Seasonality and fidelity in roost use of the Mexican free-tailed bat, Tadarida brasiliensis , in an urban setting

We studied 7 urban roosts occupied by Mexican free-tailed bats ( Tadarida brasiliensis ) in downtown Waco, Texas, from August 2001 to September 2002. We examined frequency of roost use, colony sizes, and roost fidelity in relation to gender. Use of roosts and colony sizes were highest in the fall and lowest in the winter, but fluctuated widely during the study. These roosts were not used by maternity colonies, and patterns of occupancy suggested that they served as stopover sites during migratory seasons. Individual bats exhibited high fidelity to discrete roosts included in the study. However, the bats commonly left the study area, suggesting that populations are defined at greater spatial scales than we included in this study. Male bats were recaptured more often and spent more days in the study area than female bats, suggesting a sexual difference in roosting behavior.     

New distributional records for spotted bat ( Euderma maculatum ) in Wyoming

Before 1990 the spotted bat ( Euderma maculatum ) was known in Wyoming from only 2 records. Between June 1994 and May 1997 we documented habitat use and observations incidental to conducting a bat inventory of caves and abandoned mines. By monitoring audible echolocation calls, we observed bats at mist-netting sites. Spotted bats were heard or captured on 13 nights at 10 locations, all of which were near canyons or high cliff faces. No foraging habitat preferences were noted. E. maculatum occurrence appears to be related to roost structure, roost availability, and proximity to a permanent water source.     

Distribution, foraging behaviour, and capture results of the spotted bat ( Euderma maculatum ) in central Oregon

The spotted bat ( Euderma maculatum ) has been virtually unknown in Oregon despite the existence of potential habitat in many areas of the state. In 2002 and 2003 we searched for spotted bats along the John Day, Deschutes, and Crooked Rivers and at a remote dry canyon southeast of the city of Bend in central Oregon. The species was documented through the use of mist-nets, a bat detector, and recognition of audible spotted bat calls. Spotted bats were found at 11 locations in 6 Oregon counties. Nightly activity patterns of spotted bats were unpredictable. Spotted bats were found in 78% of search areas but on only 48% of survey nights. We observed spotted bats foraging above fields and low upland slopes adjacent to rivers and creeks and along the rims of cliffs. Estimated flying heights of spotted bats ranged from 3 m to 50 m aboveground. The species was difficult to capture and was captured only after considerable experimentation with methods and materials. Three spotted bats were captured toward the end of the project in 2003 and accounted for only 0.5% of all bats captured during the study. Although we attached radio transmitters to 2 spotted bats, we found no roost locations. We believe additional spotted bat surveys in Oregon are warranted, especially in higher-elevation habitats, but recommend that to increase their effectiveness, surveys accommodate the unique foraging behavior of the species.     

Multiple-scale roost habitat comparisons of female Merriam’s Wild Turkeys in the southern Black Hills, South Dakota

Because quantity and quality of roosting habitat can affect Merriam’s Wild Turkey ( Meleagris gallopavo merriami ) distribution, we described habitat characteristics of Merriam’s turkey roost sites in the southern Black Hills of South Dakota. Varying proportions of Merriam’s turkeys in the southern Black Hills depended on supplemental feed from livestock operations during the 2 winters of our study, whereas the remainder wintered in forested habitat away from supplemental feed. We compared characteristics of roost habitat occupied by female turkeys from both groups. We located turkeys with radio-transmitters in the early morning and late evening to find roost sites. Female Merriam’s turkeys in the southern Black Hills roosted exclusively in ponderosa pine trees, primarily on the upper portions of ridges on easterly aspects. Generally, trees >30 cm diameter at breast height (dbh) were chosen for roosting, but turkeys also roosted in trees with smaller dbh. During winter months, turkeys that relied on supplemental feeding roosted adjacent to the ranch-farmstead where the supplemental food was located. Generally, these turkeys used the same roost site(s) throughout the winter, whereas turkeys that remained in the forest during winter used multiple roost sites. We suggest maintaining stands of trees >30 cm dbh on the upper portions of easterly aspects to provide suitable roosting habitat for female Merriam’s Wild Turkeys in the southern Black Hills.     

