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1.
J Exp Biol ; 214(Pt 14): 2409-15, 2011 Jul 15.
Article in English | MEDLINE | ID: mdl-21697433

ABSTRACT

Quantifying and understanding the impact of anthropogenic sound on marine mammals has been the focus of many researchers both in laboratory settings as well as in the field. This study presents the audiogram of a sub-adult Blainville's beaked whale that stranded in Hawaii. The hearing measurements were conducted using the non-invasive auditory brainstem response technique. A total of 11 sinusoidally amplitude modulated tones were tested ranging from 5.6 to 160 kHz. The audiogram data indicated that the region of best hearing was found between 40 and 50 kHz with thresholds below 50 dB. This frequency range partially overlaps with the frequency modulated upsweep that Blainville's beaked whales have been reported to use during echolocation. These results match the frequency range obtained from the hearing measurements of a Gervais' beaked whale previously tested using contact acoustic stimulation and emphasize the importance of obtaining rapid hearing measurements on live stranded animals to improve the understanding of poorly known species.


Subject(s)
Audiometry , Evoked Potentials, Auditory/physiology , Whales/physiology , Acoustic Stimulation , Animals , Auditory Threshold/physiology , Fourier Analysis , Male
2.
J Zoo Wildl Med ; 33(4): 350-5, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12564533

ABSTRACT

Diffuse hyperplastic goiter was diagnosed by histopathology in 11 perinatal bottlenose dolphins (Tursiops truncatus) that died at four separate zoos and aquaria. Thyroid morphology of these animals was compared with the histologically normal thyroids of two stranded wild bottlenose dolphin calves, a neonate and a 2-mo-old calf. Histologic changes included reduced follicular luminal diameter, markedly reduced or absent luminal colloid, hypertrophy of follicular epithelium, and follicular dysplasia. The etiology of the thyroid gland lesion was not identified. Cause of death was not determined for most of these animals, but they were presumed to have died from metabolic derangements associated with the thyroid lesion, drowning, or dystocia.


Subject(s)
Dolphins , Goiter/veterinary , Thyroid Gland/pathology , Animals , Animals, Newborn , Animals, Zoo , Female , Goiter/congenital , Goiter/pathology , Hyperplasia/congenital , Hyperplasia/veterinary , Male
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