Antigua: Land of the Lost (Snake)

This past week I found myself on the Caribbean island of Antigua, scratching my head at my strange fortune. On the one hand, I was in a stunning area of the world, staying at an amazing resort, hanging around with a motley crew of fascinating folks—and it was a work trip (BASK! GLOAT! BRAG!). On the other hand, I was as close as I will ever get to the world’s most critically endangered snake species, with absolutely no chance of playing my hand at finding one.

The Antiguan racer (Alsophis antiguae) was historically found on the islands of Antigua and Barbuda as well as many small offshore island (photo from webecoist.com):


But it is now extirpated from the main islands and hangs on only on a few tiny keys. While on the island, we were told that the snake-fearing Britons who colonized the island imported mongooses to control the “snake problem.” This notion immediately caused me to smell a “rat.” Even the most ophidiophobic limey would not go to so much trouble to kill a harmless beast like the racer! As it turns out, the mongooses were imported to kill rats that had invaded the island from ship cargo holds. Unfortunately, the diurnal mongooses never encountered the nocturnal rats, so Rikki Tikki Tavi fed heartily on racers and their eggs.

To make matters worse, the mongooses chomped up the island’s lizards, which were the snakes’ main prey items. Ground dwelling lizards are now few and far between. Here’s an Antiguan ameiva lizard (Ameiva griswoldi), which I was lucky to see a single specimen of:


At one time, scientists estimated that there were only about 50 Antiguan racers left in the wild. Conservation efforts have since increased those numbers by an order of magnitude at least. A success story of sorts! Ah, it would have been so nice to see… but alas! I was here for work, and not my usual snakey sort.

What sort of non-snakey work would bring me to a Caribbean island? One of the other octopus-arms of my job—pre-med advising at Cal Poly. A medical school on the island—American University of Antigua—hosted pre-med advisors from California to visit their campus. They have recently received accreditation in California, meaning that their graduates will be able to get residencies and practice medicine in the golden state.


This is a very good Caribbean program. The students and faculty are extremely diverse, and they learn using a combo of large lectures and small hands-on experiences. Here are some students learning how to do a breast examination:


Cool brain model:


The school has state of the art technology, including Bertha—yep, that's a birthing robot. Right now she is set to deliver breach.


Even more exciting was Sim-man, a robot that can be programmed with all kinds of symptoms. The students have to diagnose him and give him proper treatment, and he will react accordingly.


After introducing us to the campus, the trip organizers took us around the beautiful island for some sight-seeing. Antigua has a rich history, ripe with pirate tales and skirmishes between the English inhabitants and attacking French. This is a building at Nelson’s Dockyard, a historic area in English Harbour where Admiral Horatio Nelson lived in the 1700’s. The harbor is now a famous yachting and sailing area. Here's one of the historic buildings, complete with badly dressed tourist out front:


Then we went up to Shirley Heights for a view of the dockyard from high up. Beautiful!!!


Nearby you could also get a peek of Eric Clapton’s house (which is currently for rent!):


The island is home to hundreds of churches, from grand to tiny. Here is a particularly gorgeous one.

We enjoyed some excellent Caribbean beer and food:


Meghan, my cohort from Cal Poly, REALLY enjoyed this Baked Alaska!


We stayed at the Carlisle Bay resort at the south end of the island. Absolutely gorgeous! It was nestled right into the tropical vegetation:


And of course, right on the beach! Here’s a little Watt’s anole (Anolis wattsi) that I found in front of my room within about 30 seconds of arrival:


A better look at a Watt’s anole:


By far the most common lizard was the Leach’s anole (Anolis leachii), whose arboreal habits apparently keep it out of reach of mongoosedem (this is allegedly the Caribbean slang plural for mongoose).


The beach at night:


Goodnight Caribbean! See you next time!

Vandenberg Rattlesnakes

PERL has now begun conducting research on rattlesnakes at Vandenberg Air Force Base! This gorgeous area occupies a gigantic swath of land in northern Santa Barbara County. Most of it is pristine, inhabited not by humans but by a motley crew of flora and fauna, including lots of threatened and endangered species. And it is FULL of rattlesnakes-- most definitely neither threatened nor endangered.

Near the beach there are beautiful dunes:

And inland there are rocky hillsides (that's the city of Santa Maria in the background):

We saw about 15 rattlesnakes just in the rocks visible in this photo:

These are Southern Pacific rattlesnakes (Crotalus oreganus helleri), whereas for the past six years we have been studying Northern Pacifics (C. o. oreganus) about 50 miles to the northeast. It's probably a big intergrade zone, really.

Since it's fall, and the air is cool but the sun is warm, most of the snakes are hiding under the rocks, sticking body parts out into the sun:

In the words of Roger Repp, "Where's Waldo?" (Hint: There are two rattlesnakes in this photo.)

Rodent burrows are also favorite spots for snakes to hang out:

In two days out hunting, we saw about 10 male-female pairs! The Northern Pacifics would have been done with mating season by now (because inland it's cold at night?), but the coastal snakes are apparently going strong. If you look closely you'll see a little girl under this boy:

The big question is: Why are there so many snakes here? Could be the weather, could be the isolation from humans, definitely is the massive number and variety of rodents. Everywhere you look you see mouse burrows:

Ground squirrel burrows:

And gopher mounds:

The result is heaps of rattlesnakes that grow FAST. See this medium-sized male that Scott is holding?

