Most people have seen programs on television showing crocodiles attacking large animals like deer and cattle. While this is amazing, and sometimes horrifying, those creatures are not alligators. The function of a crocodile's dentition is somewhat different than an alligator's. Alligators favor prey items that will fit inside their head. That is, if they can swallow it whole, then they will normally attack it. While I've heard witnesses tell of alligators taking deer in the park, the prey was very small fawns. Alligators have also been seen with large nutria. But, most of the time, they will eat things like small fish, frogs, and crayfish. Snakes and turtles are also pursued, with alligators seeming to be especially well-adapted for eating turtles. A recent study done in Texas examined the stomach contents of about 50 alligators (which were unharmed). Research showed that only one of these alligators had eaten a bird (which couldn't be identified, it might have already been carrion when taken), and the rest had stomach full of small fish and shellfish. I've seen 11-foot alligators going after prey that was no larger than their largest teeth (very small frogs and fish).October 10, 2010 At about 8:30am I noticed two alligators with a carcass in Pilant Lake between the Spillway Bridge and the Observation Tower. One alligator was about 8' long and had control of the carcass, while a 6' alligator tried to take pieces from it. While I was watching, I realized that the carcass was the forequarters of a good-sized buck. This was obvious when I realized that I was not looking at branches behind the carcass; but antlers *on* the carcass. The remains appeared to be quite old. I couldn't smell the carcass, the meat appeared bleached and bloodless, and the skin appeared to have begun shedding fur.
large gator finally swam away with the buck, going past the Spillway Bridge
towards Elm Lake. It stopped past the Spillway to continue trying to process
the carcass by crushing it with its jaws. Most of the images below are
frame captures from video clips I shot that morning, and which I edited
into this movie
clip (82 mb).
STOLEN MOUTHFUL THE BUCK STOPPED HERE TAKING AWAY THE FOOD 1 TAKING AWAY THE FOOD 2
TAKING AWAY THE FOOD 3 SWIMMING PAST THE BRIDGE THE SMALLER DOESN'T GIVE UP
The 6' gator followed and continued trying to get pieces from carcass. The smaller alligator was quite persistant--even crawling on top of the larger alligator to bite on the carcass. However, through this entire situation, neither alligator exhibited any really aggressive behavior towards the other. In the pictures below, the smaller alligator demonstrates how poorly the jaws work for biting big chunks off of large prey--even with the prey held stationary.
NOT EASY TO GRAB A MOUTHFUL 1 NOT EASY TO GRAB A MOUTHFUL 2 NOT EASY TO GRAB A MOUTHFUL 3
the large alligator was holding the carcass firmly in its jaws, the smaller
one could pull on it, and even roll to pull off pieces of flesh, but only
by gripping a small area. I don't care much for the term "death roll".
In this case, the prey is already dead. This is a demonstration of an alligator's
habit of rolling when it encounters resistance while its jaws are clamped
upon something. In the second roll, one can see the exact moment there
is a sudden split when the carcass is overstressed by severe twisting.
One can also note that only a small part of the carcass is caught at the
end of the alligator's jaws.
NOSE-TO-NOSE FIRST PREY-TEARING ROLL 1 FIRST PREY-TEARING ROLL 2 FIRST PREY-TEARING ROLL 3
SECOND PREY-TEARING ROLL 1 SECOND PREY-TEARING ROLL 2 SECOND PREY-TEARING ROLL 3 RE-SET THE CLAMP 1
RE-SET THE CLAMP 2 THE HUGE JAW MUSCLES AT WORK
saw the large alligator try to spin the carcass only once--with pretty
spectacular results. Since nothing was holding the carcass fixed
for the larger alligator, everything moved along with the alligator. After
some time (at about 10:00am) the smaller alligator finally pulled
off a leg. When this happened the large alligator finally became a bit
agitated and tried to take the leg back, but only for a few minutes. The
smaller alligator swam off towards Elm Lake with the severed leg.
THE BIG ALLIGATOR ROLLS! 1 THE BIG ALLIGATOR ROLLS! 2 THAT'S MY LEG, SHORTY!
alligator stayed with the carcass. It moved towards one of the small islands,
and seemed to rest, so I left to visit Elm Lake.
When I came back about 30 minutes later, the large gator had cleared logs from the area. It was pushing on one of the longer ones was I watched. Soon after, the smaller alligator returned (about 11:15am). and went right for the larger alligator. Not only did it approach the larger alligator, but it approached quickly, and immediately went to the front of the larger alligator's head. It appeared to looking for the buck in the place where it had last found the carcass--in the larger alligator's mouth. (So, it appears that an alligator can accidently "food habituate" another alligator.)
TIME TO STEAL ANOTHER BITE! HEY...YOU HAD A BUCK IN THERE A WHILE AGO
Since the carcass wasn't there, the small alligator went looking for it. This caused the large alligator to become agitated, and it began trying to shove and herd the smaller one away. At one time, it even had the smaller alligator's head in its mouth, but it didn't clamp down on the smaller alligator. The large alligator also did large gape signals, but with its head mostly submerged.
