Big Cypress

National Park Service

U.S. Department of the Interior

Big Cypress 

National Preserve

American Alligator

The American alligator (Alligator mississippiensis) is an amazing reptile that has remained unchanged since the time 

of the dinosaurs. The alligator is the symbol of wildlife and of untouched lands in the Southeastern United States. The 

early Spanish settlers to South Florida were amazed by the largest lizard they had ever seen, calling it “el legarto” 

meaning “the lizard.” The term has evolved to alligator, but the feeling is still the same. 

Crocodillians have survived for millions of years and their species has changed relatively little over time other 

than in overall length. As living fossils passed down from 

prehistoric times, these relics from the past are incredible 

for their tenacity. They are the planet’s largest living reptiles. 

Part of their success can be explained by their anatomy. 

Armed with sharp conical teeth, muscular tails and tough, 

scaly skin, they are extremely efficient predators. 

A Stealthy Hunter

Known for their strong bite, the American alligator can 

exert massive pressure per bite, inflicting one of the most 

powerful bites in the animal kingdom. The jaws, however, 

are not the only weapon in the alligator’s arsenal. Like 

other nocturnal animals such as owls, the eyesight of an 

alligator is exceptional at night. Like cats, the alligator has 

a thin layer of special reflecting tissue behind each retina 

called a tapetum lucidum. This tissue acts like a mirror to 

concentrate all available light during the darkest of nights. 

It also causes the eyes to reflect when caught in a flashlight 

beam. A secondary set of eyelids, known as the nictitating 

Alligator or Crocodile?

• Alligators have a broader snout than a crocodile.

• The bottom teeth of the alligator are mostly hidden when 

the mouth is closed. The crocodile’s teeth are always 

visible. 

• Alligators tend to be grayish-black in color, but 

crocodiles have a grayish-green appearance.

• Crocodiles have a salt excreting gland in their mouths 

making them comfortable in saltwater. The alligator 

lacks these glands, and is therefore found more often in 

freshwater.

• In the US the alligator is much more common and is 

usually larger than the crocodile.

membrane, act as underwater goggles, allowing the alligator 

to see underwater. Alligators can stay underwater for much 

longer than humans. A typical dive might last 10-20 minutes. 

In a pinch an alligator can stay submerged for up to two 

hours if it is at rest. And, in very cold water, an alligator can 

last up to eight hours submerged.

What’s for Dinner?

Alligators are carnivorous. Their very strong jaws can crack 

a turtle shell. They eat snails, invertabrates, fish, birds, frogs, 

and other mammals that come to the water’s edge such 

as raccoons, otters, white tail deer, and even small black 

bears. They use their sharp teeth to seize and hold their 

prey. Smaller prey is swallowed whole, and larger prey is 

ripped into smaller, more manageable pieces. If it is very 

large, alligators take a bite, and spin on the long axis of their 

bodies to tear off smaller more easily swallowed pieces. 

Despite being a top predator, the alligator may only feed 15-

20 times per year with the majority of feeding taking place 

during the spring months. 

NPS/Niki Butcher
EXPERIENCE YOUR AMERICA

A juvenile alligator takes in some sun on a branch. 

Habitat

Out of the 11 species of crocodilians found throughout the 

world, the American alligator inhabits the coldest regions. 

The geologic flatness of Florida provides the alligator with 

ample sunshine throughout the day, which is necessary for 

the cold-blooded creature to survive. The Florida ecosystem 

also provides many millions of gallons of freshwater daily, 

which allows for easy hunting. The clear water helps the 

alligator to see and selectively choose the best prey from 

a distance. The Big Cypress Swamp is especially attractive 

to the alligator because of its protected status. There are 

over 729,000 wild acres, which offer the alligator abundant 

habitat to live and hunt with limited human interaction. This 

ecosystem allows the alligator to live between 35-60 years 

old.

New Family

Most alligators become sexually mature before reaching 

seven feet in length, although females can reach maturity 

at six feet. It may take 10–15 years for a female to reach this 

length and a male 8–12 years. Courtship begins in early 

April, and mating occurs in May or June. In late June or 

early July females deposit an average of 32-50 eggs into a 

mounded nest that she builds out of soil and vegetation. 

The eggs incubate and hatch after approximately 60-65 days, 

which typically occurs in late August or early September. 

Sex of the young is determined during the first three weeks 

of incubation. Warmer temperatures inside the nest will 

produce males, while eggs at cooler temperatures will 

become females. Unlike almost all other types of reptiles, 

the female alligator will raise her young for up to three years 

after birth. Eighty percent of all newborn alligators do not 

make it to adulthood as they are a preferred food source 

for many wading birds and other animals. The mother’s 

presence provides some protection to the young until they 

are old enough to fend for themselves. 

Survival Story 

The American alligator has been a vital part of the South 

Florida ecosystem for millions of years. From the late 1800s 

through the early 1900s, the alligator was hunted to near 

extinction as a food source as well as for their hides which 

are used to make alligator leather. In 1962, a Florida law 

was passed to protect the alligator. Part of this law included 

the creation of alligator farms to provide meat and hides, 

helping to keep wild numbers high. Since the inception 

of the Florida law, the alligator population has increased 

to more than one million in Florida. While no longer a 

threatened species the alligator is still protected under 

Florida law due to its similarity to the endangered American 

crocodile. 

Living With Alligators

Every day in the state of Florida there are over 400 new 

residents moving in and calling Florida home. As the human 

population grows there is a greater chance of an alligator 

encounter. There are a few things to keep in mind as we live 

in closer proximity to these prehistoric reptiles.

Under no circumstances should you ever approach an 

alligator; they are very agile even on land. There have been 

reports of alligators running at speeds of over 15 mph, 

much faster than a human. Stay alert when you are around 

any body of water; there is a good chance that there is an 

alligator inhabiting the waters surrounding you. Always keep 

pets safe when in alligator territory; keep them on leashes 

and within your sight at all times. Never swim in areas 

alligators inhabit unless otherwise posted for swimming. 

The American alligator, as with all wild animals, deserves 

respect and should be given the same courtesy.

Did you know?

The largest alligator measured in the United States was 19 

feet two inches, from the state of Louisiana. In Florida, the 

largest alligator ever measured was 17 feet five inches. 

References

US Fish & Wildlife Service www.fws.gov/species/species_accounts/bio_alli.

html

Florida Fish & Wildlife Commission www.myfwc.com/gators/

Florida Museum of Natural History: www.flmnh.ufl.edu/cnhc/cbd.html

NPS/JAN SHIREY

American Alligator_FINAL.indd on HQ shareall, interp publications: 4,000 printed 10/2010, stored at Oasis & WC