Recommended methods for monitoring change in bird populations by counting and capture of migrants

Abstract

Counts and banding captures of spring or fall migrants can generate useful information on the status and trends of the source populations. To do so, the counts and captures must be taken and recorded in a standardized and consistent manner. We present recommendations for field methods for counting and capturing migrants at intensively operated sites, such as bird observatories and banding stations with daily or near daily coverage. Each site should generate a daily "migration count" for each species. One or more methods are acceptable, including a visible migration count, a census or area search, banding captures, and a daily estimated total. All methods should be standardized as far as possible and a written protocol for each site should define the count area, times and locations of count and capture procedures, and other site-specific features designed to maintain consistency from day-to-day and year-to-year. The protocol should also include standards for numbers and skills of personnel and for habitat management. Several factors should be considered when selecting new migration monitoring sites, including specific questions to be addressed, presence of target andlor high priority species, turnover rate of migrants, habitat stability, property ownership and tenure, and accessibility. Sites should be operated for at least 10 years with coverage of 75% or more of the migration period of target species.

Citation

Hussell, David J. T.; Ralph, C. John. 2005. Recommended methods for monitoring change in bird populations by counting and capture of migrants. North American Bird Bander 30(1): 6-20