Here is another surprising aspect of alligator behavior. They will protect their unhatched young through incubation (about 60 days), and then will protect their hatched young for around two years. I've witnessed the care that a female alligator shows while she moves among a newly-hatched pod of baby alligators. I've faced a female alligator over her young, and stood and watched her with respect on more than one occasion. If her babies gave an alarm, she--with her eyes upon me--would quietly move closer to me, in the water. Only if I didn't give way, or if others moved quickly or loudly, would she actually begin her threatening behavior. If one gives her respect, then she remains quiet, though watchful. The picture of a silent, strong protector of its young is not the mental image most people would have of an alligator. Maybe these pages can alter the common perception of alligators.
August 27 follows!
If you were able to watch and hear the video clip with sound, then you heard 3 sounds, sort of like a cross between a chirp and a croak. Juvenile alligators make these sounds. The following information is drawn from:
Crocodilian Biology and Evolution, Gordon C. Grigg, ed. Feb, 2001. The information is in Chapter 30, written by Adam R. C. Britton. (italics are my own conclusions/thoughts)
This chapter deals with crocodilians in general, but seems to indicate that the different species share similar behaviors. In any case, it's interesting. From before they are born, young crocodilians vocalize. They begin chirping
while still inside the egg. This is thought to alert nearby adults (usually the mother, since she is normally guarding the nest) to approach the nest. Apparently, even male animals will respond with assistance (That is, they don't come to eat the young.) An interesting point is that other animals, notably predators, could also be alerted by these sounds, and could also
respond. If they reach the before the adult crocodilian, then the young wouldn't survive. Then, after they are born, the young alligators will continue to make various sounds. What is most interesting is that there are different sounds for
different situations, or to give different messages. The chapter lists 5 different calls (possibly 6). This is only one study. As with all scientific work, it is subject to further experimentation and verification. Calls in the study were analyzed with sonograms, and broken down into components. So, many differences between the calls are quite subtle, and difficult, if not
impossible to detect by humans. Some of these signals can probably be read by context. The 5 main types were: Hatching, Contact, Threat, Annoyance, and Distress.
Hatching Calls--these were divided into "pre-hatching", and "post-hatching"
calls. The study gives differences between
calls as occurring from milliseconds of duration, frequency, and harmonic. The "pre-hatching" call is thought to cause the adult to open the nest, while the "post hatching" call may help the adult locate the newborn to carry it to the water. There is also mention of another possible sound that may prevent the adult from swallowing the young while it's being carried in
the adult's mouth. However, some of these difference could be due to physical conditions around the baby, such as the egg muffling the sound (I suppose being inside an adult's mouth might cause produced sounds to be seem different also.) For those who wonder, the chapter *does* mention that how the babies can produce sounds *inside* the egg isn't known.
2. Contact Calls-- are given from time to time, and are probably used so the young animals can recognize their group. That is, this call helps keep the pod together. Sometimes one baby approaching another will make one of these sounds. Sometimes it gets an answer. These are probably the sounds that are being made on my video clip. These happen in non-threatening situations. Young crocodilians (hereafter, just "crocs") apparently respond to this sound favorably, sometimes
responding to similar sounds made by other non-threatening animals, or even the adult female.
3. Threat calls--With the social behavior of depending on adult animals for protection, young crocs normally will seek to escape, hide, and call for an adult if threatened (Who wouldn't want a dragon 10 times their size that they
could call on for help? A baby alligator is 9 inches long. A large female is 9 feet, or 108 inches long.) . On rare occasions, however, they will attempt to face down their tormentor. When doing so, they will show aggressive body postures
while making the noise. These sounds seem to be quite different from the other vocalizations. (From what I can see, these are more related to loud "hissing" noises the the "croaking" noises.)
4. Annoyance calls--These are high-pitched sounds that a young croc might make after it has been grabbed. These are used in conjunction with attempts to bite their attacker. There is no evidence either way that shows an adult would respond to these calls. These are generally a higher pitch than "distress calls".
5. Distress calls--These occur when a young croc feels threatened. They seem to be primarily for summoning an adult. Adults other than the actual parent may respond. These calls can also serve as a warning to other juveniles in the area (probably in the same pod) that there is trouble. One drawback of this behavior is that the caller could be eaten before help could arrive.
