In Botswana, crocodiles are most commonly found in and around Chobe River and the Okavango Delta. They reside in lakes, rivers and swamps and can be spotted in estuaries and mangrove swamps.
The Nile crocodile can exceed 1000kgs in weight, the weight of the average SUV. The skin of the Nile crocodile is covered in geometrically arranged, horny plates. The horny plates found on top of the crocodiles head are fused to the skull. 40% of their body length is made up of its tail which has two raised dorsal keels.
Young adult crocodiles are green with unusual black markings on its back and sides while its throat and stomach are straw-yellow. Young crocodiles dig a hole up to 3 metres long which for the first 3 to 4 years of their lives they use as a shelter. They don't spend much time in water
. As they get older they take up residence in backwaters and swamps, eating small birds, fish, Terrapins and small mammals.
Adults are darker and are olive to grey in colour with a yellow belly. Adults overcome their prey with a fast, sideways swipe of the head. They also use their tail to knock over vegetation to remove residing birds in nests or redirect fish into their mouths.
Crocodiles eat large prey by biting them into smaller pieces. They participate in what is known as supportive behavior, where the reptiles will cooperate in feeding on and breaking up prey to sizeable amounts. Crocodiles mainly eat fish (Catfish) but will also ambush and fest on game meat
such as antelope including Zebra and Buffalo. They can also be a danger to humans, as they will attack them and injure them or devour them.
On hot days, Crocodiles enjoy tanning in the sun on sandbars and river banks. Crocodiles loose excess heat by lying with their mouths open
on hot summer days. They also enjoy swimming as it is a completely effortless task, they use their tails and webbed feet to allow careful maneuvering during mating and when preparing to ambush prey.
A Crocodiles nostrils and jugular close at the back of their mouth to help them breath under water. Crocodiles can live up to 60 to 100 years of age.
©Crocodiles sun themselves on the Chobe's banks
Crocodiles reach their sexual maturity when they are 12 to 15 years of age (2 to 3 metres, 70kg to 100kg). They take good care of their young, though males may eat them. Males struggle for the right to mate in a social hierarchy during mating season. Mating takes place in water between July-August
. The female will then select a suitable sunny sand bank above the flood waters mark, that has a good drainage and cover nearby. The female will then use this sand bank for the rest of her life unless it has been damaged.
During November months the female will dig a hole 30 to 40cm deep
, and lay anywhere between 16 to 80 hard, white eggs. The nest is then heavily protected against predators and other Crocodiles. Until the eggs hatch, the mother will refrain from eating and jealously guard the nest.
The eggs will hatch between 84 and 90 days
after they have been laid. When they hatch they can be heard by their loud, high pitched chirping sound that can be heard up to 20m away. The female will then carefully open up her mouth for the young ones to climb in and then take them down to the water where she will release them, staying close together in a group for 6 to 8 weeks.
The sex of each hatchling is determined by the incubation temperature of the egg. Females are produced in temperatures between 26 to 30 degrees and males in a higher 31 to 34 degrees.