April is National Frog Month and here at CEC we think frogs and toads are pretty cool little critters especially when you think that they have been around for 200 million years and there are more than 6,000 species worldwide.
Obviously they are survivors and have developed an amazing array of adaptations. They occur in almost all regions of the planet including alpine areas, the Arctic and even deserts. Antarctica is the only continent on earth where there are no frogs or toads. Here in the Okanagan where it is very dry and hot (>30 degrees Celsius for several months) we wonder how water-dependent frogs survive when water sources dry up and how they can make a living in other hostile environments. The amazing diversity in frogs has led us to investigate and share our findings of the interesting and bizarre, both at home here in British Columbia (BC) and around the planet.
QUIZ! Think you know some stuff about frogs? See if you can answer these questions before checking the answers.
Can frogs drown? ANSWER Show MoreFrogs can drown if their lungs fill with water or if there is not enough dissolved oxygen in the water.
What do you call a group of frogs or toads? ANSWER Show More
A group of frogs is called an Army and group of toads is called a Knot.
Do frogs shed their skins? ANSWER Show More
A frog completely sheds its skin about once a week. After it pulls off the old, dead skin, the frog usually eats it.
What is the smallest frog on the planet? ANSWER Show More
The smallest frog (Paedophryne amauensis) at 8 mm (less than half the width of a dime) is from Papua, New Guinea.
What is the largest frog on the planet? ANSWER Show More
The largest is the Goliath frog from South Africa which can grow to more than 1 foot in length and weigh 7 pounds.
Do all frogs croak? ANSWER Show More
In fact, frogs were the first land animals with vocal cords but only the male frog croaks. Some species whistle or chirp like a bird, some can be heard a mile away and some species make no sounds.
How many eggs do they lay and where? ANSWER Show MoreSome frogs can lay as many as 20,000 eggs in frogspawn (jelly-like egg masses). The vast majority of frogs, and all of ours, lay their eggs in water, some frogs lay their eggs in leaf litter or above ground on vegetation, but all eggs must remain moist. In the Seychelles, there is a male frog that carries its young around on its back until they become adults. While the male Darwins Frog takes its mate’s eggs into its mouth as soon as they show signs of life and they stay there until they emerge as fully grown froglets.
What is the difference between frogs and toads? ANSWER Show More
True toads (bufonids) are frogs, they are just a bit different in that they tend to have short legs and dry ‘warty’ skin, though there are plenty of frog species that fit this description as well. Toads also tend to have toxic secretions, but so do poison dart frogs.
Do they have eyelids? ANSWER Show More
Frogs’ eyes come in all shapes and sizes. Some even have square or heart shaped pupils. But they only see in black or white. They do have eyelids, and they also have a clear nictitating membrane, which allows them to protect their eyes without obstructing their vision.
How long do they live? ANSWER Show More
The normal life span of frogs in the wild ranges from around 3 to 10 years, although they have been known to live more than 20 years in captivity. Just like trees, frog bones form a ring each year when the frog is hibernating which can be counted to age the frog.
How do they survive the winter? ANSWER Show More
When temperatures drop, many species overwinter on top of or slightly buried in the mud at the bottom of ponds, while some dig burrows and hibernate below the frost line where they remain completely still and scarcely breathing. Wood frogs are the only North American frog that lives above the Arctic Circle and the only one that freezes solid during winter hibernation, or more accurately with 65% of its body frozen (glucose in its blood acts as a kind of antifreeze). In hot, dry climates, frogs enter a state of estivation similar to hibernation. The Australian water-holding frog is a desert species that burrows underground and surrounds itself in a transparent cocoon made of its own shed skin and can remain inactive for up to seven years.
Are frogs poisonous? ANSWER Show More
Some frogs are poisonous and are boldly colored to warn predators of their dangerous toxic skins and some are not poisonous but have color patterns that mimic poisonous species for protection from predators. The Amerindian tribes use secretions from poison dart frogs to poison their darts. The golden poison arrow frog is the most poisonous and can kill people. It is interesting that poison dart frogs are not poisonous in captivity, suggesting they get their toxins from insects they eat in the wild that feed on poisonous plants.
How far can they jump? ANSWER Show More
Australia’s Striped Rocket Frog can jump a distance equivalent to 55 times its body length. That would be like you jumping a football field. The Costa Rican flying tree frog has webbing between its toes that can extend out and help it glide between branches.
What do they eat? ANSWER Show More
If you said “just about anything they can fit into their mouths” you would be correct although they will try and eat things larger than themselves. Frogs usually eat meat (bugs and worms) and swallow their food whole although they will eat anything from other frogs to snakes, small mammals and birds. Frogs are true predators and most will starve before they eat a dead insect or animal.
Do frogs drink water? ANSWER Show More
Frogs absorb water through their skin so they don’t need to drink. Frogs have been shown to absorb up to half their weight in water in an hour.
How long can they hold their breath underwater? ANSWER Show More
That depends on the species and the amount of dissolved oxygen in the water. Most frogs can spend extended amounts of time underwater by absorbing oxygen through the skin and many species hibernate underwater. Frogs have no real lungs, ribs or a diaphragm but can swallow air into air sacs and absorb oxygen internally as a secondary means of respiration.
Do frogs sleep? ANSWER Show More
It seems that no one really knows. Frogs do rest and close their eyes but there is no real evidence they sleep. In fact it appears they remain in an alert state while resting.
What are the main threats to frogs? ANSWER Show More
The causes for declines are varied but
habitat loss and fragmentation are typically the lead causes. Over the past few decades the spread of
Chytrid fungus has threatened populations and caused the extinction of many species around the world.
Species introductions can be very harmful
. The introduction of cane toads, which can grow to weigh 4 pounds, has resulted in population declines and localized extirpations in native species of reptiles and mammals in Australia. The introduction of American Bullfrogs, which can weigh almost 2 pounds, into BC has resulted in the elimination of native frogs in areas where they have become abundant as they eat or outcompete them for breeding habitat.
Due to worldwide population declines, most frogs and toads have special conservation status. Check out the worldwide database to learn about the species at risk and conservation efforts for frogs in your area at AmphibiaWeb. In BC there are seven species of frogs with designated conservation status: Provincial Red and Blue lists, Federal Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and Federal Species at Risk Act (SARA). Find out and be sure at BC Frogwatch.
How can we all help? ANSWER Show More
Almost all frogs require open water for breeding, usually preferring shallow ponds that lack fish, and many frogs overwinter at the bottom of ponds. The habitat surrounding waterbodies and other riparian habitats provide important habitat for adults during the non-breeding season. Their survival and success is therefore dependent on how their habitat is functioning. While they may divide their time between land and water, healthy water bodies are critical to their survival, and throughout the province these habitats are often threatened by human activities.
There are ways you can contribute to frog and toad survival, just by knowing a bit more about them.
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Don’t TRANSFER frogs between ponds.
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Leave as much UNDISTURBED VEGETATION as possible along waterbodies.
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KNOW what YOUR regional frogs look like! Get involved, volunteer, and educate yourself. Check out online resources like AmphibiaWeb (international) and BC Frogwatch (local frogs).
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REPORT occurrences of species at risk and introduced species observations online to the BC Ministry of Environment with their online form.
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Mark FROG MONTH (April) on your calendar when there are many opportunities to be educated on your regional frogs!
In British Columbia there are 13 species of frogs, including 2 introduced species.

