Research:

What do animals learn from members of other species, and what effect does this information flow have on the distribution of species, and the composition of communities? Are there certain systems of information flow that are more stable than others? Under what conditions is this information flow parasitic (flowing in one direction), as opposed to mutualistic (bi or multi directional)? What species play especially important roles as information sources for communities, and can such ‘nuclear’ or ‘keystone’ species be targeted in conservation plans?

Uromi and I in Sinharaja
World Heritage Reserve

In searching for answers to these questions, I study communication in mixed-species flocks of birds. ‘Birds of many feathers flock together’ throughout the world, and such flocks present a unique opportunity for community ecologists: flocks are discrete (every birds is either inside or outside a flock), easily observable communities. The goal of research on mixed-species flocks is clear: given a list of the birds in an area, and some particular characteristics of these species, can we predict which species are in flocks, and which species or nuclear species for the flocks? I believe we can, and I think that the vocal characteristics of species, and the information encoded in vocal signals, is one of the primary factors that drives the structure of these communities.

My thesis work at the University of Massachusetts, Amherst, advised by Don Kroodsma and Bruce Byers, focused on vocal communication among members of a mixed-species flock system species – particularly on alarm calling and vocal mimicry in this system (please see CV, publications). Current work looks at questions of communication and community structure from a diverse range of perspectives:

● I am beginning a two year study funded by NSF’s International Research Fellowship Program, that aims to investigate avian vocal mimicry at the developmental, cognitive and functional levels.During my thesis, I found that a species of drongo is able to contextually mimic species with which it associates in mixed-species flocks, incorporating other species’ songs in its own songs and other species’ alarms in its own alarms.Work in Sri Lanka, in collaboration with Sarath Kotagama of the University of Colombo, will focus on how such mimicry develops and whether the audience present during mimicry affects the bird’s performance.Work in Papua New Guinea, in collaboration with Lance Hill of the University of Papua New Guinea, will investigate the function of vocal and plumage mimicry in a fascinating system where one of the nuclear species is toxic (see the research of John Dumbacher).

● With Dale Joachim of the MIT Media Lab, I am investigating whether playback can be conducted remotely through cell phone technology. Remote playback has the advantages of removing the bias that may accompany the presence of humans, and large scale cell phone networks can allow one to survey or interact with animals conveniently and with high replication.

● With Emily Silverman of the Patuxcent Bird Banding Laboratory and I are working on developing quantitative tools for measuring the species relationships among bird flock members from data on the geographical variation in flocks. This project consists of both a modeling and a sampling phase, in conjunction with projects in Sri Lanka and India, below.

● With Punit Lalbhai, Masters student at the Yale School of Forestry and Environmental Science, Uromi Goodale, my wife and Ph.D. candidate at Yale, and Mark Ashton, professor of silviculture at Yale, I am studying how logging treatments effect bird diversity and abundance in the Yale-Myers Forest, an actively managed forest in southern New England.

● With the Field Ornithology Group of Sri Lanka, an NGO focusing on environmental education, I am conducted a large scale study of how human land-use affects mixed-species flocks in Sri Lanka. This project, funded by the Conservation Food and Health Foundation, aims to (a) identify whether some species are particularly important for flock conservation, using the techniques developed with Emily Silverman, (b) determine land use types that allow flocks to exist in or move through human disturbed areas, and (c) train and educate young people in the rural areas in Sri Lanka where we will work.

● With T. R. Shankar Raman of the Nature Conservation Foundation, I am planning a study similar to the FOGSL project in the Western Ghat mountain range of southern India, funded by the American Institute of Indian Studies.

● Harsha Sathischandra, Masters Student at the University of Colombo, Sarath Kotagama, and I are exploring whether drongos use alarm signals – their own and other species --to scare members of other species away from food, as first described by Charles Munn in a Peruvian mixed-species flocks system.