Nile Crocodile information

The Nile Crocodile, Crocodylus niloticus, is an African crocodile that can reach a length of at least six meters. It is spread throughout a significant part of the African continent and used to be present in parts of the Middle East as well.

Nile Crocodile taxonomy

Kingdom:      Animalia
Phylum:         Chordata
Class:            Reptilia
Order:           Crocodylia
Family:          Crocodylidae
Subfamily:    Crocodylinae
Genus:           Crocodylus
Species:         Crocodylus niloticus

Nile Crocodile conservation status

Crocodylus niloticus is listed as Least Concern on the IUCN Red List of Threatened Species.

The estimated wild population is comprised of 250,000-500,000 individuals.

Several parts of Africa (e.g. Botswana, Ethiopia, Kenya, Zambia, and Zimbabwe) are home to thriving populations and successful management programs, but there are also poorly surveyed regions where the status of this species remains unclear, particularly in the central and western parts of its range.  

The Nile crocodile was extensively hunted during the mid 20th century, chiefly for its hide but also for its meat and to be used in the field of alternative medicine. After being on the brink of extinction the species has now made a remarkable recovery thanks to national legislation and protection and international trade regulations. Sustainable-yield programs based on ranching have proven successful, especially in southern and eastern Africa.

The main threat to the Nile crocodile is no longer hunting but habitat loss, pollution and entanglement in fishing nets.

Nile Crocodile range

The Nile crocodile is not restricted to the River Nile; it is actually spread throughout a large part of the African continent and is found in the following African countries: Angola, Benin, Botswana, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Congo, Côte d'Ivoire, Egypt, Ethiopia, Equatorial Guinea, Gabon, Gambia, Ghana, Guinea, Guinea Bissau, Kenya, Liberia, Madagascar, Malawi, Mali, Mozambique, Mauritania, Namibia, Niger, Nigeria, Rwanda, Senegal, Sierra Leone, Somalia, South Africa, Sudan, Swaziland, Tanzania, Togo, Uganda, Zaire, Zambia, and Zimbabwe.

Earlier, the Nile crocodile was also found in Algeria, Jordan, Israel and the Comoro Islands but the species have now gone extinct there. The extinction was partly caused by climate change and the resulting loss of wetland habitats.

Nile Crocodile habitat

The Nile crocodile is found in both freshwater and brackish conditions, e.g. lakes, rivers, swamps, and brackish coastal habitats. 

Nile Crocodile size and appearance

How large is a Nile crocodile?
The Nile crocodile is a large crocodilian where the males average at 3.5-5 meters (11.5-16 feet). Some specimens grow even larger and confirmed reports of 6 meter (20 feet) long Nile crocodiles do exist. Reports of 7 meter (23 feet) specimens can also be found, but they remain unverified. Mature females typically meassure 2.5 to 3.9 meters (8 to 13 feet).

Some studies indicate that Nile crocodiles living in the cooler parts of the species range, e.g. South Africa, stays smaller and average around 4 meters (13 feet). There are also two known Dwarf populations of Nile crocodile; one in Mali and one in the Sahara Desert. In these environments, adults average at 2-3 meters (7-10 feet).

How much does a Nile crocodile weigh?

Male Nile crocodiles usually weigh around 1100 lbs (500 kg), but occasional specimens do reach a weight of roughly 2000 lbs (900 kg). The female is considerably lighter than the male and mature females typically stay within the 500-660 lbs (230-300 kg) range.

How big is the biggest Nile crocodile?
The largest scientifically measured Nile crocodile was 6.45 cm (21.3 ft) long and weighed approximately 1,090 kg (2,400 lbs). It was a male specimen shot near Mwanza in Tanzania. Reports of larger Nile crocodiles remain unverified.   

One of the most famous large Nile crocodiles is an alleged man-eater named Gustave. Gustave lives in Burundi and is believed to be approximately 23 feet (7 meters) long. Gustave has not been scientifically measured and attempts to catch him have been unsuccessful.                                                                                                 
Giant Nile crocodiles are believed to have been more common before the extensive hunting of the mid 20th century and the destruction of African wetland habitats.

Nile crocodile appearance
Juvenile Nile crocodiles are grayish to dark olive brown and adorned with black cross-banding on tail and body. The belly is yellowish. As the animals mature, their bodies become darker and the banding becomes less and less distinct.

Adult Nile crocodiles are dark bronze with yellow green flanks and the belly is of a dirty purplish shade. The back is dotted with black spots while the flanks sport dark patches arranged in oblique stripes. The eyes are green.

Nile crocodiles living in swift flowing waters are usually somewhat lighter in color compared to those found in slow moving waters like swamps.

Nile Crocodile mobility

The Nile crocodile normally crawls on its belly, but it is also capable of “high walk”. Small specimens are known to gallop, but this has not been observed in larger individuals. Nile crocodiles can reach speeds of up to 14 km/h (8.5 mi/h) during short bursts, e.g. when carrying out surprise attacks on prey.

