Birders Meeting Presentation Abstracts & Speaker Bios

Birds, Beans, and Trees: ecology and conservation of forest-breeding warblers

Speaker: Marja Bakermans, Worcester Polytechnic Institute

The two fastest declining warbler species in the East, Cerulean Warbler (Setophaga cerulea)and Golden-winged Warbler (Vermivora chyrsoptera), breed in unique stages of forest habitat. Unfortunately however, little habitat that meets their specific breeding needs remains on today’s landscapes. First, this presentation will follow Cerulean Warblers south to their wintering grounds to examine the role of shade coffee in bird conservation. This will be followed by an explanation of current research on the breeding grounds of both the Cerulean and the Golden-winged warbler to learn how results of these studies form the foundation of habitat management guidelines now available to natural resource professionals and private landowners. Throughout the presentation Marja will discuss how various other bird species are benefiting from habitat creation and maintenance for these two imperiled species.

Marja Bakermans grew up in Pennsylvania where, as a child, she spent countless hours in the woods with her father and became captivated by nature. This early interest grew into her lifelong passion for avian ecology and conservation. After obtaining an undergraduate degree in Biology from Bucknell University, Marja spent the next 5 years traveling around the country working as a seasonal biologist. These travels took her to New York, Florida, North Carolina, Nevada, Texas, New Jersey, and back to Pennsylvania. Ultimately her graduate research at The Ohio State University focused on the consequences of urbanization and forest management on avian communities. The favorite part of her research was following Cerulean Warblers to shade coffee plantations in Venezuela for three warm winters. Marja’s postdoctoral work examined Golden-winged Warbler habitat use in Appalachian Mountain timber harvests. Currently, Marja is continuing her research with students as a faculty member at Worcester Polytechnic Institute.


Warbler Vocalizations: what we know and how to learn them

Speaker: Tom Stephenson, co-author of The Warbler Guide

The Yellow Warbler’s familiar “Sweet sweet sweet I’m so so Sweet” is a stereotyped song heard every spring all across the United States and Canada. But individuals of this species also sing several additional songs that vary widely from area to area. Tom will discuss why this might be so, and some of what’s known about the function of songs and calls in general.

Tom will also address the conundrum of what you should do when next you hear a warbler song you don’t recognize. He will specifically offer thoughts on what you should listen for to help you identify unknown vocalizations, along with why traditional field guides often are not much help in this regard.

Ultimately he will provide some strategies for learning warbler songs and calls, including basic memorization theory and some effective techniques for memorizing warbler and other species’ songs.

Tom Stephenson has been birding since childhood and he benefited from the tutelage of Dr. Arthur Allen of Cornell University. His articles and photographs have appeared in museums and many publications including Birding, Birdwatcher’s Digest, Handbook of the Birds of the World, Handbook of the Mammals of the World, Birds of Madagascar, and Guide to the Birds of SE Brazil.

Tom has also lectured and guided groups throughout the US as well as in Asia, where he trained guides for the government of Bhutan and made numerous sound recordings of Eastern Himalayan rarities and other Asian species which he donated to Cornell’s Macaulay Library of Natural sounds.

He has participated on Zeiss’s digiscoping team during New Jersey Audubon’s World Series of Birding, and in 2011 his birding team won the World Series Cape Island Cup.  Additionally, in 2014 Tom and Scott Whittle set the US record for a Photo Big Day, taking pictures of 208 species in one 24-hour period.

As a musician Tom played concerts and did studio work for many years, working with several Grammy and Academy Award winners as well as performing with members of the NY Philharmonic and the Philadelphia Orchestra. His clients included the Grateful Dead, Phil Collins and the FBI. He joined Roland Corporation in 1991, managed the recorder division, and recently retired as Director of Technology.

Tom’s latest book, The Warbler Guide, was published by Princeton University Press and recently won the National Outdoor Book Award. The Warbler Guide App also just won the 2015 Design Award for the AAUP Book, Jacket and Journal Show.


Warbler Genes: What Does Hybridization Tell Us?

Speaker: David Toews, Cornell Lab of Ornithology

The parulid warblers (a.k.a. New World warblers or wood-warblers) of North America are a well-known avian group in which many species are distinguished by dramatic differences in plumage. These plumage characters are the presumed targets of sexual selection, and the diversification of warblers has been shown to be exceptionally high compared to many other birds. Using modern genomic tools, David and collaborators have been studying warbler genomes to better understand the evolution of these charismatic birds. In particular, these researchers are interested in the genomic consequences of hybridization and have particularly studied this phenomenon in Myrtle and Audubon’s warblers, as well as in Golden-winged and Blue-winged warblers. David will discuss what these new data have told us about the intertwined evolutionary histories of these species. He will also highlight some of his recent discoveries in identifying the genes that are involved in making these birds so colorful.

David Toews is currently a NSERC Banting Postdoctoral Researcher in Dr. Irby Lovette’s lab at the Cornell Lab of Ornithology. He is a graduate of the University of British Columbia in Vancouver, where he completed his Ph.D. with Darren Irwin in 2014. Prior to this he completed his MSc with Dr. Irwin and finished his BScH at Acadia University in Nova Scotia.

David’s current research focuses on the causes and effects of hybridization between recently diverged avian taxa. He combines field-based research with integrative laboratory techniques, using genomic tools, stable isotopes, behavior and physiology. With a group of international collaborators, his research is focusing on understanding the origin and diversity of genetic and phenotypic variation in the Yellow-rumped Warbler species complex. He is also studying the genetic consequences of hybridization between Golden-winged and Blue-winged warblers.


How Will Climate Change Affect Warblers?: A Case Study Using Black-throated Blue Warblers

Speaker: Andrea Townsend, Hamilton College

Climate change is expected to increase the risk of extinction for many species in the coming century.  Long-distance migratory birds are of particular conservation concern because they may be unable to adjust their migration tempo with the advancement of spring in their breeding areas. However, not all migratory birds are expected to respond in the same way to warming temperature trends. For example, species that are capable of raising more than one brood in a breeding season could actually benefit from extended breeding seasons in earlier springs. 

In this presentation, Andrea will describe general warbler behavior patterns that have been observed linking climate change to their behavior, fitness, and population trends.  Based on a 25-year mark and recapture study, and using climate data from the Hubbard Brook Experimental Forest in New Hampshire, she will also specifically present results of her own work with Black-throated Blue Warblers (Setophaga caerulescens). Andrea and her fellow researchers assessed the effects of spring temperature (i.e., local weather) and the El Niño Southern Oscillation index (a global climate cycle) on the fecundity and population growth of Black-throated Blue Warblers.

They found that local and global climatic conditions affected warbler populations in different—and sometimes unexpected—ways.

Andrea Townsend was a graduate student at the Cornell Lab of Ornithology.  She later completed a postdoctoral fellowship at the Smithsonian Migratory Bird Center and was a faculty member at the University of California at Davis before beginning her current position as an Assistant Professor at Hamilton College. Research in Andrea’s lab is focused on the behavioral responses of wildlife to human-induced environmental change and the consequences of these behaviors for fitness and population dynamics.  Her work is currently focused on the on interactive effects of migration and disease on cognition in urban American Crows.