A Little Bit More
As a child, I lived near a wet meadow along a creek that was full of holes in the ground. I was told that these were snake holes- sounded reasonable to me then. It wasn’t until I was an adult that I learned what was really making most of those holes!
Most people are familiar with crayfish living in lakes, streams, and rivers. But some species actually spend much or all of their lives in underground burrows in wet meadows, pastures, and marshy areas. These burrowing crayfish are not well known to people simply because they’re nocturnal and are rarely seen. Keep in mind that crayfish do have gills and must have access to water to obtain oxygen – there must be water in each burrow. But, they’re able to leave the burrow at night when the air is moist and enough retained water under their exoskeleton bathes their gills during their forays.
Except during the breeding season, each burrow contains only 1 crayfish. Each burrower constructs its home at night, removing little pellets of mud that are heaped at the tunnel’s entrance forming a miniature chimney – this is your best sign. The chimneys are usually about 15cm (6”) tall but may reach 45cm (18”) at times. The mud chimneys don’t appear to have a function but are simply the result of the crayfish’s excavation activities. Next time you see holes like these, be sure to let people know they’re not made by snakes!
Activities
Science – Self test
Objectives: Review past Electronic Naturalist units
Materials: Access to the internet
Since the internet is such a common and important part of our world and certainly our education, I’ll provide some questions for your students that can be answered easily by looking online at a few of our past Electronic Naturalist units.
Print out this short series of questions and have your students find all of the answers within the past five weeks (5 units – April 7 to May 5, 2008) of the Electronic Naturalist units.
1. Tunas need to swim constantly just to stay alive. Why?
2. Some animals make very big changes in their appearance growing from baby to adult. What animal did the Electronic Naturalist focus on to illustrate this fact?
3. Vernal pools are especially safe places for some animals to live in even though they often dry up in summer. What makes them so safe for animals that live there?
4. What is the name of the kinds of shelf-like fungi that often grows out of the trunk of a tree?
5. Is it true or false that some birds never raise their own young?
Key Concepts
Adaptations and Diversity, Behavior and Regulation, Identification, Life Cycles
Questions
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