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At least 235 records · Page 13Linked to original sources

USGS2025

Fitness consequences of catastrophic wildfire are mitigated by behavioral responses of an iconic bird

Background Drought, human disturbance, and invasive species are reshaping disturbance regimes and increasing the scale, severity, and frequency of wildfire in many ecosystems around the globe, including the sagebrush steppe of western North America. Recent studies suggested greater sage-grouse ( Centrocercus urophasianus ) adhere to strong site fidelity in the aftermath of wildfire, remaining inside fire perimeters for nesting and brood rearing despite negative consequences for survival and reproduction. Sage-grouse in Idaho exhibited context-dependent changes to space use after a large, high-severity fire that burned > 40,000 ha, yet the specific behavioral responses to fire and their fitness consequences remain unclear. We used data collected from 269 hens over a 6-year period under a multi-level before-after-control-impact design to test the hypothesis that sage-grouse mitigated fitness consequences of high-severity wildfire through adaptive behavioral responses and spatial redistribution. Results We tested predictions deduced from our hypothesis at the population and individual levels using behavioral, demographic, and life history data, including nesting metrics, brood-rearing metrics, hen survival, and body mass at capture. Fifteen of 16 predictions were supported, demonstrating that post-fire space use and avoidance of the burn was adaptive and helped mitigate fitness effects of the fire. Short-term consequences included elimination of nesting and brood rearing habitat and subsequent shifts to the distribution of usable space. Yet fitness consequences were minimal because of behavioral flexibility employed by hens during nesting and brood rearing. Conclusions Behavioral responses to wildfire by sage-grouse are more flexible than has been described, and sage-grouse demonstrated resilience by rapidly adapting space use to avoid short-term consequences of catastrophic fire when high-quality habitat remained adjacent to the burn and within their seasonal range. Our results imply behavioral and fitness consequences of fire are context-dependent and likely impacted by attributes of the fire and surrounding landscape after disturbance. Furthermore, among-study differences in behavioral and fitness outcomes of sage-grouse after fire supported underappreciated predictions from both fire ecology and site fidelity theory, and suggest conditions where behavioral flexibility should be expressed, and fidelity relaxed, based on severity of disturbance, landscape context, and species mobility.

Idaho↗

USGS2019

Global positioning system tracking devices can decrease Greater Sage-Grouse survival

Reliable demographic estimates hinge on the assumption that marking animals does not alter their behavior, reproduction, or survival. Violations can bias inference and are especially egregious for species of high conservation concern. Global positioning system (GPS) devices represent a recent technological advancement that has contributed greatly to avian ecological studies compared with traditionally used very high frequency (VHF) radio transmitters, but may affect demographic rates differently than VHF transmitters. We compared survival between VHF (necklace attachment) and GPS (rump-mounted attachment) devices from >1,100 Greater Sage-Grouse ( Centrocercus urophasianus ), a species of high conservation concern, across multiple populations within California and Nevada. We found lower survival for GPS-marked compared to VHF-marked sage-grouse across most sex, age, and seasonal comparisons. Estimates of annual survival for GPS-marked sage-grouse were 0.55–0.86 times that of VHF-marked birds with considerable variation among sex and age classes. Differences in survival could be attributed to features associated with GPS devices, including greater weight, position of attachment (e.g., rump-mount harness), and a semi-reflective solar panel. In a post hoc analysis, we evaluated additive and interactive effects between device type (GPS vs. VHF) and transmitter mass as a proportion of body mass (PBM). While the device type effect alone was the best model, the PBM interaction also had support. For GPS devices, survival decreased with increasing PBM, whereas PBM effects were not found for VHF. We attributed differences in PBM effect to placement of transmitters on sage-grouse, as weight of GPS devices was positioned rearward. This information can help managers and researchers weigh costs and benefits of GPS-based monitoring. Our results indicate demographic data collected from GPS devices should be interpreted with caution, and use of these devices should be tailored to specific ecological questions. Future research aimed at investigating behavioral impacts and GPS designs that reduce adverse impacts on survival would be beneficial.

