| The Question: We’ve recently moved to a small farm in Marshallville Ohio. In the grass around the house and barn are hundreds of tiny toads the size of my fingernail, size is only about 1/4 inch with legs tucked under body. They are brownish/greenish with some dark spots. What kind of toads/frogs are they? I’ve never seen such small toads before. Submitted by: Deb, Ohio, USA |
The Short Answer: There are two toad species commonly found in Ohio, the American toad (Bufo americanus also known as Anaxyrus americanus) and Fowler’s toad (Bufo fowleri or Anaxyrus fowleri). These are the common toads you can find across much of the eastern United States and southeastern Canada. They are very similar, and what you describe could be either one (for tips to tell the adults apart, click here). What’s surprising about the newly metamorphosed toadlets is that they are so tiny compared to the adult toads. We don’t for example, see mini-bullfrogs. The tadpoles of many species of the genus Bufo (what most people consider to be the “true toads”) metamorphose at a very small size, often all at once, and then disperse. If you live near a pond or lake or stream where the tadpoles are common, you might all of a sudden see dozens or even hundreds of these tiny toadlets for a few days, and after that, see them only occasionally.
More Information: There are at least two successful strategies for becoming a grown up frog or toad. At one extreme is the bullfrog (Rana catesbeiana). Its tadpoles typically grow for two summers and can become 7-14 cm long (3-6 inches) before metamorphosing into a legged frog. The frog continues to grow as an adult, but the growth as a tadpole is the major part of the frog’s increase in size.
American toad eggs hatch into relatively small tadpoles that grow for only a month or two to about 1.2 cm (0.5 in.) and then metamorphose as tiny toadlets, about a centimeter long ( 3/8 inch). American toads can grow to about 9 cm (3.5 in.), which is about half the length of a bullfrog, but as toadlets, they are only about one tenth the size of a bullfrog tadpole. For the American toad, the major period of growth is clearly the terrestrial stage of life, not the aquatic tadpole stage, as it is for the bullfrog. And while toad tadpoles often metamorphose in synchrony, with thousands coming out of a pond within a couple of days, bullfrogs metamorphose whenever they are individually ready.
So what are the benefits of each strategy?
With bullfrog tadpoles, larger size makes them less susceptible to predators in the water. In fact, it makes them better able to be predators themselves. Though they mostly eat algae and plant matter, they will eat any insect larvae or small crustaceans they can find. They also eat other tadpoles, including those smallish toad tadpoles. Because bullfrog tadpoles are relatively large and mobile, they can survive to live one, two, and in some cases three years, building size and storing up energy so that when they turn into frogs, they are large enough to avoid being prey to many fish and other creatures that eat smaller frogs. Because of their large tadpole size, bullfrogs are one of the few frogs in North America that will breed in permanent bodies of water that contain large fish. (Most other frogs and toads do better in vernal pools and other bodies of water that occasionally dry up … and which therefore have few, if any, fish.) Once the large bullfrog tadpoles become frogs, they give up their herbivorous/omnivorous diet and switch to a purely carnivorous diet, and again their larger size means they have a wider range of target prey.
Meanwhile, the small toad tadpoles eat just enough to build up the energy to metamorphose and get out of that dangerous pond before it dries up or a fish or predatory insect gets them. Unfortunately, this means they are very easy prey for all kinds of predators on land, especially snakes. Garter snakes, for example, will gather around ponds and pools and gorge themselves on toadlets as they emerge from the water.
Toads counteract this danger in two ways. First, they have poison glands on their backs that make most animals reluctant to eat them. If you’ve ever seen a dog frothing at the mouth after trying to pick up a toad, you’ve seen that distasteful toxin in action. Garter snakes and some other predators are immune to this toxin, however.
The second defense is the fact that so many toadlets come out of the water at the same time. This is a strategy that is very common for creatures that get heavily preyed upon at a specific stage of their life cycle. When toads metamorphose and leave the water all at once, it’s impossible for predators to eat them all, and some escape to grow into adult toads.
So which is more successful, the bullfrog tadpole “grow big and then metamorphose into big frogs” strategy, or the “grow a little and then quickly metamorphose into tiny toads” strategy used by the American toad? Given that both American toads and bullfrogs have been around a long time, and are fairly common, it’s fair to say that both strategies work.
Even More Information:
Further explanation of how metamorphosing all at once works as an adaptation to predation …
Imagine if instead of coming out of the water all at once, the toads came out spaced out over the entire summer. If a garter snake was adapted to specialize on toadlets, it could do very well with a steady diet of toadlets, which might lead to a large enough population of such snakes that it would be almost impossible for any toadlets to get past the snake gauntlet alive. But imagine if an adaptation arose that made some toadlets come out of the water at the same time. By overwhelming the predators, more of those toadlets might survive to breed than toadlets that come out at random times, and in future generations, there would be more of the synchronous toadlets and fewer of the toadlets that are not synchronized. As the adaptation became more common, the effect of overwhelming the predators would be even more pronounced. Eventually, you’d have a population of toadlets that all have that same adaptation and all emerge within a few days of each other. And while garter snakes might have a few very happy days every summer feasting on toadlets, they wouldn’t be able to specialize on them.
