ABSTRACT
Ability to discriminate familiar conspecifics is an essential competence in any group-living species, ensuring socio-spatial cohesion, but in many animals, such as mustelids, the relative importance of the different communicative modalities for discrimination is poorly understood. In otters, there is evidence of intra-specific variation in physical appearance and in feces chemical profile, but the potential for acoustic identity coding as well as for identity decoding in visual, acoustic and olfactive domains remains unexplored. We investigated the acoustic structure of contact calls in five captive groups of small-clawed otters and found that it is possible to reliably assign one particular call to a given adult male caller. Females discriminated between familiar and unfamiliar adult males based on their sound (playback) and smell (feces) but not based on their picture, suggesting abilities to memorize and use acoustic and olfactive signatures in their daily social life.
Subject(s)
Discrimination, Psychological/physiology , Hearing/physiology , Otters/physiology , Smell/physiology , Vocalization, Animal/physiology , Animals , Behavior, Animal/physiology , Feces/chemistry , Female , Male , Pattern Recognition, Physiological/physiologyABSTRACT
Striking reversible signal intense magnetic resonance imaging (MRI) lesions were observed in the occipital cortex of a 16-year-old girl who presented with an attack of transient cortical blindness as the initial manifestation of hypertensive encephalopathy (HTE). The lesions were seen to best advantage on T2-weighted imaging and were not visible on computed tomography (CT). It is proposed that such occipital lobe MRI lesions likely reflect extravasation of fluid and proteins across the blood brain barrier, damaged as a consequence of cerebral autoregulation failure.
