informative interspecific studies to better understand how bat health is affected by interactions among rapid environmental changes, physiological traits, and the social behaviour of different species. We propose a series of priority research questions and approaches that could further our understanding of bat health and disease ecology in Canada, inspired by the work of Brock, his colleagues, and students. [ABSTRACT FROM AUTHOR]

Bat conservation has become prevalent over the last few decades due to critical population declines worldwide. Our purpose was to assess whether Brock Fenton's research career coincided with increasing bat conservation research in Canada and North America. Fenton has made significant contributions to bat research during a long and productive publishing career accompanied by participation in research organizations like the North American Society for Bat Research and the Natural Sciences and Engineering Research Council. His conservation research as well as efforts to raise public awareness about these animals has coincided with work for the Committee on the Status of Endangered Wildlife in Canada and its equivalent (Committee on the Status of Species at Risk in Ontario) in ON. To assess the impact of his career, we quantified the relative amount of his peer-reviewed publications with a conservation focus and compared this with the level of conservation-related presentations at annual North American Society for Bat Research conferences. In the same manner, we assessed how often conservation-focused applications were funded by the Ecology and Evolution section of the Natural Sciences and Engineering Research Council—Canada Discovery grant program. Although it cannot be said with authority that Fenton actually initiated the increase in bat conservation research, our results indicate that his research efforts coincide with and presumably had considerable influence in driving this area of research. [ABSTRACT FROM AUTHOR]

Hibernators adjust the expression of torpor behaviourally and physiologically to balance the benefits of energy conservation in hibernation against the physiological and ecological costs. Small fat-storing species, like many cave-hibernating bats, have long been thought to be highly constrained in their expression of hibernation because they must survive winter relying only on endogenous energy stores. We evaluated behavioural microclimate selection in tri-colored bats (Perimyotis subflavus (F. Cuvier, 1832)) across a 3-month hibernation experiment under laboratory conditions. We also opportunistically tested for evidence of acclimatization in torpid metabolic rate (TMR). When given access to gradients in microclimate, bats tended to choose the warmest temperature available (11 °C) while almost completely avoiding the driest condition available (85% relative humidity at 8 °C). Furthermore, bats held at different temperatures over the course of the hibernation showed no differences in TMR when measured under common conditions at the end of hibernation. Taken together, our results suggest that selective pressures to conserve energy during hibernation are not overwhelmingly strong and further support the proposition that optimal expression of hibernation is something less than the maximal expression of hibernation unless the animal is nearing starvation. [ABSTRACT FROM AUTHOR]

We tested the hypothesis that interspecific variation in chiropteran heat tolerance and evaporative cooling capacity is correlated with day-roost microclimates, using three vespertilionid bats that occur sympatrically during summer in Saskatchewan, Canada. We predicted that hoary bats (Lasiurus cinereus (Palisot de Beauvois, 1796); ∼22 g) would have higher heat tolerance than little brown bats (Myotis lucifugus (Le Conte, 1831); ∼7 g) and silver-haired bats (Lasionycteris noctivagans (Le Conte, 1831); ∼13 g), as the latter two species roost in tree crevices or cavities that are more thermally buffered than the foliage roosts of hoary bats. We measured core body temperature (Tb; passive integrated transponder tags), evaporative water loss, and resting metabolic rate (flow-through respirometry) while exposing individuals to a stepped profile of increasing air temperature (Ta) from ∼30 °C in ∼2 °C increments. Experiments were terminated when individuals became hyperthermic (Tb ≈ 42.5 °C), with maximum Ta (Ta,max) ranging from 42.0 to 49.7 °C. As predicted, hoary bats had the highest heat tolerance and evaporative cooling capacity, reaching Ta,max ∼2.4 and 1.2 °C higher than little brown and silver-haired bats, respectively. Our results are consistent with the hypothesis that heat tolerance of bats is correlated with roost microclimates, although interspecific variation in body mass and phylogeny may confound these conclusions. [ABSTRACT FROM AUTHOR]

Non-migratory bats in colder climates use hibernation to survive winter. By reducing metabolic rate (i.e., using torpor), bats can survive winter on stored fat reserves. During hibernation, bats arouse from torpor and may move within the hibernaculum, a process called "internal migration". We hypothesized that internal migration occurs to optimize hibernation energetics in that bats move to select a microclimate to minimize energy expenditure both by seeking cooler areas of the hibernacula and avoiding those with large temperature fluctuations. Early in the winter, we observed that 62% of bats were roosting in the warmer, less energy efficient, deepest 50% of an abandoned mine hibernaculum. Late in the season, there was a shift towards the cooler entrance area, thereby decreasing energy demands during the torpid period, with 78% of bats in the mine roosting within 50 m of the entrance. Although there was no significant effect of hibernation period (i.e., early vs. late winter) on the number of bats in huddles, the largest huddles occurred close to the entrance in late winter. To fully understand and manage bat populations, it is important to understand that hibernation is a dynamic process with bats moving and interacting with one another throughout the season. [ABSTRACT FROM AUTHOR]

Recent technological advances have permitted collection of immense data sets through automated recordings that are primarily aimed at capturing bat echolocation. Analyses of echolocation calls are used to identify species, relative abundance, and some aspects of behaviour, such as foraging or commuting. Here we propose that social calls recorded in flight are also valuable tools for understanding bat ecology and behaviour. First, we examine how and why the acoustic structure of social calls differ from echolocation. Differences in form make social calls often, but not always, easy to identify. We then use a case study on in-flight song in Brazilian free-tailed bat (Tadarida brasiliensis (I. Geoffroy, 1824)) to show that what may appear as echolocation may instead be predominantly used for social communication. Next, we review three basic functions of in-flight social calls, including examples of each, and develop a framework for testing these alternative functions using automated recordings. In a second case study, we use automated recordings of the endangered Florida bonneted bat (Eumops floridanus (G.M. Allen, 1932)) to illustrate how behavioural information can be gleaned by examining patterns of social call production. Finally, we discuss why and how social calls provide novel information that can be crucial for conservation and management efforts. [ABSTRACT FROM AUTHOR]

Effective conservation of forest bats requires knowledge of daytime and nocturnal habitat use. Although many bat species use different habitats during the daytime and nighttime hours, these data are rarely collected simultaneously. We radio-tagged 48 adult Rafinesque's big-eared bats ( Corynorhinus rafinesquii (Lesson, 1827)) in a bottomland hardwood forest in Kentucky from 2009 to 2011. We tracked bats to 64 day roosts over 549 bat-days and found bats roosted almost exclusively in trees located in forested wetlands ( n = 59; 92%), and that reproductive females established their home ranges closest to these habitats ( P < 0.0001). Although few ( n = 4; 6%) roosts were located in deciduous forests on drier soils, these forests were important foraging habitats for pregnant females, which foraged closest to these habitats within their home ranges ( P = 0.04). Abundance of Lepidoptera differed among habitats ( P = 0.03), with higher abundance in deciduous forests and along forest-field edges. Deciduous forests were the only habitat preferentially selected by any lepidopteran family (Notodontidae), and the only habitat not avoided by any family. These data confirm the importance of forested wetlands to the ecology of Rafinesque's big-eared bat and demonstrate the benefit of proximally located deciduous forests that provide habitat for their moth prey. [ABSTRACT FROM AUTHOR]