Our Research Blog
WE’RE STILL LEARNING FROM OUR ANIMALS!
Thanks to research by ﬁeld biologists, television shows, and our own observant keepers, our understanding of the many fascinating species at The St. Augustine Alligator Farm Zoological Park continues to grow.
Crocodiles using tools?
Using objects as hunting lures is very rare in nature, having been observed in just a handful of species. We report the use of twigs and sticks as bird lures by two crocodilian species. At least one of them uses this method predominantly during the nest-building season of its prey. This is the first known case of a predator not just using objects as lures, but also taking into account the seasonality of prey behavior. It provides a surprising insight into previously unrecognized complexity of archosaur-ian behavior.
Can Crocodiles change color?
Many species alter skin color to varying degrees and by different mechanisms. Here, we show that some crocodylians modify skin coloration in response to changing light and environmental conditions. Within the Family, Crocodylidae, all members of the genus Crocodylus lightened substantially when transitioned from dark enclosure to white enclosures, whereas Mecistops and Osteolaemus showed little/no change. The two members of the Family Gavialidae showed an opposite response, lightening under darker conditions, while all member of the Family Alligatoridae showed no changes. Observed color changes were rapid and reversible, occurring within 60–90 minutes. The response is visually-mediated and modulated by serum α-melanocyte-stimulating hormone (α-MSH), resulting in redistribution of melanosomes within melanophores. Injection of crocodiles with α-MSH caused the skin to lighten. These results represent a novel description of color change in crocodylians, and have important phylogenetic implications. The data support the inclusion of the Malayan gharial in the Family Gavialidae, and the shift of the African slender-snouted crocodile from the genus Crocodylus to the monophyletic genus Mecistops.
SAAF Film Credits
1. Surfing Hallow Days 1961 2. Realm of the Alligator 1993 3. Illegally Yours – Rob Lowe 1988. 1:34 they are at the front of the park and she is wearing one of our hats. 4. “Lost Worlds: Vanished Lives” (1989) 5. 2 Boyd Mattson shows 6. Lateshow 7. NGTV Super Croc 2001 8. The […]
Yacare caiman eating the eggs of a conspecific during oviposition
The St. Augustine Alligator Farm Zoological Park in Florida has reported many interesting behaviors from crocodilians: young alligators eating their vegetables, others swallowing their food underwater, crocodiles feeding their young, and now Caiman yacare eating the eggs of a conspecific as she was in the process of oviposition. The enclosure is occupied by five female Caiman yacare, that were fed a diet of Mazuri crocodilian pellets earlier that day. Around 7:00pm, one female was observed intently watching another female depositing the eggs and then proceeded to grab an egg from the nest. After swallowing that egg, she grabbed another and entered the pool to eat the second egg. A third female was observed watching the event, but did not appear interested in the activity.
Put Your Money Where Your Mouth Is…
It is a strange tradition to throw your money away, but that is exactly what people want to do when they see a pond. The problem for our animals is that the coins are toxic to them and, in the case of alligators and crocodiles, the coins can sit in their stomach for years leaching […]
Are Crocodilians Like Dinosaurs?
Modern crocodilians and birds are the only living representatives of the Archosauria, a group that also includes non-avian dinosaurs and pterosaurs. Modern crocodilians originated during the early Cretaceous period and dispersed globally. Examples of physiological similarities between living crocodilians and birds include similar amino acids in b-keratins among crocodiles, turtles and birds; oviduct homologies between crocodilians and birds; similar forelimb structures in crocodiles and other archosaurs and similarities in gene expression in limb development in alligators and chickens.
Crocodilian Immune Activity
Serum samples from all twenty-three known living members of the Crocodylia were tested for antibacterial activity against eight bacterial species. These data were used to generate an immune profile for each crocodylian species. Statistical analyses revealed that the three living lineages of crocodylians, Alligatoroidea, Crocodyloidea, and avialoidea, were distinguishable by their immunological activities. For instance, species within the Alligatoroidea and Crocodyloidea exhibited remarkable immune activity similarities to others in their own lineages. Comparisons of the members of the different lineages, however, revealed substantial differences in immune profiles. Furthermore, species that are in the same genus were shown to exhibit more immune similarities to each other than to members of other genera within the same family. Finally, our immunological analyses reveal that Tomistoma schlegelii aligns more closely with the Gavialoidea than the Crocodyloidea.
