Hummingbird Migration Update: April 8, 2003


Today's Report Includes:

• Rufous Hummingbird Migration Stalled: Challenge Question #11
• Ruby-throated Hummingbirds Surging Ahead!
• Hummingbirds Go to the Principal's Office
• An Unexpected Visitor
• Hummingbird Food Chains: Challenge Question #12
• Big vs. Small: Discussion of Challenge Question #8
• Shoreline Migration: Discussion of Challenge Question #9
• Ruby-throats in Canada? Discussion of Challenge Question #10

Rufous Hummingbird photo copyright by Jerry Blinn

Hummingbirds seem to be visting feeders more than usual. Do you think this might be because cold weather slows down nectar production? Mike writes, "Many observers west of the Cascades have been reporting that numbers at feeders seem much higher than in past years, especially evident at dusk when multiple hummingbirds are using feeders together. My feeder has also been much busier than I'm used to for this time of year."

Rufous Hummingbird Migration Data Migration Map Courtesy of Mike Patterson Neawanna Wetland Ecological Observatory

Look at the map. Right now there are hummingbirds all the way up in Alaska, but none in central Oregon! Rufous Hummingbird migration is a perfect illustration of how it can be warmer in Alaska than in the Cascades Mountains, though Alaska is much farther north.

We all know that "heat rises." So why does it get colder as you go up mountains? You tell us!

Challenge Question #11:
"Why does the temperature go down as you go up a mountain?"

(To respond to this question, please follow the instructions below.)

If YOU see a Rufous Hummingbird in the West, make sure you report it to Mike Patterson. And if you see hummers, make sure you let him know if any flowers are blooming, too!

Calliope Hummingbird Photo by Marie Osterbuhr

Although the Kansas Ornithological Society has accepted 7 records of Calliopes, this tiny visitor has come to the state more times than that. Some people who saw one never told anyone in the KOS about it. And some people who saw one didn't record important information necessary to include a bird on a state or province's official list.

Try This! Do some research to find out what organization keeps the official records of bird sightings in your state or province. See if you can find a listing of "accidental" or "rare" species. What is the coolest rare bird ever seen in your neck of the woods?

Let's look at some hummingbird food chains and see how energy is transferred from the sun to a Ruby-throated Hummingbird. Here's a simple one:

This hummingbird is getting energy by eating nectar from this jewelweed plant, which got its energy from the sun. Every hummingbird food chain has at least two things, because hummingbirds cannot get energy directly from the sun.

The next hummingbird is getting its energy by drinking sap from an aspen tree.

The hummingbird can't get the sap by itself. It needed a helper--a Yellow-bellied Sapsucker--to do the work of drilling holes in the bark. So the sapsucker is contributing energy to help the hummingbird get its energy. We don't show the sapsucker on the food chain, because it's not transferring its energy directly to the hummingbird, but it plays an important role in getting energy to a hummingbird in the same way that cars play an important role in many Turkey Vulture food chains.

Now let's look at a longer chain. In this one, a hummingbird is eating an aphid that had been eating the leaves on a rose plant. Think about how the sun's energy goes from the plant into the aphid, and then from the aphid to the hummer.

When people set out hummingbird feeders, the hummingbird is getting its energy from sugar, which came from sugar beet plants or sugar cane plants that got their energy from the sun. But some people set out another kind of feeder for hummingbirds: chunks of melon in a mesh bag. The hummingbirds don't eat the melons, but they do eat tiny little fruit flies, as you can see in the next food chain.

Hummingbirds are often part of the food chains for predators. Look at this food chain:

The hummingbird was getting nectar from a jewelweed plant when a big-mouth bass jumped out of the water and gulped it down. But then a snapping turtle came by and chomped down the bass. A year later, when the snapping turtle was waddling back to the water after laying her eggs, a big black bear came and ate it.

Here's another food chain:

After this hummingbird ate, it was perched in a little shrub when a preying mantis came seized it and ate it! Later, a garden spider ate the mantis. Later a robin ate the spider, and then a hawk ate the robin.

Challenge Question #12:
"How many different hummingbird food chains can you come up with? Can you make a hummingbird food chain that includes an oriole? That includes a Bald Eagle? See if you can make a food chain that includes a hummingbird and at least 8 other animals and plants in it."

(To respond to this question, please follow the instructions below.)

Rufous Hummingbird scientist Mike Patterson, holds an American Robin. It would take over 25 Rufous Hummingbirds to balance this one robin.

IMPORTANT: Answer only ONE question in each e-mail message.

1. Address an e-mail message to: jn-challenge-humm@learner.org
2. In the Subject Line of your message write: Challenge Question #11 (OR #12).
3. In the body of EACH message, give your answer to ONE of the questions above.

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