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Hummingbird Migration
Hummingbird migration takes place in the spring and fall in North America. Many birds leave the food-scarce north for more abundant sources to the south. Hummers are not any different. Their diet of flower nectar and insects depends on warmth to be available. Birds that can't survive on the food that is available in the north, leave for better pickings. Most North American species winter south of the U.S. - Mexico border. But researchers have found individuals of a dozen species wintering in the southwest. Wintering birds are also becoming more common in the southwestern part of the U.S. Some species in the west and Florida stay all year around. The Anna's and Allen's species in the west do not migrate, but may stay in a general area, moving around to follow the food. Food alone doesn't hold hummingbirds to a place long after common sense says to leave. Food and weather have little direct influence on the timing of migration. Most birds leave long before food sources are exhausted. When the urge to migrate south comes in summer, the birds begin a feeding frenzy, gorging on nectar and insects.They store any excess energy as fat. A bird may double it's body weight before beginning the trip south. They may stop and eat, gaining more energy, along the way. Southwest gardens that have bountiful food (nectar and insects) may host wintering hummers year after year. The birds have excellent memories and will return to good food sources. Any bird that lingers after all other migrates have gone are usually sick, underweight, injured or have some other problem. Leaving feeders up may give underweight or injured birds a chance to recover before flying south. In the tropics there is abundant insects and nectar year-around. Tropical species rarely migrate or just move around locally to better food sources Most migrating hummers travel over land. These are non-stop flights across the Gulf of Mexico in both spring and autumn. In spring, the PacificFlyway is used by Rufous and Allen's species. Ruby-throats travel up the Yucatan Peninsula and across the gulf of Mexico to their breeding grounds in the north. In fall, the exact same route as the spring is not necessarily taken. The route may vary due to weather or safety. But, most still fly south and end up of the in Mexico. The birds travel almost entirely in the daytime (diurnal). It seems to be triggered by changes in the length of daylight (photoperiod). The Ruby-throated is an exception and traveling mostly at night. While migrating, the birds are aggressive and unfriendly. I guess that is why they travel alone and not in groups. To navigate, they seem to follow land forms and use various Young birds must inherit their travel instructions because they know where to go and what routes to take. The young birds travel without flocks or parents. They seem to have an innate desire to fly south and to a certain distance. The website www.hummingbird.net provides a map for first sightings of hummingbirds in spring. This will be useful in gauging when hummingbirds arrive in your area and when to put out feeders. Return to Birds from Hummingbird Migration
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