California, Nevada↗

USGS2024

Intrinsic and environmental drivers of pairwise cohesion in wild Canis social groups

Animals within social groups respond to costs and benefits of sociality by adjusting the proportion of time they spend in close proximity to other individuals in the group (cohesion). Variation in cohesion between individuals, in turn, shapes important group-level processes such as subgroup formation and fission–fusion dynamics. Although critical to animal sociality, a comprehensive understanding of the factors influencing cohesion remains a gap in our knowledge of cooperative behavior in animals. We tracked 574 individuals from six species within the genus Canis in 15 countries on four continents with GPS telemetry to estimate the time that pairs of individuals within social groups spent in close proximity and test hypotheses regarding drivers of cohesion. Pairs of social canids ( Canis spp.) varied widely in the proportion of time they spent together (5%–100%) during seasonal monitoring periods relative to both intrinsic characteristics and environmental conditions. The majority of our data came from three species of wolves (gray wolves, eastern wolves, and red wolves) and coyotes. For these species, cohesion within social groups was greatest between breeding pairs and varied seasonally as the nature of cooperative activities changed relative to annual life history patterns. Across species, wolves were more cohesive than coyotes. For wolves, pairs were less cohesive in larger groups, and when suitable, small prey was present reflecting the constraints of food resources and intragroup competition on social associations. Pair cohesion in wolves declined with increased anthropogenic modification of the landscape and greater climatic variability, underscoring challenges for conserving social top predators in a changing world. We show that pairwise cohesion in social groups varies strongly both within and across Canis species, as individuals respond to changing ecological context defined by resources, competition, and anthropogenic disturbance. Our work highlights that cohesion is a highly plastic component of animal sociality that holds significant promise for elucidating ecological and evolutionary mechanisms underlying cooperative behavior.

Ecology↗

USGS2025

Integrated patterns of residence and movement create testable hypotheses about fish feeding migrations

Developing and testing alternate hypotheses about patterns, mechanisms, and consequences of movement in geographically-large, heterogeneous, natural systems can advance the scientific understanding of animal migration and benefit the conservation of most mobile species. Within organismal movement trajectories, different combinations of residence and movement are predicted from existing ecological theories (e.g. long distance migration, site fidelity, central place foraging, ideal free distribution, habitat shifts). However, testing these conceptually-based, spatially-explicit hypotheses about animal movement and migration in the field can be logistically challenging. Here our purpose is to introduce Resmo , a framework of metrics and analyses that integrate site-specific RESidence and across-site MOvements. We illustrate the ecological insights from this framework using the empirical example of coastal Striped Bass ( Morone saxatilis ) during their seasonal feeding migration. Our use of site-specific Resmo applied to empirical telemetry data enhanced the understanding of feeding behavior of migratory fish, suggested testable ecologically-meaningful hypotheses about foraging, and identified criteria on which to base the selection of future sampling locations. In summary, the Resmo approach provides a useful new direction for thinking about animal migration, animal movement, biological conservation, and future priorities for empirical field data collection related to understanding the distribution of mobile organisms.

Scientific Reports↗

USGS1999

Florida Bay: A history of recent ecological changes

Florida Bay is a unique subtropical estuary at the southern tip of the Florida peninsula. Recent ecological changes (seagrass die-off, algal blooms, increased turbidity) to the Florida Bay ecosystem have focused the attention of the public, commercial interests, scientists, and resource managers on the factors influencing the structure and function of Florida Bay. Restoring Florida Bay to some historic condition is the goal of resource managers, but what is not clear is what an anthropogenically-unaltered Florida Bay would look like. While there is general consensus that human activities have contributed to the changes occurring in the Florida Bay ecosystem, a high degree of natural system variability has made elucidation of the links between human activity and Florida Bay dynamics difficult. Paleoecological analyses, examination of long-term datasets, and directed measurements of aspects of the ecology of Florida Bay all contribute to our understanding of the behavior of the bay, and allow quantification of the magnitude of the recent ecological changes with respect to historical variability of the system.

