The interesting story of the Clarion Island Nightsnake

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jonathan
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The interesting story of the Clarion Island Nightsnake

Post by jonathan »

Considering the recent talk about cryptic herps that end up on offshore islands, I just read about an incredible example.


Exhibit A: Clarion Island

Clarion Island is 7 square miles of island way out in the Pacific Ocean.

Clarion Island is arid/semiarid. There aren't any peaks high enough to induce rainfall, so the whole place stays dry. There are two small brackish pools on the island...and that's it. They can dry up in summer.

Clarion Island is over 400 miles from the Mexican mainland. It's a good 200 miles away from the nearest meaningful island.

A 7 square mile island with poor habitat that's 400 miles from the mainland. Seriously, Clarion Island should not have any herps. And yet...



Exhibit B: Clarion Island's well-known herps

Clarion Island has an endemic wren species, an endemic burrowing owl subspecies, and an endemic mourning dove subspecies. They also have a genetically distinct raven population. That's all crazy enough - the few species of breeding land birds shows how difficult it is even for flying animals to end up living in this crappy place. And yet...

Clarion Island somehow has an endemic tree lizard. Urosaurus clarionensis is found on Clarion Island and nowhere else. Can you imagine how that tree lizard floated on a log in the ocean for 500 miles and somehow hit that tiny island...and then survived and bred there? Was there a group on the log? A pregnant female whose offspring inbred to prosperity? Did they fly in on the backs of woodpeckers?

Even stranger, you have an endemic whipsnake too! Masticophis anthonyi, the Clarion Island Whipsnake. Again, crazy to imagine how that whipsnake ended up on that tiny island and bred. The chances had to be astronomical.

Other than the tree lizard and the whipsnake, the island doesn't have any non-flying native vertebrates. Well, except, maybe...



Exhibit C: The Clarion Island Nightsnake

In 1936, the naturalist William Bebee spotted a snake which he called the "Clarion Island Nightsnake". It was identified as a subspecies of the mainland nightsnake. No one had ever seen such a thing on the island. No one saw it again.

By the time the herpetologist B.H. Brattstrom visited the island repeatedly in the 1950s and still hadn't seen such a snake, he decided that it probably didn't exist. Bebee had visited a lot of islands and could have mixed up his records. Brattstrom scratched the snake off the island's species list.

Brattstrom's decision appeared well-founded. For the next 60 years, more researchers would visit the island to study the birds and herps. Remember, it's not a big island, and the habitat isn't very dense. But none of them saw this mystery one-time nightsnake.



Exhibit D: The researcher who didn't know better

Daniel Mulcahy, a Smithsonian researcher, was studying Hypsiglena. He was fascinated by all the forms found on all sorts of little islands off Mexico. He noticed the Clarion Island Nightsnake waaaay out there, and didn't realize that it had been struck.

One day he was looking through Clarion Island animal photos and realized that there were no night snake photos. He contacted a researcher who had been working on the tiny island for 25 years, and was told that he'd never seen anything like a nightsnake. He contacted other people who had spent time on the island, and none of them had seen or heard of anything like a nightsnake either.

But he really believed the nightsnake would be there. Bebee's original account was limited, but convincing. And so he went to Clarion Island to find it again.

He carefully checked Bebee's 79-year-old notes to find the same habitat (lava rock limited to a small part of the island). They searched it at night. Two of his students found nightsnakes on the first night. They ended up finding 11 in 15 days.

Turned out, it wasn't just a subspecies. Entirely new species, Hypsiglena unaocularus. One more reptile that had floated a long, long way to get there. (And probably had to happen sometime after the tree lizards had already well established themselves, otherwise there ain't really much to eat.)



I just got tickled by this story when I read about it in an old Scientific American article. Tiny island. Middle of nowhere. Crap habitat. No one ever sees it. And yet....look at that thing, right there.

