The crocodile life cycle has four stages.

The Fascinating Crocodile Life Cycle

Jane Marsh - July 1, 2024

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Crocodiles look like living fossils. For those who love dinosaurs, looking at them feels like looking into the past, even though they are not directly related. However, they and other reptiles share a similar aging process that has varying developmental stages. Learn more about the fascinating world of the crocodile life cycle, as well as crucial information about the species.

What Are the Four Stages of the Crocodile Life Cycle?

The four stages of crocodile development are egg, hatchling, juvenile, and adult. Explore the many exciting details of each stage.

Egg

To start things off, a female crocodile will lay what is called a clutch of eggs near a body of water, preferably within mud and plants. She will stick around to incubate the eggs and guard them from predators looking for an easy snack. These impressive moms can lay up to 60 eggs per breeding season and must guard their clutches for around three months while they develop.

Fascinatingly, the temperature at which the eggs incubate determines the sex of each hatched crocodile. Temperatures above 86˚ Fahrenheit — or 30˚ Celsius — indicate that all the babies will be male. When they go below that mark, the clutch will hatch only females. This process is known as temperature-dependent sex determination.

Hatchling

Next comes the hatchling stage. When the infant crocodiles are ready to emerge, they break their shells open with what is called an egg tooth. This small growth — not really a tooth at all — helps them crack open their little homes and will fall off a bit after they hatch. The adult female who laid them will occasionally use her teeth to help the babies if their egg teeth are insufficient.

She will carry all the fresh hatchlings to the water in her mouth to keep them from becoming prey once again — and for a good reason. Some species of crocodile will only have one hatchling reach adulthood per 25 babies hatched. The eggs and infants have many predators — sometimes even bigger crocodiles — so the female must stay on guard.

Following hatching, the new crocodiles can catch their own food, but they will stay with their moms or in hiding for the next couple of years. They need to stay safe until they are big enough to fend off attackers. At this stage of their lives, they eat small critters like snails, small fish and crustaceans, insects, and tadpoles.

Juvenile

A crocodile will stay in the juvenile phase of its life from 2 to 8 years of age. During this time, the now-pre-adults will practice catching bigger prey like fish, frogs, and birds so they can reliably obtain meals in adulthood. This preparation includes the patience and stealth they require to snag their food every time.

Now is also the time for the juveniles to learn the many ins and outs of the crocodile social structure. The biggest males will always have the best basking spots, and while most species are not territorial, the little ones might get a harsh welcome if they do not act accordingly. However, saltwater crocodile males will not accept any other males in its space. Additionally, females get first priority when a large kill comes in.

They must also know a few vocalizations. Some species can mean over 20 varying things with their calls, so knowing what they mean is a must. Infants will instinctively chirp or make distress sounds when they are hatching or threats are nearby. However, they must also learn the hatching call that means a female has laid eggs, the threat call to ward off danger, and bellowing, which males do during the breeding season.

Adult

A crocodile is considered an adult when it reaches 8 years old. At this point, they are ready to have babies of their own, but they have since learned which males have territory where. Freshly adult males must find their own spots where they can hunt and try to find a mate. As discussed before, they will make bellowing sounds to alert females of their presence.

The females must also find safe locations for their eggs. They often build two kinds of nests — holes in the ground and piles of mud and sticks. In the former, she lays the eggs in layers and adds sand in between them to distribute heat. This keeps them warm enough to incubate, and if the temperature gets too hot, she will add water to the surface to cool it down. The latter nest warms the eggs as the plant matter rots.

How Does Global Warming Affect the Crocodile Life Cycle?

Since temperature is so critical to crocodile egg incubation, the warming planet is naturally having effects. According to researchers, these increases can lead to cardiac arrest in embryos. Additionally, they can influence the size, survival rate, behavior, length of incubation, performance, and shape of hatchlings. Temperature is also a significant factor in sex determination, which means their ratios will change, affecting their communities and populations.

However, not all is lost yet for this ancient species. Scientists at the University of Bath’s Milner Centre for Evolution set out to study 20 types of crocodiles to see how global warming was currently affecting them. Incredibly, because female crocodiles spend so much time carefully choosing where they lay their eggs and burying them, they have greater resistance to temperature shifts. On the other hand, turtles lay their eggs at the same beaches, meaning they resist adapting to the variations and more females than males hatch.

At the moment, crocodile populations can change where they lay their eggs and dote on them enough to accommodate the new weather patterns. If the planet’s heat continues to climb, it may start to affect sex and behavioral variations in hatchlings that majorly disrupt the hierarchy and ability to reproduce.

The Intriguing Life of the Crocodile

The crocodile life cycle has several stages that are critical to the animal’s survival. However, shifts in the climate could affect those steps unless people take action. Learning more about this amazing creature and the direct influences of temperature changes can inspire individuals to adjust their habits to eco-friendlier ones and help save the crocodiles.

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About the author

Jane Marsh

Starting from an early age, Jane Marsh loved all animals and became a budding environmentalist. Now, Jane works as the Editor-in-Chief of Environment.co where she covers topics related to climate policy, renewable energy, the food industry, and more.