Fall's Journey South Update: October 8, 1999
Today's Report Includes:
All Aboard the Frog Ferry!
Why did the frog cross the road? If it lives in Minnesota's Baker Park Reserve, itís migrating to an overwinter home to escape the freezing cold. But a busy county road separates the frogs' summer breeding ponds from the overwintering lake within the park. Frogs hop along their migration route but once they reach the highway, thousands of cars make the migration into a road kill derby. Now the question is: HOW do the frogs cross the road? The answer is the frog ferry, a carry-the-frogs-to-safety program run by Hennepin Parks wildlife technician Madeleine Linck. Madeleine told Journey North about this life-saving bucket brigade for Baker Park's northern leopard frogs:
At first (1994) the crew used big nets to catch frogs as they moved away from the lakeside in the spring migration. Volunteers ferried the frogs in buckets across the highway. But spotting and netting frogs is harder than it sounds. These critters are slippery, hard-to-see, and elusive. Frogs can cover a yard with each leap, and they bounce in a crazy zigzag pattern to confuse their chasers even more. Minutes may go by without a frog reaching the edge of the road; then suddenly, several try to cross at once. Leaping frogs and racing cars are everywhere! Now a temporary 800-foot drift fence is put up along the road to help. Five-gallon buckets are sunk into the ground every 50 feet along the fence. Plop! Hopping frogs land in the buckets, safe from frog-flattening vehicles. Volunteers carry the buckets across the road and release the frogs at the lake, their overwinter home.
Madeleine and her volunteers started helping the frogs cross the road in 1994. Older folks who can come at the spur of the moment (like the frogs do!) make the best volunteers as they can safely handle the traffic and the dark, rainy fall nights when frogs like to migrate. (Frogs like rain because it keeps their amphibian skin wet.) The first year 300 frogs were carried. In the fall of 1997, about 5,925 frogs got a ride. And thanks to the Frog Ferry, 1700 frogs made it safely across on a recent Halloween when they decided to move during rush hour traffic, early darkness, and pouring rain!
No Hoppers Yet
Last year the frog migration started in mid-October and lasted into the third week of November. It's early yet, and Madeleine said the fence just went up this week. She has seen no sign of moving frogs, but it won't be long. She'll be checking the heaviest migration area daily now, looking for road kills and for frogs along the fence to announce that migration is underway!
Off to the Lake: Challenge Question #3
During the winter, northern leopard frogs hibernate at the bottom of deeper lakes, far beneath the ice. Madeleine reports that the youngest frogs are typically the first to head for the lake, even though it's a place they've never been. The older frogs usually come later, but early arrivals hang out in the vegetation along the shore. They stay out of the lake until they're ready to hibernate, as hungry fish would gladly make a meal of them. Frogs that arrive later, when weather is colder, have been seen swimming way out to deeper water, ready to begin hibernating. Once on the lake bottom in deep water, the frogs settle quietly behind logs and other debris to hide from predators.
As you hop into the topic of frog migration, see if you can answer
Watch Out for Migrating Frogs
Frogs could be migrating in your area, too. How tough is their trip? To find out, you can look for frog migration routes. Start by checking where heavily traveled roads bisect wintering and breeding habitats. If you notice dead frogs on the road, chances are good that you've found a migration route. What adults can you speak to about a possible frog ferry, crossing culvert, or "Frog Crossing" sign to help your important local frogs survive migration so they can lay eggs next spring?
Which Frogs Live Near You?
Northern leopard frogs are among the most wide-ranging frogs in North America. They are not endangered or even rare, but they need to be protected because their population is very important in the food chain. Do leopard frogs live near you?
Response to Challenge Question #2
Hurricane Floyd did most of its damage along the Atlantic coast, where there aren't many ruby-throats. For the most part, migrants along and over the Gulf, where hummingbirds migrate, didn't suffer more than a bit of inconvenience.
Of course, the rain and high winds of Floyd probably sent some hummers scurrying away from the coast sooner than normal. As K. London wrote, "Here on the northeast coast of Florida, ours usually stay until October. When I returned from our evacuation because of Floyd, they were gone, and have not been seen since!" (KLondon95@aol.com)
Another student noticed that the northward course of Floyd might have slowed down some migrants. "My friend and I think that the hurricane did affect the ruby-throated hummingbirds because when they were flying the hurricane's wind was blowing north and that could have slowed them down and tossed them off course." (firstname.lastname@example.org) This is the kind of complex situation that is never entirely clear with such a tiny species.
Get Ready to Track the Frog Migration Next Spring!
Next spring, please report the FIRST frogs you hear singing! While the frogs are hibernating this winter, practice listening to their calls.
How to Respond to Today's Challenge Question:
1. Address an e-mail message to: email@example.com
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