Scientists have known for quite a while than animals in one area used different vocalizations from individuals of the same species inhabiting other areas. These 'dialects' are known in many bird species, and in some it has been shown to be due to environmental factors, such as ambient noise leading to pitch shifts in the songs of bird in cities (Slabbekoorn & Boer-Visser 2006 and Nemeth & Brumm 2009). But this study on Chimps shows something altogether different. This new research builds on older studies such as the ones that show vervets have calls with distinct meanings: leopard, snake or eagle (Seyfarth & Cheney 1980). We now know that chimp 'word' for objects are not fixed and that they exert a large amount of control over the sounds they make: they're not just instinctive, emotional outbursts.
The study was done by recording all of the vocalizations of chimps at an Edinburgh zoo, one of which had been translocated from the Netherlands to Scotland. This chimp learnt to new 'Scottish word' for apple, changing from their original 'Dutch'.
But it wouldn't be me commenting on a primate paper without pointing out that the sample size is one, and I only do this to annoy on of the studies authors Dr Simon Townsend! It's still a very important and interesting piece of work.
New Scientist piece on the research.
Link to the paper: http://www.sciencedirect.com/science/article/pii/S0960982214016352
Watson et al. (2015) Vocal learning in the functionally referential food grunts of chimpanzees. Current Biology DOI: 10.1016/j.cub.2014.12.032
SummaryOne standout feature of human language is our ability to reference external objects and events with socially learned symbols, or words. Exploring the phylogenetic origins of this capacity is therefore key to a comprehensive understanding of the evolution of language. While non-human primates can produce vocalizations that refer to external objects in the environment, it is generally accepted that their acoustic structure is fixed and a product of arousal states . Indeed, it has been argued that the apparent lack of flexible control over the structure of referential vocalizations represents a key discontinuity with language . Here, we demonstrate vocal learning in the acoustic structure of referential food grunts in captive chimpanzees. We found that, following the integration of two groups of adult chimpanzees, the acoustic structure of referential food grunts produced for a specific food converged over 3 years. Acoustic convergence arose independently of preference for the food, and social network analyses indicated this only occurred after strong affiliative relationships were established between the original subgroups. We argue that these data represent the first evidence of non-human animals actively modifying and socially learning the structure of a meaningful referential vocalization from conspecifics. Our findings indicate that primate referential call structure is not simply determined by arousal and that the socially learned nature of referential words in humans likely has ancient evolutionary origins.