Tail as old as time

Alligators and crocodiles are both members of the reptile order Crocodilia who’s evolution can be traced back to the Jurassic and Cretaceousperiods, more than 150 million years ago!

Although they may look similar, scientists have estimated that alligators and crocodiles diverged (started evolving to become separate groups) about 80 million years ago!  

My, what a lot of teeth you have! 

All the better to hold and shake my prey with! 

Alligators are ambush predators, they wait hidden in the water for an animal to get close to the water's edge, before they lunge towards the unsuspecting prey.  

Once an alligator catches its prey in its mouth, it holds on so tight and may shake its head so hard to subdue its meal that it may lose a few teeth. But not to worry, they have up to 80 teeth in their mouth at any one time, and can have up to 3,000 teeth throughout their lifetime! 

Scientists have measured the bite force of an alligator when clamping its mouth shut. The strongest bite measured had a force of more than 9,000 newtons. That’s the same as having 900kg on top of you; the same as three adult zebra or two grand pianos! With a bite force like this, it is not unusual for alligators to have a few fractured teeth in their mouth before shedding and replacing them. 

Despite being able to clamp their mouth shut with such huge force, alligators don’t have very strong muscles to open their mouths. This is why humans can hold an alligator's jaws shut with their hands if they need to restrain them.

The age-old issue: who is who?

There are two quick ways to tell the difference between two distant relatives, alligators and crocodiles: 

When viewed from above, does it have a blunt and rounded ‘U’ shaped snout? 

  • Yes - Alligators
  • No - Crocodiles have a elongated and pointed ‘V’ shaped snout  

Are the lower rows of teeth hidden when its mouth is closed? 

  • Yes - In alligators the upper jaw is wider than the bottom jaw, this means their bottom teeth are hidden when their mouth is closed. 
  • No - Crocodile jaws are more similar in width, so usually both sets of teeth can be seen when their mouth is closed.   

At the Zoo

Our alligators live along the South America Rainforest Track.  

When peering over the edge of the bridge you might be able to tell the difference between them. But good luck if they are submerged in the water! 

Basking lights- enough to make any ‘gator grin

Alligators are ectothermic. This means they use the temperature around them to control their body temperature; the colder it is outside, the colder they are internally, which starts to make it hard to function properly! 

At the zoo the alligator habitats have basking lamps that provide them with artificial sunbathing opportunities even when it’s not actually sunny. Access to these heat lamps and the cool pool is important year-round to allow our alligators to regulate their temperatures.

Their habitat also features varied terrain, substrate, shade and light levels, all providing natural ways for the alligators to thermoregulate. 

Extreme dieting!

Alligators are opportunistic carnivores, eating what they can, when they can, and their prey is usually relatively small. At the zoo the alligators get a varied diet including fish, eels, rats, chicken, pigeon and rabbit which they swallow whole, bones, fur, feathers and all – just like they would in the wild This provides them with important nutrients and replicates natural feeding behaviour.   

They don’t need to eat often, maybe once every few days in the summer. When the temperature isn’t warm enough the alligators metabolic processes don’t function well enough to digest food so over colder months they stop eating all together for about 3 months!

Close enough for a check-up

Like any other animal at the zoo, the keepers check on their well-being daily. They do this by monitoring their appetite, their behaviour, their posture, and their activity. When anything looks unusual the keepers organise a closer look. This requires at least three keepers and some special tools and techniques to keep everyone, keepers, vets and alligators, all safe during an examination.

In the Wild 

Origin: The American alligator is found across the south-eastern states of the USA. The only other alligator species alive today is the Chinese alligator – a Critically Endangered distant relative from the Yangtze River.

Caiman are also in the alligator family, at least half a dozen species of which are found throughout Central and South America.

Habitat: Found in and near fresh water sources like swamps and marshes, lakes, rivers and increasingly golf courses and even peoples swimming pools! 

Conservation status: Least concern.

Other South American Species