Revisiting the most widely heard amphibian voice

In 1951, George S. Myers, an ichthyologist and curator at the Standford University Natural History Museum, published a paper in Copeia titled “The most widely heard amphibian voice.” He described how the calls of pacific chorus frogs appeared in movies set around the world, often far outside of their native range. These frogs range from Baja California north to British Columbia, but their conspicuous calls and distribution around Hollywood led to their voices being recorded and used in many movies.

Their call is distinctive, described by Myers as “rurrkk-uk, rurrkk-uk, rurrkk-uk” and in Robert Stebbins’ field guide as “Kreck-ek”. You can hear recordings or watch videos of them on my frog call page.

My colleagues and I have made jokes about the misplaced calls of Pacific Chorus Frogs for many years, but I haven’t paid much attention to specific movies with the frogs until this month. After hearing pacific chorus frogs calling in both Marco Polo and Gone Girl, I decided to start taking notes on the movies where I heard the frogs. A much longer list of movies using pacific chorus frogs outside of their native range can be found at the Internet Movie Database. Listed below are just my observations since January 2015. I’ll update the map as I notice more movies featuring these frogs.

The red section of the map below illustrates the natural geographic range of the pacific chorus frog (although they are sometimes accidentally moved outside of their range). The numbers indicate the settings of movies featuring the calls of pacific chorus frogs.

(1) The Netflix series Marco Polo featured calling pacific chorus frogs in a garden in a Song Dynasty city about nine minutes into episode seven.

(2) The movie Gone Girl was largely set in Missouri, and featured the calls of pacific chorus frogs in many of the nighttime scenes.

Map of Pacific Chorus Frogs heard in movies

Original map obtained from the NASA website

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Snake-shaped pancake video!

Amazing pancake art in the shape of snakes! More videos at Saipancakes.

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Annual christmas migration of chorus frogs to Alaska

At the end of November I received a very interesting email from Tasha, who lives in Anchorage, Alaska. Tasha and her family had just brought home a Christmas tree. To their surprise, a small frog came hopping out of the tree! They noticed that it was unlike the other frogs they had seen in Alaska. They contacted me after searching the internet, and I confirmed that their frog was a Pacific Chorus Frog. Here is Tasha’s frog:

Chorus Frog found on Christmas tree in Alaska

What makes this a particularly interesting observation is that Pacific Chorus Frogs are not native to Alaska. Their natural geographic range is from British Columbia down to Baja California (although it is likely that there are several similar-looking species lumped together as Pacific Chorus Frogs). So the frog that Tasha and her family found in their Christmas tree was probably accidentally transported from a tree farm in Washington or Oregon.

It turns out that frogs riding in Christmas trees is not an unusual situation. In 2009 I was contacted by the Alaska Department of Fish and Game to identify a frog found in Christmas trees. That was also a Pacific Chorus Frog, and the little frog ended getting quite a bit of attention as a national new story. Pacific Chorus Frogs have also been documented traveling in Christmas trees to Arizona (Rorabaugh et al. 2004 Southwestern Naturalist), and even Guam (Christy et al. 2007 Diversity and Distributions).

I am aware of only one documented introduced population of Pacific Chorus Frogs in Alaska, and that is in southern Alaska. However, as the climate continues to warm, it is possible that the continued Christmas hitchhiking of Pacific Chorus Frogs could lead to their establishing a population in Alaska. I would be interested in hearing about more cases of Pacific Chorus Frogs transported in Christmas trees. If you have found a frog in your Christmas tree, please let me know! I can be contacted by email: mfbenard --

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Making herpetological coloring pages for kids

I recently posted a bunch of printable pdf coloring pages for kids on the main mister-toad website. They were easy and fun to make. Here is how I did it:

I start with a photo of some charismatic animal, usually an amphibian, reptile or insect. For example, this picture of a calling make gray treefrog is one of my favorites.

Male Gray Treefrog

I opened it up in photoshop elements, and made an outline in a separate layer. Then I deleted the background, so just the outline was left.

Photoshop processing

I resized the outline, and saved it as a pdf.

Gray Treefrog Coloring Page

Then just print, and it is ready to color! Here is the coloring page transformed into a “fire-fighting tree frog”!

Gray Treefrog Coloring Page

Here is one showing a cottonmouth snake:

Cottonmouth Coloring Page

And here is another showing a larval tiger salamander:
Tiger Salamander Coloring Page

Have a favorite … or a request? Let me know!

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One thousand photos of snakes capturing prey in nature

The internet has been a tremendous boon for gathering and sharing observations about nature. Outlets for natural historians range from interactive websites run by academics like the Cornell Laboratory of Ornithology’s ebird, to informal discussion forums like the FieldHerpForum.

One of my favorite sources for natural history observations is the photo website flickr. Flickr is free to join, and is used by people from around the world. Flickr users’ backgrounds in photography are diverse: some are serious professionals, others are outstanding amateurs, and many just want to share snapshots. Consequently, many different kinds of photos are posted on flickr. When I started using it, I was struck by the enormous number of photos that illustrate the same concept in vastly different ways. You can easily see this by running a search for your favorite ecological term, from “amplexus” to “zooplankton“. You’ll get a huge pile of photos, many of them beautiful illustrations of nature. But running searches has some drawbacks: many off-topic images can clutter the search, and you may miss good images if they aren’t tagged with the search terms you used. One way around this problem is the use of groups, in which images and videos can be arranged by theme.

