Maintain a healthy environment for raising frogs...
Raising frogs is really very simple! You just need to ensure a few basic conditions are met throughout the project.
Here are some key points to consider......
Clean Water! This is the most important thing to monitor.
Water temperature is usually not critical as long as it is reasonable. (40 - 80 F) Eggs in cold water take longer to hatch. This is because the speed of the development of young frogs is directly related to the amount of degrees of heat they accumulate (sometimes called Accumulated temperature units).
Pacific Northwest amphibians need Good Aeration of their environment. Even though some tadpoles and polliwogs do fine in murky, low oxygen water, the tadpoles in the western Pacific Northwest do not. They need constant aeration. There are two ways to accomplish this and also help keep the water clean:
- Use an Under gravel filter with dual to quad aeration pickups. These have the advantage of being out of sight, out of mind, and not having to be cleaned weekly.
- Use a magnetic Whisper outside the tank filter with a long pickup tube that draws water from just about the gravel level. These have the advantage of flexibility, but the disadvantage of requiring almost weekly cleaning!
Aquarium filtration systems:
Under gravel vs Outside Filters
We've tested both types of filters in our tanks. Under gravel types work best for frogs in the egg and tadpole stage. Whisper type Outside filters work best for the emergent frog and adult stages! That's because the Outside, especially Whisper tank filters will keep pumping water as you lower the water level. When the adult frogs emerge, we've found it best to float a small, thin plank practically covered with moss on the water surface so the emergent frogs can climb out on it and keep the tank 1/2 to 3/4 full with water for the remaining tadpoles to swim and eat in. Then shake small crickets onto the plank for the frogs to consume. Gribbet!! Also a Whisper type filter keeps the humidity up in a covered tank. Frogs seem to like this!
The Red Legged Frog needs clear, cold water!
Materials needed for raising frogs in the classroom:
- Standard 20 to 60 gallon hooded Aquarium set up with filter system. It should be completely set up a week before egg masses are due to be placed in the tank for each classroom. A thermostatic heater is not necessary.
- Water testing kits. We used pH and ammonia.
- Auxiliary equipment. Siphon hose, buckets (5 gal), nets, portable aerator, and netting to cover the intake if you have a cascade filter system. Important: Be sure to wrap the net over the intake so that the tadpoles don't get sucked up into the filter.
- Frog food. For tadpoles, spinach microwaved in water for a minute, Tetramin flakes, or alfalfa pellets work great. For emergent and growing frogs, week old crickets work fine for the first six weeks or so. Bigger crickets are needed later. We order these by the thousand from Flukers Farms (1-800-735-8537) for about $10.00/thousand. These were kept in a spare twenty gallon aquarium with a screened top. The crickets should come in a box filled with egg carton material and a thousand of the little crickets. The cartons and the crickets were placed into the aquarium. The crickets were fed cut up potatoes or corn flour and given water (in a petri dish with sand in so they don't drown!). We took the cartons out and tapped crickets onto a plank once the frogs started to emerge. It is really funny to see the newly developed frogs sitting on the plank with crickets perched on their noses! However they soon get the hang of it and the crickets start disappearing. Always be sure there is some food present. If they don't eat right away, don't panic. Tadpoles get nutrition from their tails as they absorb them. To encourage them to eat keep the land area small so they can find the crickets easily.
- A small plank or cedar shake, partially covered with moss, to float in the tank so the emergent frogs can crawl out onto it. This is the great part to watch! Kids love it!
Notes to consider:
- Amphibians tend to release hormones that inhibit growth of others in the tank. This results in pinhead sized tadpoles sharing the same space with larger emergent frogs. To prevent this, don't overcrowd, use standard aquarium practice of one inch of fish per gallon of water. Release extras, or get multiple tanks to handle the overage. We used extra tanks, released some early, and gave others away to other teachers and had plenty left for our students.
- Juvenile frog predation of one another is uncommon, although we did note two instances of this in a very crowded tank of Red Legged Frog tadpoles. However, Juvenile Salamander predation of one another is very common! So if your tadpoles are constantly eating each other, look closely at them. They may really be polliwogs!!
- In the Puget Sound Area Professor Klaus Richter, King County Resource Land Section, is a great contact and possible resource. Much of the success of our project was due to his help and perseverance! (206-205-5622)
Releasing the Frogs
- Of course, since these frogs are native you ought to send them back home where they belong, like their home pond. However, it probably isn't a good idea to release them until at least early May in the Pacific Northwest. That's when the weather stabilizes (ho ho) and there is a healthy amount of insect hatches going on. Although late April might work too in some warmer years.
- That means that you will have to feed some of the early maturing frogs crickets for awhile prior to release.
- To release them, put them all into a 5 gallon bucket and cover them with a lid. You can put tadpoles in there too. Just have enough water in the bucket so that they will be comfortable for the time you are transporting them. Take a small pitcher or bucket with.
- On site take some pond water and put it into the bucket. Wait a bit and put more in to slowly raise the temperature of the water in the bucket.
- When you are satisified that the temperatures match within a couple degrees, return your amphibian friends back to their home!