Northern Leopard Frog (Lithobates pipiens)
- BC Populations are Red Listed (At Risk) and listed as Endangered (COSEWIC and SARA). Eastern Canadian populations are considered Not at Risk.
- Once common but now restricted to the Creston area.
- Burrows into the mud at the bottom of ponds to overwinter.

Oregon Spotted Frog (Rana pretiosa)
- BC Populations are Red Listed (At Risk) and listed as Endangered (COSEWIC and SARA).
- Eyes are positioned upward so when you look down it is looking up at you.
- More aquatic than other frogs and therefore more susceptible to fragmentation.

Pacific Tailed Frog (Ascaphus truei) and tadpole rasping mouth parts.
- Rocky Mountain Tailed Frog (Ascaphus montanus) is BC Red Listed (At Risk) and listed as Threatened (COSEWIC), and Endangered (SARA)
- Pacific Tailed Frog (A. truei) is BC Blue Listed (considered vulnerable to human actions) and a species of Special Concern (COSEWIC and SARA).
- Tadpoles may take up to four years to become adults.
- Tadpoles scrape algae from submerged rocks with specialized rasping mouthparts.
- Adults can’t extend their tongues so must pounce on prey.
- May live up 15-20 years making them among the longest living frogs in the world.
- Do not have eardrums and do not call.