Look at his rattle! This snake is no older than three years. He's huge for that age! Nothing like a steady supply of tasty voles to fuel rattlesnake biomass.

And one more cool thing: BABIES! (These are Northern Pacifics from inland though)

Stay tuned for a lot more snakey updates from VAFB!

Rattlesnake Research at Cal Poly

Celebrating 5 fun-filled years of rattlesnake research in the Physiological Ecology of Reptiles Laboratory at Cal Poly! In this post, I want to introduce you to some of the cool things we have seen rattlesnakes doing, and to the students who have made it all happen.
We do not keep a colony of rattlesnakes at Cal Poly. We only keep rattlesnakes in captivity for short periods of time while they are outfitted with radiotransmitters for our research on their physiology and behavior. The students spend most of their quality time with the snakes not in the lab, but in the field.

One of the great things about studying rattlesnakes is that they are large enough that we can insert a Holohil Systems 13-gram radiotransmitter (about half the width and length of a tube of lipstick) into the snake's body cavity. The battery last for two years, allowing us to track the same snake for extended periods without multiple surgeries.

To anesthetize the snake, it is gassed with isoflurane in a plastic tube (all surgery photos by M. Feldner):
Then a small incision into the body cavity is made, and the sterilized radiotransmitter is inserted:
We also insert a Thermochron iButton datalogger, which collects data on the snake's internal body temperature at whatever intervals you like (usually every 1-2 hours in our studies):
All sutured up:
To wake the snake up, a tracheal tube is inserted into its glottis:
Then I blow into the tube to inflate the snake's lung with air, so when the air comes out, so does the isoflurane, and snake wakes up.
Then the snakes are returned to the field site and can be radiotracked to locate them as often as you want, to get data on behaviors, movement, etc., or to collect the snakes for blood sampling. Here is Kyle, one of the first students to work on snakes with me at Cal poly (2007). (Incidentally, Kyle couldn't stay away and is beginning his graduate work with me next month... on lizards!)
Snakes are recognizable in the field not just by radiotracking, but by their unique, colored rattle paint code:
Our field site is the Chimineas Ranch unit of the Carrizo Plain Ecological Reserve. This is a ~30,000 acre ranch that is managed for cattle, game, and wildlife. Its northern edge is studded with water impoundments and rocky outcrops that comprise perfect rattlesnake habitat:
The ranch also has a beautiful house with pool and hot tub that you can rent while you do research.
Current graduate student Tony in the poolside cookhouse:
The past five years of research on this species, the northern Pacific rattlesnake, have yielded all sorts of interesting natural history data. A very common sight in the spring (also in the fall, but less so) is courting rattlesnakes. Males coil next to or on top of a female, and run their chins all over the female's back in the hopes that she will become receptive to his advances. Males often stay with females for prolonged periods of time.

In the late spring the rattlesnakes are commonly found with food bulges that are suspiciously similar in size to a juvenile ground squirrel:
Sometimes we are lucky enough to witness the feeding events itself. Recently graduated grad student Matt (now off to start his PhD studying venom ecology at Ohio State) took this photo of a snake mowing a kangaroo rat.
Another snake eating a kangaroo rat, this time on the ranch house grounds (photo by J. Ahle):
Here is one of our radiotagged snakes eating a bird. We didn't get close enough for a positive ID on the bird for fear of disturbing the snake, but it might be a cowbird or blackbird:
Rarely, we found the predator becoming prey. Here, an adult California kingsnake is constricting an adult female rattlesnake (photo by M. Feldner):
We strive to make our activities accessible to as many people as possible, to demystify rattlesnakes and show the public how docile and beautiful rattlesnakes are in their natural habitats. We bring groups of students from Cal Poly's Wildlife Club, Herpetology class, etc. to the ranch to see the herps. Here Tony is allowing students to touch a safely restrained rattlesnake.
Jordan was an undergraduate studying thermal biology of the rattlesnakes (2009):

Bree did her undergraduate research project with me in 2009 on rattlesnake spatial ecology, and is now getting her PhD studying rattlesnake-rodent behavioral interactions (You can read her blog here).

Peter (left) and Craig were respectively undergraduate and graduate students doing some of the earliest work on rattlesnakes in my lab (2007-2008). Craig is now pursuing his PhD studying physiology of timber rattlesnakes at the University of Arkansas.

Vince, a community college student doing research on snake brains in my colleague Christy Strand's lab, came out for a chance to hold one of his study animals (2010):

Those pair-bonded to the PI also get a chance, especially when he finds 75% of the snakes in a given day. Here's Steve holding his first rattlesnake (2010):
Other than outreach, why are we actually holding rattlesnakes? Because our research questions often require us to collect blood samples to measure hormone concentrations, lending us the dubious titles of Snake Vampires. Here, current undergraduate Scott (left) and Tony take a blood sample from the caudal vein of a snake:
On another day, Tony and Matt take a sample:
You can read more about PERL's rattlesnake research at our website and publication site. Look for more coming soon as all the boys (and Bree gal) publish their stuff!