Springtime is full of new life, and it is an excellent time of year to tackle the concept of life-cycles in your curriculum. Many people tend to think of seeds and plants or caterpillars and butterflies. These are great fun, but I would suggest this year to focus your study on the amazing transformation of frogs and salamanders.
Amphibians are not only fascinating but are also important indicators of healthy ecosystems. Since they spend part of their life-cycle in water, they help indicate where healthy water is. There are so many natural and environmental science concepts inherent in the study of these creatures that you can create a unit for virtually any and every grade-level you teach.
Life Cycles: Metamorphosis
At the elementary level, you’ll want to study the life cycle or metamorphosis of frogs and salamanders. They both begin their lives looking completely different than what they look like as adults.
From Egg to Frog
If you get a chance to visit a pond or wetland in the spring, look for frog eggs! Adult frogs lay masses of hundreds of eggs underwater. When the eggs hatch, a small tadpole emerges. Basically, just a large head and tail, this tadpole will go through many different growth stages before it changes into a frog. Eventually the shape of the tadpole’s mouth and head changes, and it sprouts its hind legs, then its front legs.
The frog’s tail shrinks, its gills disappear, and its lungs enlarge. Eventually it will hop out on land as an adult frog that spends time in the water and on solid ground.
From Egg to Salamander
Adult salamanders lay a few eggs at a time on vegetation on the bottom of ponds. The young salamanders look different from frog tadpoles in that they have frilly external gills. Salamander young grow hind legs, then front legs. The changing salamander loses its tail fin, and a tail takes its place.
Similar to adult frogs, the salamander grows lungs and loses its gills. It can live in the water and out on land.
For upper elementary students, you’ll want to tackle the extremely important ecosystems classified as wetlands. These include bogs, marshes, swamps, vernal pools, etc.
Vernal pools are crucial to frog and salamander metamorphosis and survival. These are temporary bodies of water that develop in low lying land and fill with snow-melt or rainwater in the spring. They are perfect for amphibians and many types of insects to lay their eggs in. These pools provide a fish an other predator-free environment that exists just long enough for metamorphosis to take place.
Check with your local nature center in the spring to see if they are offering any vernal pool programs. It makes for a great field trip!
Big Night: Citizen Science
In many places during the spring, adult frogs and salamanders migrate from the woodland areas where they spent the winter months to a pond or wetland to mate and lay their eggs. Depending on the weather conditions, the species and the area, this migration may happen all at once with the animals traveling en masse.
Usually, the salamander and frog migration will happen on the first warm, rainy night of the season. It is known to wildlife enthusiasts as “Big Night”. People love to go out and watch or help stop traffic in areas where the amphibians must cross the road.
Teach kids about “Big Night” by reading, Big Night for Salamanders by Sarah Marwil Lamstein. You can find a free student study guide to accompany this highly acclaimed book on the author’s website.
Check with your local nature center or wildlife groups to see if there are “Big Night” events where you live. It is a great opportunity to participate in wildlife watching and even citizen science, as recording data about amphibians can teach us a lot about water quality and the health of ecosystems.
Water Quality Testing
Speaking of water quality and ecosystem health brings us to a great way to engage upper elementary and middle school-aged students. Study water quality! Salamanders and frogs are very sensitive to toxins in the water supply. Therefore they are an important indicator when something is wrong.
Head to a local pond, stream or other water way with your homeschool group or class and measure the water quality. This is fairly easy chemistry, and the kids will learn all about collecting real scientific data. Explore this link for all sorts of ways you can monitor water health with kids, many of which only require supplies you probably already have at home.
If you are looking to buy a water testing kit, I’ve had great success with my students using the water testing kits from Lamotte, which hold enough supplies to test several times with a small to medium sized group.
My name is Sarah Benton Feitlinger and I am a science educator with over 10 years experience sharing science in nature and environmental centers, museums and schools. I have been studying science and nature in one way or another pretty much my whole life! Currently I’m a work-at-home mom, a freelance K-12 science curriculum developer, children’s science writer and blogger. I have a passion for making science understandable, and my goal is to make it accessible for everyone. My blog focuses on connecting current events in science to resources and activities for teachers, parents and students.