American toad breeding season seen through four videos

The American toad breeding season has come and gone in northeast Ohio. I spent part of one evening at a pond with over a hundred toads, and took a few videos. Many male toads were waiting on the edge of the pond for females to arrive. Other male toads were in the pond, making their loud, trilling call to attract females. Two other species of frog were calling that night. The spring peeper has a short, high-pitched “peep” noise. You can hear many spring peepers in the videos. The gray treefrog has a short trill sound. Only two or three gray treefrogs were calling, but you can hear their occasional calls in the background of some of the videos. Toad calls can be distinguished from both of these species because the toad calls have a faster trill that is of a higher pitch.

A male toad sat calling next to a spring peeper. I watched these two calling for a while, and they did not seem to pay any attention to each other. Eventually the male toad saw a female toad, and hopped past the peeper to reach her.

Two male toads spent several minutes calling near each other. You can tell that these two males are watching and responding to each other.

Male toads will fight with one another for the opportunity to mate with female toads. In this video, we see three male toads trying to mate with a female toad. The female is the largest toad on the very bottom of the toad pile. The successful male will end up in amplexus, a copulatory embrace in which the male clings to the female and fertilizes the eggs as she lays them. In the video, you can see how the males cling tightly to the female with their front legs, and use their hind legs to try to push away the other males.

Despite the chaos of the breeding season, pairs of males and females eventually successfully reproduce. In the video below, the pair of toads on the left is one such successful pair. At first glance, the pair of toads on the right also appears to be successfully mating. But a closer look reveals that the male toad is trying to mate with a dead female toad. Unfortunately mortality is common during the breeding season. During all of the fighting to mate, both male and female toads can end up drowned. Some toads have such a strong drive to mate that they appear to be unaware that partner is dead. Many other frogs show a similar overdeveloped drive to mate, such as this example of wood frogs trying to mate with tiger salamanders.

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Pacific Chorus Frogs in Eagle Nests


Calling Pacific Chorus Frog During the breeding season, frogs are often easy to find: just follow sound of their songs. But where do they go outside of the breeding season? While a few frogs, like the bullfrog, stay around their ponds, many other frogs move far away from where they breed. Finding out where they go is important – to protect these animals, we need to know all of the habitats that they use through their entire life cycle. If we fail to protect the habitats where the adults spend their time, it doesn’t matter how well we protect the breeding habitat where tadpoles develop. Without adult habitat, the amphibians won’t make it.

The pacific chorus frog is conspicuous during the breeding season, but hard to find the rest of the year. Like some other amphibians, they likely spend a lot of time underground, living in rodent burrows. But they turn up in other places too. I fondly recall a few pacific chorus frogs that lived in the tank of a field station toilet, and clambered out of a crack in the lid with each flush. Brattstrom and Warren (1955 Copeia) remarked on finding forty adult pacific chorus frogs living inside of an old cattle skull. But some of the most interesting hideouts for these frogs are high above the ground.

Pacific chorus frogs are in the treefrog family, and one of their distinguishing characteristics is the presence of toepads that help them to climb. The use of arboreal habitats in Pacific chorus frogs was demonstrated in a paper by Forsman & Swingle (2007 Herpetological Conservation & Biology). They examined over 1,400 tree vole nests in Oregon and California. They also searched through old field notes and records archived in natural history museums like the Slater Museum of Natural History, the Museum of Natural History of L.A. County, and the California Academy of Sciences. Between these historical records and their own observations, they found quite a few records of amphibians in vole nests. These were mostly salamanders like the arboreal salamander, but several pacific chorus frogs were also noted in tree vole nests. The nests containing frogs ranged in height from about 5 to 20 meters above the ground. So these frogs were capable of going quite high!

Near the end of their paper, Forsman and Swingle remarked that remote infra-red cameras might be a valuable tool to study amphibians in vole nests, but with the caveat that this is a labor-intensive way to collect data. Their comment was auspicious – only a few years later, cameras focused on eagle nests and observed remotely by a cohort of citizen-scientists are providing insight into the tree-dwelling habits of pacific chorus frogs.

I heard about the frogs in the eagle nests when Kathryn Fitzgerald Shramek sent me an email. The images on the left are a few of Kathryn’s screenshots that show the pacific chorus frogs in the nests. Intrigued, I followed the links to find a community based around live feeds from cameras focused on eagle nests high in the trees. The cameras were set up by the Institute for Wildlife Studies for the purpose of watching the eagles. The Humboldt Bay Eagle Nest Cam feeds are shared online with the public; anyone with an internet connection can peek in at the eagles’ nest. While watching the cameras, you can communicate with fellow nest-watchers through their Humboldt Bay Eagles Facebook, chat and an online forum.