Springtime movements, boost Use, and foraging activity of Townsend's big-eared bat ( Plecotus townsendii ) in central Oregon

Seasonal movements, roost-site fidelity, and foraging activity patterns are largely unknown for western populations of Townsend's big-eared bat ( Plecotus townsendii ). We used miniature radiotelemetry units to track springtime movements of six bats inhabiting forested lava flows in central Oregon, and found that bats moved up to 24 km from hibernacula to foraging areas. Individual bats returned to the same foraging area on successive nights but shifted to different areas in presumed response to changes in insect availability. Both sexes apparently use a series of interim roost sites between emergence from hibernation and the time females enter into maternity colonies, with little individual fidelity to these sites. In regions characterized by extensive lava-flow topography, suitable daytime roosts are numerous and dispersed over a large area, allowing bats to move relatively great distances to locate foraging ranges. Hence, the actual area of concern for effective management of individual populations can be considerably larger than indicated solely by locations of hibernacula and maternity caves of this declining species.     

Roost sites of the silver-haired bat ( Lasionycyeris noctivagans ) in the Black Hills, South Dakota

We investigated the roosting ecology of silver-haired bats ( Lasionycteris noctivagans ) in the Black Hills, of western South Dakota. Using radiotelemetry, we located 39 roosts, 10 of which were maternity aggregations containing 6 to 55 bats. The roosts were mostly in ponderosa pine ( Pinus ponderosa ) snags that averaged 39 cm diameter at breast height. Solitary bats preferred roosting under loose bark or in crevices in trees, regularly moving among trees. All maternity aggregations were found in tree cavities, primarily those created by woodpeckers. Roost trees were located in patches of forest with relatively high snag densities, about 21 snags/ha. This study suggests that snags play an important role in maintain silver-haired bat populations in ponderosa pine ecosystems.     

Reproduction and seasonal activity of silver-haired bats ( Lasionycteris noctivagans ) in western Nebraska

Silver-haired bats ( Lasionycteris noctivagans ) were thought only to migrate through Nebraska; however, recent surveys in eastern Nebraska report summer records of females and their young. Our study in western Nebraska also shows that silver-haired bats are summer residents. We discovered the 1st reproductively active L. noctivagans in this part of the state. We caught lactating females and volant young in riparian forests along the North Platte River and in forested areas of the Pine Ridge. Previously, adult males were not known from Nebraska in summer, and only 4 records of L. noctivagans were known from western Nebraska during migration. On 28 July we captured an adult male in a coniferous forest of the Wildcat Hills, and we have more than 100 records of migrating individuals. Lastly, an obese L. noctivagans captured on 4 November may represent an individual preparing to hibernate in the state.     

Morphological changes during postnatal growth and reproduction in the brown long-eared bat Plecotus auritus: implications for wing loading and predicted flight performance

Patterns of postnatal growth, and changes in mass and wing loading during reproduction were studied in captive free-flying brown long-eared bats (Plecotus auritus, Linnaeus, 1758). The bats were fed on noctuid moths occasionally supplemented with mealworms. Growth in body mass was best described by the von Bertalanffy model (n = 5 individuals), while growth in forearm length, wingspan and wing area, were best described by the logistic equation (n = 5 individuals). Because the wings developed more rapidly than body mass, wing loading decreased from high levels following birth to a minimum at around 30 days of age. Predicted mechanical power requirements for flight (minimum power P_mp and maximum range power P_mr) and the corresponding flight speeds (V_mp and V_mr) as well as the minimum theoretical radius of a banked turn (r_min) also reached minima at this time. At 30 days of age juveniles could fly with lower predicted power requirements and were more manoeuvrable (could fly more slowly at minimum power and make tighter turns) than adults. These minima corresponded to the time when juveniles first left the roost box to fly. Reproductive females (n = 6) displayed a near two-fold increase in body mass and wing loading over 50 days prior to birth. This resulted in a three-fold increase in the predicted mechanical power requirements for flight (P_mp and P_mr), and a decrease in predicted flight manoeuvrability. Non-reproductive individuals (n = 22) had a similar pattern but increased in body mass and wing loading to a lesser extent. Over days 1 to 40 postpartum, both mass and wing loading declined in lactating females, but continued to increase in the non-reproductive bats.     