Another concept I hadn't considered was an alligator's voice changing as it grows (similar to the way ours does). As they grow, and some species can grow to more than 10 times their birth size, the structures that make the sounds also grow. Generally, the "peak frequency" of their calls lowers. That is, their voices get deeper. There is mention that adults respond more rapidly to higher-pitched distress calls, than to lower ones. I surmise that after a certain point, the adult no longer recognizes or responds to a distress call that falls outside a certain frequency window. Although they still may make distress calls, the adult will not respond. I also believe that with this comes another behavior, where the young alligator has become large enough to be recognized as a threat to the current brood, and may be chased off. I see many alligators around 3 feet long by themselves at the park. I see few between 2 and 3 feet long alone. If this interests you at all, I urge you to locate the book, and either buy it or borrow it. The book is a collection of different papers by different study groups. Much of it is quite technical, but it's still interesting.
important news: BABY ALLIGATORS at the park! Readers may recall that
a few weeks ago (see heading August 18 above) the park naturalists had
to relocate 28 eggs from an alligator nest that had flooded. On wednesday,
August 21, the eggs hatched! Actually, 19 of the 28 eggs hatched. The remaining
9 eggs turned out to have been infertile. Not bad! Not bad at all! I wish
I could have been there, but alas, I was at work, and the eggs began hatching
around 3:00 pm. However, today (Sunday) I was able to visit the new additions
to the park. The image below (SOME HANDFUL) shows my hand holding some
of these new alligators. The young gators were surprisingly docile, and
did not show much alarm at my approach. Of course I only handled these
animals with permission from the park naturalists. More images of these
4-day-old babies follow.
They are about 9 inches long (YOUNG SIZE, below). We have 3 live alligators in the Visitor's Center that were born almost a year ago. Here are two pictures comparing the two. Note that the young in the VC are not fed as often as they'd like to be, but they *do* eat all year.
SOME HANDFUL YOUNG SIZE COUSIN? BIG DEAL, ONE YEAR
Therefore the wild alligators may be a bit larger than this one. (see COUSIN?, and BIG DEAL, ONE YEAR, above). Even after 4 days, the yolk sack they are born with is still visible (see YOLK SACK, below)
Like many other reptiles, alligators are born with a "Developmental Chamber Escape Tool" (my term), otherwise known as an "egg tooth". This is a temporary sharp "tooth" that is usually at the tip of the skull (near the nostrils), that is used to tear through the egg membrane, and sometimes the softer shells of reptile eggs. Sometime later, this "tooth" falls off. Here is a young alligator's face (see BABY PICTURE, below) and a close-up of the egg tooth (EGG TOOTH, below). The egg tooth is the white triangular spot on the tip of the snout. The entire young alligator, as it lies quietly in my hand (IN MY HAND, below).
YOLK SACK BABY PICTURE EGG TOOTH ------IN MY HAND
Also, David (park naturalist) attempted to give these young alligators their first meal. Remember, there are born with a yolk sack, and this sustains them for their first few days of life. Two of the young alligators did take the food (large chunks of diced earthworm...LE YUM!), while most of them ignored it; although a few did bite on the worms, chew them and spit them out. I was able to get a few film clips of this first successful feeding.
Here are three links (the pictures below are from the clips):
4-day-olds, with a few chirps. (flv video 433kb, see BROTHERS AND SISTERS , below)
4-day-old's first attack (real video 503kb, see AM I SUPPOSED TO EAT THIS?, below).
4-day-old's first prey (flv video 478kb, see MMMMM...BOY!, below).
BROTHERS AND SISTERS AM I SUPPOSED TO EAT THIS? MMMMM...BOY!
This was a pretty successful hatching. Usually, the mother alligator would have assisted with this hatching. That means that when the babies started croaking, the mother would have gently scraped the top off the nest and helped the babies leave their eggs. The mother gators have been observed gently cracking the shells in their jaws, and carrying the live babies to the water. Even after the hatching the mother will protect her young, for two years or so. In spite of all this protection, one alligator in 60 (yes--ONE IN SIXTY) will survive the first 3 years of life. This high mortality rate is due mostly to predation by numerous animals which view young alligators as a food item. These can include snakes, turtles, wading birds, fish (remember the giant alligator gar we found at the park?), raccoons, river otters (these have been observed at Brazos Bend State Park), and other alligators. A particularly severe winter can also cause smaller alligators to die. Therefore, I considered myself very lucky to be able to observe such a group of newborn alligators so closely.
