We have initiated a project in a contact zone between two species of Alouatta in Brazil. Contact zones in this genus have been highlighted in the literature since the early 1970s. We would like to establish a database of research projects focusing on scientific questions related to contact zones, broadly defined including sympatric zones. Although we are particularly interested in contact zones in the Neotropics, other geographical regions are also of interest (for example, the zones of contact among baboon species and subspecies). These studies are of particular importance to primatologists studying behavioral mechanisms of reproductive isolation (vocalizations and others such as reinforcement) as well as the preservation of primate biodiversity due to increasing fragmentation of habitats and other anthropogenic perturbations.

We conducted a search of “speciation” on PrimateLit, which yielded only 123 citations. Most of these references pertained to Paleotropical species and only one paper mentioned bioacoustic character displacement (without any data). Studies such as the one we propose have been conducted with insects, anurans, fish, and birds (see, for example, Loftus-Hills and Littlejohn, 1992; also see Johnstone, 1997), which could provide helpful templates for primate research on these topics. The environmental (abiotic and biotic) changes experienced by numerous taxa provide natural experiments for changes in signaling systems, species integrity, and other important topics for long-term projects involving multidisciplinary input (for example, identification of hybrids with genotyping).

We solicit your interest on these and related topics, including registry of any contact zones of which you may be aware or where you are currently focusing your studies. Please contact one or both of us at the addresses below (preferably via e-mail).