Florida↗

USGS2026

Seasonal variation in wild pig (Sus scrofa) diet revealed by DNA metabarcoding

Invasive species within North America, particularly wild pigs ( Sus scrofa ), pose a serious threat to native ecosystems through both direct and indirect impacts. Wild pigs are a large-bodied omnivorous species native to Eurasia and introduced to North America. Using DNA metabarcoding of fecal samples, we investigated the diet of wild pigs at a bottomland hardwood forest ecosystem within Felsenthal National Wildlife Refuge in southern Arkansas. We found that the wild pig diet was diverse and included at least 74 plant families and 106 genera, dominated by plant matter with Fagaceae (oaks and hickories), Poaceae (grasses), and Asteraceae (asters, sunflowers, and daisies) comprising over 50% of total dietary detections. Hard mast was a primary food source in fall and winter, while herbaceous vegetation peaked in spring. We documented DNA from 23 species of vertebrates in wild pig fecal samples, including mammals, birds, fish, frogs, and turtles. Vertebrate matter was most frequently detected in autumn. Vertebrate consumption constituted ~17% of wild pig diet by relative read abundance. Our results highlighted the potential long-term ecological consequences of wild pig foraging behaviors, particularly competition for critical food resources with native wildlife and impact on forest regeneration through the consumption of mast. Understanding dietary dynamics is crucial for managing wild pig populations and mitigating impacts on vulnerable ecosystems and wildlife.

Arkansas↗

USGS2019

Assessing the impact of charr research past, present, and future

The 9th International Charr Symposium convened on 18–21 June 2018, in Duluth, Minnesota, USA to gather scientists with an interest in charr biology and management from the entire geographical range of the genus Salvelinus. The symposium was attended by 169 individuals from six countries, and included 99 oral and 32 poster presentations, 28 of which were published in the ensuing proceedings. Topic areas of presentations and publications included: (1) cultural anthropology; (2) genetics, evolution, taxonomy and systematics; (3) behavior, movement and habitat; (4) reproductive ecology, developmental ontogeny and physiology; (5) population ecology, dynamics and life history; (6) trophic ecology, parasites, predators, toxicology and pollution; and (7) management. Research reported in these proceedings has built upon the history of earlier symposiums and will be continued with the 10th symposium scheduled to convene in Nikko City, Tochigi Prefecture, Japan, in 2021.

Hydrobiologia↗

USGS2003

Carbon dynamics and land-use choices: building a regional-scale multidisciplinary model

Policy enabling tropical forests to approach their potential contribution to global-climate-change mitigation requires forecasts of land use and carbon storage on a large scale over long periods. In this paper, we present an integrated modeling methodology that addresses these needs. We model the dynamics of the human land-use system and of C pools contained in each ecosystem, as well as their interactions. The model is national scale, and is currently applied in a preliminary way to Costa Rica using data spanning a period of over 50 years. It combines an ecological process model, parameterized using field and other data, with an economic model, estimated using historical data to ensure a close link to actual behavior. These two models are linked so that ecological conditions affect land-use choices and vice versa. The integrated model predicts land use and its consequences for C storage for policy scenarios. These predictions can be used to create baselines, reward sequestration, and estimate the value in both environmental and economic terms of including C sequestration in tropical forests as part of the efforts to mitigate global climate change. The model can also be used to assess the benefits from costly activities to increase accuracy and thus reduce errors and their societal costs.

Journal of Environmental Management↗

USGS2018

Overview of the oxygen isotope systematics of land snails from North America

Continental paleoclimate proxies with near-global coverage are rare. Land snail δ 18 O is one of the few proxies abundant in Quaternary sediments ranging from the tropics to the high Arctic tundra. However, its application in paleoclimatology remains difficult, attributable in part to limitations in published calibration studies. Here we present shell δ 18 O of modern small (<10 mm) snails across North America, from Florida (30°N) to Manitoba (58°N), to examine the main climatic controls on shell δ 18 O at a coarse scale. This transect is augmented by published δ 18 O values, which expand our coverage from Jamaica (18°N) to Alaska (64°N). Results indicate that shell δ 18 O primarily tracks the average annual precipitation δ 18 O. Shell δ 18 O increases 0.5–0.7‰ for every 1‰ increase in precipitation δ 18 O, and 0.3–0.7‰ for every 1°C increase in temperature. These relationships hold true when all taxa are included regardless of body size (ranging from ~1.6 to ~58 mm), ecology (herbivores, omnivores, and carnivores), or behavior (variable seasonal active periods and mobility habits). Future isotopic investigations should include calibration studies in tropical and high-latitude settings, arid environments, and along altitudinal gradients to test if the near linear relationship between shell and meteoric precipitation δ 18 O observed on a continental scale remains significant.

