Red-eyed treefrogs differ in color, body size, and male advertisement call across populations in Costa Rica and Panama. We are conducting a series of female choice experiments to determine the role of sexual selection in mediating this population level variation. Our research examines mate choice across allopatric and clinal populations to understand the strength at varying scales of geographic and genetic distance. Future experiments will examine the mechanisms that underlie choice (such as color pattern, behavior, advertisement call, chemical cues).

To test for female choice, gravid (sexually receptive) females are field collected, placed into an enclosure, and presented with models of males for 10 minute trials. Male models are sculpted and painted to reflect the spectra of their populations and placed on a robotic platform to simulate movement. All trials are conducted under natural moonlight and viewed with an IR-sensitive camera. Our lab collaborates with Kristine Kaiser (CSUN) and Andres Vega (AMBICOR, Costa Rica).

Screen Shot 2015-09-12 at 1.04.43 PM

Field team 2014: Cassandra Owen, Maria Akopyan, Cindy Hitchcock, Neva Savant, Giorgia Robertson

DSCN2916 copy

Dakota Spear (field team 2015)

Red-eyed treefrog, La Selva Biological Research Station, Costa Rica

Red-eyed treefrog, La Selva Biological Research Station, Costa Rica


A male and female pair of Red-eyed treefrogs in amplexus (copulatory position with larger female on the bottom) in the foreground. A pair of Hourglass treefrogs in the background.


Collaborators (left to right): Andres Vega, Dr. Kristine Kaiser, Cindy Hitchcock

IMG_0464 copy

Plasticine models represent five distinct color morphs of A. callidryas. Models sculpted and painted by Cindy Hitchcock (Fine Art America). Robotics designed by A. Robertson using VEX Robotics.

IMG_5930 copy

The “Andres Vega maneuver”. How to transport a field enclosure.