An alligator sporting a Crittercam. Photo via. J.C. Nifong.
This week, Motherboard has covered falcon-cams and bee backpacks, but the animal-monitoring fun is far from over. A team based led by J.C. Nifong of the University of Florida has upped the ante by strapping Crittercams onto American alligators. The results of the study were published in PLOS One yesterday, and reveal a wealth of new information about these streamlined apex predators.
Surprisingly, Nifong's team is the first to use “animal-borne imaging” to examine the hunting and feeding habits of any crocodilian species, though attempts have been made before. Because crocodilians can be sensitive to observation, the Crittercam approach was particularly successful in shining more light on this mysterious predator.
Highlights from the gator-cam experiment. Video via LiveScience.
“Animals do things totally differently in the absence of humans,” Nifong told Motherboard. “You just get a chance to see things that are almost impossible either through binoculars or from afar–especially with crocodilians that occupy aquatic habitats or dense vegetation.”
The team snared 15 adult alligators, nine from Merritt Island National Wildlife Refuge and six from Guana Lake. Within roughly 20 minutes of capture, each individual was measured, fitted with a Crittercam, and released back into their estuaries. Each camera recorded six to eight hours of footage, staggered in 30-minute chunks across all hours of the day and night. The recording began a minimum of six hours after their capture, to give the animals an opportunity to recover from the whole weird experience.
The data revealed that alligators are more active at night, and that their precision is far more impressive than previously assumed. Of the 59 attacks recorded, 31 were successful. The high comparative success rate is due to the many special adaptations that have been fine-tuned over millions of years.
A table of data predicting prey-capture attempt frequency. Photo via. J.C. Nifong.****
“They are very skilled predators,” Nifong said. “In addition to that, they have mechano-receptors around the head and jaws that are very sensitive. They are similar to the cells in the eardrum, so they sense acute vibrations.” Alligators also enjoy a higher success rate because they are “sit-and-wait predators.”
“The success rates of predators that chase their prey are generally fairly low compared to something that just sits around and waits for something to come by,” Nifong explained.
These results expose a lot of new information about crocodilian behavior, and highlight the need for round-the-clock monitoring. For example, the selected alligators only did 22 percent of their foraging between the hours of 6 AM and 6 PM, so limiting observation to the daytime only tells a quarter of the story. The Crittercams also revealed that 30% of all prey-capture attempts took place while the animal was submerged, and 36 percent took place in thick vegetation, emphasizing the limitations of studying alligators without animal-borne imaging.
Letting animals be their own documentarians seems to be a more effective way than stalking them like the creepy Peeping Toms we are. Indeed, it could even help save whole species. “I'm really interested in doing it on different species of crocodiles, because we don't know a lot about some of these highly endangered species,” said Nifong. “We need to know more in order to conserve them, so that might be a different avenue also.”
The Siamese crocodile of South Asia is critically endangered. Photo via Rlevse.
Sure, it's tough to make a bee wear a backpack, and we've learned that falcons are shaky cinematographers. It also takes serious dedication to research to capture a scaly, dagger-toothed predator from its comfy home, then tell it to go out and make a home movie. But if it leads to more accurate insights, especially where endangered species are concerned, animal-borne imaging is clearly worth the trouble.