Image
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chrish
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Re: The interesting story of the Clarion Island Nightsnake

Post by chrish »

Interesting story. That's an amazingly isolated snake!
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Jeff
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Re: The interesting story of the Clarion Island Nightsnake

Post by Jeff »

Beebe did, in fact, keep the specimen, which went to his base of operations at the American Museum of Natural History. Using that pickled specimen, Wilmer Tanner described it as a new subspecies (Hypsiglena ochrorhynchus unaocularis) in 1946, and using the newly collected things, Mulcahy recently elevated it to species status.

It is baffling how a small, secretive animal could survive a journey to a remote island that has never been connected to a continent.

Jeff
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Re: The interesting story of the Clarion Island Nightsnake

Post by condyle »

Whoa!!!
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Re: The interesting story of the Clarion Island Nightsnake

Post by Fieldnotes »

:beer: Interesting post!!
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Bryan Hamilton
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Re: The interesting story of the Clarion Island Nightsnake

Post by Bryan Hamilton »

Really cool post. I know Dan Mulcahy and had the pleasure to meet Wilmer Tanner before he passed. Both great herpetologists.
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Kyle from Carolina
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Re: The interesting story of the Clarion Island Nightsnake

Post by Kyle from Carolina »

Thanks for the great story. We need more of this kind of stuff around here!
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jonathan
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Re: The interesting story of the Clarion Island Nightsnake

Post by jonathan »

Jeff wrote:Beebe did, in fact, keep the specimen, which went to his base of operations at the American Museum of Natural History. Using that pickled specimen, Wilmer Tanner described it as a new subspecies (Hypsiglena ochrorhynchus unaocularis) in 1946, and using the newly collected things, Mulcahy recently elevated it to species status.

It is baffling how a small, secretive animal could survive a journey to a remote island that has never been connected to a continent.

Jeff

Thanks for that info! The stuff I read in the story seemed to implicitly contradict that (like Mulcahy using Beebe's description to confirm the snake rather than the specimen itself), but maybe that was just a way of writing it more dramatically. It hadn't implicitly said he didn't collect it, I only assumed that from the story details, so I'll take that sentence out.
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Re: The interesting story of the Clarion Island Nightsnake

Post by VICtort »

jonathan wrote:Considering the recent talk about cryptic herps that end up on offshore islands, I just read about an incredible example.


Exhibit A: Clarion Island

Clarion Island is 7 square miles of island way out in the Pacific Ocean.

Clarion Island is arid/semiarid. There aren't any peaks high enough to induce rainfall, so the whole place stays dry. There are two small brackish pools on the island...and that's it. They can dry up in summer.

Clarion Island is over 400 miles from the Mexican mainland. It's a good 200 miles away from the nearest meaningful island.

A 7 square mile island with poor habitat that's 400 miles from the mainland. Seriously, Clarion Island should not have any herps. And yet...



Exhibit B: Clarion Island's well-known herps

Clarion Island has an endemic wren species, an endemic burrowing owl subspecies, and an endemic mourning dove subspecies. They also have a genetically distinct raven population. That's all crazy enough - the few species of breeding land birds shows how difficult it is even for flying animals to end up living in this crappy place. And yet...

Clarion Island somehow has an endemic tree lizard. Urosaurus clarionensis is found on Clarion Island and nowhere else. Can you imagine how that tree lizard floated on a log in the ocean for 500 miles and somehow hit that tiny island...and then survived and bred there? Was there a group on the log? A pregnant female whose offspring inbred to prosperity? Did they fly in on the backs of woodpeckers?

Even stranger, you have an endemic whipsnake too! Masticophis anthonyi, the Clarion Island Whipsnake. Again, crazy to imagine how that whipsnake ended up on that tiny island and bred. The chances had to be astronomical.

Other than the tree lizard and the whipsnake, the island doesn't have any non-flying native vertebrates. Well, except, maybe...



Exhibit C: The Clarion Island Nightsnake

In 1936, the naturalist William Bebee spotted a snake which he called the "Clarion Island Nightsnake". He identified it as a subspecies of the mainland nightsnake, but he didn't keep the specimen. No one had ever seen such a thing on the island. No one saw it again.

