Crocodile and alligator reproduction: from mating to nest
Crocodiles have a bad reputation because of their aggressive nature. Yet the mating ritual, mating and brood care are remarkably gentle. However, an aggressive dominant attitude of the male remains important in order to keep possible competitors at bay. The female crocodile takes care of her young for four years. Her maternal care might be considered excessive but there are many robbers lurking to eat her young. Compared to crocodiles, alligators reach sexual maturity much faster. There are more similarities between alligators and crocodiles when it comes to the number of eggs and the breeding time. What is the difference between a crocodile and an alligator? Are there any similarities or differences in the mating ritual, mating, and birth of the young?
- What is the difference between a crocodile and an alligator?
- The mating ritual of crocodiles and alligators
- The way of mating depends on the species of crocodile or alligator
- Crocodile and alligator nesting
- Sexual maturity, incubation time and number of eggs: an overview
- How does the birth of a crocodile or alligator go?
What is the difference between a crocodile and an alligator?
Typical features of crocodiles
The crocodiles mainly live in Africa, Southeast Asia, Australia and South America. There are fourteen different types of crocodiles. Their food consists mainly of birds and large mammals. You can recognize a crocodile by its teeth. For example, the teeth in the lower jaw fit between the teeth in the upper jaw. So you see, especially when the mouth is closed, the teeth of the upper jaw and those of the lower jaw.
Typical features of alligators
Alligators mainly live in North America and China. There are two types of alligators and they mainly eat fish, reptiles and mammals.
In alligators, one cannot see the teeth of the lower jaw as the teeth of the upper jaw cover them.
The mating ritual of crocodiles and alligators
The course in crocodiles
In the Nile crocodile, the males cough or bark and occasionally make a rumbling sound with their mouths open. The male will often use his aggressive dominance to drive off rivals. For example, he will fight with every possible competitor to impress the female he has his eye on or to defend his berth on the bank. In these fights it often happens that they lose a leg or that a rival is killed.
The behavior of the female
When a male is to the liking of a female, everything becomes much calmer. They then swim side by side until the female allows the male to mate. The female shows her submission to the male by briefly putting her head and tail under the water with a characteristic movement. The male responds to this gesture by rubbing his head on the female’s neck.
The course in alligators
It is quite noisy with the alligators. Alligator males roar loudly when in the water, causing their entire body to vibrate. These vibrations cause small fountains where their backs are still slightly submerged. The other alligators in the area do just the same, turning the mating season into a chorus of alarming roars.
The way of mating depends on the species of crocodile or alligator
The species of crocodile or alligator determines the way in which mating proceeds. The following two examples illustrate how different mating can be.
The Nile crocodiles
Mating in the Nile crocodiles usually takes place in the early afternoon, after they have spent a morning bathing in the sun. The dominant male lies down next to the female in the water. He presses his body against hers in twisting movements. He rubs the bottom of his jaws on the neck of the female. Only when the female agrees to this behavior and thus cooperates, does mating take place. Mating itself takes about two minutes. The male holds the female with his claws. The dominant male mates with most of the females in the group. This way he can mate several times during the same afternoon. It is true that he always rests for about an hour between each mating.
Before Missisipialligators mate, the male will court the female for a long time. He caresses the female with his front legs and rubs his throat on her neck. As a result, its throat glands emit a scent that should stimulate the female to proceed to copulation.
Crocodile and alligator nesting
Crocodiles lay eggs with hard shells. They usually bury them in a shady spot in a hole by the water. After mating, the male no longer plays a role. However, the female guards the nest for ten to twelve weeks until the eggs have hatched.
Nesting of alligators, caimans and Australian crocodiles
American alligators but also Australian crocodiles and some species of caimans build a nest. This nest consists of a round heap of plant material and is located above the ground. In that hope they lay their eggs. Because the plant material starts to compost, heat is released so that the eggs have a constant temperature of 30 to 32 degrees. The mother guards the nest after laying the eggs in it.
Do alligators make a nursery?
While they wait, mother alligators dig a pool close to the nest. This pool is a kind of nursery where the young can go just after birth. This provides the mother with better protection against potential dangers in the rivers.
Sexual maturity, incubation time and number of eggs: an overview
Number of eggs, sexual maturity and breeding time in crocodiles
The number of eggs depends on the species. This is also the case with the breeding time and the sexual maturity of the females.
|Kind of crocodile||Sexual maturity||Hatching time||Number of eggs|
|Nile crocodile (= Crocodylus niloticus)||After 10 years||11-13 weeks||50 to 80 pieces|
|Sea crocodile (= Crocodylus poropus)||After 10 to 15 years||13 weeks||20 to 90 pieces|
|Swamp Crocodile (= Crocodylus palustris)||After 6 years||8-11 weeks||10 to 50 pieces|
|Beaked Crocodile (= Crocodylus acutus)||With a length of 2.5m||12 weeks||30 to 60 pieces|
|Orinoco Crocodile (= Crocodylus intermedius)||After 7-10 years||6 -7 weeks||15 to 70 pieces|
|New Guinean Crocodile (= Crocodylus novaeguineae)||After 8-10 years||11-13 weeks||23 to 45 pieces|
|Siamese crocodile (= Crocodylus siamensis)||After 10-12 years||10 weeks||20-50 pcs|
|Australian crocodile (= Crocodylus johnsoni)||After 11 years||10-12 weeks||18 pcs|
|Armored Crocodile (= Crocodylus cataphractus)||After 10-15 years||13-14 weeks||13-27 pcs|
Number of eggs, maturity and breeding time in alligators
There are really only two types of alligators. That’s the Mississippi alligator, Alligator mississippiensis, and the Chinese alligator, Alligator sinensis. Females reach sexual maturity earlier in alligators than in crocodiles. Alligators are sexually mature after 4 years, while in many crocodiles this is only after 10 years.
Their breeding time is then again similar to the crocodiles. For example, the nesting time of the Mississippi alligator is 9 to 10 weeks. This is 10 weeks for the Chinese alligator.
The number of eggs depends on the species of alligator. For example, the Mississippi alligator lays 30 to 55 eggs. Now it is true that the older females lay more eggs than the young females. The Chinese alligator lays between 10 and 40 pieces.
Robbers on the coast
The main enemies of the crocodile females are monitor lizards and wild dogs during the breeding period. But raccoons also love the eggs.
How does the birth of a crocodile or alligator go?
The birth of a crocodile
The young of a crocodile hatch themselves from the eggshells. In this way their head comes out of the egg first, then their front legs and finally the rest of their body. The crocodiles can swim immediately after birth. They keep their noses just above the surface of the water so that they can breathe sufficiently. Their eyes also remain above water in order to better see what is happening.
The birth of alligators
The young of an alligator will not hatch themselves. When the shell breaks, they stay inside and only stick out their snouts. When they notice the vibrations of their approaching mother, they begin to make a squeaking noise. The mother alligator responds to this squeaking sound by opening the nest mound and carrying the young away. She breaks the eggs that are not fully cracked yet with her jaws to free the trapped young. The American mother alligator carries the young to the nursery where they can stay safely in the pool.