Notes on the spotted bat ( Euderma maculatum ) from southwest Utah

In May 1974 four male spotted bats were netted near St. George, Utah. Contrary to published speculation on Euderma, indications are that the spotted bat in southwest Utah (1) is not a late flyer, (2) does not feed solely on moths, (3) may drop to the ground on occasion to forage, (4) is not a rapid flyer, and (5) appears to utilize crevices as roosting sites.       

Ecology of flannelmouth sucker in the Lee's Ferry tailwater, Colorado River, Arizona

We investigated ecology of flannelmouth sucker ( Catostomus latipinnis ) from 1992 to 1997 in the 26-km Lee's Ferry reach of the Colorado River immediately below Glen Canyon Dam, Arizona. We captured by electrofishing a total of 212 fish and recaptured 52 previously tagged by others. Flannelmouth sucker were captured throughout the tailwater but tended to aggregate about 5 km of the dam, possibly reflecting blockage of historic migration routes. Catch per hour of electrofishing did not differ among years but was greater from November to February than other periods, suggesting seasonal movements of flannelmouth sucker into the tailwater: Mean lengths and weights of fish did not differ among years or seasons. Length frequency analyses also indicated there were no significantly yearly trends in proportion of catch within size classes of fish. Mean condition differed only among seasons and was greatest in February, lowest in August, coinciding respectively with pre- and post-spawning periods of flannelmouth sucker in tributary just down from Lee's Ferry. Recaptured fish migrated from initial tagging locations 1.4-23.1 km downstream from Lee's Ferry. Fifty-nine percent of recaptured fish with known initial tagging locations increased in length, and fish tagged initially as subadults or adults, respectively, grew an average of 45.9 mm and 5.5 mm per year.     

Factors affecting selection of winter food and roosting resources by porcupines in Utah

Ecological and phytochemical factors potentially affecting winter dietary discrimination by porcupines ( Erethizon dorsatum ) in the mountain brush zone of Utah were studied. Porcupines utilized gambel oak ( Quercus gambelii ) as their primary winter food and roosting resource. Big-tooth maple ( Acer grandidentatum ) was the most common tree species in the study area but was rarely utilized by porcupines. Conifer species were used as a food and roosting resource significantly less often than they occurred in the study area, despite thermal advantages provided by their relatively dense canopies. Oak feed trees were successfully separated from conifer feed trees by discriminant analysis 100% of the time. Oak trees were correctly classified as feed and nonfeed trees 71% of the time. Gambel oak contained higher amounts of crude protein, fiber, and tannins, but was lower in either extract fractions and fatty acid content than conifers. A layer of adipose tissue used as an energy reserve by porcupines may have relaxed energy intake demands sufficiently to permit them to concentrate on a diet of oak tissue, which is high in protein, rather than a high-fat conifer diet. A diet relatively high in protein may have facilitated digestion of food material high in fiber. Temperature did not affect selection of tree species for roosting. Rock and snow caves were utilized infrequently and the study population ranged widely. Three of 15 study animals were eaten by predators.     

Differential utilization of bat boxes by house wrens ( Troglodytes aedon )

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Pine boxes nailed to trees in four habitat types in southeastern Utah as roosting sites for bats proved ineffective for bats but were utilized by house wrens in all but one habitat. Boxes were most often utilized in the aspen habitat. Hypotheses to account for differential utilization are presented.       

Bats along the Republican River and its tributaries in southwestern Nebraska: distribution, abundance, and reproduction

Thirteen species of bats occur in Nebraska, but limited information is available on those inhabiting southwestern parts of the state. We investigated the distribution, abundance, and reproductive activity of bats in 5 counties in extreme southwestern Nebraska (Chase, Hays, Dundy, Hitchcock, and Red Willow). From April 2007 to April 2008, we deployed mist nets on 15 occasions at 8 localities over the Republican River and its tributaries. We captured 100 individuals representing 5 species, including the evening bat ( Nycticeius humeralis ), eastern red bat ( Lasiurus borealis ), hoary bat ( Lasiurus cinereus ), big brown bat ( Eptesicus fuscus ), and silver-haired bat ( Lasionycteris noctivagans ). All species raised young in this region of Nebraska, except L. noctivagans , which was documented only during migration. Lactating females of N. humeralis captured on 15 June and volant young captured on 23 June extend known dates of reproductive activity for this species in the state, and an adult female captured on 30 April represents the earliest seasonal record of this species from Nebraska. Our records of evening bats also extend the known distribution of this species farther west in Nebraska than previously reported. Changes in land use throughout the Great Plains during the last century have altered many habitats, such as gallery forests associated with rivers, and distributions of mammals, including bats, have shifted to reflect those ecological changes.     