Although the cameras were initially set up to watch eagles, people began to notice frogs in the nests. This was a significant observation, because it was the first time pacific chorus frogs were noted in eagle nests. However, data collection has progressed byeond solely documenting the presence of the frogs. Jim Campbell-Spickler is the biologist leading the citizen-science study of the frogs in the eagle nest. He developed an online form (see image to left) that nest watchers used to enter data about frog sightings. The information collected through the form included the local time, number and location of frogs observed, insects observed, and other variables. Jim and the citizen-scientists have gained a more detailed view of what the pacific chorus frogs are doing in the nest. These data will be published in a scientific journal later this year. For now, they are no longer using the online form to collect data on the frogs. But they plan to continue the work with a new data collection procedure in the future. You can learn more through the Humboldt Bay Eagle Facebook group or online forum. Ultimately, their work will provide wonderful insight into the role of eagle nests in the lives of pacific chorus frogs.

Below is a video from eagelwhisperer18 showing the frogs as they hop about the eagle nests at night.

This research also raises further questions. Do the frogs seek out eagle nests specifically, or are they just as abundant (and active!) high in the canopy of trees without nests? Do pacific chorus frogs spend time in the nests of other birds? Certainly some raptors, like red-tailed hawks, will actually eat pacific chorus frogs. Do they avoid some bird species? Do the frogs provide some benefit to the eagles?

This work wouldn’t be possible without the efforts of the citizen-scientists collecting data. Why would they spend their time watching these animals online? I asked Kathryn this question, and her answer indicated the importance of an affection for nature and a good community of fellow online naturalists: “I watch because I love all wildlife and this gives me an opportunity to view the bald eagles in their nest doing their thing to raise their offspring. I enjoy the friendships I have made chatting with others who share an interest in these wonderful birds.” You too can join this community; just direct your browser to the cameras, and start watching for the frogs and eagles!

Note: Maintaining these cameras costs money. In setting up the cameras, IWS received funding from the Humboldt Wildlife Care Center and the Sequoia Park Zoo. You too can support the eagle cams and the people who make them possible through donations to the IWS.

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Pacific Chorus Frogs singing with New Order

While listening to the New Order album “Substance”, I was startled to hear the sound of frog calls. In fact, I initially thought that one of my frog recordings had started playing simultaneously with the New Order album. Then I realized the croaks were part of the song.

My first reaction was that I was hearing the sound of a pacific chorus frog. After listening to the song a few times, I am even more convinced that these are pacific chorus frog sounds. You can listen and judge yourself with the two videos below.

The frog calls start about 5 minutes and 50 seconds into the song “The Perfect Kiss”:

Here is a Pacific Chorus Frog calling:

New Order emerged from the Manchester music scene of the 1970s and 80s (portrayed in the interesting and entertaining film 24 Hour Party People). Pacific chorus frogs don’t live in the UK, but the band could have used a stock recording. This wouldn’t be a new phenomenon, as the calls of these frogs are widely used in in movies. I’ve read several accounts about New Order incorporating frog call samples into “The Perfect Kiss”, but I can’t find any article that confirms what type of frog call they used.

What do you think? Did New Order use the call of a pacific chorus frog? Or are they using a different species? I would be interested in reading your opinion in the comments!

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Photo of unisexual Ambystoma vs. smallmouth salamander

The photo below shows two female Ambystoma salamanders from Cuyahoga County, Ohio. The salamander on the left is a unisexual hybrid, based on head and body shape. The salamander on the right appears to be a pure smallmouth salamander (Ambystoma texanum), but it is possible that it is also a hybrid. Without directly genotyping her, it is impossible to be certain that she is a pure smallmouth salamander.

This group of salamanders is incredibly interesting. Thousands of years ago, hybridization between several species (primarily Jefferson’s salamander and the blue-spotted salamander) resulted in offspring that contained the nuclear genomes of both parental species. The descendants of these initial hybrid offspring are entirely female, and reproduce clonally. However, the hybrid females need to use the sperm of male salamanders to initiate egg development. In most cases, the male genome is discarded after the sperm is used to initiate egg development.

You can find biologists researching this interesting genus at Ambystoma.net.

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Newt photobombs spring peepers in amplexus

The spring peepers (Pseudacris crucifer) have been going strong in Cuyahoga County for about two weeks now. Recently I took at trip out to watch them at a local wetland. It was a perfect night: warm and overcast with occasional sprinkles of rain. Hundreds of males were calling from bushes, cattails, and the pond’s edge. I also saw a few pairs of male and female peepers in amplexus. As one pair swam by me, I took a few photos. It wasn’t until later that I realized one of my photos contained a third individual: an eastern newt (notophthalmus viridescens). This newt popped its head up to the water’s surface just as I took this photo.

Newt photobombs mating spring peepers

The newts won’t harm the adult spring peepers. However, adult newts will stay in the ponds long after the adult peepers have laid their eggs and left. The newts are predatory, feeding on invertebrates and small amphibian larvae. So it is possible that the tadpoles of these mating peepers could be chased or even eaten by this same newt later in the summer.

Here are a couple photos of calling male peepers from the same night:

Cleveland Spring Peeper

Cleveland Spring Peeper

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