Project Description: A Neotropical migratory bird, the Louisiana Waterthrush (hereafter LOWA) breeds in a single North American biome, has a limited population of only about 260,000 individuals, is listed as a PIF Stewardship Species, and is a Priority Species or a Species of Conservation Concern for four Bird Conservation Regions. It winters throughout Central America and the Caribbean, often on highly threatened mountain streams. LOWA's are largely dependent upon aquatic macroinvertebrates, like mayflies, that are sensitive to stream sedimentation, acidification, and inputs of other pollutants. Initial studies on breeding LOWA's suggest that territory density and size, mating success, and productivity, vary between acidic streams contaminated by mine runoff and circumneutral streams. But studies are lacking to identify landscape-level factors, territory characteristics, and specific stream quality measures associated with reproductive success or over-winter survival. To the extent that LOWA population dynamics are associated with changes in habitat quality at a variety of scales, they may be used to help identify streams at-risk, and monitor stream responses to management and recovery efforts.

This study seeks to provide baseline information to guide conservation of LOWA and other members of riparian bird communities. We are relating measures of forest cover, landscape-level land use, territory characteristics, and stream quality to LOWA abundance, demographic indices (sex and age ratios), density and territory size, body condition, site fidelity, reproductive success, and survival. We are using these data to assess the value of LOWA as an indicator of habitat conditions, and combining data from throughout the year, we are evaluating the relative importance of habitat conditions throughout the annual cycle in affecting population dynamics of LOWA. These data will generate new specific recommendations for the conservation of riparian habitat to benefit resident and migratory birds, and recommendations of the value of LOWA as an indicator of ecosystem health.

As in many of our projects, the training of wildlife biologists and managers is an important aspect of our work. Students and aspiring biologists work alongside local experts to perform all of the field work associated with this project. In 2007, 2 Dominican biologists were brought to Pennsylvania to train in LOWA field studies. After 4 months of intensive work they then returned to the DR to coordinate studies on the over-wintering grounds and to train 4 additional field assistants. In 2008-2010, we expect that at least 6 additional trainees will gain intensive experience in many aspects of avian field research techniques. Participants will learn protocols for bird captures, measurements, and the characterization and quantification of habitat variables. This not only allows us to build capacity multi-nationally, but it also helps insure the collection of high quality data with little variation due to inexperienced collaborators among sites.

Recent Results: In a pilot study in 2007 we monitored 39 nests on breeding streams in Western Pennsylvania, and color-banded and monitored over-winter survival of 39 waterthrush on streams in the Dominican Republic. At all study sites, comprehensive maps are being produced that include characteristics of streams, vegetation, and surrounding land uses. Water quality and abundance of stream macroinvertebrates and flying insects is also being quantified.

Funding: This project has been supported by The Nature Conservancy, U. S. Forest Service-International Programs, and PRBO Conservation Science.

Related Scientific Publications:

Latta, S. C. 2003. Effects of scaley-leg mite infestations on body condition and site fidelity of migratory warblers. Auk 120:730-743.

Latta, S. C., and J. Faaborg. 2002. Demographic and population responses of Cape May Warblers wintering in multiple habitats. Ecology 83:2502-2515.

Latta, S. C., and J. Faaborg. 2001. Winter site fidelity of Prairie Warblers in the Dominican Republic. Condor 103:455-468.

Wunderle, J. M., Jr., and S. C. Latta. 2000. Winter site fidelity of Nearctic migrant birds in isolated shade coffee plantations of different sizes in the Dominican Republic. Auk 117: 596-614.

Latta, S. C., and M. Baltz. 1997. Population limitation in Neotropical migratory birds: Comments on Rappole and McDonald (1994). Auk 114:754-762.