Ask a Croc Expert
Read Dr. Britton's responses on the following croc topics:
Crocodile Predators
Crocodile Speed
Croc/Human Interaction
Crocodile Size
Crocodile Hunting
Crocodile Defense
Alligators vs. Crocodiles
Crocodile Mothering
Crocodile Infections
Crocodile Bites
Crocs in Water
Croc Body Heat
The Crocodile Heart
Q: On Crocodile DefenseDo all members of the crocodilian species have the same body posture when they are ready to defend?
Thank you,
Monte
A: To some extent yes — after all, there's no point being ambiguous about your feelings when you're threatened. There are some differences between species, mostly depending on the intensity of the signal they're conveying.
At very low levels, when a crocodilian is best described as "slightly concerned," it will gape to expose the teeth and yellow tongue. It's an effective way of saying "Hey you! See these teeth? Don't try anything!" and is common to all species. If this doesn't work, the crocodile gets a little more agitated and typically begins to vocalize. The universal reptile signal for "I'm not happy with this!" is a hissing sound — air is passed through a constricted opening (e.g. nostrils or glottis) to create an unmistakable sound.
After this, the crocodile starts to get serious, changing its posture dramatically to make itself look more intimidating. The body is inflated to increase apparent size (a very volatile signal between crocodiles), small to medium-sized crocodiles often stand up if on land, and most species arch the tail if in water. Many species, if standing, tilt their body axis toward the attacker, perhaps to present a more armored surface to potential attack. If the threat persists, then most species become more active — some twitch or flick their tails, some produce fluttering infrasounds or vibrate their entire bodies to send pressure waves through the ground or water, some produce groaning vocalizations and some snap their jaws together. In water, several species will "bite" the water and produce a loud popping noise and plenty of bubbles. Intimidation is the key word here.
At any stage during this routine, the crocodile may decide to flee if it doesn't feel secure. Alternatively it may attack. Again, the type of attack can vary — some species try and bite, some will use their heads as sledgehammers and literally smash an opponent, some will rush or swim toward the threat from a distance, even chasing them onto land or galloping after them for a few steps!
Ultimately, all this posturing serves a simple purpose — to avoid an attack unless absolutely necessary. Violence is not always desirable because the crocodile risks injury, whether it's fighting a rival or facing a potential predator. Most individuals will flee first or try and bluff their way out of an encounter. As humans, it's a good idea for us to learn the basic crocodilian threat signals! The best advice is always to maintain a respectable and safe distance.
