Biodiversity Monitoring at Safari Park Reserve

Western whiptail

Robert Fisher began surveying reptiles in the coastal sage scrub at the San Diego Zoo Safari Park Reserve in 1995 as a graduate thesis project. The Applied Animal Ecology Department of the San Diego Zoo Institute for Conservation Research, in partnership with the U.S. Geological Survey, has continued monitoring the biological diversity of the Safari Park Reserve since 2002. For one week a month, three seasons a year, the small mammals, amphibians, and herptofauna of the coastal sage scrub are surveyed by capture and release via pit-fall trapping arrays at 20 sites.

Granite spiny lizard

Each morning we visit every site to check every trap, identify each species, determine sex, and identify the age group. We then take a series of measurements on each individual including weight, tail length, body length, or even hind foot or ear length for mammals. Some measurements aid us in identifying some of the mammal species while others allow us to determine the sex of a snake. In the ever-changing mosaic environment of the coastal sage scrub, with rainy years followed by years of drought, or even fires that have changed the landscape, this monitoring project provides significant insights into the population ecology of the native species of the Safari Park Reserve.

After months of seeing many California voles due to the rainy year, we only saw four this month.  Voles are a species classically studied because they “boom” and “bust” in their population sizes.  Voles increase in number rapidly when resources are plentiful but quickly decrease once their resources have dried up. However, during their period of boom, California voles provide a valuable food source to the many predators that eat them, including hawks, snakes, coyotes, and owls. Overall, small mammals were few this warm month, with gray shrews and western harvest mice being the most common.

Orange-throated whiptail

June was definitely the month of the orange-throated whiptail! We collected data on 119 individuals, including many that we have collected before. The males are out in their beautiful breeding orange, and we observed several pregnant females or females with spur marks from breeding. I even had one bucket trap that contained four males and one female. We might start to see some orange-throated whiptail hatchlings next month! Unfortunately, these lizards are listed as a species of concern by the California Department of Fish and Game, because they only remain on 25 percent of their historic range due to habitat destruction. This month does mark the start of this year’s hatchlings! So far we have processed side-blotch lizard, western fence lizard, and western skink hatchlings.  Besides the orange-throated whiptails, we have seen some large and gorgeous western whiptails as well.

Black-headed snake

The snakes sighted this month were all exciting species. We found two kingsnakes, two California black-headed snakes, and one coast patch-nosed snake. The kingsnakes, though common, are unique in that the San Diego variety can be either striped (as were the snakes found this month) or banded, which is the more common pattern. California black-headed snakes are exciting to find due to the relative rarity of sighting one. They are a small species and often hide under and around rocks so are seldom seen, though they are a relatively common snake to catch in the traps. As for the coast patch-nosed snake, it is a particular favorite of mine due to the fact that it is a truly adorable species (and how often can you say that about a snake?). On top of that, it is exciting to find, since it is officially considered to be a protected species due to habitat loss. The fact that we see the patch-nosed snake at all shows, in my opinion, how wonderful it is that the San Diego Zoo has such a habitable reserve for such a variety of species.

Christine Slocomb is a research technician at the San Diego Zoo Institute for Conservation Research. Elizabeth Davis is a conservation education technician at the Institute.




Scaly Animal Ambassadors

It is easy to see how Floyd and his kind were named blue-tongued skinks!

Part of being an educator at the San Diego Zoo is connecting wildlife to our guests by using animals as a way to trigger interest and concern, especially for children who just love to get close to an animal they’ve never seen before. As a part of the Zoo’s Education Department, I take care of some pretty neat animals that are ambassadors for their species.

Our group of reptile ambassadors is seen by thousands of children a year through school assemblies, animal presentations, sleepovers, and summer, spring, and winter camps. Probably our most famous ambassador is Floyd, the blue-tongued skink. He has been around for quite some time and has the most amazing temperament—always a gentleman and very tolerant of small hands petting him. And personally, he is my favorite to take care of!

Another favorite is Monty, a ball python. Very eager to be handled and always popular with children, one of the best things about Monty is he helps take away the image many people have that snakes are slimy creatures when in fact snakes are smooth and have a special feel all their own. All of the snakes I take care of have a different feel to their scales.

An educator shows off the beautiful colors on Tex.

Tex, a Mexican milk snake, is getting older and doesn’t come out as much; when he does, children love to see his beautiful red, yellow, and black bands. A new addition to our ambassador group has been an albino Nelson’s milk snake. He is more of a pinkish color and even has red eyes. His name is Peppermint Pat and is still getting used to coming out for children, as he is very friendly but also very squirmy!

