The Dendrobaters

Evan Twomey is a PhD student originally from Maine. After completing his undergraduate degree in zoology at the University of Maine, he enrolled in the masters program at East Carolina University to study under Dr. Kyle Summers. He recently completed an MS in biology (April 2008). His thesis work dealt with species distribution ecology, habitat selection, and biogeography in the genus Ameerega. He has also worked closely with Jason Brown on the taxonomy and systematics of Peruvian poison frogs. Though currently residing in the US, Evan has spent over a year living in Tarapoto, Peru while conducting field research for his masters thesis and for the monitoring of the INIBICO project. Evan is currently doing a PhD with Kyle Summers, focusing on mate choice in the context of mimicry in Ranitomeya imitator.

Evan's beer rankings page

Jason Brown is originally from South Dakota. Trained in molecular techniques as an undergraduate, he is now applied these methods in his dissertation research on the evolution of parental care in the genus Ranitomeya. Jason has spent considerable time in Costa Rica, Venezuela, and Peru over the past 4 years. In addition to his doctoral research, he and Evan have mounted several expeditions to remote areas of Peru which have documented numerous undescribed species of poison frogs. In 2009, Jason finished his PhD under Kyle Summers at ECU and is now working as a postdoc in Anne Yoder's lab at Duke. He has published papers in phylogenetics, biogeography, and behavioral ecology in some of the most respected journals of the field.

Personal website:

Jason’s beer phylogeny page
Justin Yeager is graduate student originally from Pennsylvania. He graduated from the University of Delaware with a degree in Wildlife Conservation. He did his masters work under Dr. Kyle Summers, focusing on mate selection behavior in dendrobatids. Currently he is a PhD student at Tulane working with Corrine Richards. He also has several conservation projects including Tree Walkers International ( and an educational program called Operation Atelopus ( He has spent a great deal of time traveling South America, most recently living in Peru.

Mark Pepper is a Canadian conservationist working out of Iquitos, Peru. Together with his colleague Manuel Sanchez, the two have designed and implemented a project for the conservation of poison frogs through habitat purchase and protection. By selling captive-bred Peruvian frogs, Mark is able to generate money which is used for the purchase of critical areas for conservation. To date, Mark and Manuel own and protect several plots of land near Iquitos, Tarapoto, and Yurimaguas. Mark is also the most active in the field of all the Dendrobaters. Since 2004, he has traveled extensively and almost without rest throughout most of north and central Peru, documenting several new morphs of A. bassleri, R. lamasi, and R. fantastica.
Visit his website:

Manuel Sanchez is a Peruvian conservationist working out of Iquitos, Peru. Together with Mark Pepper, Manuel has helped protect several areas of critical poison frog habitat, and is currently working on obtaining a substantial land concession for conservation purposes. Manuel travels constantly throughout Peru and has played a central role in numerous expeditions.


Other contributors

Wouter Olthof - Wouter is a Dutch university student with a passion for conservation. He has spent time near Tarapoto, Peru accompanying Evan, Jason, and Mark on many expeditions in 2006. By many he is thought of as a good luck charm and has been referred to as 'the ultimate tourist', as he has seen more dendrobatids in the field than most specialists. Since his visit, Wouter has begun a project in Holland to sell dendrobatids to raise money for conservation and travel. He will be dealing 100% legal frogs with documentation. Visit his website (in Dutch):
See his account of Excidobates mysteriosus.

Daniel Mejia Vargas - Daniel is a university student in Bogota, Colombia investigating distribution and taxonomy of species in the genus Andinobates. He has encountered many rare dendrobatids in the field (see his account for Andinobates fulguritus) , and dozens of morphs of Oophaga histrionica over the past few years. Many more expeditions will be coming, though unfortunately the unstable political conditions prevailing in Colombia are hampering travel to many areas.

Marcus Bartelds
- Marcus has travelled extensively through Central and South America, particularly Suriname, French Guiana, and Ecuador. He has extensively documented many morphs of Dendrobates tinctorius (accounts coming soon) and runs an exceptional website,

Sea McKeon
- Sea received his masters degree as a student of Dr. Kyle Summers, focusing his project around tadpole deposition strategies in response to predators in Allobates femoralis. Working extensively in southern Peru, Sea has documented and photographed several of Peru's southern dendrobatids, contributing accounts for Ranitomeya sirensis, Ameerega macero, and A. simulans.

© 2009 Evan Twomey & Jason Brown | Hosting donated by Mark Pepper of Understory Enterprises