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Critterguy / Care / Amphibians
Care: Frogs, Toads, and Salamanders

northern American bull frog (female)
northern American bull frog (female)
Basics of Captive Care

Frogs, toads, and salamanders belong to a class of animals called Amphibians. They are vertebrates (back-boned animals) with smooth (moist) or warty skins. They lay unshelled eggs, usually in water, and most species have a gilled, swimming larval stage (such as a tadpole). Amphibians are "cold-blooded" (they aren't always cold, but their body temperature is dependent on the temperature of their environment).

Generally Speaking

Native Michigan amphibians need a moist (humid) environment, moderate temperatures (around 65° to 75°F), shelter from enemies and extreme temperatures, and nutritious food (most adult amphibians eat insects or worms or other small creatures).


Conservation

Catching one or two specimens of the more common amphibian species will not harm wild populations, but the large scale collection of frogs or salamanders by pet or bait dealers or the taking of frogs for "frog legs" can result in over-harvest and a serious reduction in amphibian numbers. Some species are already rare, due to habitat destruction or other factors, and are protected by state laws.

Always check with the Department of Natural Resources Fisheries Division website (visit their website...) for current regulations before capturing amphibians for any reason.

Remember: frogs, toads, and salamanders are an important part of a healthy environment. Most species depend on ponds, lakes, and other wetlands for survival. Support the preservation of these habitats in your community and elsewhere.


Recommended Species:
These species are fairly hardy and relatively common.
  • larger toads and frogs (green, leopard, and bullfrogs)
  • large salamanders (tiger, spotted)

Species Not Recommended:
These species are more difficult to keep, potentially dangerous, or grow too large.
  • smaller frogs (peepers, chorus frogs, etc.) are hard to feed
  • small salamanders are delicate and choose to stay out of sight

More Detailed Information for Adult Amphibians

spotted salamander
spotted salamander
Housing

A glass or plastic aquarium will work well. It can be turned into a "woodland terrarium" suitable for salamanders, toads, and treefrogs. Use a moistened sterile mix of potting soil and sand, include a few small plants (leave in pots to facilitate cleaning), and pieces of bark for animals to hide under. A shallow water dish will allow specimens to soak or drink. Large frogs need a larger water area so they can swim freely, but they also need a retreat out of the water. Always cover the tank; a ventilated plastic cover will hold in humidity and prevent escapes.

Change a portion of the water daily and the soil substrate several times per year, to prevent build-up of animal waste products.

Note: Most amphibians absorb water through their skins. This makes them very sensitive to pollutants in their environment. Amphibian tanks must be kept clean, but avoid use of cleaning or disinfectant products; residues may be harmful to the animals.

Aquatic species such as newts, mudpuppies, and "axolotls" (a type of tiger salamander that retains its gills as an adult) can be housed in regular aquariums, set up as you would for freshwater fish. Water must be kept clean; a good aquarium filtration/ aeration system is recommended. Keep water level an inch or two below the rim and cover the tank, to prevent escapes. Smooth "pea" gravel can be used on the tank bottom. Aquatic plants will provide hiding places and make the tank look more natural; keep them in pots to facilitate cleaning. Chlorinated tap water should be "aged" in a bucket for a day or two before use.


Lighting

leopard frog
leopard frog
Amphibians generally do not need artificial light as a heat source, and most salamanders and some of the smaller frogs habitually avoid bright light. Never place an amphibian tank in direct sunlight, as it can overheat quickly. If artificial lighting is desired, a low-heat, wide-spectrum fluorescent light can be used (such as the Vita-Lite® by Duro-Test Corp.).


Temperature

Native amphibians usually do well at normal room temperatures (from 65° to 75°F). Larger frogs may prefer slightly higher temperatures (75-80°F) when active and feeding. However, higher temperatures ("mid-80's" and above) can stress many species. On hot summer days, move the tank to a basement or other cool place.


Handling

Handle amphibians as little as possible, and only with clean hands. Most frogs and salamanders have rather thin, moist skins, and frequent or prolonged handling can be harmful. The heat of human hands is stressfull to them, and injury to their skins may lead to infection. Aquatic species should be moved with a soft net.

Native amphibians are largely harmless to humans, but some species do have toxic skin secretions meant to repel predators. Toads do not cause warts, but small mammals that bite them may be sickened or even killed by the secretions of the large paratoid glands behind the toad's eyes. Pickerel frogs produce a skin toxin that may poison other frogs kept with them, and some salamanders produce an irritating, sticky substance when attacked or roughly handled. Simply picking up these creatures won't hurt you, but avoid getting skin secretions in your eyes, nose, or mouth, and always wash your hands after handling any animal.