Spotted bats ( Euderma maculatum ) from Mt. Taylor, New Mexico

The spotted bat ( Euderma maculatum ) is an elusive and rarely captured species in western North America. In the United States, it is known from 12 western states. In New Mexico, few individuals have been reported in recent years, and multiple individuals are known from 9 of 12 capture sites. This study reports on additional captures of E. maculatum from Mt. Taylor (Cibola County) for 2 consecutive summers and includes evidence of a reproducing population in the area. On 30 June/1 July 2006, I captured 4 individuals of E. maculatum , including a lactating female, and on 5 June 2007, I captured a nonreproductive female. The flight of this species was directional and deliberate; I captured 5 of 6 spotted bats that came low over the earthen pond. This study demonstrates how human-made sources of water in an arid region provide opportunities for many species of bats to drink.     

Reproductive ecology of a Tibetan frog Nanorana parkeri (Anura: Ranidae)

Endemic to the Tibetan Plateau, Nanorana parkeri figures among the highest altitude amphibians in the world. The present work, which was conducted in an alpine marsh at 4300 m altitude, is the first report of the species’ reproductive ecology. The breeding season, as indicated by the presence of amplectant pairs and fresh eggs in ponds, lasted from early Mary to early July. The ratios of adult male to female were 1.3 in hibernation ponds and 2.3 in spawning ones. Males were smaller than females. Amplexus was typically axillary (81.7%), with a few exceptional amplexus in which a male clasped another male or object rather than gravid females. Scramble competition occurred in 6.8% of the normal amplexus located. The body sizes of amplexed couples correlated positively. Deposited eggs were attached to submerged plants solitarily (60.5%) or in small clusters (39.5%), and the scattered arrangement of individual eggs could be a strategy to ensure embryonic development in oxygen-poor environments. Clutch size averaged 189 [standard deviation (SD) = 64], and correlated positively with female body size; egg size averaged 2.18 mm (SD = 0.10), independent of female body size; both traits within a clutch were negatively related with each other even controlling for female body size. Relatively few and large eggs laid by the Tibetan frogs, compared with those by lowland aquatic-spawning anuran species, should be adaptive to the harsh high-altitude conditions. Larvae hatched from eggs after 16.4 days on average (SD = 5.8). Froglets emerged between late July and early August, but some tadpoles were present in winter. These findings may help to understand the evolution of amphibians in extreme environments and to protect these remote species.     

Field identification of Myotis yumanensis and Myotis lucifugus: a morphological evaluation

Myotis lucifigus and Myotis yumanensis are 2 species of bats subject to potentially high rates of misidentification because they are often difficult to differentiate in the hand under field conditions. We tested the utility of a suite of external morphological characteristics frequently cited in regional keys to differentiate the 2 species in the field. Forearm length, dorsal pelage sheen, ear color, and forehead slope were examined from 101 bats captured in central Oregon during 2002–2003. Post hoc genetic analysis was performed on tissue samples collected from the 101 bats to confirm identification. Forearm lengths overlapped considerably between species. Only 18% of M. yumanensis and 17% of M. lucifugus were correctly identified with probability ≥95% using forearm length alone. Pelage sheen, ear color, and forehead slope successfully identified 96%, 82%, and 77% of individual bats, respectively. When forearm length was considered together with other traits, identification rates ranged from 92% to 20%. Ability to correctly identify M. yumanensis was 2–6 times greater than for M. lucifugus. Pelage sheen was useful in our study; however, using this character required a subjective decision from the observer, and the result often contradicted other characters for species identification stated in regional keys. For these reasons, we recommend that morphological features be used judiciously and only as supportive criteria for field identification in combination with voucher echolocation calls and genetic confirmation.     