Field Research in Gambia
On behalf of myself, Matt Shirley, both the Gambian and Senegalese Divisions of Wildlife Management, and the Croco’s Ark Trust, I would like to express our sincerest thanks. Your support for field supplies enabled us to conduct the first official surveys for crocodiles in both countries in over 20 years! This not only afforded us the opportunity to officially assess the status of Osteolaemus tetraspis and Mecistops cataphractus in the Sene-Gambia region but also provided a unique training opportunity for Gambian and Senegalese park rangers.
Crocodile Laying Eggs After a Move
The St. Augustine Alligator Farm Zoological Park imported a pair of adult saltwater crocodiles from Australia on October 24, 2003. The female was gravid at the time of importation and laid a clutch of eggs in the water within a month of arriving at our facility. The eggs she laid were fertile as evidenced by the band that developed on each egg.
Crocodiles and Alligators are not picky eaters, but they do need a balanced diet if they are going to grow up to be healthy and reproductive. That is why we partnered with Purina to help create Mazuri Crocodilian Diet. That’s right, Purina even makes alligator chow!
Crocodilian Enrichment: The good, the bad, and the untried
Managing a large number of crocodilians in a variety of settings can be quite a challenge. Each time we interact, or don’t interact, with these animals can greatly affect all aspects of crocodilian husbandry. This paper highlights several types of enrichment we’ve applied at our zoo and how it’s affected the animals, our staff, and even the guests that visit daily.
Crocodilian Stationing: Incidental Benefits to a Basic Training Technique
Crocodilian training is becoming increasingly common in both zoos and private collections for a variety of reasons. Often times a training program is implemented with a single goal in mind. Stated training goals typically include increasing show quality, improving keeper safety or increasing animal activity. These goals can easily be measured as whether they succeed or not. Recent changes in feeding protocols at the St. Augustine Alligator Farm Zoological Park has revealed several unexpected additional benefits to even the simplest of training programs. By conditioning crocodilians to feed in a regimented manner, it is now possible to monitor the animals overall state. Body condition, temperament, appetite, dental condition, injuries, and total food consumption along with a variety of other aspects can now be closely monitored on a regular basis.
Crocodilian Tooth Replacement
We know that crocodilians replace their teeth on a regular basis and in a very specific pattern. (Edmund, A. G. , Tooth replacement phenomena in the lower vertebrates. Contribution 52, Life Science Division, Royal Ontario Museum, Toronto, Canada). Maximo, our 15’ 3” saltwater crocodile had orange teeth because of the tannins in the water where he lived in Australia. After he moved to the St. Augustine Alligator Farm Zoological Park in October 2003, any time Maximo lost a tooth it was extremely obvious, because the old orange-stained teeth were replaced with bright white new teeth.
Of course we all assume that alligators purposely drink water, but it is rarely witnessed. In September 2004 I witnessed an adult female America alligator Alligator mississippiensis drinking water. She had been out of the water most of the night and when I noticed her she was still lying on land. She moved her head over the pond and let her lower jaw settle into the water. She tilted her head down toward the water at almost a 45-degree angle.
Pheromone Collection from Crocodilians
Crocodilians possess several unique skin glands that have been shown to produce unusual compounds. the paracloacal glands are a set of glands located on either side of the cloaca of all crocodilians. Although their function has been difficult to clarify, Dr. Paul Weldon had been working to better understand the makeup and purpose of the chemical secretions porduced by these glands.
The Chinese Alligator, Alligator sinensis, is one of the most endangered vertebrates on our planet. With less then 100 animals remaining in the wild, their situation is truly critical. The St. Augustine Alligator Farm Zoological Park has had success breeding Chinese Alligators and has been lucky enough to be able to participate in a program to bring some of our offspring back to China.
The San Diego Zoo houses the Center for Reproduction of Endangered Species (CRES), which keeps frozen genetic samples of animals that could one day prevent the extinction of a species. The St. Augustine Alligator Farm Zoological Park is glad to work with Val Lance, a senior scientist at the center.
