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These bat location estimates have been reported by Bogan and others (In press) and come in the form of a GIS shape file. Three species of nectar-feeding phyllostomid bats migrate north from Mexico into deserts of the United States (U.S.) each spring and summer to feed on blooms of columnar cacti and century plants (Agave spp). However, the habitat needs of these important desert pollinators are poorly understood. We followed the nighttime movements of two species of long-nosed bats (Leptonycteris yerbabuenae and L. nivalis) in an area of late-summer sympatry at the northern edges of their migratory ranges. We radiotracked bats in extreme southwestern New Mexico during 22 nights over two summers and acquired location...
Nesting strategies and use of important in-water habitats for far-ranging marine turtles can be determined using satellite telemetry. Because of a lack of information on habitat-use by marine turtles in the northern Gulf of Mexico, we used satellite transmitters in 2010 through 2012 to track movements of 39 adult female breeding loggerhead turtles (Caretta caretta) tagged on nesting beaches at three sites in Florida and Alabama. During the nesting season, recaptured turtles emerged to nest 1 to 5 times, with mean distance between emergences of 27.5 km; however, several turtles nested on beaches separated by ~250 km within a single season. Mean total distances traveled throughout inter-nesting periods for all turtles...
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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...
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A crepuscular or nocturnal lifestyle has evolved in bees several times independently, probably to explore rewarding pollen sources without competition and to minimize predation and nest parasites. Despite these obvious advantages, only few bee species are nocturnal. Here we show that the sensitivity of the bee apposition eye is a major factor limiting the ability to forage in dim light. We present data on eye size, foraging times, and light levels for Megalopta genalis (Augochlorini, Halictidae) in Panama, and Lasioglossum (Sphecodogastra) sp. (Halictini, Halictidae) in Utah, USA. M. genalis females forage exclusively during twilight, but as a result of dim light levels in the rain forest, they are adapted to extremely...
Global climate change scenarios predict an increase in air and ocean temperatures, storm intensity, storm surge and inundation of low-lying coastal areas and small islands. Projections of changing oceanographic conditions and inundation are at levels that could affect seabird populations including those of the black-footed albatross (Phoebastria nigripes; BFAL). The resilience of BFAL populations in the face of more frequent extreme weather events and nesting habitat loss is therefore a critical issue for wildlife managers. Colony establishment behavior and dispersal biology are poorly understood for BFAL. Despite this uncertainty, management decisions to safeguard BFAL breeding populations in the face of climate...
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Sea otters are well-known tool users, employing objects such as rocks or shells to break open invertebrate prey. We used a series of generalized linear mixed effect models (GLMEs) to examine observational data on prey capture and tool use from 211 tagged individuals from five geographically defined study areas throughout the sea otter’s range in California. Our best supported model was able to explain 75% of the variation in the frequency of tool-use by individual sea otters with only ecological and demographic variables. In one study area, where sea otter food resources were abundant, all individuals had similar diets focusing on preferred prey items and used tools at low to moderate frequencies (4-38% of prey...
The Lower Colorado River provides critical riparian areas in an otherwise arid region and is an important stopover site for migrating landbirds. In order to reverse ongoing habitat degradation due to drought and human-altered hydrology, a pulse flow was released from Morelos Dam in spring of 2014, which brought surface flow to dry stretches of the Colorado River in Mexico. To assess the potential effects of habitat modification resulting from the pulse flow, we used foraging behavior of spring migrants from past and current studies to assess the relative importance of different riparian habitats. We observed foraging birds in 2000 and 2014 at five riparian sites along the Lower Colorado River in Mexico to quantify...
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Prey fish were collected at 17 Forster’s tern breeding colonies during colony visits from 2005-2015. Prey fish were identified to the lowest taxonomic category. We present relative abundances by colony and year for each of the 10 major species groups. Unidentified fish species or rarely observed species were combined into an “Other” category. We calculated an arithmetic mean, standard deviation (sd), 25th quantile, and 75th quantile for dry standard length (SL; mm) and dry mass (g) for each fish species at each colony. These data support the following publication: Peterson SH, Ackerman JT, Eagles-Smith CA, Herzog MP, Hartman CA (2018) Prey fish returned to Forster’s tern colonies suggest spatial and temporal differences...
This study demonstratest he correlationo f an arrayo f ecological characteristicsw ith foraging mode in sit-and-wait foraging Crotalus cerastes and widely foraging Masticophis flagellum. Crotalus cerastes are chiefly nocturnal and spend most of their time on the surface either coiled on or partially buried in the sand waiting to ambush prey. Masticophis flagellum are strictly diurnal predators and cruise through the habitat searching for active and sedentary prey. In this study, C. cerastes averaged 7.2 ? 0.7 (SE) h/day on the surface, almost twice the time of M. flagellum (3.9 ? 0.9 h/day). Body temperatures (Tb's) of active M. flagellum, determined from surgically implanted radio transmitters, were significantly...


    map background search result map search result map Light intensity limits foraging activity in nocturnal and crepuscular bees Local distribution and foraging behavior of the spotted bat (Euderma maculatum) in northwestern Colorado and adjacent Utah Tool-use frequency by individual sea otters in California Radio telemetry data on nighttime movements of two species of migratory nectar-feeding bats (Leptonycteris) in Hidalgo County, New Mexico, late-summer 2004 and 2005 Prey fish returned to Forster’s tern colonies in South San Francisco Bay during 2005-2015 Prey fish returned to Forster’s tern colonies in South San Francisco Bay during 2005-2015 Local distribution and foraging behavior of the spotted bat (Euderma maculatum) in northwestern Colorado and adjacent Utah Radio telemetry data on nighttime movements of two species of migratory nectar-feeding bats (Leptonycteris) in Hidalgo County, New Mexico, late-summer 2004 and 2005 Tool-use frequency by individual sea otters in California Light intensity limits foraging activity in nocturnal and crepuscular bees