The same principle applies with insects like cicadas that all emerge at the same time. This explanation even seems to explain “mast years” in oak trees. Every few years, all the oaks in an area produce bumper crops of acorns at the same time, overwhelming the ability of “seed predator” animals like squirrels and deer to eat them all. By not having a bumper crop every year, the oaks limit the ability of seed predators to specialize on their acorns.
Sources:
Sams, E, & Boone, M. (2010). Interactions between recently metamorphosed green frogs and American toads under laboratory conditions. The American midland naturalist, 163(2), 269-279.
Smith, G, & Awan, A. (2009). The roles of predator identity and group size in the antipredator responses of American toad (Bufo americanus) and bullfrog (Rana catesbeiana) tadpoles. Behaviour, 146, 225-243.
ARNOLD, S, & WASSERSUG, R. (1978). Differential predation on metamorphic anurans by garter snakes (Thamnophis) – Social-behavior as a possible defense. Ecology, 59(5), 1014-1022.
Beck, C, & Congdon, J. (1999). Effects of individual variation in age and size at metamorphosis on growth and survivorship of southern toad (Bufo terrestris) metamorphs. Canadian journal of zoology, 77(6), 944-951.
Boone, M, Little, E, & Semlitsch, R. (2004). Overwintered bullfrog tadpoles negatively affect salamanders and anurans in native amphibian communities. Copeia, (3), 683-690.
Boone, M. (2005). Juvenile frogs compensate for small metamorph size with terrestrial growth: Overcoming the effects of larval density and insecticide exposure. Journal of Herpetology, 39(3), 416-423.
GOATER, C. (1994). Growth and survival of postmetamorphic toads – Interactions among larval history, density, and parasitism. Ecology, 75(8), 2264-2274.
thank you for this information…. I caught 3 of these tiny toads… i put about 5 snails and a rollie pollie in the home made habitat. Will they eat them or will the other things hurt them?
Hi Alyssa,
Are you trying to find things to feed them? The toads might be too small to eat the snails and rollie pollie now. It’s hard for me to know without seeing them. Basically frogs and toads will eat pretty much anything that will fit in their mouths. The toads might be better off finding their own food, but if you really want to try and keep them, what some people feed to small frogs and toads is fruit flies. You can grow your own by putting a piece of banana in the cage. Or local pet store probably has tiny crickets or worms. Tiny earthworms are also a great food for small frogs. You can usually find them in any soil or compost pile.
How far will the toadlets travel from water? We’ve seen lots of toadlets in our yard this spring and the closest ponds are pretty far away.
Cindy, toads will move as much as a mile from water. But American toads can breed in ditches and vernal pools that don’t have water all year round, so if you’re farther than a mile from a lake or pond, it may be that there’s an area that fills with water for long enough in the spring and early summer to successfully grow toadlets.
I’v seen these small toads in my yard or the last two years. I also have been having very bad experience getting new grass to grow. Do these (I believe they’re called fowler’s toads, or American Toads) Do these little fellows eat vegetation? eg: new grass seed? Do they do my lawn any good?
Curt
I’m very happy for the explanation of the dozens of little tiny 1/4 in toads I saw yesterday at a pond in Medford, MA! I couldn’t find a discussion of how big the toads are at transformation in any of my guidebooks, so you’ve been a great help!
Lise
This comment was responded to in a new post: http://askanaturalist.com/tiny-toad-growth/. I work at a farm in northeast PA. I have been enjoying seeing the hundreds of these mini toads as I garden. You are saying that the ones that survive will become full grown toads? They are still only about an inch long, how long does it take for them to reach full size? I’m fascinated with them and would like to learn more about them. This is the first time I’ve seen them. Could you tell me their scientific name so that I can research more?
I have to be very carefull when I cut my grass due to the number of these small toads. Luckily they can be seen as they move out of my way! Some are brownish in color. Others are grey. I have seen a ocouple that were a reddish rust color. Been here for 54 years and dont really remember seeing them before the last couple years. We have had two very snowy winters and the rain this year has been extraordinary. One day we had 6-inches of rain. If I have gloves on I will pick one up. They are so cute. Cut grass today and saw at least 6 of them all around the house. Hope they stay.
We have lived in our country home in northern CA for 17 years and I have seen a few large handsome toads. Now for the past two weeks we have zillions of the daring little toadlets, And yes we are surrounded by vernal pools. I hope many of them grow up to eat bugs and squeak @ each other.
How do Gord’s normally live?
What is a gord, and what does it have to do with toads?
I don’t know what I have they r dark green with some bumps tiny either frogs or toads like climbing the walls and swimming
Hi Cassandra,
Can you take a photo? Where are you seeing these frogs or toads?
I Live In Massachusetts And I Found One
How do toads normally live?
