“They converse
with precision.
They repeat
their observations.
They brag
of how much they do.
They comment
on everything that exists.”
Photograph by Almodovar Photography
We study birds to learn about the evolution of interactive communication.
Research
Photograph by Gary Tucker
An Adelaide's warbler, held by Orlando Medina. A unique combination of colored plastic rings on the bird's legs will help us identify him in the future. Photograph by Orlando Medina.
Our study Species
Adelaide’s warblers are little gray and yellow songbirds that live in Puerto Rico all year long. Since they never have to migrate, individuals can maintain the same territories year after year. Neighbors have long-lasting relationships, which they mediate with vocalizations, visual displays, and fights. The Birdsong Lab is working to make our study population of Adelaide’s warblers a model system for research on interactive vocalization, song type use, and song performance.
Song type use
Most songbirds can sing more than one type of song. For example, each male Adelaide's warbler has about thirty song types in his repertoire (click here to hear six different song types). We study song sequences in both solo singing and vocally interacting birds. Our goal is to improve our understanding of the function of song types. We are particularly interested in applying new ways of visualizing and analyzing song sequences to study social influences on song type choice.
A network describing morning singing in a male Adelaide's warbler. Circles (nodes) represent different song types, and their size shows how common they are. Arrows (edges) represent transitions from one song type to the next, with more common transitions represented by heavier arrows. Graph by Paloma Sanchez-Jauregui.
Adelaide's warblers "warm up" during morning singing. This scatterplot shows how song performance (measured with the metric frequency excursion) improves during morning singing.
Song Performance
Why do some birds sing so fast? Perhaps extreme sexual display behaviors, like fast singing, evolve because females prefer to mate with males that give more intense display than those that display more modestly. Female preferences for fast singing males could be adaptive if singing speed reliably indicates male quality (health, motor function, etc.). We study different kinds of ‘extreme’ singing behavior in Adelaide’s warbler to better understand the evolution of song structure and song type use.
A Puerto Rican Parrot preens his mate. Our lab has studied pair bonding and dialect formation in this endangered species. Photograph by Tanya Martinez.
Other projects
David and his students have studied everything from personalities in giant cockroaches to resource competition in tadpoles. We have ongoing collaborative projects on wasps, Venezuelan troupials, and Puerto Rican parrots.