Rufous Hummingbird Migration: Temperature, Patterns and Timing

Hummingbirds

Rufous Hummingbird and Spring Migration
Temperature, Patterns, and Timing
Slideshow

Russ Robertson	Long Distance Traveler The Rufous Hummingbird makes one of the longest migratory journeys of any hummingbird in the world. During spring migration, it travels almost 4,000 miles from Mexico to Alaska. This is a marathon journey for a bird that weighs less than two U.S. pennies.

	Coastal Route The Rufous begin their migration from the wintering grounds as early as January. Traveling along the Pacific Coast, they reach the northernmost point of the breeding range in Alaska by mid-May.

	First Day of Spring By March 20th, Rufous Hummingbirds are already entering Canada. At the same time, Ruby-throated Hummingbirds are in the southern United States, along the Gulf Coast. Measuring by latitude, the Rufous is 1,000 miles farther north than the Ruby-throat on the first day of spring. How can such similar birds have such different migration patterns?

D Repasz	Adapted for Cold Rufous Hummingbirds are well adapted to cold temperatures. This allows them to migrate into areas where night time temperatures in early spring may drop below freezing. They can survive sudden cold and snows typical in springtime. Many hummingbirds use torpor occasionally to survive cold nights, but Rufous Hummingbirds routinely go into torpor at night, probably because it may freeze at night even in July in their nesting grounds in Canada and Alaska.

	Spring Temperatures Rufous travel with warm temperatures along the Pacific coast from Mexico to Alaska. Cold temperatures in eastern North America prevent Ruby-throats from moving as far north as early as Rufous.

	Moving Inland In early April, an interesting pattern emerges on the map. As temperatures warm inland, the migration expands eastward — away from the coast — toward the Rocky Mountains. Throughout migration, the Rufous Hummingbird migrates into areas where warm temperatures have produced the spring flowers and other foods it needs.

	Track and Predict How will this spring's temperatures affect the timing and patterns of hummingbird migration? Report your observations. Track the migration.