New Directions for BFL

By Stefan Hames and Diane Nacci
July 2002

Birds in Forested Landscapes (BFL) enters its sixth field season this spring, and it is worth noting that some things about the project have remained the same, while others have changed quite a bit. For example, the basic protocol followed by BFL citizen-scientists has remained the same, except for the addition of the "mobbing" tape playback in the behavior watch (see "Mob Mentality," Birdscope, Spring 2001) and the expansion of the original 9 study species to 48 species of conservation concern. The basic question that we are seeking to answer, the effects of habitat fragmentation on birds breeding in North American forests, also remains substantially the same but is being expanded to address other potential threats to wild birds as well. The Cornell Lab of Ornithology is maintaining and developing new scientific partnerships to address these larger issues.

One of the new questions that we are addressing using data from BFL is the effect that habitat fragmentation has on forest birds when it is combined with other human-caused stressors such as disturbance, or pollution. For example, our scientists, in conjunction with partners in the USDA Forest Service, are working to understand the effects that recreation may have on breeding birds in our National Forests (see "The Thrush Still Sings," Birdscope, Spring 2002). There are many other potential stressors to wildlife that are caused by humans, such as the acid rain that has been implicated in the steep population declines of several bird species in parts of Europe that regularly receive highly acidic rainfall. That's why we are conducting research, using BFL data, to test the extent to which the combined effects of forest fragmentation and acid rain may explain the declines of thrush populations in parts of the East that also receive highly acidified rain. Our research has strong parallels with research being conducted by the Environmental Protection Agency's (EPA) National Health and Environmental Effects Research Laboratory (NHEERL) on the effects of multiple stressors to birds and other wildlife. It is these complementary research interests, approaches, and areas of expertise that have led Lab of Ornithology and NHREEL scientists to work together towards forging stronger links between the two organizations.

NHEERL serves as the EPA's focal point for scientific research on characterizing the occurrence and effects of contaminants and other stressors on natural systems. For example, NHEERL has developed the Environmental Monitoring and Assessment Program (EMAP), which develops methods, and assists in the collection and analysis of data describing the condition of our national environmental resources. EMAP maintains this information in large, publically-accessible data bases, to promote the use of these data that may help explain how human activities are affecting the environment. NHEERL has also supported the development of the ECOTOX database, which contains information about the effects of more than 7,000 chemicals on terrestrial and aquatic organisms. Scientists in NHEERL's Wildlife Research program are developing risk assessment methods that incorporate information on stressors and their effects to diagnose causes and predict responses to changing environmental conditions. This approach is being applied to their study of the effects of the biomagnification of mercury and human disturbance on the Common Loon breeding on acidified lakes.

Like acid rain, much of the mercury contamination of aquatic environments in eastern North America can be traced to the emissions from coal-fired powerplants in the Midwest. Additionally, mercury contamination's negative effects may be compounded in fish-eating bird species like the Common Loon, whose breeding habitat is being severely restricted by human development for resorts and vacation homes. This is very similar to what we think is happening to the Wood Thrush, whose forest habitat is possibly being degraded both by fragmentation and by changes to the vegetation and availability of prey species caused by acid rain.

The BFL dataset records the presence or absence of breeding birds belonging to our study species, of predators and nest parasites, as well as a detailed description of the study site and its vegetation, and the degree to which the forest in the surrounding 2,500 acres (1,000 ha) is fragmented. Pooling across years, these data describe more than 3,000 BFL study sites in the United States and Canada. These data are crucial for understanding the effects of fragmentation on our study species, and especially in understanding differences in response across region, or in the response at center of a species range as opposed to that at the periphery. However, these sorts of detailed data, gathered across a very large geographic area, are also ideal for combining with other environmental datasets. That is exactly what Lab scientists are doing - combining BFL data with data on soil properties and estimates of the amount of acid rain received by each study site, in order to determine what effect acid rain combined with fragmentation may have on thrush species. This kind of research is made much easier by the availability of Geographic Information System software that allows us to combine data from many sources based on their locations, and by the availability of environmental data that can be accessed on the internet. That's why it seems very appropriate that making BFL data available to researchers on the Web has always been one of the goals of the project. NHEERL's extensive experience in the complicated process of providing Web access to large environmental datasets-including data quality assurance, the production of "metadata," or descriptions of how the data are collected and stored, and implementing access-is just one of the reasons that Lab scientists are excited by the prospects of cooperation with the scientists at NHEERL.

Pooling knowledge and resources between the BFL scientists working to assess the risks to forest thrushes of acid rain and forest fragmentation, and NHEERL scientists working to assess the risk to the Common Loon of mercury contamination and development, has the potential to strengthen both projects. This cooperation would combine the Lab of Ornithology's expertise in conducting research across wide geographic regions using citizen-scientists, and our long experience in conducting bird-related conservation research, with NHEERL's expertise in studying the ecological effects of human-caused contamination of the natural world, and its growing expertise in performing risk assessments for wildlife. Such collaboration would really be for the birds. And in this case, that's a good thing.