Something many people may not be aware of is the role the St. Augustine Alligator Farm Zoological Park plays in facilitating crocodilian research. Recent work involved renowned crocodilian expert Dr. Kent Vliet, Director of Biological Labs at the University of Florida and Dr. John Hutchinson of The Royal Veterinary College in England. Dr. Hutchinson is an expert in the biomechanics of terrestrial vertebrates.
Alligator CT Scan
A CT Scan of an alligator was conducted at Flagler Hospital.
Crocodilians Eating Their Vegetables
Scientific literature is filled with research regarding the stomach contents of crocodilians. Almost all of them refer to the plant material found in the animals’ stomachs as either an accident (i.e., the crocodilian got leaves in its mouth while trying to swallow a prey item), or secondary (i.e., the crocodilian swallowed a prey item that had grass or leaves it its stomach).
Crocodilians Swallowing Underwater
Crocodilians have the ability to swallow prey under water: The palatal valve, in the back of a crocodilian’s mouth, is a unique adaptation that seals the throat off from both air and water. With the palatal valve shut a crocodilian can grasp food underwater and not have the water flood past into the esophagus or glottis. Essentially the inside of a crocodilian’s mouth is outside its body.
Crocodiles as Parents
Siamese Crocodiles as parents: In May of 2000 the St. Augustine Alligator Farm decided to do things a little differently. Typically, when the alligators or crocodiles lay eggs the keepers collect the eggs and put them in an incubator.
Crocodiles Feeding Their Young
Crocodilians feeding their young?: More and more we are realizing how closely birds and crocodilians are related. They have many similar adaptations and behaviors. However one distinct difference is that crocodilians are not known to feed their young. Unlike most birds, hatchling crocodiles are ready to feed on their own soon after hatching. In spite of this, there have been occasional observations that may suggest that some parent crocodilians provide a little extra help to their offspring.
Courtship Behavior of American Alligators
Courtship behavior was observed in a captive group of about 150 individually-marked, adult American alligators Alligator mississippiensis over a three year period.
Social Displays of the American Alligator
Adult alligators perform two conspicuous social displays, bellows and headslaps. Both of these behaviors are preformed from a “head oblique tail arched” (HOTA) posture.
Green screen technology was used by National Geographic Television to make a great video of all 23 species of crocodilians morphing from one species to the next. Since the St. Augustine Alligator Farm Zoological Park is the only place in the world that has every species of crocodilian, we were the only place that could provide National Geographic this unique opportunity.
Insights into the Ecology and Evolutionary Success of Crocodilians Revealed through Bite-Force and Tooth-Pressure Experimentation
Endoscopy of Crocodilians
By using an endoscope (a small camera that can be inserted in the body cavity), Dr. Maud Lafortune of the University of Florida’s Veterinary Medical Teaching Hospital, was able to evaluate the respiratory tract of alligators. The camera was slowly inserted down the trachea of the alligator and into the lungs. There is a tiny light at the end of the tiny camera and during the procedure everything can be seen on a nearby television monitor.
An ancient ironreveals new mysteries: mummy DNA ressurects a cryptic species with the Nile crocodile.
The Science behind Mythbusters on Discovery Channel.
- Crocodiles using tools?
- Can Crocodiles change color?
- SAAF Film Credits
- Yacare caiman eating the eggs of a conspecific during oviposition
- Put Your Money Where Your Mouth Is…
- Are Crocodilians Like Dinosaurs?
- Crocodilian Immune Activity
- Field Research in Gambia
- Crocodile Laying Eggs After a Move
- Crocodile Food
- Crocodilian Enrichment: The good, the bad, and the untried
- Crocodilian Stationing: Incidental Benefits to a Basic Training Technique
- Crocodilian Tooth Replacement
- Crocodilians Drinking
- Pheromone Collection from Crocodilians
- Chinese Alligators
- Frozen Zoo
- Galloping Crocodilians
- Alligator CT Scan
- Crocodilians Eating Their Vegetables
- Crocodilians Swallowing Underwater
- Crocodiles as Parents
- Crocodiles Feeding Their Young
- Courtship Behavior of American Alligators
- Social Displays of the American Alligator
- Green screen
- Crocodilian Bite-force
- Endoscopy of Crocodilians
- Mummy Crocodiles