by Bill Bousman
The first Palo Alto Summer Bird Count (SBC) was held on 31 May 1981. Since that initial count, most of the SBCs have been held during the first week in June. The discussion in Part 1, here, addresses the population trends over the first 40 years of some selected species. Part 2 will examine changes in the aggregate numbers of all species.
by Chris Johnson
At some point in a birder’s journey, you may ask yourself the following question: Who is monitoring bird population trends and what might I learn from the collected data? The answer to the first part of the question is relatively easy. The Breeding Bird Survey (BBS) is the primary source of information on population change for most Northern American bird species and is the primary data source for conservation status assessments. The survey data has been collected annually since 1966 by experienced observers on preestablished, roadside survey routes between April and July.
