Point Transect Surveys for Songbirds: Robust Methodologies
نویسنده
چکیده
منابع مشابه
Seabirds At-Sea Surveys: The Line-Transect Method Outperforms the Point-Transect Alternative
Methods: We tested whether modeling of detection probabilities, and density estimates with their coefficients of variation obtained from the point-transect method provided more robust and precise results than the more commonly used line-transect method. We subdivided our data by species groups (alcids, and aerialist species), and into two behavior categories (flying vs. swimming). We also compu...
متن کاملAbundance of Blue and Humpback Whales in the Eastern North Pacific Estimated by Capture-recapture and Line-transect Methods
We estimated humpback and blue whale abundance from 1991 to 1997 off the west coast of the U.S. and Mexico comparing capture-recapture models based on photographically identified animals and line-transect methods from ship-based surveys. During photo-identification research we obtained 4,212 identifications of 824 humpback whales and 2,403 identifications of 908 blue whales primarily through no...
متن کاملAt-sea Density Monitoring of Marbled Murrelets in Central California: Methodological Considerations
We conducted at-sea line transect surveys for Marbled Murrelets (Brachyramphus marmoratus) to determine density off the coast of central California and to explore the utility of various survey protocols. Surveys were designed to compare line versus strip transect methods, and reveal the effects of distance from shore, viewing conditions and seasonal trends on density estimates. On consecutive d...
متن کاملCoral Reef Benthic Video Surveys Facilitate Long-Term Monitoring in the Commonwealth of the Northern Mariana Islands: Toward an Optimal Sampling Strategy
This study describes a step-by-step process used to design an effective benthic video survey component of the Commonwealth of the Northern Mariana Islands long-term monitoring program. Documenting abundance of major benthic groups at relatively large spatial scales, at the appropriate localities, can empower monitoring programs with the capacity to detect changes over time and assess whether ma...
متن کاملCost-effective abundance estimation of rare animals: Testing performance of small-boat surveys for killer whales in British Columbia
Top predators are often rare, subject to anthropogenic mortality, and possess life-history traits that make them inherently vulnerable to extinction. IUCN criteria recognise populations as Critically Endangered when abundance is <250 mature individuals, but estimating abundance of rare species can be more challenging than for common ones. Cost-effective methods are needed to provide robust abun...
متن کامل