FINAL Hummingbird Migration Update: May 20, 1999 Today's Report Includes: Ruby-throated Hummingbird Migration Data Rufous Hummingbird Migration Data Thank You, Lanny! Hummer Chore List Spend Summer with a Hummer Discussion of Challenge Question #12 Discussion of Challenge Question #13 Have a Great Summer! Thank You, Lanny! This is Journey North's final hummingbird migration update for Spring, 1999. With today's data, your migration map should be complete. Most of the hummingbird data was gathered by Lanny Chambers, whose expertise, commitment, and generosity are shared with so many through his wonderful web site. Thank you so much, Lanny! Visit the "Hummingbirds" WWW Site for the Latest Migration Maps Ruby-throated Rufous Hummer Chore List Hummingbirds spend their summers in the north every year, but half of them don't get much of a summer vacation. Female Ruby-throats have the following assignments that all have to be done before fall: find food build nest mate lay eggs incubate eggs protect eggs and nestlings find food for and feed nestlings keep nestlings clean teach fledglings how to fly Meanwhile, males have the following assignments: eat mate defend territory No wonder the males finish their jobs first and migrate south again in July! Spend Summer with a Hummer If you live near hummingbirds of any species, watch them this summer. Using binoculars and patience, follow females from your feeder and see if you can figure out where they're nesting. DON'T DISTURB THE NESTS! But if you discover a nest, let us know! Always try to keep a safe distance from hummingbirds you're studying so they don't become stressed, seriously cutting down the chances of successfully raising their babies. And keep the sugar water in your feeder fresh. When days are hot, sugar ferments, (changes to alcohol) very fast, Three-day-old sugar water has sometimes fermented enough to cause liver damage in hummers. Discussion of Challenge Question #12 "How would you design an experiment to prove that hummingbirds really do migrate on their own power?" The way scientists do this is to capture and weigh Ruby-throated Hummingbirds on both sides of the Gulf of Mexico during migration. Weights of hummers on the Yucatan Peninsula in spring are MUCH higher than the weights of hummers arriving in Texas or Louisiana. Scientists calculating the energy requirements of their flight and how long it takes them to go 600 miles without stopping have proven that the weight they lose exactly matches the amount of energy they would need to expend to migrate without any assistance. Discussion of Challenge Question #13 "Why did Rufous Hummingbirds appear all the way up in Alaska two weeks before they arrived 10 degrees south of there in Idaho?" The places that hummers arrive in Alaska are near the coast. The ocean keeps coastal land warmer than inland places in winter and spring. Idaho is not only inland--it's also mountainous. Land at high elevations is colder than land at lower elevations. So the hummers wait to invade Idaho until they can be sure spring will really be there! Have a Great Summer! This is our final Hummingbird Migration Update for spring. We hope you enjoyed learning about these avian jewels as much as we enjoyed learning about YOUR hummingbird migrants! See you next year!! Copyright 1999 Journey North. All Rights Reserved. Please send all questions, comments, and suggestions to our feedback form