A Preliminary Study of Riparian Songbirds in Costa Rica, with Emphasis on Wintering Louisiana Waterthrushes

Abstract

We made preliminary observations on the winter distribution, ecology and behavior of Louisiana Waterthrushes (Seiurus motacilla) in Costa Rica during January 1999 and 2000. We visited 24 headwater streams in three of the four principal mountain ranges in the country (Cordilleras Tilarán, Central, and the Talamanca) and confirmed the presence of waterthrushes on ten of these. In all three regions waterthrushes occurred on medium to high gradient streams, averaging 3.5 meters across (range, 1-8m) and at estimated densities of 2-10 birds per kilometer of reach length. Individuals of one to three species of resident obligate riparian songbirds, e.g., Torrent Tyrannulet (Serpophaga cinerea), American Dipper (Cinclus mexicanus), and Buff-rumped Warbler (Basileuterus fulvicauda), were observed along with waterthrushes at three sites (all four species were observed at a single site). Resident riparian passerines were observed at three sites where we did not detect any Louisiana Waterthrushes. We observed agonistic interactions (e.g., agitated chipping, aerial chases, and countersinging) among waterthrushes on three streams, indicating that the species is territorial in winter. We observed no behavioral interactions, however, among riparian songbird species, including at a site where multiple individuals of four species were present. Similar to relationships established for the waterthrush on its breeding grounds in Pennsylvania, headwater habitat characteristics such as extensive forest canopy cover, lack of sedimentation, and abundant aquatic invertebrates, especially within the orders Ephemeroptera and Trichoptera, appear to support the greatest numbers of over-wintering waterthrushes and/ or the most diverse riparian songbird communities in Costa Rica.

Parent Publication

• Bird Conservation Implementation and Integration in the Americas: Proceedings of the Third International Partners in Flight Conference. 2002 March 20-24; Asilomar, California, Volume 1 and 2

Citation

Master, Terry L.; Mulvihill, Robert S.; Leberman, Robert C.; Sanchez, Julio; Carmen, Ernesto. 2005. A Preliminary Study of Riparian Songbirds in Costa Rica, with Emphasis on Wintering Louisiana Waterthrushes. In: Ralph, C. John; Rich, Terrell D., editors 2005. Bird Conservation Implementation and Integration in the Americas: Proceedings of the Third International Partners in Flight Conference. 2002 March 20-24; Asilomar, California, Volume 1 Gen. Tech. Rep. PSW-GTR-191. Albany, CA: U.S. Dept. of Agriculture, Forest Service, Pacific Southwest Research Station: p. 528-532