Hi Bob, Are you asking what they eat, how they breed, and thats sore of thing? If so, I wrote about some of that here: http://askanaturalist.com/do-toads-eat-worms/. Or, you could to the National Wildlife Federation page at: https://www.nwf.org/Wildlife/Wildlife-Library/Amphibians-Reptiles-and-Fish/Toads.aspx.
My question is — How long do toads normally live?
Bob
Ah, now I see. Toads are one of those creatures where the actual lifespand and the potential lifespan are very different. If you were to look at the average lifespan “in the wild,” it’s pretty short because the vast majority are eaten as tadpoles or as tiny toadlets. However, once a toad reaches adult size, it’s odds get much better and wild toads can live to be 10 years old or a little more. In captivity, with constant food and no predators, American toads have lived as long as 35 years!!
Thanks
What is the name of this toad
How small are the toads
What most people see in North America are American toads, Bufo americanus. The toadlets are a little less than a centimeter or about 3/8 inch.
Hi I live in South East Kentucky. When I was little around 1990 we would catch tons of little frogs under trees every summer during Bible school. All the kids would get a foam cup and we would have them half full of these little frogs. Another time around 92 during a summer rain storm I caught dozens of the smallest frogs you could imagine, they looked like flea frogs. I never see these little guys anymore.
Hello! I live in a suburb of Milwaukee, WI and I just started seeing little frogs/toads (I’m not sure which they are) in my yard last year. I finally got rid of my weed ‘lawn’ (it’s nice and grassy now) and I am thinking that is partly why they now migrate in. I have close up pictures and I’m wondering if you can tell me what they are? I’m not in a rural area so it surprised me when they started hopping into my yard! Lol
Sure, you can email photos to me at tom@askanaturalist.com. Send them in the highest resolution you have. Tom
Is it ok for a Fowler’s toad to eat a little green tree frogor is it bad I have no idea but my one of my toads ate a green tree frog that I put in there and closure and I don’t know if that’s good or bad they eat fried mealworms and they’ve been eating them and they’ve been eating crickets that I found in
my yard and they ate them so please reply and thank you for this information it’s going to really help out
HI Kyleigh, I sent you an email. Tom from Ask a Naturalist
Hello, I was cutting grass today and found what I think is a baby Fowler’s toad. Had a big one make an appearance on my front porch a few years ago and sing to me every night. There are quite a few holes in my yard and wondering if that may mean more toads nearby? What can I do to help them thrive? Thanks!!
Hi Andrea, I don’t usually see toads in holes. Do you have chipmunks? They make lots of holes and the last few years seem to have been good years for chipmunks. There are lots of them. But back to toads. I’ve usually seen them under logs or under rocks, where there is a space. They hide there during good parts of the day for protection from predators and from the heat. They sell simple toad houses, which might encourage them, or you can make your own. This site has some ideas, but the basic idea is a relatively small, dark place near water, with a door for going in and out. https://www.gardeningknowhow.com/special/children/garden-toad-house.htm.
do birds feed on these finger nail size frogs I wike up one morning and have hundreds of tiny frogs, I love to watch them hop all over the place and would like to protect them what can I do to insure many survivors.
You know, I’m not sure. I would think they would. Most toads have toxins that make most animals stay away, but those little tiny ones. It seems likely that birds might be able to eat them. Tom
A very tiny toad was hanging on the outside of my door this morning in Newport Ky after a
Hard rain over night. It is bright green. Most toads I have seen are large and brownish- this one is only about a quarter of an inch long.
Does that mean there are many more here in my yard?
Hi Linda, if it was bright green, it’s more likely to be a green tree frog. Can you take a picture? There are frogs and toads everywhere even if you don’t see them, so I would say it’s very likely that there are more in your yard. Tree frogs, both the green and the gray ones, are largely nocturnal, so people don’t see them very often. Tom
Heard something in the house that sounded like a cricket. The next evening, I found this little (abt 1″ long) toad climbing up the window of my glass slider. I gently coaxed it out the door onto the deck. Haven’t seen it since. I reckon it provided sustenance for something else.
I live in MD and my yard backs up into the woods, which is likely where it came from. How it got into the house is a mystery to me.
Hi Adrian, did you get a photo of it? Sounds like a gray tree frog. They look sort of toad-like. Toads aren’t likely to be climbing glass. But gray tree frogs will. Tom
My early morning routine consists of rescuing toads from our swimming pool. The toads are of all sizes from large and fat to tiny toads. I often have to work pretty hard to save the larger ones (and the tadpoles) as I believe they see me and my net as a giant predator. Catching them takes skill and patience. The tiny toads are easy to catch. Both kinds of toads are especially plentiful after a rain. Unfortunately, not all of the rescues are successful and about half of the toads are (or appear) dead — I presume from drowning. My question is: How long can a toad live in a pool without becoming exhausted and drowning? I have tried checking at night but I never see any, so I’m pretty sure they enter the pool very late in the evening or very early in the morning. Secondly, why are there more of them after a rain?
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