Quaternary Research↗

USGS2015

Linking dynamic habitat selection with wading bird foraging distributions across resource gradients

Species distribution models (SDM) link species occurrence with a suite of environmental predictors and provide an estimate of habitat quality when the variable set captures the biological requirements of the species. SDMs are inherently more complex when they include components of a species' ecology such as conspecific attraction and behavioral flexibility to exploit resources that vary across time and space. Wading birds are highly mobile, demonstrate flexible habitat selection, and respond quickly to changes in habitat quality; thus serving as important indicator species for wetland systems. We developed a spatio-temporal, multi-SDM framework using Great Egret ( Ardea alba ), White Ibis ( Eudocimus albus ), and Wood Stork ( Mycteria Americana ) distributions over a decadal gradient of environmental conditions to predict species-specific abundance across space and locations used on the landscape over time. In models of temporal dynamics, species demonstrated conditional preferences for resources based on resource levels linked to differing temporal scales. Wading bird abundance was highest when prey production from optimal periods of inundation was concentrated in shallow depths. Similar responses were observed in models predicting locations used over time, accounting for spatial autocorrelation. Species clustered in response to differing habitat conditions, indicating that social attraction can co-vary with foraging strategy, water-level changes, and habitat quality. This modeling framework can be applied to evaluate the multi-annual resource pulses occurring in real-time, climate change scenarios, or restorative hydrological regimes by tracking changing seasonal and annual distribution and abundance of high quality foraging patches.

PLoS ONE↗

USGS2006

Atlas of climatic controls of wildfire in the western United States

Wildfire behavior depends on several factors including ecologic characteristics, near-term and antecedent climatic conditions,fuel availability and moisture level, weather, and sources of ignition (lightning or human). The variability and interplay of these factors over many spatial and temporal scales present an ongoing challenge to our ability to forecast a given wildfire season. Here we focus on one aspect of wildfire in the western US through a retrospective analysis of wildfire (starts and area burned) and climate over monthly time scales. We consider prefire conditions up to a year preceding fire outbreaks. For our analysis, we used daily and monthly wildfire records and a combination of observed and model-simulated atmospheric and surface climate data. The focus of this report is on monthly wildfire and climate for the period 1980-2000. Although a longer fire record is desirable, the 21-year record is the longest currently available and it is sufficient for the purpose of a first-order regional analysis. We present the main results in the form of a wildfire-climate atlas for 8 subregions of the West that can be used by resource managers to assess current wildfire conditions relative to high, normal, and low fire years in the historical record. Our results clearly demonstrate the link between wildfire conditions and a small set of climatic variables, and our methodology is a framework for providing near-real-time assessments of current wildfire conditions in the West.

Scientific Investigations Report↗

USGS2009

Nocturnal movements of desert bighorn sheep in the Muddy Mountains, Nevada

Adequate management of a species requires complete knowledge of its ecology, including both nocturnal and diurnal behavior. Knowledge of the movement behavior of bighorn sheep can provide insight for understanding spatial population processes as the combined result of individual behavior, physiological constraints, and fine-scale environmental influences. However, because of past difficulties in tracking radio-collared animals in the dark, little is known about nocturnal movements of many ungulates, including desert bighorn sheep (Ovis canadensis nelsoni). The use of GPS collars that supply sequential location records over a 24-hour period has provided new opportunities for recording movements of animals. We report findings from a preliminary analysis of data on nocturnal movements of desert bighorn sheep wearing GPS collars in the Muddy Mountains, Nevada. The study is part of a larger research project on movement patterns aimed at assessing the connectivity of bighorn sheep populations that comprise the metapopulation in southern Nevada. We recorded nighttime locations at 2100 and 0400 PST and calculated a total of 8,758 nocturnal movement distances for 12 ewes and 16 rams. Nocturnal movements were characteristic of all individuals. Bighorn sheep varied in the magnitude of movement from night to night and there were significant differences among individuals in the mean distance moved. Females had a greater proportion of short movement distances when compared to males; males had the greatest proportion of long distance movements. Movement distances were affected by sex, season, and percent of the moon’s surface illumination. Mean movement distances of males were greater than those of females. For both males and females, mean movement distances were shortest during the late spring months (April-June) and greatest during summer (July–September). Mean movement distances were greatest when the moon was brightest for all seasons except late spring, when movement distances for both sexes were shortest. We also describe movement distances >1 km (19% ewes, 81% rams) relative to movements within or between 50% core use areas, and nighttime intermountain and intra-mountain travel.

