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To examine the effects of spatially complex habitat (i.e., cluttered) and prey availability on habitat selection by bats, we constructed 3-dimensional 'clutter cones' and monitored activity of free-ranging bats in them. Cones were paired with cones of equal clutter density and size in which we placed ultraviolet (UV) light sources to attract nocturnal insects and hence increase prey availability. We tested predictions arising from resource-partitioning experiments in previous works from laboratories and the field. Activity by bats of all sizes was unaffected by density of clutter, and activity by small-sized bats at all UV-illuminated sites increased significantly, whereas activity by large-sized bats was unaffected. Also, Myotis lucifugus did not negotiate clutter densities as complex as those in previous laboratory work. This suggests that habitat complexity is likely one means by which foraging areas are partitioned between those bats that can exploit them (i.e., smaller species) and those that cannot and that cluttered habitats are avoided except when they may serve a purpose such as an energetic benefit. Although behavioral studies conducted in the laboratory serve to obtain data on ultimate capabilities, differences between results from the laboratory and the field suggest that an animal's behavior may be specific to its present environment. Key words: echolocation, ecomorphology, Eptesicus fuscus, foraging, habitat use, Lasionycteris noctivagans, Lasiurus cinereus, Myotis lucifugus, resource partitioning

Two distinct grouse were regularly observed at two Greater Sage-Grouse (Centrocercus urophasianus) leks in both 1999 and 2000 in southeastern Alberta. Physically and behaviorally, the birds exhibited characteristics of both Greater Sage-Grouse and Sharp-tailed Grouse (Tympanuchus phasianellus), suggesting they were hybrids. DNA analyses of blood and feather samples indicated that both birds were males with Greater Sage-Grouse mothers and thus, fathers that were likely Sharp-tailed Grouse. Key words: Alberta, DNA, Greater Sage-Grouse, hybrid, Sharp-tailed Grouse.

We tested externally applied, temperature-sensitive, radiotransmitters for determining the body temperature of big brown bats (Eptesicus fuscus) in various ambient temperatures (226 [degrees] C). There was a slight, but significant, effect of ambient temperature on skin temperature (measured by the transmitters), but skin temperature accurately reflected rectal temperature in torpid and active bats, and it was never >3.3 [degrees] C below rectal temperature. External radiotransmitters are, thus, useful in studies of torpor in bats, even when only small decreases in body temperature occur. Key words: Eptesicus fuscus, bats, heterothermy, body temperature, radiotelemetry, torpor

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Migratory connectivity is the degree to which populations are linked in space and time across the annual cycle. Low connectivity indicates mixing of populations while high connectivity indicates population separation in space or time. High migratory connectivity makes individual populations susceptible to local environmental conditions; therefore, evaluating migratory connectivity continuously across a species range is important for understanding differential population trends and revealing places and times contributing to these differences. The common nighthawk Chordeiles minor is a widespread, declining, long‐distance migratory bird. Variable population trends across the nighthawk breeding range suggest that knowledge of migratory connectivity is needed to direct conservation. We used GPS tags to track 52 individuals from 12 breeding populations. We estimated migratory connectivity as 0.29 (Mantel coefficient: 0 = no connectivity, 1 = full connectivity) between the breeding and wintering grounds. We then estimated migratory connectivity at every latitude (spatial connectivity) or day (temporal connectivity) of migration and smoothed those migratory connectivity estimates to produce continuous migratory connectivity 'profiles'. Spatial and temporal connectivity were highest during migration through North America (around 0.3–0.6), with values generally around 0 in Central and South America due to mixing of populations along a common migratory route and similar migration timing across populations. We found local peaks in spatial and temporal connectivity during migration associated with crossing the Gulf of Mexico. We used simulations to estimate the probability that our method missed peaks (spatial: 0.12, temporal: 0.18) or detected false peaks (spatial: 0.11, temporal: 0.37) due to data gaps and showed that our approach remains useful even for sparse and/or sporadic location data. Our study presents a generalizable approach to evaluating migratory connectivity across the full annual cycle that can be used to focus migratory bird conservation towards places and times of the annual cycle where populations are more likely to be limited. [ABSTRACT FROM AUTHOR]

Analysis of the ability of free-flying echolocating bats to distinguish between prey under natural foraging conditions reveals that these bats attack any moving target and fail to discriminate on the basis of target texture and shape, contradicting their behavior in laboratory conditions. Short prey identification range intrinsic in echolocation and the rapid flight of bats contribute to their inability to distinguish among prey. Bats attack stationary prey less than moving prey.

Hoary bats (Lasiurus cinereus) and silver-haired bats (Lasionycteris noctivagans) are species of conservation concern because of the documented annual mortality that occurs at wind energy facilities. Several recent studies have predicted continental-scale declines of hoary bat populations due to interactions with wind turbines. We predicted a decrease in captures at a summer site over 20 years where researchers have captured bats using generally consistent methods. We developed a hierarchical Bayesian model to estimate the relative change in the expected number of captures while controlling for time of year, temperature, and netting effort. We found no decrease in the number of captures for either species. We suggest that the lack of decrease observed at our study site may be a result of compensatory immigration, despite potential broader-scale population declines. [ABSTRACT FROM AUTHOR]