OUR SECOND IN MY SERIES of answers to your bird questions is about birds on the move: the miracle of hummingbird migration, and when birds fly in large formations, from vee’s to follow-the-leader. Ellen Blackstone of BirdNote, the daily public-radio show I love, will once again be our guide for exploring what’s going on as we look skyward at such highly organized activity.
Remember the BirdNote backstory from last week: In 2002, the then-executive director of Seattle Audubon heard a short public-radio show called StarDate. “We could do that with birds,” she thought. In 2005 the idea became a two-minute, seven-day-a-week public-radio “interstitial” (as short programs are called) that recently caught my ear. I asked BirdNote to help me answer all the recent bird questions you had asked me. (In case you missed it last week, for installment Number 1, we tackled this subject: How do birds make themselves at home—even in winter?)
Parts of Ellen’s answers below are in the 2-minute clips you can stream (all in the green links–or you can read the transcripts of each episode at those links if you prefer). Here we go:
how do hummingbirds do it?
Q. The miracle of hummingbird migration amazes all of us. How do they manage to migrate from the northern United States all the way to Mexico and beyond?
A. The rufous hummingbird flies 49,000,000 times its body-length as it makes its full migration loop. Other hummingbirds may fly directly across the Gulf of Mexico, a journey of nearly 600 miles. The birds often follow a “floral highway,” making their way north as the plants that can sustain them come into bloom. From BirdNote, listen to the myths of hummingbird migration.
Rufous hummingbirds begin to turn up in the Pacific Northwest as early as February, when the red-flowering currant begins to bloom. East of the Mississippi, ruby-throated hummingbirds that arrive too early for flowers to be in bloom may raid the sapwells drilled by sapsuckers. True: here’s that story. [The photo up top shows a broad-billed hummingbird on the move; image by Tom Grey.]
when birds fly en masse
Q. There is no sight quite like birds moving in large groups, and A Way to Garden readers asked me about a kettle of hawks; pigeons taking off and maneuvering together again and again as if in some orchestrated dance, and even geese in formation. What gives?
A. Riding thermals is an energy-efficient way for soaring hawks to search for prey. As a Red-tail–or any other soaring hawk–reaches a desired altitude, it slides off the thermal and, gliding lower, finds another thermal to ride upward. Listen to the details of how.
Pigeons actually follow the leader! Like this (the audioclip).
Certain types of larger birds, like geese and pelicans, may fly in a vee-formation. This helps them conserve energy and–because they can see and hear each other better–avoid mid-air collisions. Hear more on that.
next week’s topic, and how to get birdnote
NEXT WEEK’S ANSWERS from among the most popular of 150-plus questions you asked me recently will be about daring bird behavior–drumming on someone’s house, for instance, and also fearlessly mobbing bigger birds, chasing them through the sky.
Meantime, listen to BirdNote’s latest podcast anytime on the player below, or by visiting their website. Subscribe to the podcast or RSS, free. More than 100 public radio stations playing BirdNote are listed here; if you like what you hear, why not ask your local station why they don’t carry it.