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Full-Text Articles in Organisms

The Fine-Scale Habitat Use Of Risso’S Dolphins Off Bardsey Island, Cardigan Bay (Uk), Marijke N. De Boer, Sonja Eisfeld, Mark P. Simmonds Dec 2014

The Fine-Scale Habitat Use Of Risso’S Dolphins Off Bardsey Island, Cardigan Bay (Uk), Marijke N. De Boer, Sonja Eisfeld, Mark P. Simmonds

Mark P. Simmonds, OBE

The main objectives of this study were (1) to estimate the population size of Risso’s dolphins off Bardsey Island using mark-recapture techniques (De Boer et al., 2013); and (2) to study habitat-use in relation to fine-scale oceanographic features. This work provides preliminary information on the habitat-use of Risso’s dolphins and will benefit future studies, along with the development of effective conservation measures for this species throughout the region.


Calf Development: Most Births At Night, Robert H.I. Dale Jun 2014

Calf Development: Most Births At Night, Robert H.I. Dale

Robert H. I. Dale

For many years, field researchers studying both African (Loxodonta africana) and Asian (Elephas maximas) elephants have indicated that they have observed relatively few births in situ, suggesting that most elephant dams give birth at night. For example, according to Cynthia Moss, "Possibly the majority of births occur at night and perhaps those that do take place in the daytime happen in secluded places" (1988, p. 151). Others, for example, Clive Spinage, have referred to "the old beliefs that the cows retreated to 'calving grounds' or that birth took place at night." (Spinage, 1994, p. 90). Although observers in several areas …


A Survey Of The Management And Development Of Captive African Elephant (Loxodonta Africana) Calves: Birth To Three Months Of Age, Nicole L. Kowalski, Robert H.I. Dale, Christa L. H. Mazur Jun 2014

A Survey Of The Management And Development Of Captive African Elephant (Loxodonta Africana) Calves: Birth To Three Months Of Age, Nicole L. Kowalski, Robert H.I. Dale, Christa L. H. Mazur

Robert H. I. Dale

We used four surveys to collect information about the birth, physical growth, and behavioral development of 12 African elephant calves born in captivity. The management of the birth process and neonatal care involved a variety of standard procedures. All of the calves were born at night, between 7PM and 7AM. The calves showed a systematic progression in behavioral and physical development, attaining developmental milestones at least a quickly as calves in situ. This study emphasized birth-related events, changes in the ways that calves used their trunks, first instances of behaviors, and interactions of the calves with other, usually adult, elephants. …


Eavesdropping By Bats: The Influence Of Echolocation Call Design And Foraging Strategy, Jonathan Balcombe, M. Brock Fenton Jun 2014

Eavesdropping By Bats: The Influence Of Echolocation Call Design And Foraging Strategy, Jonathan Balcombe, M. Brock Fenton

Jonathan Balcombe, PhD

We used playback presentations to free-flying bats of 3 species to assess the influence of echolocation call design and foraging strategy on the role of echolocation calls in communication. Near feeding sites over water, Myotis lucifugus and M. yumanensis responded positively only to echolocation calls of conspecifics. Near roosts, these bats did not respond before young of the year became volant, and after this responded to presentations of echolocation calls of similar and dissimilar design. At feeding sites Lasiurus borealis responded only to echolocation calls of conspecifics and particularly to "feeding buzzes". While Myotis, particularly subadults, appear to use the …


Vocal Recognition In Mexican Free-Tailed Bats: Do Pups Recognize Mothers?, Jonathan Balcombe, Gary F. Mccracken Jun 2014

Vocal Recognition In Mexican Free-Tailed Bats: Do Pups Recognize Mothers?, Jonathan Balcombe, Gary F. Mccracken

Jonathan Balcombe, PhD

Mother Mexican free-tailed bats, Tadarida brasiliensis mexicana, produce 'directive' calls while searching for pups inside cave maternity roosts. These calls consist of highly repetitive pulses of sound uttered in rapid sequence. Calls are sufficiently intense that they are perceptible above the substantial background noise within roosts at distances of at least 1m. Calls are stereotyped within individuals, and statistically discriminable between individuals. These characteristics are expected for vocalizations that function for mother-pup reunions, and are shared with directive calls described previously in other bats. Mother T. b. mexicana directive calls are statistically no less discriminable than are the isolation calls …


Vocal Recognition Of Pups By Mother Mexican Free-Tailed Bats, Tadarida Brasiliensis Mexicana, Jonathan P. Balcombe May 2014

Vocal Recognition Of Pups By Mother Mexican Free-Tailed Bats, Tadarida Brasiliensis Mexicana, Jonathan P. Balcombe

Jonathan Balcombe, PhD

The ability of Mexican free-tailed bat mothers and pups to recognize vocalizations of their presumptive kin (pup isolation calls and mother echolocation calls, respectively) was tested using playbacks of recorded calls. Captive individuals were presented with calls of two bats, one presumptive kin and the other a stranger, from opposite sides of a circular wire arena. Response was determined by amount of time spent on each side of the arena, time spent in contact with a cloth bat model in front of each speaker, and number of separate contacts with each model. For the latter two measures, mothers showed a …