(birds chirping) (gentle serene music) - We're in the Central Oregon Cascades between 4,000 and 6,500 feet elevation.

There are lots of lakes in this area and the animals that I work with breed in the lakes.

(toad chittering) This is a male Western toad.

He's coming in for breeding.

Breeding happens as soon as the snow melts.

Toads and frogs are related organisms, and in many ways you could call a toad a type of frog.

In general, toads are more terrestrial.

They need to go to water for their breeding activity, but after that they do not require that water.

You're probably a grandson of somebody that I have seen before.

I've been coming here since 1982.

Initially, I was studying their breeding, you know, like are females attracted to certain males?

Is there a male mating advantage by size or by their call?

And my PhD thesis sort of un-wove those threads.

(gentle upbeat music) The males usually are the first ones that you see.

They go into the lakeside and hang out, trying to grab any toad they see, hoping it's a female.

(toads chittering) That's a release call.

If they clasp another male, that receiving male puts out a release call and the other male releases it.

So you have this ongoing (imitates toads chittering) as males are clasping each other and then releasing.

Guy, you're probably, I think you're three years old.

Well, maybe there'll be a first-year female here and you'll get lucky.

(gentle upbeat music continues) The females are larger, and they come to the mating area for breeding.

A male, or many males, will come over and try to clasp her.

She avoids it though.

And if that male is small, he falls off.

(gentle upbeat music continues) (gentle upbeat music swells) (toads chittering) Once the male has clasped, then the female is in charge of navigation at this point.

She is in the driver's seat.

She'll dive and the male will kick to make them go faster and they orient towards the egg-laying area.

In this species, all the pairs lay their eggs in the same place.

There could be a couple hundred pairs breeding in the same place at the same time.

The female extrudes the eggs out of her cloaca and they come out of the female as strings.

The male is on her back, holding on, and he lets his sperm go on top of the eggs.

(gentle lilting music continues) So you have these long strings of eggs that are intertwining among all the pairs that are laying their eggs over just a couple day period.

At the end of that breeding period, you can have over 1 million eggs in this communal egg mass.

It is astounding.

(gentle lilting music swells) The female has just vanished at that point.

They come in, lay their eggs, and are gone.

They just disappear.

(gentle wistful music) The eggs are black, and they'll hatch within probably another week and a half.

And then they're tiny little tadpoles.

The tadpoles are omnivorous at this point.

They'll eat plant matter and animal matter, anything dead or alive that it finds.

And as the hatchlings start to grow, the tadpoles start becoming mobile.

But they don't just go swim off into the lake, they stay together.

So they develop schools, and the entire communal egg mass can result in being a school of tadpoles.

If there were a million eggs laid, that's a million tadpoles that are now hanging out together.

(gentle wistful music continues) Oftentimes they're in a school that snakes along the lake shore for hundreds of yards.

(bright lilting music) (bright lilting music swells) The tadpoles grow and grow through the summer, and then they start developing legs.

(gentle serene music) It absorbs its gills and develops lungs.

It's really a different type of life, and it only takes them about two and a half months to complete that larval growth and metamorphose into tiny little toadlets.

I think they're cute.

They have these giant eyes and almost this smiley face as toadlets.

They need to metamorphose and get out onto the land before it snows.

So it's a race, I think, for them.

(bright upbeat music) So, usually by the first of September, the toadlets are coming out of the lake.

They come out as hoards, you know, just gazillions it seems like, almost simultaneously.

And they start a terrestrial lifestyle.

And then you have a million metamorphs or toadlets, baby toads (chuckles) along the lake shore.

It is a massive sight to see, and you are worried you're gonna step on the animals because there's so many.

(bright upbeat music swells) As the metamorphose, the rather small mouth of the tadpole becomes the large gape of that toadlet.

And once they're a toadlet, they are not omnivorous anymore, they are carnivorous, and they'll eat anything that they can get in their mouth.

It becomes a predator.

They venture into uplands.

People have found these toads miles from water.

They go to hidey-holes, which may be rodent burrows or under logs.

And then they are hibernating over the cold part of the year.

And so they really require terrestrial habitats, riparian and aquatic habitats.

(gentle wistful music) They connect the food web, they're sort of this central engine.

They transfer the energy from the little critters up to the big critters.

That energy wouldn't get up to those top predators if you didn't have that intermediate cog in the engine of a food web.

And that's where these guys are really important.

I really love working with these toads.

Another male.

(toad chittering) And becoming one with the location and the animals and the activities that are occurring there.

You were here.

I feel like they're part of my family, I've been working with them for so long, and I'd like to see these animals persist through time.

So, we need to be good stewards of the land and keep this place as pristine as it can be into the future.

(gentle music swells)