We have two Australian womas named Mickie and Nooroo (see post Wonderful Womas). One of my favorite things about them is their coloring. At first they look pale green, but as you bring them into the light they seem to have a metallic sheen with a greenish, purple haze. These snakes have a very small head for their body, but they can eat full-grown mice.

A Zoo camper meets Manja, a Madagascar ground boa.

Manja is our biggest snake; this Madagascar ground boa constrictor is a handful for two adults. When we first take him out of his enclosure, he is still waking up and getting used to being outside. But soon he is wiggling everywhere and really makes us work for a smooth animal presentation.

Last but not least is Spot, a spotted salamander who is our only amphibian ambassador. He’s a slimy guy that makes kids, and even adults, giggle when they touch him. He is dark gray with yellow spots and has a good appetite for earthworms and crickets!

These animals are fantastic ambassadors for our zoo. The best part of my job is when I can make a child fall in love with an animal he or she may have never heard of before but now cares deeply about and never wants to hear of them on the Endangered Species List. So keep an eye out for our amazing group of reptiles that work overtime for the San Diego Zoo.

Anastasia Horning is an educator at the San Diego Zoo. Read her previous post, Yun Zi Redecorates.


Biomimicry Looks at Snakes

Can tree snakes inspire biomimics?

Biomimicry and flight go way back. Leonardo da Vinci, and others who came after him, studied avian flight to learn how to get humans off the ground and into the air. Unfortunately for Leo, his machines didn’t fly. But eventually the Wright brothers got the proper principles down, and now we have cargo planes that can transport everything from every-day commuters to endangered rhinoceroses. But there is always room for improvement, and now biomimics are looking to an unlikely candidate to study flight—snakes!

Now, of course, snakes don’t really fly per se; they actually glide. But they still utilize the same principles of lift and drag that govern bird flight. “Flying” snakes are unique among the gliding creatures such as flying squirrels and flying fish because they lack the extra membranes that these other organisms use for gliding. Instead, these animals flatten their bodies while in the air and slither as a snake would if on the ground. In effect, their whole body becomes one big wing.

Scientists have been awarded funding to better understand how paradise tree snakes in southeast Asia are able to glide long distances from tree to tree. Where did this funding come from? The U.S. Department of Defense. How exactly the United States is going to use this knowledge is yet unclear; it is purely an informational study at this point.

On that note I ask, What would you make that’s inspired by a “flying” snake?

Dena Emmerson is a biomimicry research assistant at the San Diego Zoo. Read her previous post, Butterfly Sparks Industry Revolution.

Read more about biomimicry and the San Diego Zoo.


Boas in the Caribbean

Turks and Caicos rainbow boa

Turks and Caicos rainbow boa

In mid March, I spent nine days on Big Ambergris Cay in the Turks and Caicos Islands conducting research on the Turks and Caicos rainbow boa Epicrates chrysogaster. Of course, I wasn’t alone! I was with a team of three volunteer assistants and Graham Reynolds, a collaborator and population geneticist from the University of Tennessee. Our project, now in its second year, is focused on understanding the natural history, genetics, and population density of boas in order to formulate a comprehensive plan for their conservation and management.

Big Ambergris, a 1.5-square-mile (4-square-kilometer) private island, is undergoing extensive development and is believed to support the most abundant population of this species remaining. Fifty-nine boas were tagged in 2008, and so far 103 new boas have been tagged in 2009. Out of 165 total captures to date, only 3 have been recaptures of previously tagged individuals, suggesting the population is indeed very large and dense.

My research on boas received considerable media attention during my recent research trip as well! A film crew from the TV show Timbuktu, a popular animal documentary series in Italy, filmed the team in the field; Graham and I were interviewed about our research with boas (and iguanas) by two local TV channels in the Turks and Caicos Islands; and the Turks and Caicos Sporting Club, which manages Big Ambergris Cay, highlighted my research in a press release.

Turks and Caicos dwarf boa

Turks and Caicos dwarf boa

While working on Big Ambergris Cay in March, we also found the first specimen of the endemic Turks and Caicos dwarf boa Tropidophis greenwayi greenwayi recorded from the cay since it was described in the 1930s. Several herpetological surveys conducted in past decades failed to record the species on the cay and concluded, in error, that the species had been extirpated from the island. The snake was photographed, measured, tagged, sampled for genetics, and released. If other specimens are found, they will also be tagged so that information can be compiled on this rare and endemic species.

Glenn Gerber is head of the San Diego Zoo’s Caribbean Regional Program.

Here’s more information about Glenn’s study
Here’s more information about boas