In 2009 I started a flickr group for one of my favorite types of natural history observations: snakes seen capturing and consuming prey in nature. The group has grown to include over 1,000 images encompassing tremendous diversity. My post today will highlight just a tiny bit of the diversity found in the Snakes Eating in Nature group. Later posts will pick out a few of the neat insights into snake ecology and behavior that come from the photos.

There are a few genera and species that are disproportionately represented in the group. From Asia, the keelback snakes (genus Rhabdophis), from Europe the water snakes (genus Natrix), from North America the rattlesnakes (genus Crotalus), the rat snakes (genus Pantherophis), and the water snakes (genus Nerodia) are all well-represented. One of the neat things about having many observations within a single genus or even a single species is that it gives a sense of the diversity of prey items. A great example of this diversity is the many photos of different prey items captured by the garter and ribbon snakes (genus Thamnophis). These snakes are found throughout much of North America, and vary in habits from fairly aquatic to mostly terrestrial. One of their most commonly documented prey items are frogs and toads. In many cases, the snakes are preying on breeding adult male frogs, such as this ribbon snake observed eating a Green Treefrog one warm July night in Florida:

Frogs aren’t the only amphibian that garter snakes enjoy; there are also quite a few photos of salamanders being eaten by garter snakes, like this shot by antonyrw showing a garter snake eating a newt:
One of the particularly neat aspects of this observation is that these newts are highly toxic to most predators (including humans), yet some species of garter snakes have evolved the ability to safely consume them.

Fish are also a frequent prey item seen in the group, as illustrated by this photo by Bill Gorum:
garter eating fish

Members of this genus will also feed on invertebrates, as illustrated by a photo of a gartersnake eating a slug taken by Christine Majul:

While we often think of garter and ribbon snakes as feeding on amphibians and invertebrates, they will also eat mammals, as shown in this shot by Matt Jalbert showing a garter snake eating a mouse:

Not even other squamates are safe from garter snakes, as demonstrated in this photo by Rob Klotz of a garter snake swallowing a horned lizard.

Within a single group like the garter and ribbon snakes, there can be great diversity in prey items. Moving beyond this genus finds even more diverse types of prey. For example Jordan Vos contributed this photo of a Stimson’s python capturing a bat:

Similarly, Paul Garrett shared a photo of a North American cornsnake coiling around a bird prior to eating it:


In nature predators are often themselves preyed upon by other creatures. That was the case for a garter snake I observed by a pond in Napa County, California, one spring day. Upon arriving at the pond I spotted a mix of black, white, yellow and red coils on the pond’s edge. Closer inspection revealed these two animals struggling. When I arrived the kingsnake had just grabbed the head of the garter snake. Ninety minutes later I watched the last bit of the garter snake’s tail disappear down the kingsnake’s throat.

Most of the snakes shown above are in the family Colubridae. The Colubridae is the most species-rich snake group, encompassing nearly 2,000 species. Most colubrids are non-venomous, although there are a few dangerously venomous species . While many of the photos in the Snakes Eating in Nature group show colubrids gulping down their prey, there are also photos of snakes from other groups, including venomous snakes and very large snakes. One of the most well-known groups of venomous snakes are the vipers. One example of a viper eating is this photo of a Massasauga rattlesnake eating a vole by Nick Scobel

Vipers eat a diverse range of prey, not just mammals. A great example is Kenneth Gisi‘s photo of a Southern Copperhead eating a cicada:
Kenneth also had an excellent video of a copperhead eating a cicada that was the focus of an earlier blog post.

Another major group of venomous snakes are the elapids. This group is well-known for their largely neurotoxic venom, and includes species like cobras. In North America, the only native elapids are the coral snakes, and they also show up in the Snakes Eating in Nature group. Here is a case of coral snake eating another snake, shown in this photo by HGHJim:

The Snakes Eating in Nature group has photos of hungry elapids from around the world. Here is krait eating another squamate in this photo by cowyeow:

And here is a photo by Ryan Francis showing an elapid called a bandy-bandy.

The snakes in the two photos above show some similarities. They are both eating other squamates and they both have similar patterns of white bands on black backgrounds. However, these two species are only distantly related and they are geographically separated. The krait was photographed in Hong Kong while the bandy bandy was photographed in Australia.

The group also contains several photos of particularly large snakes in the families Boidae and Pythonidae. For example, here is a photo by Marcos Cesar Campis showing Brazilian anaconda eating a large lizard:
anaconda eating

This is just a small sample of the many photos in the group. In the next post I’ll point out a few of my favorite photos that illustrate neat aspects of snake natural history. In the meantime, feel free to browse Snakes Eating in Nature and enjoy its diversity. If you have your own photos of snakes catching prey in nature, please feel free to add them!

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