Black Mountain, Muddy Mountain↗

USGS2026

Cook Inlet beluga whale calling varies by group characteristics, behavior, and tidal state

Communication allows social species to exchange information among group members. In aquatic environments, acoustic signals are among the most effective forms of communication and are important for many species, including cetaceans. Beluga whales ( Delphinapterus leucas ) are highly social and vocal, yet little is known about the functionality of their social calls. To examine context-dependent vocal behavior in belugas, we collected passive acoustic data and fine-scale behavioral observations for the endangered Cook Inlet beluga population. The resulting dataset includes 1,720 annotated vocalizations collected over 21 behaviorally encoded encounters. We fit generalized linear mixed models to these data to investigate the effect of behavioral state, group size, calf presence, and tidal state on (1) calling rate (number of calls/minute) and (2) call category (whistles, pulsed calls, combined calls). Belugas were more likely to call when traveling and had higher calling rates during flood tides. Group-level calling rate increased sublinearly with group size, suggesting that individuals called less in larger groups, possibly reflecting increased listening, vocal coordination, or a strategy to avoid acoustic masking. Group calling rate increased before transitions between traveling and milling, suggesting a possible link between communication and behavioral transitions. Whistles were more prevalent when traveling, while pulsed calls were more prevalent when milling. Combined calls occurred only when calves were present, indicating the importance of these calls in communication with calves. Identifying these communication patterns and the contexts in which they occur can enhance our understanding of beluga whale ecology and aid in conservation efforts via passive acoustic monitoring.

Alaska↗

USGS2006

Spatial nonlinearities: Cascading effects in the earth system

Nonlinear behavior is prevalent in all aspects of the Earth System, including ecological responses to global change (Gallagher and Appenzeller 1999; Steffen et al. 2004). Nonlinear behavior refers to a large, discontinuous change in response to a small change in a driving variable (Rial et al. 2004). In contrast to linear systems where responses are smooth, well-behaved, continuous functions, nonlinear systems often undergo sharp or discontinuous transitions resulting from the crossing of thresholds. These nonlinear responses can result in surprising behavior that makes forecasting difficult (Kaplan and Glass 1995). Given that many system dynamics are nonlinear, it is imperative that conceptual and quantitative tools be developed to increase our understanding of the processes leading to nonlinear behavior in order to determine if forecasting can be improved under future environmental changes (Clark et al. 2001).

Book chapter↗

USGS2011

Removal of nonnative slider turtles (Trachemys scripta) and effects on native Sonora mud turtles (Kinosternon sonoriense) at Montezuma Well, Yavapai County, Arizona

The National Park Service (NPS) estimates that 234 national parks contain nonnative, invasive animal species that are of management concern (National Park Service, 2004). Understanding and controlling invasive species is thus an important priority within the NPS (National Park Service, 1996). The slider turtle (Trachemys scripta) is one such invasive species. Native to the Southeastern United States (Ernst and Lovich, 2009), as well as Mexico, Central America, and portions of South America (Ernst and Barbour, 1989), the slider turtle has become established throughout the continental United States and in other locations around the world (Burke and others, 2000). Slider turtle introductions have been suspected to be a threat to native turtles (Holland 1994; da Silva and Blasco, 1995), however, there has not been serious study of their effects until recently. Cadi and Joly (2003) found that slider turtles outcompeted European pond turtles (Emys orbicularis) for preferred basking sites under controlled experimental conditions, demonstrating for the first time direct competition for resources between a native and an exotic turtle species. Similarly, Spinks and others (2003) suggested that competition for basking sites between slider turtles and Pacific pond turtles (Actinemys marmorata) was partly responsible for the decline of Pacific pond turtles observed at their study site in California. They concluded that the impact of introduced slider turtles was 'almost certainly negative' for the western pond turtle. In the most recent critical study to assess the effects of introduced slider turtles on native turtles, Cadi and Joly (2004) demonstrated that European pond turtles that were kept under experimentally controlled conditions with slider turtles lost body weight and exhibited higher rates of mortality than in control groups of turtles comprised of the same species, demonstrating potential population-level effects on native species. Slider turtles are not native to Arizona but have been introduced in several areas in the southern and central part of the State, including Montezuma Well (the Well). The only native turtle at the Well is the Sonora mud turtle (Kinosternon sonoriense). Interactions between sliders and mud turtles have not been investigated at the Well or elsewhere. However, basking sites preferred by aquatic turtles are rare at the Well, suggesting one potential avenue for resource competition between sliders and Sonora mud turtles. In this study, we collected data on both species to evaluate the possible effects of slider turtles on Sonora mud turtles at Montezuma Well. During live trapping in the spring, summer, and early fall of 2007 and 2008, we removed slider turtles that we captured in the Well. We also collected ecological data on the mud turtles captured in the trapping effort. Separate behavioral observations of the turtles in the Well provided additional information on the ecology of the two species in the unusual environment of the Well, and also of interactions between the sliders and mud turtles. In this report, we describe the results of 2 yr of study of the turtles of Montezuma Well. We incorporate older data on the mud turtles in the Well to assess long-term population trends and potential response to the introduced slider turtles. We also report on aspects of basic ecology for the poorly understood Sonora mud turtle. The National Park Service requested that we incorporate public outreach as part of this research effort, so we also describe the outreach efforts associated with the turtle study.

