Song copying by humpback whales: themes and variations

Male humpback whales (Megaptera novaeangliae) produce long, structured sequences of sound underwater, commonly called songs. Humpbacks progressively modify their songs over time in ways that suggest that individuals are copying song elements that they hear being used by other singers. Little is known about the factors that determine how whales learn from their auditory experiences. Song learning in birds is better understood and appears to be constrained by stable core attributes such as species-specific sound repertoires and song syntax. To clarify whether similar constraints exist for song learning by humpbacks, we analyzed changes over 14 years in the sounds used by humpback whales singing in Hawaiian waters. We found that although the properties of individual sounds within songs are quite variable over time, the overall distribution of certain acoustic features within the repertoire appears to be stable. In particular, our findings suggest that species-specific constraints on temporal features of song sounds determine song form, whereas spectral variability allows whales to flexibly adapt song elements.Electronic Supplementary Material Supplementary material is available for this article at .     

Creating Internships in Marriage and Family Therapy: A Collaboration Between a Training Program and an Offender Reentry Facility

The literature on clinical internships in marriage and family therapy is limited in the discussion of the development of clinical sites as well as the benefits and challenges experienced by students and programs. This article focuses on the development of a marriage and family therapy internship in an offender reentry facility. The process of how students are referred and trained, the rewards and challenges of their work, and the supervision experience are described. The purpose is to inform marriage and family therapy programs about a potential resource for training students.     

“Best possible” systematic estimates of communalities

At least four approaches have been used to estimate communalities that will leave an observed correlation matrixR Gramian and with minimum rank. It has long been known that the square of the observed multiple-correlation coefficient is a lower bound to any communality of a variable ofR. This lower bound actually provides a best possible estimate in several senses. Furthermore, under certain conditions basic to the Spearman-Thurstone common-factor theory, the bound must equal the communality in the limit as the number of observed variables increases. Otherwise, this type of theory cannot hold forR.This research was facilitated by a grant from the Lucius N. Littauer Foundation to the American Committee for Social Research in Israel in order to promote methodological work of the Israel Institute of Applied Social Research.