Tracking the Life Cycle of Frogs 
Objective: To learn about the life cycle of frogs, the vital role frogs
play in the health of ecosystems, and the importance of water in frog development, as well as creating awareness about amphibian extinction.
Abstract: Frogs have been on earth since the age of dinosaurs, yet nearly half of all amphibian species are now in danger of becoming extinct! The leading causes of extinction are habitat loss, pollution, invasive species, climate change and disease. Frogs and other amphibians play a critical role in the global ecosystem: they are both predator and prey to other creatures; they eat pest insects, which benefits agriculture and minimizes the spread of disease; their skin offers promising medical cures for humans; and they act as indicators of environmental quality because of their sensitivity to pollution. Frogs are often the first species to be affected by environmental stressors, so when their numbers decline in a particular area, it serves as a warning to other species, including humans.
Water is essential to frog development – their entire life cycle is dependent upon it! By taking part in this project, participants will watch the metamorphosis of an egg into a frog, and while doing so will also learn about the vital role frogs play in their environment and the importance of protecting the water in frog habitats.
Number of Participants: 2 or more
Total Hours of Planning Time: 3 hours
Total Hours for Participants: minimum 6 weeks
Appropriate age of Participants: 5+ years
Materials:
- Small net
- Fish tank
- Water (from pond)
- Stones and mud (from pond)
- Something that protrudes from water, like a stick or rock
- Lettuce (to feed the tadpoles)
- Insects, preferably flies (to feed the frogs)
Action Plan:
1) Contact your local conservation authority (or similar organization) to determine the best location to collect frog eggs and tadpoles. (Contact information is provided below.)
2) Bring a fish tank—or glass jars, or strong watertight plastic bags—along with you to the pond to transport the eggs and tadpoles you collect. Try not to slosh the water around too much because water movement can damage the eggs and tadpoles during transport.
3) Use a small net to collect frog eggs from a local pond. If you see a floating clump of eggs (frog spawn), it’s safe to carefully remove a few eggs from the spawn without damaging the rest. Look for spawn hanging off plants close to shore. You may also want to collect a few tadpoles too, just in case the eggs don’t develop. You should have about 2L of water for every egg or tadpole you collect.
Note: Don’t forget to pay attention to the area where you find your eggs and tadpoles, so you can locate it again to release the fully-grown frogs.
4) Try to re-create the ecosystem where you found the eggs and tadpoles inside the fish tank. Collect water and a bit of mud from the bottom of the pond for your tank. You should also add an object (e.g. a rock or stick) that protrudes from the water that the frog can climb up on. Keep the tank in a place where it’s not in direct sunlight or is subject to extreme temperatures.
5) Feed tadpoles twice a day. (Learn how using the resources listed under “tips on raising tadpoles” below). Change the tank water every 1-2 weeks, depending on how fast it gets dirty. Tap water contains chlorine, which must first be removed. This can be done by leaving water out in the sun for 5-7 days.
6) Observe the eggs and tadpoles regularly to see signs of metamorphosis. The entire process of development from tadpole to frog varies, but will likely take 6 to 12 weeks, as it transforms from an aquatic into a terrestrial creature. Depending on the species of frog, and the weather, sometimes the development process can take up to 8 months!
7) While watching the frogs develop, use the resources below to learn about the important role frogs play in their ecosystem, the importance of water for frog development, and how we can protect frogs and the water they depend on.
8) After the frogs are fully grown, be sure to return them back to the habitat in which you found them!
9) Share your experience by uploading your project report onto the online Project Database.
Resources to get you started
All about frogs – for students
The frog’s life: A teacher’s backgrounder
Tips on raising tadpoles
http://www.live-tadpoles.com/raising-tadpoles.html
http://mdc.mo.gov/conmag/1995/07/06.html
Saving Frogs: educational activities and resources
Canadian Amphibian and Reptile Conservation Network – includes Canadian amphibians by province
Conservation authorities in Ontario
Conservation organizations outside Ontario
The Jane Goodall Institute is not responsible for the content of external websites.
Contact:
For more information about this project, contact roots_shoots@janegoodall.ca
