Frog Egg Clutch

A Frog’s Clutch of Eggs: Numbers, Frequency, & Survival

The life cycle of a frog is rather fascinating; from egg to tadpole to adult, their whole life is full of changes. One of the most interesting parts is the sheer number of eggs they can lay. Some species lay more 10,000 eggs while others lay far less. Also, some frogs lay a “clutch” of eggs (where they’re all grouped together) and others lay a string of eggs.

On this page, I’ll be answering three questions. First, we will look at the size of the clutch (the number of eggs). After that, I’ll explain how often frogs lay eggs and finally, I’ll finish by talking about their survival rate.

Clutch Size – The Number of Eggs

One of the most asked questions involving frogs and their offspring is “How many eggs do frogs lay?”. Answering that question is a bit complicated but not bad. The short answer is “a lot”. The more complex answer is “it depends on the species and health of the frog.”

Frog Eggs - Tadpoles

Some frogs lay tens of thousands of eggs while others lay only a few. Most frogs, both male, and female abandon their eggs shortly after mating. This is precisely why they lay so many eggs – they have a low survival rate.

For now, let’s talk about quantities. Listed below are 5 different frogs and the average number of eggs they lay at a time.

  • Cane Toad: 8,000 – 25,000
  • Pacman Frog: 1,000 – 2,000
  • North American Bullfrog: 12,000 – 20,000
  • Poison-Dart Frog: 2 – 12
  • White’s Tree Frog: 200 – 1,000

As you can see from the list above, the number of eggs they lay varies between the species. Another thing to consider is that these are the numbers per clutch (how much they lay at a time). Some of these frogs lay multiple clutches of eggs per year. Some frogs lay eggs only once per year.

Frequency – How often frogs lay eggs

Now that you have an idea of how many eggs frogs lay per clutch, let’s learn about how often they lay eggs. The mating season for amphibians is linked to the seasons of the year. First, I’ll quickly explain the mating season so you’ll know about how much time is available for them in a given year.

The rainy season prompts breeding for frogs. This happens during the springtime. After several winter months of cool weather, less rainfall, and less food, the rainy season “sets the mood”, so to speak.

American Toad Eggs
Photo credit: U.S. Fish and Wildlife Service Northeast Region / Flickr

It’s really a combination of things; higher temperatures, more water (rain), and more food. Spring brings warmer temperatures but it’s really the increased rain that gets things going. The rain creates puddles, refills ponds and creek beds, and gives the frogs plenty of places to lay their eggs.

A frog’s mating season lasts as long as the rainy season does. Now, in some parts of the world, you might find amphibians mating during the summer months, after a heavy rain. This is why you hear frogs croaking after it rains – they’re looking for a mate.

So, most frogs have the opportunity to mate for a few months each year. Some have more time than others – it just depends on the climate. Then how often do the females lay a clutch of eggs?

The answer to that question is much like clutch size; it depends on the species. Some frogs lay a few eggs at a time but do this several times during the mating season. Others lay thousands at a time and only do this once or twice. Listed below are more examples.

  • Cane Toads: 1 – 2 times per year
  • Poison-dart Frogs: 3 + times per year

Most frogs lay one to two clutches of eggs per year. Should a frog lay eggs two or more times per season, it will lay fewer eggs than it did the first time.

Each species is different, too. Poison-dart frogs, for example, lay eggs for a male to fertilize them. Eventually, the mother carries those fertilized eggs into the jungle canopy and places them in small pools of water within a bromeliad plant. Once the eggs hatch and the little tadpoles are swimming around, the mother lays unfertilized eggs with each tadpole in order to feed them. This also passes along the toxins needed in order to make the tadpoles poisonous.

With that in mind, the poison-dart frog is laying eggs multiple times per year.

Survival – How many eggs survive

Last but not least is the survival rate of the eggs. Like the other sections, this all depends on the type of frog that lays the eggs. Most amphibians leave their eggs shortly after laying them. This is part of the reason they lay so many eggs.

The defenseless eggs are left to fend for themselves. Most of them will die but with such large numbers, it almost always ensures at least a few of those eggs will transition into tadpoles and eventually become full-grown, adult frogs.

Glass Frog with Eggs

I mentioned the poison-dart frog earlier because they have a unique life cycle. They lay a small number of eggs, usually between two and twelve at a time. The reason for this is because both the mother and the father protect them from the time they’re eggs until they grow into little froglets. Naturally, their survival rate is much higher than the eggs that are abandoned.

Poison dart frogs are just one example, too. Glass frogs are known to protect their offspring – a job that falls on the father. Male Darwin’s frogs actually swallow their offspring as eggs and keep them in their vocal sac until they’ve metamorphosed into little, jumping frogs.

These behaviors are interesting but they’re nothing in comparison to the Suriname toad; their means of protection is downright bizarre. Once the male Suriname toad fertilizes the eggs, he embeds them into their mother’s back. The eggs remain there until they hatch into tadpoles and grow into young froglets!

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