30, 2002 It had been raining all weekend.
Not steadily, but enough to make things wet and the air close and sticky.
I hadn't been at the park very long, before it started raining on me. I
was near the water station on Elm Lake Trail, and between that point and
to about 75 yards past the first pier, I saw 8 alligators lying still in
the water. For at least 15 minutes, all the alligators were unmoving, and
facing the trail (SEE RAINY MORNING, below) . Two smaller alligators
were very close to the shore, and one of them is the rickubiscam shot for
this week. After this brief period of stillness, during which the rain
paused for a short time, the the some of the alligators began moving around.
There were two larger alligators (probably males), near in the group. Two
of the midsize alligators (about 6 feet long) started moving first. The
alligators slightly tilted their heads as they swam, showing the their
lips above the surface, but keeping the head almost horizontal. They also
showed most of their upper back and tail as they swam at a leisurely pace.
Eventually, all the alligators had scattered.
The rain finally stopped, at around 10:00. I wandered the trails for a while, which were clear of visitors.
Sometime later, I, and a couple others, went to visit one of our new alligator nests. Alligators build nests during this month, and two have nested within easy sight of one of our most accessible trails, the Creekfield Trail. The first nest is about 10 minute's walk from the Visitor's Center, and close enough to be seen easily from the trail, yet far enough away from the trail for the mother to be undisturbed (and therefore not moved to vigorously defend her nest). Although we are far enough away from her nest, the female is definitely keeping an eye on us. See SHE'S WATCHING ME, below. She is actually behind the nest (from the viewpoint of the trail). The nest is the pile of old grass and logs in front of her. This female has put some pretty large pieces of wood into her nest. If her nest remains unharmed (unfortunately, there are many raccoons in the area she chose), she will guard her nest for the 60 days required to incubate her eggs. This is one of the largest females-if not the largest-that I've seen at the park. It's not possible to be 100 percent sure of an alligator's sex unless one does a physical examination, but nest-guarding behavior is not shown by male American Alligators.
RAINY MORNING SHE'S WATCHING ME MY VISITOR
important news: WE GOT RAIN at the park! About 9 inches worth, and now
the park looks like it should. Unfortunately, the two alligator nests
by the Creekfield trail were threatened by the raised water level. In fact,
one nest was totally submerged, so the eggs were relocated. The other
nest was left alone, since the top of it was still above water. The
nest looked like this before the rain (see DRY NEST, below.) And now, it
looks like this (see WET NEST, below.)
DRY NEST WET NEST
September 23, 2001. Have I mentioned that I think alligators are pretty cool? Of course I have! Maybe I haven't made this clear. Actually, I'm not doing this to make anyone believe they are interesting. I do this because I already think that they are. Alligators are not typical reptiles. They are among the largest living reptiles. They have a 4 chambered heart (other reptiles have 3 chambers), and they protect their young for up to two years. This time, I was fortunate enough to encounter a litter of baby alligators (BABIES!, below), along with their mother...or at any rate, an adult alligator who was very protective. I'd already heard of her...interactions with some of the park staff. The water level was still high at the park, so the water came up very close to the paths. When someone approached too close to her brood, the mother would hiss, and/or slap the water with her tail or jaw (by slapping with her head). At this point, the prudent person leaves the area. At Brazos Bend Park, the alligators have the right of way at all times. I approached to about 15 feet, and then let the video camera do the work of zooming in closer. The mother alligator kept a close eye on me, anyway. Here is a video clip of the alligators and their protector. (flv video 747kb)
If you'd like to know more about the park follow these links:
Brazos Bend State Park The main page.
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.
Adam Britton's Pages 1
Adam Britton's Pages 2
Fish and Wildlife Page (Text)
Fish and Wildlife Endangered Species
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 RICKUBISCAM page.
Go back to the See the World page.