When swimming, the Nile crocodile can move at speeds of 30-35 km/h (19-22 mi/h) for extended periods of time. It swims by moving body and tail in a sinuous fashion. 

Nile Crocodile feeding and diet

Nile crocodile hatchlings feed chiefly on insects and aquatic invertebrates, and will then gradually start including amphibians, reptiles and birds in their diet as they grow larger.  

Large Nile crocodiles are apex predators that can overcome almost any animal that ventures close enough to the shoreline, but a significant part of the diet consist of fish and other small vertebrates even for these giants.

The Nile crocodile is famous for killing midsized to large mammals such as warthogs, waterbucks, lechwe (a type of antelope), sitatunga (another type of antelope), wilderbeest, zebras, and young hippopotamuses. It will readily prey on domestic animals like goats, sheep and cattle. 

Really big specimens can even eat giraffes and Cape buffalos, and there is at least one record of a group of crocodiles killing a female Black Rhinoceros. Predators like hyenas, leopards, lions and other crocodiles can also be killed, especially if prey is scarce. If given the choice even large Nile crocodiles will however prefer to attack less risky animals to avoid getting injured in the struggle.

As mentioned above, Nile crocodiles are capable of working together to catch prey and have for instance been seen using their bodies and tails to herd groups of fish towards the shoreline or block migrating fish by positioning themselves in a semicircle across a stream or river. When crocodiles hunt together, the most dominant member of the group will eat first.

If provided with the opportunity the Nile crocodile gladly scavenges, even on animals killed far from the shore, but it will avoid rotting meat.   

Nile Crocodile breeding

Sexual maturity
Females reach sexual maturity at around 6.5-8.5 feet (2-2.5 metres), while males have to wait until they’re about 10 feet (3 metres) long. Under normal conditions, these lengths are not attained until crocodile is roughly 10 years of age.  

Courting
During the mating season, the male crocodile will try to attract females by slapping his snout in the water, bellowing, blowing water out of his nose, and make a variety of enticing sounds. Generally speaking, the largest males are the most attractive ones in the eyes of the females. When the male has managed to catch the fancy of a partner, the couple will warble (“sing”) and rub the underside of their jaws together. 

Nesting
About two months after mating, the female will lay 25-80 eggs in a hole excavated by her. Nesting takes place in November and December, i.e. during the dry season in northern African and at the onset of the wet season in southern Africa. The female prefers to excavate the nest in a riverbank, sandy shore or dried out stream bed. The nest is typically placed several metres from the water and can be up to 50 cm (20 in) deep. Sometimes, several females nest near each other.   

Parental care
The female will stay near the nest during the incubation period, and it is also common for the father-to-be to protect stay in the area. Both parents will chase away anything that comes close. Despite this, it is common for crocodile eggs to be eaten by animals such as lizards and hyenas, typically when the parents have to leave the nest to thermoregulate in the water. 

When the eggs hatch after 70-100 days the female will aid the offspring by opening the nest as soon as she hers the characteristic high-pitch chirpings emitted by emerging crocodile hatchlings. Both males and females have been observed helping the young by carefully cracking the eggs open using their tongue and upper palate.  The female will then lead or even carry the young to the water.

The female will protect the offspring for up to two years and may form a crèche with other mothers in the area. Females have been observed protecting their young by placing them inside the mouth or in the throat pouch. The mother can also let the young ride on her back.   

Juvenile crocodiles
Hatchlings are roughly 30 cm (12 in) long when they emerge from the egg and will be roughly twice that length at the end of their first year. At an age of two years, when the crocodiles are around 1.2 m (4 ft) long, they will leave the breeding territory to avoid confrontation with territorial adults.  

Sex ratio
The sex of Nile crocodiles depend on the average temperature in the nest during the middle third of the incubation period. Males are only produced within the 31.7-34.5 °C (89.1-94.1 °F) range. If the temperature is lower or higher, the offspring will be female.

Nile Crocodile facts

Nile Crocodile facts # 1
Crocodylus niloticus means “Crocodile of the Nile River”. The first part of the name, Crocodylus, is derived from the Greek word krokodeilos which literally means "pebble worm". Kroko is Greek for pebble while deilos means worm or man. The name is a reference to the rough skin of the crocodiles. 

Nile Crocodile facts # 2
Within its native range the Nile crocodile is known under many different names, such as Mamba in Swahili, Ngwenya in Ndebele and Garwe in Shona.

Nile Crocodile facts # 3
The Nile crocodile will normally dive for no more than a couple of minutes, but it can hold its breath for up to two hours if it stays inactive. It is equipped with a four-chambered heart that is very efficient at keeping the blood oxygenated.

Read more Nile Crocodile facts

Nile Crocodile lifespan

Since crocodiles belonging to large growing species tend to have longer lifespans than those belonging to small growing species, the Nile crocodile is believed to have an average lifespan of 70-100 years.