By the time the herpetologist B.H. Brattstrom visited the island repeatedly in the 1950s and still hadn't seen such a snake, he decided that it probably didn't exist. Bebee had visited a lot of islands and could have mixed up his records. Brattstrom scratched the snake off the island's species list.

Brattstrom's decision appeared well-founded. For the next 60 years, more researchers would visit the island to study the birds and herps. Remember, it's not a big island, and the habitat isn't very dense. But none of them saw this mystery one-time nightsnake.



Exhibit D: The researcher who didn't know better

Daniel Mulcahy, a Smithsonian researcher, was studying Hypsiglena. He was fascinated by all the forms found on all sorts of little islands off Mexico. He noticed the Clarion Island Nightsnake waaaay out there, and didn't realize that it had been struck.

One day he was looking through Clarion Island animal photos and realized that there were no night snake photos. He contacted a researcher who had been working on the tiny island for 25 years, and was told that he'd never seen anything like a nightsnake. He contacted other people who had spent time on the island, and none of them had seen or heard of anything like a nightsnake either.

But he really believed the nightsnake would be there. Bebee's original account was limited, but convincing. And so he went to Clarion Island to find it again.

He carefully checked Bebee's 79-year-old notes to find the same habitat (lava rock limited to a small part of the island). They searched it at night. Two of his students found nightsnakes on the first night. They ended up finding 11 in 15 days.

Turned out, it wasn't just a subspecies. Entirely new species, Hypsiglena unaocularus. One more reptile that had floated a long, long way to get there. (And probably had to happen sometime after the tree lizards had already well established themselves, otherwise there ain't really much to eat.)



I just got tickled by this story when I read about it in an old Scientific American article. Tiny island. Middle of nowhere. Crap habitat. No one ever sees it. And yet....look at that thing, right there.

Image

Jonathan, this is interesting to me. I too marvel at the improbability of any vertebrate establishing itself there. I have been to Clarion Island, diving around it, not actually setting foot upon it. It was emerald green when I visited, it looked like Ireland...and we had to leave early and hurriedly due to an oncoming Hurricane. These ripping Hurricanes make it difficult for trees to grow on these Revilligedo Islands.

Clarion lies in the path of Pacific hurricanes and tropical storms, and strong oceanic currents. It is subject to major tempests and rain, and I wonder if large masses of vegetation, log jams and palm thatch make it there?

It is also amazing how various creatures wander and establish themselves...we had a Eurasian dove land on our vessel which was 150 miles seaward/Westerly of the central Baja coast, apparently seeking new lands to populate.

interesting topic, how is it you happened to read about this esoteric topic?

Vic
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Re: The interesting story of the Clarion Island Nightsnake

Post by jonathan »

VICtort wrote:interesting topic, how is it you happened to read about this esoteric topic?
I was reading up on jaguars in the USA, in relation to another thread on here. One of the articles I read was "Jaguars Win Critical Habitat in U.S." Somewhere in the "related articles" or something like that, I spotted a title, "Found, A Snake Species No One Believed Existed". That title was easily enough to get me to click on it, and that's how I got to reading about it.
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Re: The interesting story of the Clarion Island Nightsnake

Post by AndyKraemer »

Well that was fun!

Thanks, Jonathan.
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Re: The interesting story of the Clarion Island Nightsnake

Post by Fieldnotes »

There is a similar island account on Santa Cruz Island. Many, many, many years ago one was found on that island, but none have been found since.
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Re: The interesting story of the Clarion Island Nightsnake

Post by AndyKraemer »

Fieldnotes wrote:There is a similar island account on Santa Cruz Island. Many, many, many years ago one was found on that island, but none have been found since.
Which Santa Cruz Island?
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Re: The interesting story of the Clarion Island Nightsnake

Post by Hans Breuer (twoton) »

Thanks very much for this very interesting post!
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Re: The interesting story of the Clarion Island Nightsnake

Post by Fieldnotes »

VertNet: 1939 record form Santa Cruz Islands (Santa Barbara Co.) off the coast of Southern California.

No Night snake has been found since.
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