Panama 2007-2008: Research Highlight

The following is adapted from a 'research highlight' I wrote for the NSF (my funding agency). I also have a web album up with more pictures

Forested area on right is one of my study sites

My research will show how some forest songbirds use degraded, fragmented forest habitats. In Panama, forest has regrown in much of the former Canal Zone, even as human developments continue to spread. The lands surrounding these forests are used for different purposes, such as roads, buildings, housing developments, pasture, and agriculture. I am testing how birds use both forested and non-forested lands, and how the type of land use affects the birds’ movement and behavior. Understanding this topic is extremely important in planning for the protection of tropical bird species that use forested habitats. While large land reserves such as national parks will always be important to birds, tropical forests are being cut down at a rapid pace. As human populations grow, there will be more and more human-dominated landscapes in the world. My research will show how birds use such lands, and how we may better plan land use to provide habitat for birds that depend on forests.

I am capturing, radiotagging and releasing individual birds from three focal species: the dusky antbird, red-throated ant tanager, and cocoa woodcreeper. The three species are different sizes and from different bird families, and are all relatively common in the forests of central Panama. We capture the birds in areas with both forested and non-forested habitat, as well as a variety of ‘edge types.’ For example, in these landscapes forest patches may be adjacent to a road, or buildings, or stands of Canal grass (a tall, invasive non-native species), or have natural gaps (forest openings) that create edges of forest with more-open habitat.

tanager, woodcreeper, and male and female antbirds (clockwise)

Once a bird is radiotagged, we track the bird’s movements and record behavior and habitat types during 1-hour observation periods. Using GIS software to compile land cover and land use data, we compare relocations of each individual bird with the habitat and surrounding landscape. The resulting data will be analyzed to determine if each species has particular habitat preferences, if their behavior or movement rates are different in different habitats or edge types, and how large a gap or forest opening the birds will cross.

Working with Isis Ochoa to tag a bird

During field work in 2007, we radiotagged and tracked 39 individuals in three sites. Preliminary analyses indicate that dusky antbirds and red-throated ant tanagers are largely confined to forest habitat, that is, they do not use the more-open habitat surrounding forests. Cocoa woodcreepers spend most of their time in forest habitat but will also forage on individual trees growing in park-like surroundings and back yards. Both woodcreepers and ant tanagers were observed crossing gaps of up to 30 m to move from one forest patch to another. All three species were observed foraging in and moving through edges of forests, and are able to use edgy, patchy habitat as long as there is sufficient forest.

Work planned for 2008 will include surveys of forest patches that are different sizes and that are different distances from other forests. I will use the results from the radiotracking study and studies by other STRI researchers to make predictions of the minimum size of a forest patch necessary for several songbird species. I will then test these predictions with the new survey data. Together with the complete results from the radiotracking study, this research will provide conservation planners with critical information about the species expected to persist in highly fragmented, human-dominated landscapes, and what types of land uses are compatible with providing habitat to birds.

I am being supported for 15 months in 2007-2008 at the Smithsonian Tropical Research Institute (STRI) in Panama by a fellowship from the International Research Fellowship Program (IRFP). My host scientist at STRI, Dr. Bill Laurance, has studied the effects of habitat fragmentation on tropical forest ecosystems for many years. I will publish results of my research in peer-reviewed journals and present my findings at international conferences. I will also make presentations to Panamanian staff at the national parks in which I worked, as well as local conservation groups such as the Panama Audubon Society. I have benefited professionally from the connections made at STRI and has already submitted a research proposal to work on the effects of landscape change on bird communities in North America. I have also taken advantage of teaching and training opportunities in Panama by teaching a class on the principles of radiotelemetry for Panamanian college students. In addition to research experience, the IRFP is providing me with invaluable experience in managing my own research budget and hiring and supervising assistants in a cross-cultural setting.