Great Basin Spadefoot (Spea intermontana)
- BC Blue Listed (species considered vulnerable to human actions), Threatened (COSEWIC and SARA).
- Adapted for desert conditions, the eggs hatch in two days to a week.
- May live up to 10 years.
- Can lose almost half (48%) of their body moisture without ill effect.
- Can enter a torpor during summer dry periods or hibernate for up to seven or eight months of the year.
- Can quickly dig itself into the soil when threatened.

Western (Boreal) Toad (Anaxyrus boreas)
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- BC Blue List (considered vulnerable to human actions) and a species of Special Concern (COSEWIC and SARA).
- Tadpoles can be seen in very large (hundreds to thousands) dense schools along shorelines.
- Toadlets are miniature (as small as 6 mm) adults.
- Hibernates below frost line up to 1.3 m underground.

Northern Red-legged Frog (Rana aurora)
- BC Blue List (considered vulnerable to human actions) and a species of Special Concern (COSEWIC and SARA).
- Males call to females from up to 1 m underwater.
- Aurora literally means “the dawn”, referring to the pinkish colour on the underside of the hind legs.
- Very fast, using long low hops to escape predators, even people.

Wood Frog (Lithobates sylvaticus)
- Only amphibian that occurs north of the Arctic Circle.
- Freeze solid in winter, thaw and hop away in spring.
- May occur up to elevations of 3,050 m.

Columbia Spotted Frog (Rana luteiventris)
- Have no vocal sacs so calls carry only 15-30 meters.
- Burrows into the mud at the bottom of ponds to overwinter.
- Tadpoles may develop into adults in a month in southern populations and may overwinter as tadpoles in northern populations.
- Females may not breed until their 6th year.
- Can live up to 10 years or more.

Pacific Chorus (Tree) Frog (Pseudacris regilla)
- Adults spend much of their time climbing around on vegetation.
- Adults can change colour in response to temperature/humidity.
- Calls often used in movies for a tropical background.
- Can throw their voices making them difficult to find by calls.

Boreal Chorus Frog (Pseudacris maculata)
- Smallest frog in BC.
- Hibernate in relatively dry sites and can endure temperatures to a few degrees below zero due to high blood sugars preventing ice crystals from forming.

American Bullfrog (Lithobates catesbeiana)
- Introduced into BC and grown for frog legs.
- Adults are very large and can weigh 1.6 lbs.
- Will eat anything it can fit into its mouth including birds and unfortunately other native frog species.
- Hibernate at the bottom of their breeding ponds.

Green Frog (Lithobates clamitans)
- Introduced into BC, likely for the pet trade.
- Burrows into the mud at the bottom of ponds to overwinter.
Some Useful Links
The BC frogwatch website lists all of the species, provides an interactive map for each region and includes sound clips of their calls. AmphibiaWeb is a great tool to discover listed amphibians (and frogs) worldwide. For a list of what can be found in other provinces check out the Canadian Biodiversity website or the NatureWatch website. CEC’s Resource page has some identification keys.
Can we help YOU with identifying a frog or toad you encountered?
Send us your frog photo, question or frog story!
Photo Credits: In addition to our photos and those publicly available, CEC extends a special thanks to our friends who contributed to this photo collection.
- Northern Leopard Frog “Northern Leopard Frog” by Original uploader was BuBZ at en.wikipedia – Transferred from en.wikipedia. Licensed under CC BY-SA 3.0 via Wikimedia Commons.
- Oregon Spotted Frog. “USFWS Oregon Spotted Frog Photo“. Licensed under Public Domain via Wikimedia Commons.
- Pacific Tailed Frog. Jim Trask.
- Great Basin Spadefoot Toad. Jim Trask.
- Western (Boreal) Toad (header and thumbnail photos). Jim Trask.
- Northern Red-Legged Frog. Jim Trask.
- Wood Frog. Jim Trask.
- Columbia Spotted Frog. Jim Trask.
- Pacific Chorus (Tree) Frog. Jim Trask.
- Boreal Chorus Frog. Jim Roberts.
- American Bullfrog. “North-American-bullfrog1” by Carl D. Howe – Carl D. Howe, Stow, MA USA. Licensed under CC BY-SA 2.5 via Wikimedia Commons.
- Green Frog. “Male Green Frog” – Hunterdon County, NJ” by Contrabaroness – Own work. Licensed under CC0 via Wikimedia Commons.