When learning about crocodiles and alligators, most people wonder if they can reproduce together. It’s easy to see why someone would think so, as both crocodiles and alligators share similar habitats and appearances.
Crocodiles and alligators cannot mate due to both animals being different species despite originating from the same genetic ancestor over 95 million years ago and looking extremely similar. While some crocodiles can hybridize, no study has found that these two animals can produce viable offspring.
Read on to learn more about the similarities and differences of the members in the order of Crocodilia and why they cannot form a hybrid!
The Order of Crocodilia
The order of Crocodilia is the closest living relative to birds as they both are the last known survivors of the Archosauria, a clade of diapsids that also once included the now extinct non-avian dinosaurs.
The order of Crocodilia is comprised of true crocodiles, alligators, caimans, and the gharial and false gharial. This group can be colloquially called crocodiles but often in order to reduce confusion from the true crocodile, they are referred to as crocodilians.
As a large reptile, crocodilians have many similarities across the species in appearance and similar habitats, with many of the differences leading to small divergences attributed to the differences in salt and fresh water and their further environments.
American Alligators
Alligator Appearance
Alligators have broad snouts, and have four legs, with the forefeet having five separate toes while the hindfeet have four webbed toes. Juvenile alligators have yellow cross banding over black, creating effective camouflage that slowly fades as they mature.
Their adult coloration varies between habitats and can range from olive, brown, grey, or nearly black with a cream underside. Female alligators tend to reach maturity at 6 feet in length but grow to be around 8.5 feet while male alligators range from 9.8 to 15 feet.
Habitat
American alligators live in the southeastern United States and those that live in the Everglades National Park live in the southern extreme of the range. Alligators are a freshwater species that can tolerate a degree of salinity for short periods and can occasionally be found in the brackish mangrove swamps that crocodiles live in.
They primarily live in and around freshwater swamps and marshes, in freshwater rivers, lakes, and smaller bodies of water.
Their dens are burrowed into the shore and dry land and used as shelter and a safe place for torpor when the winter temperatures fall — or in the Everglades — when the conditions are very dry. Alligators can tolerate a short period of freezing conditions so it is not an instant death sentence if they are outside of their dens.
Mating Habits Of American Alligators
The mating season for alligators occurs in the spring and summer. Male alligators use a mixture of a ritualized mating dance and scents to attract mates by raising their tails and smacking the water with their jaws. Once a female alligator has come over to investigate, there is a wrestling competition between the two of them as they rub and press each other’s snouts and backs.
If the female alligator deems the male as stronger and ‘better’ than other male alligators, they will further the courtship. A female alligator will mate several times during the season as alligators are not monogamous and will have several partners throughout.
A typical clutch of eggs ranges from 20 to 50 eggs. The mother alligator will remain near the nest during the incubation period of her clutch, which averages 58 to 63 days. The sex of the hatchlings is determined not by chance but by the temperature at which the eggs are incubated.
Male eggs incubate at temperatures ranging from 90 to 93 degrees Fahrenheit, while female eggs incubate at 82 to 86 degrees. Intermediate temperatures result in a mix of male and female hatchlings.
The mother alligator will then carry her hatchlings into the water using her tongue as a pouch in her mouth, 8 to 10 hatchlings at a time. The juveniles will stick together in pods which could include other hatchlings from other nests and remain close to the mother usually around one year but can sometimes last for two or three years. (Source)
American Crocodiles
Crocodile Appearance
Crocodiles have long muscular tails and four short legs with five toes on the front feet and four on the hind feet. Their narrow snouts are triangular and have the fourth tooth of their jaw on both sides visible when their mouths are closed.
Crocodiles eardrums are protected by flaps of skin that can move that are located behind the eyes at the top of their head. Their nostrils are located at the end of their snouts.
Due to the positioning of their eyes, ears, and nostrils, they can be submerged underwater, leaving only the top of their head above water, and still be able to see, breathe, and hear.
Males are bigger than females and can reach 20 feet in length in captivity. They rarely grow past 14 feet in the wild but certainly can. Females crocodiles range between 8 to 12 feet in length.
Habitat
Crocodiles live in the coastal areas of southern Florida, and can also be found in the islands of Jamaica, Cuba, and Hispaniola. They can also be found along the coasts of southern Mexico and Central America, Venezuela, and South America.
Crocodiles are ectothermic and regulate their body temperature by basking in the sun or moving to a location that contains either warmer or cooler water to shift their temperature.
American crocodiles build nests that are holes in mounds of sand and other earthy material.
Mating Habits Of Crocodiles
Male crocodiles will bellow at ranges that humans cannot hear, sending out infrasound vibrations that can be seen in the water and felt. Males will slap their snouts against the water, blow water from their noses and release an oily musk that floats along the water to entice female crocodiles.
The female will respond in the dance and eventually the two will get closer and rub snouts, ride on each other’s backs and even sometimes blow bubbles back and forth. Courtship can last up to several hours while the act of mating only lasts a short while.
Crocodiles are not monogamous and clutches will have mixed genomes from several different crocodile males in one clutch from the season. A clutch can range from 20 eggs to 60 eggs.
The mother crocodile will not spend time near the nest during incubation, often returning with more frequency as the eggs near hatching, assisting freshly hatched crocodiles to the water or other nursery sites where they are left to fend for themselves after several days.
Like alligators, crocodile eggs require specific temperatures to determine the sex of the offspring. Temperatures of 88 to 91 degrees Fahrenheit result in male hatchlings while anything below 88 degrees Fahrenheit results in female hatchlings. However, the viability of the hatchlings requires that the temperature must stay above 82 degrees Fahrenheit for at least 85 days.
Alligators and Crocodiles Living Together
Alligators considerably outnumber crocodiles in the US, especially in the Everglades. (Source)
Alteration to the Florida water ecosystem due to human development in Florida Bay has resulted in lower salinity and water levels. Crocodile nests that are either too wet or too dry have led to egg mortality and many suitable year-round crocodile habitats have been destroyed with the development of the Florida Keys.
However, despite the worldwide population of American Crocodiles being federally listed as endangered, the status of the Florida Everglades Crocodiles has been changed to threatened due to conservation efforts.
Alligators were once listed on the endangered list as well due to over hunting. Due to alligator farms and the Endangered Species Act of 1973, alligators are continuing to thrive and as of 1987 are no longer listed as endangered.
Though alligators and crocodiles might live in the same environment, alligators and crocodiles do not mate together.