In Ancient Egypt, the Nile crocodile (Crocodylus niloticus) was considered a sacred animal, so much so that roy alty raised these animals in their temples and gardens. The god Sorek, who took the form of a crocodile, was the Egyptian deity of fertility. To understand why, it is enough to know a little more about the reproduction of these great reptiles.
Crocodiles (order Crocodylia) can have dozens of young in a single breeding season. This is not a very common feature in other animals of this size. In addition, crocodiles present a series of very particular mating and reproduction rituals. Do you want to meet them? Don't miss this article on our site in which we tell you how crocodiles are born, from courtship to the care that females give their young.
Characteristics of a crocodile
Before knowing how crocodiles are born, we must ask ourselves what a crocodile is. As we explained in the article on Types of crocodiles, the order Crocodylia includes gharials (Gavialidae), alligators and caimans (Alligatoridae), and true crocodiles (Crocodylidae). Despite their differences, all these reptiles have a number of characters in common.
- Anatomy: Crocodilians have their bodies covered with scales or hard plates that protect them. They all have a strong tail that they use to swim and propel themselves towards their prey. Their powerful jaws allow them to hunt very large animals. Their nose, located on the front of their heads, gives them the ability to breathe while submerged in water.
- Sexual dimorphism: Although females develop and grow earlier, males can reach considerably larger sizes. Also, their behavior is different. Males are often more dominant and violent, so they spend a lot of effort defending their territory.
- Semitterrestrial: They can spend many hours both in and out of the water.
- Freshwater or S altwater: Alligators and gharials always live in freshwater habitats. However, true crocodiles can inhabit s alt water, such as s alt marshes or mangroves.
- Ectotherms: Like all reptiles, they are cold-blooded animals. This means that they cannot regulate their body temperature on their own, but need to bask in the sun to warm up.
- Carnivores: All crocodiles eat other animals. However, their diet is very varied among the different species. Therefore, they can eat animals as diverse as a dragonfly, a fish or a buffalo.
- Social behaviors: Most crocodiles have a gregarious behavior. As a cause or consequence of this fact, these animals communicate with each other through visual, acoustic and chemical signals (hormones).
- Oviparous: female crocodilians lay eggs. This feature gives us a clue about how crocodiles are born.
- Parental care: as we will now see, mother crocodiles take care of their eggs and their young.
On the other hand, it should be noted that crocodiles are very long-lived animals, being able to live up to 80 years. In addition, crocodiles are archosaurs, meaning that their ancestors, who appeared 250 million years ago, were among the few that survived the Cretaceous-Tertiary extinction. That's right, the crocodile is a descendant of the dinosaurs
How do crocodiles reproduce?
The reproduction of crocodiles is sexual, that is, the union of a female gamete (ovum) and a male gamete (sperm) is necessary for the formation of a new individual. As we discussed in the article on How crocodiles reproduce, these huge reptiles are polygamous A single male can mate with more than a dozen females during the mating stage. reproduction.
To get a group of females, the males must dispute the territory in which they live. The winner will mate with the females, but not before perform a mating ritual This consists of swimming together, putting their bodies in contact and emitting acoustic signals. If the female agrees, they dive under the water. It is then that the male climbs on top of the female and inserts her curved penis into her cloaca
When copulation is over, the females begin to mark the territory where they are going to lay their eggs. In some species, several females nest together and protect each other's territory. Even so, it is common for them to defend the specific place where they are going to lay their eggs. This is because they all want to spawn in the most sheltered and sunny spot. Now we will see why.
How are crocodiles born?
The conditions in which crocodiles hatch are very different for each species. However, there are a number of common characteristics in their nesting, birth and parental care. Let's see them!
Crocodile nests
The story of how crocodiles are born begins with the construction of the nest by their mothers. Although this is very different in each species, there are two basic structures: the mound and the hole. All females begin by scraping the soil from the banks of the river or lake. Thus, they remove the vegetation, leaving only the sand. Then they build a mound of earth or dig a hole It is in these places that they lay their eggs.
Crocodile eggs are laid at night and can last between 1 and 2 hours. When they are finished, the mothers-to-be reshape the nest to hide the eggs, covering them with soil and/or plant debris. For this reason, the incubation of the eggs depends only on the temperature of the sand. When the earth is too cold or too hot (35°C or more), the embryos die and the little crocodiles never hatch. For this reason, it is feared that climate change will affect their reproduction.
In addition, the temperature of the sand determines the sex of the young A low temperature (29-31 ºC) determines that the young crocodiles are female, while a higher temperature (about 33 ºC) causes them to form males. When crocodile eggs are incubated at a temperature of 32ºC or higher than 34ºC, both males and females appear. Sex determination by temperature also occurs in the reproduction of turtles and other reptiles.
Unlike most reptiles, mother crocodiles visit their nests very frequently. In this way, they protect the eggs from possible predators and ensure that the incubation conditions are the most suitable. If the nest suffers a mishap or is exposed, the mother-to-be will be there to fix it. However, in some species the females barely guard the nest. Nest guarding has been detected in males on rare occasions.
Birth of crocodiles
Crocodile incubation lasts between 2 and 3 months, depending on the species and environmental conditions. When the crocodile eggs hatch, the female helps her little ones getout of the sand. This is how crocodiles are born. Oddly enough, the young are so small that they fit in their mother's mouth. In fact, she puts them in it to transport them from the nest to the water. Once there, some females build a second nest to protect her litter
In many species, the mother crocodile is not alone, but several mothers come together to defend the young against potential predators. In other species, however, the female defends the territory against any intruding crocodile. The little ones, for their part, collaborate by emitting vocalizations. Thus, they inform their mother about the presence of danger or when they are hungry. In this way, the group remains cohesive for several months or up to 2 years in some species.