Open-File Report↗

USGS2002

Ecological and evolutionary traps

Organisms often rely on environmental cues to make behavioral and life-history decisions. However, in environments that have been altered suddenly by humans, formerly reliable cues might no longer be associated with adaptive outcomes. In such cases, organisms can become 'trapped' by their evolutionary responses to the cues and experience reduced survival or reproduction. Ecological traps occur when organisms make poor habitat choices based on cues that correlated formerly with habitat quality. Ecological traps are part of a broader phenomenon, evolutionary traps, involving a dissociation between cues that organisms use to make any behavioral or life-history decision and outcomes normally associated with that decision. A trap can lead to extinction if a population falls below a critical size threshold before adaptation to the novel environment occurs. Conservation and management protocols must be designed in light of, rather than in spite of, the behavioral mechanisms and evolutionary history of populations and species to avoid 'trapping' them.

Trends in Ecology and Evolution↗

USGS2017

Spatial ecology and movement of reintroduced Canada lynx

Understanding movement behavior and identifying areas of landscape connectivity is critical for the conservation of many species. However, collecting fine‐scale movement data can be prohibitively time consuming and costly, especially for rare or endangered species, whereas existing data sets may provide the best available information on animal movement. Contemporary movement models may not be an option for modeling existing data due to low temporal resolution and large or unusual error structures, but inference can still be obtained using a functional movement modeling approach. We use a functional movement model to perform a population‐level analysis of telemetry data collected during the reintroduction of Canada lynx to Colorado. Little is known about southern lynx populations compared to those in Canada and Alaska, and inference is often limited to a few individuals due to their low densities. Our analysis of a population of Canada lynx fills significant gaps in the knowledge of Canada lynx behavior at the southern edge of its historical range. We analyzed functions of individual‐level movement paths, such as speed, residence time, and tortuosity, and identified a region of connectivity that extended north from the San Juan Mountains, along the continental divide, and terminated in Wyoming at the northern edge of the Southern Rocky Mountains. Individuals were able to traverse large distances across non‐boreal habitat, including exploratory movements to the Greater Yellowstone area and beyond. We found evidence for an effect of seasonality and breeding status on many of the movement quantities and documented a potential reintroduction effect. Our findings provide the first analysis of Canada lynx movement in Colorado and substantially augment the information available for conservation and management decisions. The functional movement framework can be extended to other species and demonstrates that information on movement behavior can be obtained using existing data sets.

Wyoming↗

USGS1976

Roosting ecology of the pallid bat, Antrozous pallidus

Daytime roosting behavior of pallid bats ( Antrozous pallidus ) was studied in central Arizona. Bats were present in the area from March or April until November and roosted in cliffs in colonies generally including 20 or more individuals. Pallid bats were highly selective in their choice of roost sites and minimized diurnal energy output by adaptive hypothermia and behavioral thermo-regulation. In spring and autumn the bats roosted in vertical crevices responsive to changes in ambient temperatures. Here temperatures remained low and the bats were torpid for much of the day, but when the crevices became heated in the late afternoon the bats were passively warmed prior to emergence. Deep, horizontal crevices were preferred in summer; cliffs function as massive heat sinks, and in summer crevice temperatures remained moderate and relatively stable. Throughout most of the day both the deep parts of the crevices and the body temperatures of the bats remained close to 30ºC; at this body temperature pallid bats have unexpectedly low metabolic rates (Trune, 1974). By adjusting their positions and closeness to other bats in the thermal gradient within the crevice, bats dissipate heat early in the day, maintain a low metabolic rate through most of the fat and elevate the body temperature prior to emergence in the evening. Of vital important to pallid bats in the summer are social behaviors that promote communal roosting at "traditional" crevices.

Journal of Mammalogy↗