Loon Migration Update: February 22, 2001
Welcome to the Journey North Spring Loon Migration Season!
Where Are Loons Right Now?
Meet Loon Biologist Kevin Kenow
In late July 2000, Kevin placed PTTs on two adult loons, but the batteries expired before migration began. His co-investigators this time were Walter Piper of Chapman University in Orange, CA and Michael Meyer of Wisconsin DNR. One more loon was radiomarked in September 2000, and you'll meet that loon today. These scientists have generously chosen to share data from this single loon with Journey North so YOU can join in this groundbreaking research. It's almost as good as flying with a loon!
What are Kevin's goals for the study? "The objective in marking this bird was to assess the feasibility of capturing and radiomarking a juvenile common loon with the intent of conducting a large scale study of movements and survival of juvenile loons."
One Loon On-Line: #15746
The loon in the current study was captured on Lost Lake, Vilas County, WI on September 26, 2000. Kevin and his co-investigators fitted the bird with a PTT--and it became Loon #15746. (No photo of Loon #15746 available.) Then the scientists released it and watched their computers to see what happened. While Kevin had hoped track the bird through spring, the battery signals grew very weak. At this writing, Kevin is still receiving data from #15746, but says, "Some of the sensor data is non-sensical and indicates to me that the battey voltage may be critically low."
But here's ONE thing Kevin discovered with the help of Loon #15746: "After
reviewing the bathymetry data it appears that this bird has been in water depths
of 20 feet to 120 feet." Read on to see how you can use the migration data in
today's report to make some other discoveries for yourselves!
You're the Scientist: Challenge Question #1
Then take a good look at the map. Look at the data for dates and distances traveled when this loon moved. Think about facts shared by Kevin above, and research what food this loon might be eating on her wintering grounds. Your challenge is to measure Loon #15746's "winter home range," and to analyze her movements. (See Teacher Tip below.) Remember to create a clear topic sentence for your paragraph and try to write the best verbal description you can.
Range and Territory: Some Definitions
When a bird species is migratory, its range is customarily divided into breeding range, where the species nests, and winter range, where the species resides between fall and spring migrations. Here are some definitions that should help with your work today:
For this report, we are calling the locations occupied by Loon #15746 a "winter
home range" on the individual level.
Teacher Tips: Using Satellite Data
Depending on the age of your students, the skills you want to teach (and your own comfort level with satellite data!), you may want use the migration data in different ways. Here are some tips and background lessons to help you get ready:
Make Your Own Migration Map, Or Print and Analyze Ours
The satellite data provides an excellent exercise in use of latitude and longitude, and plotting the data develops students' mapping skills. We provide the same data points that Kevin Kenow receives from the satellite. However, if mapping is too difficult or laborious (or if it simply doesn't meet the skills your students are learning), you can skip the mapping step completely and simply print out our maps for analysis. Our Challenge Questions usually refer to the interpretation and analysis of data, so even if students do not make their own maps, they won't miss this important component.
Calculating the Wintering Range
The map in this report makes it clear that loons migrate between freshwater lakes and saltwater oceans. Ocean life is very different from the freshwater lakes where a loon hatches and begins life. Suddenly, loons are drinking saltwater and eating saltwater fish. When it rains, a loon can drink fresh rainwater dribbling along its beak. While it's raining, it may also drink from the water's surface before the lighter fresh water gets mixed in with salty ocean water. But if days pass without rain, the loon has no choice but to drink saltwater. If you drank just half a glass of saltwater, you'd very likely vomit--a good thing because it would protect your body tissues from the life-threatening dangers of too much salt. Why is salty water so dangerous to living things that aren't adapted for it? Try this demonstration for some ideas:
Freshwater to Saltwater: Challenge Question #2
You can imagine how hungry loons may be after a long flight when they first reach the ocean. A loon's body needs to be able to handle salt immediately! How? That's the question!
How to Respond to Today's Challenge Questions:
1. Address an e-mail message to: firstname.lastname@example.org
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