Marvelous Migrants (West)
Birds are on the move! Migratory birds are traveling from their wintering grounds in Mexico, Central and South America to the U.S. and Canada, where they feast on abundant insects and plant foods during spring and summer. How do they know when to leave and where to go?
Birds that migrate short distances – such as waterfowl that migrate within the U.S. – learn migration routes and from older individuals who are more experienced, usually family members. Most long-distance migrants are genetically programmed to head in a specific direction for a specific distance. A bird’s first long-distance migration is completely genetically determined, but more experienced birds may incorporate information learned on past journeys – for example, they may use learned information to return an especially good breeding location in future years.
Tip: The spring migrants you will see depend on where you live, the time of year and weather conditions.
- Black-headed Grosbeak will begin to appear in southern and central California, but probably won’t reach the Pacific Northwest for another couple of weeks.
- Southern Arizona and parts of California will see Vaux’s Swifts, but stormy and cool weather in the Pacific Northwest will delay their arrival there for a few more weeks.
- Southwest and California residents can also look for Lawrence’s Goldfinch.
The migrant bird forecasts for each region were developed using data from the Cornell Lab of Ornithology’s eBird program, along with weather information from NOAA. Weekly forecasts are available at ebird.org. If you would like to contribute your own bird observations, learn more at ebird.org/content/ebird/about.
Black-headed Grosbeak
U.S. Fish and Wildlife Service (click for high-res photo)
(Source: Deinlein, M. “Neotropical Migratory Bird Basics.” Smithsonian National Zoological Park, Migratory Bird Center. http://nationalzoo.si.edu/ConservationAndScience/MigratoryBirds/Fact_Sheets/default.cfm?fxsht=9; eBird. BirdCast Migration Forecast: 30 March-6 April 2012, http://ebird.org/content/ebird/news/bcf20120330)