Local distribution and foraging behavior of the spotted bat ( Euderma maculatum ) in worthwestern Colorado and adjacent Utah

This study investigated local distribution and foraging behavior of the spotted bat ( Euderma maculatum ) in Dinosaur National Monument, Colorado-Utah, by monitoring audible echolocation calls. The occurrence of this species was verified in a variety of habitat types in canyon bottoms and other relatively low elevation sites, indicating that the animals were widely distributed and locally common in the area. Foraging spotted bats concentrated flight activity in the open-air space above meadows occasionally exploited near-canopy habitat (within 8 m of foliage). Bats began to forage shortly after dark, and activity levels were relatively constant throughout the night. Foraging spotted bats attacked airborne prey every 2.15 min on average. Consistent with published observations, spotted bats maintained exclusive foraging areas. Distinct vocalizations indicating agonistic encounters occurred when a bat encroached on the foraging area of a conspecific.     

New records of bats (Chiroptera: Mammalia) from Malawi,east-central Africa,with an assessment of their status and conservation

This paper reports 97 new species-locality records of bats from Malawi. Of particular interest are four species of bats (Rhinolophus swinnyi, Triaenops persicus, Eptesicus flavescens, Tadarida nigeriae) which have not been recorded previously from Malawi. The relative status of bats in Malawi was estimated and the species were placed in five categories ranging from ‘rarely-recorded’ to ‘very commonly-recorded’. Of the 59 species of bats known to occur in Malawi, 28 are rarely-recorded in Malawi. The relative status and species-locality records of bats were analysed to assess which species, and which localities, need special conservation effort. Seventeen species which are rare throughout their ranges in Africa as well as being rarely-recorded or seldom-recorded in Malawi, are considered to require special effort. Checklists of bats are given for 11 localities, including Liwonde NP in the Upper Shire Valley (29 spp.), two localities on the Shire Highlands (28, 22 spp.), Thyolo on the boundary between the Shire Highlands and Phalombe Plain (22 spp.), and Chiromo in the Lower Shire valley (30 spp.), which have particularly rich bat faunas. Localities in need of urgent conservation effort include Ntchisi FR in the Central Region, and Chiromo. Ninety-two percent of the species of bats known to occur in Malawi have been recorded from the Southern Region. Most of these species will probably continue to survive in southern Malawi provided that the National Parks (especially Liwonde NP) are maintained and well-managed, and there is no further destruction of the indigenous vegetation at Chiromo and Thyolo, and on the Shire Highlands.     

Summer habitat use and selection by female Sage Grouse ( Centrocercus urophasianus ) in Oregon

Cover types and vegetative characteristics (e.g., grasses, forbs, shrubs) used by female Sage Grouse ( Centrocercus urophasianus ) during summer were compared with available habitat on two study areas in southeastern Oregon. Broodless hens, which constituted 114 of the 125 (91%) radio-marked hens studied, selected big ( Artemisia tridentata ) subspp.) and low sagebrush ( A. arbuscular ) cover types at both study areas. At Hart Mountain, broodless hens did not select specific vegetative characteristics within cover types. However, at Jackass Creek, forb cover was greater ( P = .004) at broodless hen sites than at random locations. Differences in habitat use by broodless hens between study areas were associated with differences in forb availability. Broodless hens used a greater diversity of cover types than hens with broods. Broodless hens gathered in flocks and remained separate from but near hens with broods during early summer. By early July broodless hens moved to meadows while hens with broods remained in upland habitats.     

Roost sites used by Sandhill Crane staging along the Platte River, Nebraska

We assessed the influence of water depth, extent of unobstructed view, and human disturbance features on use of roost sites by Sandhill Cranes along the Platte River, Nebraska, during spring migratory stopover. Aerial photos taken near dawn were used to determine areas of flock use and habitat availability in four sample reaches, and measurements were made on the ground at flock roost areas. In general, depths of 1-13 cm were used by sandhill cranes in greater proportion than those available. Exposed sandbars and depths >20 cm were avoided, while depths of 14-19 cm were used in proportion to their availability. Sites 11-50 m from the nearest visual obstruction were used significantly greater than their availability, while sites 0-4 and >50 m from visual obstructions were avoided. Sandhill Cranes avoided sites near paved roads, gravel roads, single dwellings, and bridges when selecting roost sites; however, they did not appear to be disturbed by private roads, groups of residential buildings, gravel pits, railroads, or electrical transmission lines.