SLOWLY CHASING THE SMALLER 1 SLOWLY CHASING THE SMALLER 1 BIG JAWS COVER SMALLER HEAD 1
BIG JAWS COVER SMALLER HEAD 2 BIG JAWS COVER SMALLER HEAD 3
BIG JAWS COVER SMALLER HEAD 4 UNDERWATER GAPE DISPLAY 1 UNDERWATER GAPE DISPLAY 2 UNDERWATER GAPE DISPLAY 3
The smaller gator finally found the carcass, and swam towards Elm Lake with it; while somehow avoiding the notice of the large alligator.
I followed the smaller alligator and the food, and when it got about 20 yards away, the large alligator started bellowing. It bellowed about 5 times, and then stopped. It did not pursue the smaller alligator. The smaller alligator took its prize, and eventually pulled it past one of the islands and into Pilant Lake and out of view. (about 12pm) Throughout those hours, many park visitors came by, and I was able to talk with them through some of this adventure and explain what was going on.
I am still amazed by the tolerance of the larger alligator. While it is true that it did attempt to dissuade the smaller alligator; it didn't try very hard; and was most passive about it. I did hear an occasional hiss, but at the distance I was watching, I couldn't tell which alligator was hissing. This also was short, and not very loud. There was not a single sudden aggressive movement directed towards either alligator. There was lots of close physical contact, particularly around the snout and eyes; but the smaller one also climbed across the back, head, and snout of the larger one many times. The placing of the jaws around the head of the smaller one seemed very gentle--although the small one did snatch its head from out of there (BIG JAWS 4 above shows the head whipping out from under the top jaw). The end of the top jaw poking out of the water (which I assumed was actually an intimidation gape being done mostly under water) was interesting, too.
SMALLER WITH STOLEN CARCASS BELLOWING--FOR LOST CARCASS? SMALLER ONE WITH THE STOLEN BUCK
I was able to catch different parts of this on video. I shot almost all of it at high speed because I expected to see some kind of aggressive social interaction and I wanted to slow it down. It turned out that there was hardly any aggression at all. I created a film using this footage and the few photos I shot. I sped up segments of the "slow motion" video to preserve the motion paths, but to allow it to happen in a reasonable time. Otherwise, everything else is as I filmed it. The edited video is about 12 minutes long, distilled from about 83 pieces of video and photos. We don't see this kind of thing at Brazos Bend State Park very often-- not with a deer, and not one this large. One of our visitors named Sandy shot photos of a deer being eaten on the Pilant Slough side of the Spillway bridge in June of 2009. It does happen and sometimes we get to see it. It's usually unknown how an alligator would get a deer in the first place. In this case, it seems likely that the deer was killed or wounded by a human hunter and the alligators just found it. Later, a large alligator was sunning itself on the trail just past the Spillway, and because of a couple features (one bad eye, possible scar under the good eye) I identified it as the same large alligator. Comparison with my 6' walking stick showed the alligator to be about 8 feet long. The images on this page are from the edited video clip (82MB wmv).
I had the day off, and had visited the park again, hoping to find an Otter.
While I was walking the trail, I talked to some park visitors and mentioned
that I had been looking for an Otter. They got excited and told me that
they'd seen an alligator with a large furry carcass in its jaws. The alligator
was in 40 Acre Lake, and I was walking back from Elm Lake on the Spillway
Trail when I had this conversation. They's seen the alligator at
least an hour before I talked to them, and they thought that the carcass
might be an Otter, but they couldn't tell because the alligator was on
one of the islands. I quickly walked back to 40 Acre Lake to try
to find the alligator, and identify its prey. I feel that this information
could be important for a few reasons.
First, I have the opinion that although alligators are predators, and often eat Nutria; Otters are also predators and are therefore smarter and faster than Nutria. Predators have to stalk and chase their prey, and therefore require more effort to catch their prey. Herbivores don't have to chase their prey. Although both predators and herbivores also can be hunted by other predators (and would have to have some means of escaping from them) I believe that predators have more physical skill. I also feel that Otters are smarter than alligators, can swim at least as fast as they can, and have more stamina than Alligators. So, I believe that alligators rarely catch Otters.
Second, I believe that Otters are predators that share a niche with Alligators (they both exploit the same types of food). However, since they are warm-blooded, they require much more food than Alligators do. The park could not support a population of over 200 Otters, although that many alligators can easily live there. So, the number of Otters in the park must be small, and it would be worthwhile to note the loss of an Otter.
Third, I like Otters. I like Alligators, too, and understand the need for them both to share the environment. But, I was concerned that an Otter was lost, and would have been saddened by it.
Nutria (Nutrias?) (Myocaster Coypus) are large rodents similar to Muskrats and Beavers. Unlike both of these though, the Nutria is a non-indigenous animal--an "invasive species". I've heard a few explanations of how they got here from South America. One is that they were brought here to cultivate for fur, and then they escaped (I heard a hurricane in Louisiana blamed). I've also heard that they were purposely introduced to some waterways to help control invasive plant species (like water hyacinth); but that the Nutria starting eating everything. They are displacing the smaller, native Muskrats, and are breeding more. Fortunately, here in the South, Alligators are here to help eat Nutria. I've got a short video clip of a Nutria swimming by on my Otter page, here.
