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Distribution And Abundance Of The Amazon River Dolphin (Inia Geoffrensis) And The Tucuxi (Sotalia Fluviatilis) In The Upper Amazon River, Omar Vidal, Jay Barlow, Luis A. Hurtado, Instituto Tecnológico Y De Estudios Superiores De Monterrey (Itesm), Patricia Cendón, Zully Ojeda
Distribution And Abundance Of The Amazon River Dolphin (Inia Geoffrensis) And The Tucuxi (Sotalia Fluviatilis) In The Upper Amazon River, Omar Vidal, Jay Barlow, Luis A. Hurtado, Instituto Tecnológico Y De Estudios Superiores De Monterrey (Itesm), Patricia Cendón, Zully Ojeda
United States Department of Commerce: Staff Publications
A boat survey was conducted from 5 to 26 June 1993 to estimate the abundance of the Amazon river dolphin (Inia geoffrensis) and the tucuxi (Sotalia fluviatilis) along ca. 120 km of the Amazon River bordering Colombia, Peru, and Brazil. Two survey methods were used: line transects during 5 d and strip transects during 15 d. The line transects were used to estimate the abundance of both species in the main channels of the Amazon at distances greater than 200 m from river banks and islands, and strip transects were used to estimate abundance in the …
First Estimates Of Vaquita Abundance, Jay Barlow, Tim Gerrodette, Greg Silber
First Estimates Of Vaquita Abundance, Jay Barlow, Tim Gerrodette, Greg Silber
United States Department of Commerce: Staff Publications
The abundance of the only population of vaquitas, Gulf of California harbor porpoise (Phocoena sinus), is estimated from four surveys conducted in Mexico between 1986 and 1993, using a variety of methods. A line-transect approach was applied, using some parameters estimated from a related species, the harbor porpoise (Phocoena phocoena). Vaquita abundance is estimated as 503 (CV = 0.63) from 1986-1988 boat surveys, 885 (CV = 0.50) from 1988-- 1989 aerial surveys, 572 (CV = 1.43) from a 1991 aerial survey, and 224 (CV = 0.39) from a 1993 ship survey. A weighted log-linear regression in …