Maternal behaviors of gray whales (Eschrichtius robustus) on a summer foraging site

The weaning period for gray whale (Eschrichtius robustus) calves is important for maternal instruction and learning. We examined observational and acoustic data from a foraging site for evidence of calf development and mother-young information transfer. Site survey data demonstrated an initial prioritization of calf protection by using shallow shoreline areas. Foraging in more open water was only noted in late summer, perhaps an indicator of the maturation of the calf. Other indicators of development were found in acoustic recordings made over two summers. Motherese call types have been reported from recordings made in breeding lagoons, but have not before been described outside of calving regions. They were present in recordings from this study site, predominantly in the early summer and not heard past late July. We suggest vocal repertoire may evolve as the calf ages, and more adult calling behaviors eventually replace motherese. Long-term mark-recapture analyses demonstrated a high return of calves to the area to forage in summers subsequent to weaning, suggesting maternally inherited prey preference and site use behaviors. From our findings we suggest a calf's first summer is a highly critical period for development and may be formative in shaping future behaviors and habitat use patterns.     

Responsiveness and perceived intelligence as predictors of speech addressed to cats

Abstract

Speech addressed to a cat was examined to test whether the use of child-directed language (CDL) with a companion animal is related to perceived intelligence of a listener and/or listener responsiveness. Fifty-one undergraduates briefly entertained a cat using a toy, and the vast majority of these participants spoke to the animal. The language used was similar to CDL, and two aspects of this language (number of questions and attribution of thoughts to the animal) were positively related to ratings of the animal's intelligence. The cat's responsiveness, as measured by time spent in proximity of the participant during the interaction, was not strongly correlated with measures of speech use. The results suggest that speech used with companion animals follows a model in which the human first perceives a social interaction, and therefore uses speech. This speech is then modified, based on the perceived comprehension of the listener, regardless of who this listener may be.     

Oxytocin shapes parental motion during father–infant interaction

An infant-oriented parental repertoire contributes to an infant''s development and well-being. The role of oxytocin (OT) in promoting affiliative bonds and parenting has been established in numerous animal and human studies. Recently, acute administration of OT to a parent was found to enhance the carer''s, but at the same time also the infant''s, physiological and behavioural readiness for dyadic social engagement. Yet, the exact cues that are involved in this affiliative transmission process remain unclear. The existing literature suggests that motion and vocalization are key social signals for the offspring that facilitates social participation, and that distance and motion perception are modulated by OT in humans. Here, we employed a computational method on video vignettes of human parent–infant interaction including 32 fathers that were administered OT or a placebo in a crossover experimental design. Results indicate that OT modulates parental proximity to the infant, as well as the father''s head speed and head acceleration but not the father''s vocalization during dyadic interaction. Similarly, the infant''s OT reactivity is positively correlated with father''s head acceleration. The current findings are the first to report a relationship between the OT system and parental motion characteristics, further suggesting that the cross-generation transmission of parenting in humans might be underlaid by nuanced, infant-oriented, gestures relating to the carer''s proximity, speed and acceleration within the dyadic context.