I finally got to 40 Acre Lake, and there, right near the short footbridge, was an alligator with a furry carcass. This didn't surprise me, since Alligators are very possessive of their food, and most of the other Alligators were out near the island. This Alligator had moved away from the others. When I first approached, the Alligator slid off the bank and into the water. I had to wait, without moving, about 15 feet away until the Alligator decided that I wouldn't be coming any closer (in fact, I'd retreated a few steps to indicate submission). The Alligator returned to the bank, and came ashore. The front of the carcass was inside the jaws, and the rest of it was on the opposite side of the alligator. So, I couldn't tell what the animal was, aside from the fact that it had fur. It was still wet, and I'm able to tell an Otter pelt from a Nutria's judging from the texture of the fur.
In the past, I'd been able to identify a mammal in an alligator's jaws by shooting bursts of photos of it while it chewed on a carcass. All I needed was a single shot that would show the prey's face clearly enough so that the huge incisors of a rodent would be visible (or not). My new camera can shoot a LOT of images in burst mode, but it can also shoot high-speed video. I decided to go for the video.
I've observed alligators trying to fragment prey before. Previous examinations of how this works can be seen on one of my pages here.
I hadn't gotten ready to film the alligator before he did two prey-whipping movements, and then he was done. I probably couldn't have asked for a better video.
The images below are all frame grabs from one of two video clips I shot.
I have not shown parts of the latter part of the first clip as photos here. Predators feed by eating other animals. In almost every case, the capture and subsequent handling and processing of the prey is...not without violence, or implied violence. Images showing this process can upset some people. Sorry, but that's what happens when predators eat. Something has died, and then it has to be eaten. I was able to capture the moments when an alligator is successful in tearing prey by pulling against what seems to be--air.
The series of images below show the the mechanics of what I've called a "prey whip". Clicking the images will show them in their original size (320 x 240). I've got short descriptions below each image.
I've edited the clip, with text explanations. I've added some background music. The video can upset those people who are easily upset. If you (yes, you visitor to my site) are easily upset seeing dead creatures, do NOT watch the video clip. Otherwise,you can see it by clicking on this link (wmv 39mb). From the evidence in the clip, and from photos I shot afterwards, I'm sure that I can identify the carcass as that of a Nutria.
Gator has repositioned the prey. The gator lifts its body and head. Gator cocks its snout right. Lifts foreleg.
Tremendous jaw muscles clamp shut. This clears the carcass from the ground. Lifted foreleg will allow body to fall foreward.
Gator lets body fall forward. Gator body stops, but snout continues. Snout continues past body axis.
Snout starts to swing with fall. Snout crosses body axis, carcass moving fast. Centrifugal force is increasing weight
Carcass starts acceleration. at back end of carcass!
--Shoulders of gator move back relative to radius of carcass swing. Alligator's snout swivels back towards body axis and head moves straight
back, pulling section of body in jaws against increased weight of rear of carcass with hard jerk (the "whip"). Carcass extends straight as huge force is
brought to bear against swivel point just outside jaws. Sooner or later, this will cause the carcass to rip, or break, or part (and it does, in the video clip).
I am fascinated by the amount of mechanical interaction that is brought to bear on something as apparently simple as just swallowing something. Also in the clip is reference to a function for that large pouch that can be seen under the lower jaw on some alligators, especially as they high walk. With the head held erect off the ground, this pouch is quite visible. This is called a "gular pouch" and helps guide prey down to the throat.If you'd like to know more about the park follow these links:
Brazos Bend State Park The main page.
Brazos Bend State Park Volunteer's Page The volunteer's main page.
Here are a few links to more information on alligators. There's a LOT of it out there.
Here are my "alligator behavior" pages:
|SOCIAL INTERACTION||CONFLICT AND CANNIBALISM||FEEDING||BABY ALLIGATORS||ALLIGATOR DENS||ALLIGATORS ON LAND||FOSSIL CROCS|
|SIGNALS 1||CONFLICT 1||FEEDING 1||BABIES 1||DENS 1||ON LAND 1||FOSSILS 1|
|SIGNALS 2||CONFLICT 2||FEEDING 2||BABIES 2||ON LAND 2|
|SIGNALS 3||CONFLICT 3||FEEDING 3||BABIES 3||ON LAND 3|
|SIGNALS 4||FEEDING 4||BABIES 4||ON LAND 4|
|SIGNALS 5||FEEDING 5||BABIES 5||ON LAND 5|
|SIGNALS 6||FEEDING 6||BABIES 6||ON LAND 6|
|SIGNALS 7||ON LAND 7|
And, this page shows alligators at the park, on land, near various landmarks at the park.
Go back to my main alligator page, Alligators
Go back to my home page, Welcome
Go back to the See the World page.