Feeding

blue-spotted salamander
blue-spotted salamander
Adult amphibians are carnivorous, feeding mostly on insects, worms, and other small animals. Some large frogs will eat other frogs, and almost anything else they can swallow. Frogs, toads, and many salamanders usually will not respond to food that isn't moving. Thus, their food must be alive, or at least move as though it were alive.

Most toads, large frogs, and the larger salamanders will eat earthworms. If worms are not available, you may be able to substitute small strips of liver or beef heart, wiggling it in front of them. When using these foods, you can sprinkle a powdered vitamin/mineral supplement (available in pet shops) on the food to provide a proper nutrient balance. Natural foods are always desirable, however.

Frogs and toads should be offered a variety of live insects, but avoid feeding house flies, hard-shelled beetles, ants, and stinging insects. You can get insects in the warmer months by sweeping an insect net through tall weeds or grasses. Crickets and mealworms (flour beetle larvae) can be raised or purchased from pet shops at other times. Keep in mind that the nutritional value of artificially raised insects is directly related to what they are fed. Mealworms raised on variety of grains and vegetables will be more nutritious than those raised on wheat bran- as is the practice in many pet shops. Crickets can be "dusted" with powdered vitamin supplements manufactured for pet amphibians and reptiles.

Aquatic amphibians can be offered small earthworms, "tubifex"worms, and small pieces of very lean liver or beef. Some commercial foods available in pet shops, such as pelleted fish food and brine shrimp, are also suitable. Don't let water become foul with uneaten food.

Some salamanders and large frogs or toads may do well on two to four feedings per week, but more active specimens, like treefrogs, may need daily feedings during the summer. Feed your specimens enough to keep them "filled out" but not obese. Modify feeding schedules to fit the animal and its energy needs.


Hibernation

American toad (male)
American toad (male)
Native frogs, toads, and salamanders spend the winter hibernating under water or buried in the soil, depending on species. In general, salamanders, toads, wood frogs, and frogs in the treefrog family (chorus frogs, peepers, and Gray treefrogs), hibernate on land, while most "true" frogs (leopard, green, bullfrogs) overwinter in ponds or lakes. If you do not need specimens year-round, it is best to release them in Fall, so they can hibernate normally. If you do keep them indoors in winter, plan ahead to provide adequate food supplies.


Health Problems

Rare in properly maintained amphibians. Most diseases of frogs and salamanders are the result of crowding, contaminated water, or improper housing or diet. Prevention is always easier than treatment. Some veterinarians at zoos or major universities specialize in diseases of amphibians and reptiles and may be able to assist you with specific problems.


More Detailed Info. for Tadpoles and Salamander Larvae

Most amphibians begin life in the water, "breathing" with gills. Tadpoles (the young of frogs and toads) tend to be herbivorous, eating algae and other plants, but also scavenging dead animals—including other tadpoles. The tadpoles of most Michigan species can be raised successfully using similar methods. Collect egg masses or small tadpoles in spring. Keep in clean pond water (or dechlorinated tap water) in an aquarium or other container, and change a portion of the water frequently. Do not crowd tadpoles. It is best to keep just a few, releasing the others where you found them. Tadpoles can be fed algae or soft water plants. They will also eat softened flake fishfood and the boiled (softened) leaves of dandelion or dark green lettuce. As the legs develop and they begin to look more "frog-like," provide a sloping rock or other object for them to climb out on. As their lungs develop, the froglets will drown if they are unable to leave the water. They will stop feeding during transformation. New, tiny froglets and toadlets eat extremely tiny insects ("fruit-fly" size) and are thus very hard to feed—it is best to release them in proper habitat soon after full transformation.

tiger salamander
tiger salamander
The gilled aquatic larvae of salamanders are carnivorous and thus are more challenging to feed. Small ones can be fed live baby brine shrimp, tubifex worms, or daphnia ("water fleas", often abundant in shallow ponds). Larger specimens will eat small worms—or each other! When gills begin to disappear, provide an escape from the water.

Most native amphibians will transform from egg to larva (tadpole) to a land-living subadult in a few weeks or months, but the larger frogs (bull and green frogs) may require two or three years. Teachers attempting to demonstrate amphibian metamorphosis in the classroom should keep this in mind!


For More Information

Check out our Critter Field Guide or obtain a good written field guide.


Recommended Books

Amphibians and Reptiles of the Great Lakes Region by J.H. Harding. 1997. University of Michigan Press, Ann Arbor.

A Field Guide to Reptiles and Amphibians of Eastern and Central North America by R. Conant and J.T. Collins. 3rd Ed. (1998, 1991) Houghton-Mifflin, Boston.


green frog
green frog
Acknowledgement

James Harding
MSU Museum
Michigan State University
East Lansing, MI 48824
(517) 353-7978
hardingj@msu.edu

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