The Lizard Log

The Langkilde Lab in Action

The Elusive Bushmaster

Leave a comment

by Mark Herr

Bushmasters have every characteristic of a mythical creature. When someone describes a bushmaster, they describe a giant, secretive, dangerous snake which lurks the shadows of only the darkest forests. They aren’t mythical beasts, though; they are real – but very rare. This rarity has resulted in the completion of very few studies concerning their natural history, and as such they remain quite a mystery to science. This mystery is all the more dramatic given how impressive and well known they are – bushmasters are the longest vipers in the world and the only vipers in the new world to lay eggs. What’s more, females brood their eggs, guarding them until they hatch – a behavior that’s quite rare among venomous snakes.

What is known about them? We know that they are mammal eaters, with studies suggesting that they specialize on eating spiny rats. We know that there are three species in Central America, with another (possibly two) in South America. We know that bushmaster bites are a particularly severe medical emergency – although I’ve heard independently from a number of herpetologists that they are behaviorally quite docile. What I think is most interesting is that we know they are restricted to virgin rainforest. Virgin forest is forest which has never been cut, or at least hasn’t been cut for so long that it’s reached the final stage of floral succession.

Why are bushmasters confined to virgin forest? There are theories, but the fact is that nobody is sure. The question could have interesting implications to ecology or conservation, especially given that primary rainforest is being cut at an alarming rate globally.

In order to explore this question and simply gain insight into the natural history of bushmasters, The Orianne Society has recently initiated its Bushmaster Conservation Project. The project’s goal is to study bushmasters in their natural habitat and document important aspects of their natural history, with the objective of learning how these rare snakes might be better conserved. So it was with this project and these goals that I went to Panama with Steve Spear of The Orianne Society and 3 other biologists this July.

The project is still in its early stages, and in order to begin studying bushmasters, you need to find them. That was really our goal for the trip, we were to evaluate the study site to determine whether or not enough bushmasters could be found to begin a field study. Our target area was the primary forest in and around General Omar Torrijos Herrera National Park near the town of El Cope, Panama.

Would we find our target? Bushmasters are unbelievably rare – I want to make sure you got that. At the World Congress of Herpetology in 2012 I heard Harry Greene (one of the few to have ever studied bushmasters in the wild) say that for his study, it required approximately 400 jungle hours to catch one snake. We had five biologists, one local guide, and would be in the field for 7 days. If we worked 10 hour field days that would be 420 jungle hours. We could do it.

Or maybe not. We never found a bushmaster. I wish I could give you some explanation, but in the end they are simply that elusive. The trip was a phenomenal experience for me. Not only did gain insight into tropical ecology and the biogeography of Panama (where I had never been before this), I also learned to have some serious respect for the energy that it takes to study rare species in the wild. It’s an unreal task. If anyone is up to that task, though, I’m absolutely confident that it’ll be the folks at Orianne.

I’ll leave you with a set of photos from the trip. We ended up with ten species of snakes in 7 field days, plus a bunch of other herp species.

Our view of the Panama Canal as we drove from Panama City to El Cope.

Our view of the Panama Canal as we drove from Panama City to El Cope.

We caught this Bird Snake (Pseustes poecilonotus) in the middle of a clearcut on the hike back from our first day in the field. Hours in perfect virgin rainforest without a snake, and then we catch one within minutes of entering a disturbed area.

We caught this Bird Snake (Pseustes poecilonotus) in the middle of a clearcut on the hike back from our first day in the field. Hours in perfect virgin rainforest without a snake, and then we catch one within minutes of entering a disturbed area.

In addition to our own surveys, there was a team of Salamander researchers working in El Cope to document the natural history of Bolitoglossa and Oedipina salamanders. We went out with them on their surveys a few times, and managed to find both genera during the nighttime transect. Here is the Oedipina the next day.

In addition to our own surveys, there was a team of Salamander researchers working in El Cope to document the natural history of Bolitoglossa and Oedipina salamanders. We went out with them on their surveys a few times, and managed to find both genera during the nighttime transect. Here is the Oedipina the next day.

This amazingly iridescent Stenorrhina degenhardtii specializes in eating scorpions and spiders.

This amazingly iridescent Stenorrhina degenhardtii specializes in eating scorpions and spiders.

We found this Rhadinaea decorata immediately after the Stenorrhina, it’s actually a congener of the Pine Woods Snake found in the southeastern United States.

We found this Rhadinaea decorata immediately after the Stenorrhina, it’s actually a congener of the Pine Woods Snake found in the southeastern United States.

Dendrobates auratus, the Black and Green Poison Dart Frog. According to the Dart Frog expert on our trip, the D. auratus around El Cope are the more toxic than at any other locality.

Dendrobates auratus, the Black and Green Poison Dart Frog. According to the Dart Frog expert on our trip, the D. auratus around El Cope are the more toxic than at any other locality.

On the second to last day in the field we found our first and only venomous snake: a small eyelash viper, Bothriechis schlegelii. The local name in Panama and Costa Rica for this species is Bocaraca. I’ve been asking for years and I still can’t get anyone to explain to me what that means.

On the second to last day in the field we found our first and only venomous snake: a small eyelash viper, Bothriechis schlegelii. The local name in Panama and Costa Rica for this species is Bocaraca. I’ve been asking for years and I still can’t get anyone to explain to me what that means.

A panorama of the cloud forest. Steve is loving that Eyelash Viper.

A panorama of the cloud forest. Steve is loving that Eyelash Viper. (Click to view in all its panoramic glory.)

One of the ways that we searched for bushmasters was to use a video camera scope to search deep inside burrows where we suspect they spend much of their time. Here is Steve scoping out a rodent burrow.

One of the ways that we searched for bushmasters was to use a video camera scope to search deep inside burrows where we suspect they spend much of their time. Here is Steve scoping out a rodent burrow.

I’ve spent time in the Central American rainforest before, but I’ve never been to Panama. One of the most interesting things about the Panamanian jungle is that you can encounter lots of South American taxa at their northern distribution limit. This Spiny Dwarf Iguana is one such species. The genus Enyalioides, is primarily South American, and only this species (E. heterolepis) makes it into Central America (only into Panama).

I’ve spent time in the Central American rainforest before, but I’ve never been to Panama. One of the most interesting things about the Panamanian jungle is that you can encounter lots of South American taxa at their northern distribution limit. This Spiny Dwarf Iguana is one such species. The genus Enyalioides, is primarily South American, and only this species (E. heterolepis) makes it into Central America (only into Panama).

The one turtle of the trip was this Rhinoclemmys annulata. This species is known to be more terrestrial than other members of its genus, and we found this one deep in the forest far from any obvious water source.

The one turtle of the trip was this Rhinoclemmys annulata. This species is known to be more terrestrial than other members of its genus, and we found this one deep in the forest far from any obvious water source.

The last snake of the trip was this juvenile Chironius grandisquamis

The last snake of the trip was this juvenile Chironius grandisquamis.

Identifying Neotropical colubrids can be a challenge. We ended up having to use the key in Gunther Kohler’s The Reptiles of Central America to ID the Chironius.

Identifying Neotropical colubrids can be a challenge. We ended up having to use the key in Gunther Kohler’s The Reptiles of Central America to ID the Chironius.

 

 

 

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s