What is a Neotropical Migratory bird?Much like the human "snowbirds" who flock to Arizona every winter, many of their feathered counterparts travel south as well. Birds that breed in the United States and Canada, but winter south of the United States/Mexico border are known as neotropical migratory birds.
Approximately 238 of the more than 500 species of birds found in Arizona are neotropical migrants. While not all neotropical migrants breed in Arizona, they comprise well over half of the nearly 300 species of breeding birds in the state. They include familiar birds such as hummingbirds, swallows, warblers, and orioles.
Why do some birds migrate?
Birds need to eat more to maintain body heat when temperatures drop during the fall and winter. However, they have less time to forage because winter days are shorter. Most neotropical migrants eat a variety of insects and spiders, which are not as abundant here in the winter. By migrating, birds can feast on them all summer on their breeding grounds and all winter in the tropics.
Where do Neotropical Migrants go?
Most migrants that breed in the West spend the winter in northern and western Mexico, while eastern breeders tend to winter mainly in Mexico, the Caribbean, and Central and South America.
What are Migration Corridors or Stop-Overs?
Arizona's rivers and isolated mountain ranges or "sky islands" provide relief to neotropical migrants passing through the state's arid landscape. The lush vegetation of a riparian corridor or sky island stop-over provides food and cover for the weary travelers. The San Pedro and Verde Rivers are some of the better examples of migration corridors in Arizona.
Why are fewer birds migrating?
Migrating birds face a tough journey between their winter and summer homes. Unfortunately, studies have shown that fewer birds are surviving to make this extraordinary trip each year. Not only do they face natural perils such as storms, predation, and drought, they now contend with ever increasing human caused threats. These threats include contamination from pesticides, herbicides, and industrial pollution. Birds are also losing their homes and migration stop-overs through timber harvesting, urbanization, grazing, and farming.
Land management practices that "fragment" habitat into smaller, more isolated patches, make it easier for predators and cowbirds to find nests of other species. Cowbirds parasitize these nests by laying their eggs in them. This leaves the "foster parents" to raise cowbird young at the expense of their own.
What does all this mean to you?
More than you might think. Migratory birds are integral parts of our culture, heritage, and economy. Their arrival and departure heralds the changing seasons, and their beauty adds to our quality of life. They play vital roles in our environment by controlling insect populations, spreading seeds, and pollinating flowers. Their sensitivity to declines in environmental quality makes them useful as an early warning system for human welfare. The great diversity of neotropical migratory birds found in Arizona attracts thousands of birdwatchers each year, pumping millions of dollars into the state's economy.
What are Arizona Partners In Flight members doing to help?
Inventory, Monitoring, and Research:
