 Merlin D. Tuttle,BCI |
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Signs of Spring Update: April 11, 2003
Today's Report Includes:
- Flower-powered Bats
- Meet Katy Hinman, Lepto Expert
- A Closer Look at Leptos
- Counting Calories in Cactus Flowers: Challenge Question #17
- Katy?s Video Clips and the Scientific Process
- Taking Off With Leptos: Links to More Lessons
- Please Report YOUR Bats! Links to Activities
- Current Happenings
- Growing Needs: Discussion of Challenge Question #16
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What will the bat do
on this cactus flower? Slurp nectar! Photo by Merlin D. Tuttle, Bat Conservation International |
They?re not birds, but they fly with wings. They?re not blind, but they "see" with their ears. They?re not vicious, but some are vampires. What are they? Bats. If bats have a bad rep, today?s report will fix that! Lesser long-nosed bats log as many as 3,200 miles on their round-trip journey each year. Each spring pregnant bats of this endangered species fly up to 100 miles a night, following the wave of cactus blooms from south-central Mexico to Arizona, New Mexico, and Baja California Mexico. They head back south after bearing their young, fueled along the way by flowering agave plants. Lesser Long-nosed Bats time their migration to match up with the flowering and fruiting of various food plants. In other words, they follow "flower highways" that serve as nectar trails to fuel their flights. In the process of moving from one plant to another, these flying critters are not only feeding; they are also pollinating.
If you?ve ever wondered what good are bats, you?ll find out today. Get ready for a trip to the desert, where you?ll go batty about bats!
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Katy Hinman, Lepto Expert |
Dear Journey North Students,
My name is Katy Hinman and I am the Bat Project Coordinator for the Arizona Game and Fish Department. That means that all I do all day is think about bats! Here in Arizona we have 28 different species of bats, but I know that you folks are interested in one in particular-- the lesser long-nosed bat. The lesser long-nosed bat is our only endangered species of bat, so we?ve been working hard to get to know more about it. Nectar-feeding bats, like the lesser long-nosed bat (or Lepto, as we like to call it), are important players out here in the desert. They pollinate the flowers of saguaro cacti, organ pipe cacti, and century plants. They also eat the fruit and spread the seeds of the saguaro and organ pipe. Since lots of other desert animals depend on these plants, the Leptos can be very important to the health of the whole desert system!
Of course, we also have lots of other species of bats here. Most of the rest of them eat bugs. One of them even eats scorpions and centipedes right off the ground! So even the bats that don?t pollinate are important to the ecosystem. And they sure help out at keeping insect levels down.
But I have to admit, even though I love all bats, I have a special place in my heart for the Leptos. I even did all my PhD research on them and our other species of nectar-feeding bat, the Mexican long-tongued bat.
How did Katy get interested in bats? What is she trying to find out in her field work? What techniques does Katy use to help her learn about these fast-flying, nighttime creatures? What do bats eat? What is the most important thing Katy has learned? Find out here:
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Did you know that, when fully extended, a lepto?s tongue is longer than its head? Why is a saguaro flower a perfect fit for a lepto?s head? How do leptos find the flowers with only starlight to guide them? See a lepto?s face covered with pollen. Why does Katy wear gloves when working with bats? Find those answers and more in our Lepto Photo Gallery:
Counting Calories in Cactus Flowers
How much energy does it take to operate a bat? How many flowers must a bat visit to stay alive? Get ready to count the calories in a cactus flower. Here?s how:
Then send us your answer to---
Challenge Question #17:
"How many saguaro flowers does a bat have to visit to sustain it for one day?
(To respond to this question, please follow the instructions below.)
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Bats often eat from white
flowers. How do these flowers help them? Photo by Merlin D. Tuttle, Bat Conservation International |
Observation is the first step in the scientific process. Video clips provide an opportunity for students to make scientific observations, and what could be more fascinating than bats? Scientists themselves sometimes use video to enhance their own direct observations. Video allows scientists to replay an event, see it in fast or slow motion, make time-lapse observations, freeze action, document changes, focus more closely, and more. That?s exactly what you?re invited to do with Katy Hinman?s video clips. See her comments as you view clips like you?ve never seen before, and check out our suggestions for viewing video clips as a scientist. It?s all here:
- Bat Videos: Going Batty! (Katy Hinman?s video clips)
Taking Off With Leptos: Links to More Lessons
For years, the mysterious lives of bats have presented challenges to scientists and others trying to learn about them. The details of their lives are hidden under the cover of darkness. Facts about them are not easy to discover. If you?d like to delve deeper, here?s a feast of our lessons and a menu to choose from:
Please Report Your Bats!
Which did you see first this spring: a bat or a mosquito? How can you find a bat to report? What should you record or investigate? What does Journey North want to know about the bats in your area? See:
Even if you can't go out and look for bats yet, you can plan for their arrival by building and setting out bat houses. Then enjoy the benefits of these good neighbors. See plans here:
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This killdeer survived
migration and is enjoying summer. Insects! Yum Yum! |
Snow and ice hit many areas this past week, leading to some sad migration events. On April 8, some birders in Burlington, Ontario, saw a pitiful sight. A Louisiana Waterthrush on a beach “did not look well and may not make it through the night. It attempted feeding, had its feathers fluffed to the maximum and slept for periods. As we watched it, a Killdeer fell over and died. Although we know thousands of birds are dying this week it still is disconcerting to see it actually happen.”
Under the best of circumstances, birds die during migration. Some crash into picture windows. At nighttime, some crash into radio and TV towers and tall lighted buildings. Hawks fuel their migration by eating smaller birds that migrate at the same time.
But spring migration also often coincides with some of the worst weather of the year—blizzards and ice storms. And birds sometimes get caught in the bad weather. Some are more vulnerable than others. Robins can eat fruit as well as worms, so a sudden snowstorm doesn’t affect them nearly as badly as it does killdeer, with a diet that’s 98% invertebrates. In years when bad weather kills many early migrants, later migrants raise a lot more babies. In years when weather doesn’t hurt migrants, the early birds raise a lot more babies. And in the long run, populations include some “early” and some “later” migrants, so no matter what the weather brings, species can continue to flourish.
Growing Needs: Discussion of Challenge Question #16
Last time we asked, "What are two different reasons why the number of feeding trips increases sharply when the babies are about a week old?"
When baby wrens are tiny, they simply can't fit as much food in their tummies as they can when they've grown bigger. That explains why they get more food the second week than they did the first week. But why the sudden sharp increase? At that point the babies have feathered out enough, and have enough control over their body temperatures, that their mother no longer needs to incubate them to keep them warm during the day. So now she can spend a lot more time searching for food for the babies. And based on those hungry wren mouths we saw in one of the wren videos, we bet the babies are glad!
How to Respond to Today's Challenge Questions:
IMPORTANT: Answer only ONE question in each e-mail message.
1. Address an e-mail message to: jn-challenge-spring@learner.org
2. In the Subject Line of your message write: Challenge Question
#17
3. In the body of EACH message, give your answer to ONE of the questions above.
The Next Signs of Spring Update Will Be Posted on April 18, 2003
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