About us: We own the Wild Birds Unlimited nature shop in East Lansing, Michigan,
a store that provides a wide variety of supplies to help you enjoy the birdwatching hobby.

This blog was created to answer frequently asked questions & to share nature stories and photographs.
To contribute, email me at bloubird@gmail.com.

Monday, April 9, 2018

How birds know when it is time to migrate

There is still some mystery as to how birds decide it is time to return in the spring. Through observation, it is believed migration is triggered by amount of daylight, hormones, weather conditions, and the availability of food.

Healthy Ruby-throated hummingbirds can tolerate nights in the teens as long as there is tree sap, bugs, blooms and feeders available. Hummingbirds.net explains that most Ruby-throated Hummingbirds winter between southern Mexico and northern Panama and begin moving north as early as January gorging on insects and spiders to add a thick layer of fat in preparation for flying to the U.S.

Once in North America, migration continues at an average rate of about 20 miles per day, generally following the earliest blooming of flowers. The northern limit of this species coincides with that of the Yellow-bellied Sapsucker; if the earliest males arrive in Michigan before sufficient flowers are blooming, they raid sapsucker wells for sugar, as well as eat insects caught in the sap.

Along with following the blooms and bugs, hummers also use tail winds to their advantage. The average speed of a migrating hummer without wind is 25 to 30 miles per hour, but if they wait for a good tail wind they can double that speed. The northward migration is complete by late May. Banding studies show that each bird tends to return every year to the same place it hatched, even visiting the same feeders. See the Ruby-throated migration map for the species' range and earliest arrival dates.

Related Articles:
What is the nectar recipe for hummingbirds? http://goo.gl/MK3AU
Fun Facts about Ruby-throated Hummingbirds http://goo.gl/jcjcr
The Best Hummingbird Feeders http://bit.ly/L4yY3i
Why the color on a hummingbirds’ throat flashes http://bit.ly/JZ31qX
When did people start to feed hummingbirds?: http://bit.ly/o8Y8HR

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