What the inside of an alligator smells like

Ever wonder what an alligator's breath smells like? One of the perks of my research is I get to hang out within sneezing distance of the amazing reptiles and I can tell you from first hand experience that their breath smells like death. Two of the major questions I try to answer with my research is what do alligators eat in the coastal Everglades and where do they eat it? To get at these questions, I use two different techniques: stomach contents analysis (SCA) and stable isotope analysis (SIA).



For SCA, me and my team catch alligators at night using high powered spotlights and steel snares attached to long poles. Once an alligator has been caught and its mouth taped shut, we bring it up on board our boat, strap it to a long wooden plank so it can't move, place a PVC pipe into its mouth to hold it open, and then thread a tube down its throat and into its stomach. The other end of the hose is attached to a water pump which we use to fill the gator's stomach with water, and then we use a modified Heimlich maneuver to force the water and anything floating in it out of the gator and into a bucket (check out a video of this process here). It may sound like a rough experience for the gator, but it's very similar to how humans get their stomachs pumped at a hospital. Also, in the old days alligator stomach contents could only be gathered by killing the animal and then cutting its stomach out of its body, so our technique is obviously much more preferable.





I've found that alligators eat a wide variety of different foods, including blue crabs, anhingas, rice rats, mink, anchovies, catfish, pond apples, and even non-food items like string and balloons. Alligators are very curious animals and will basically eat anything they can fit their mouths around.

Pieces of blue crab, anhinga, and shrimp pulled out of a gator's stomach.
SCA gives us information about what kinds of animals alligators ate over the past two or three days, but to get a sense of what they eat over longer time periods I use SIA, a technique that uses complex machines to determine the chemical components (like carbon and nitrogen) of animal tissues. Different animals and different food webs can exhibit different types of carbon and nitrogen, and we can use the relative abundances of these different types of elements in animal tissues to get an idea of where they've been feeding and when. By using SCA and SIA together I can get a better overall picture of how alligators fit into the coastal Everglades food web, and this information will be very useful to Everglades ecosystem managers as they figure out how best to restore the Everglades to what it once was.

Comments

  1. Probably some confused/mad/hungry alligators that have been through this experience! What are the wormlike things on the top left of the stomach contents picture?

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    Replies
    1. The worm-like things are intestinal parasites that almost every alligator has. I'm not exactly sure where they come from, but one enterprising alligator researcher in Louisiana (Steve Gabrey) wrote a paper about trying to determine what prey an alligator ate just based on the types of parasites it has.

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