How Different Is Saltwater Crocodile From The Others

Australia has two types of crocodiles, the freshwater crocodile, which mainly eats fish, and is not considered a danger to man, and the saltwater crocodile, a true meat eater. Crocodiles are true dinasaurs, and have changed little in the evolutionary stakes over millions of years.

The Saltwater Crocodile, or 'Salty' as Australians refer to it, is found as far down as Broome on the western coastline, and Rockhampton on the eastern coastline. It inhabits the surrounding islands off the coastline also, and has been known to swim as far as 1,000 klms (620 miles) by sea to reach its destination.

In times of extreme drought, it has also been known to travel across land many klms to find a safe waterhole to ensure its survival. Although it prefers salt water, it can survive quite readily in fresh water. Its diet consists of fish and small mamals and birds, which venture too close or unwittingly near the waters edge. The Salty spends most of its time sleeping, and in summer avoids the hot sun, hunting mostly during the cooler hours of the day.

When hunting for food, the usual procedure is to expose only its eyes and nostrils above the waterline until prey is spotted, then sinking without a ripple, swims effortlessly underwater and attacks its prey from underneath the water, lunging upwards. Or moving with amazing agility and speed, will spring from the water and up onto the bank. Razor sharp teeth, and astounding jaw pressure ensures a firm grip on its prey, the salty then drags its hapless victim into the water and procedes to go into the 'death roll', rolling over and over and in the case of larger prey, such as buffalo or cattle, dragging its prey underwater where it consequently drowns.

In order to eat its food, it is impossible for the Salty to eat underwater, and food must be consumed on top of the water. A careful examination of the above photograph, you will notice a flap of skin at the back of the throat, this acts as a safety valve, closing whilst the mouth is open under water. This prevents it from drowning.

Saltwater Crocodiles have been recorded as big as 7 metres in length (23 feet). Although the most common length of a fully grown male crocodile would average 5 to 6 metres (18 to 20 feet).

It is impossible to judge accurately the age of a croc, unless a bone sample is obtained. Their bones have 'growth rings' much the same as trees. Salties mature sexually at around 16 years of age for males and 12 to 14 years of age for females.

The Basic Knowledge About Rare African Dwarf Crocodile

Deep in the swampy forests of West Africa, lies the dwarf crocodile, a miniature version of their large crocodile relatives. The crocodiles are so tiny they are not hunted for their skin, but for food. This has resulted in fewer of them remaining in their natural habitat. Will they become extinct?

Living in both terrestrial and freshwater ecosystems, the West African dwarf crocodile is five and a half to six feet in length. Built more like a smaller version of crocodiles of normal size, they are darker in color with a yellowish belly. Black patches cover their reptilian bodies, from the end of their tails to the blunt snout. The baby dwarf crocs are lighter brown with patterns sprawled out over the head.

These compact crocs consume fish, crustaceans and frogs, however, they will make meals of terrestrial animals, such as mice. Food sources will change with the seasons depending on the abundance of the various edible creatures. During the dryer season of Africa, they can be seen scooting around on land, searching for their next meal. The crocs fall under the category of carnivores.

As with the larger crocodile relatives, the dwarf crocodile has impressive jaw power to slam down on their prey with a powerful force, although they cannot bite off pieces and chew their prey. The jaw is set up for eating in larger amounts at one time, without the smaller jaw motions to consume the tinier bites. The side-to-side motion doesn't exist, although the powerful up and down movements seem to feed the crocodiles just fine.

Pulling clumps of rotting vegetation into a pile during the wetter season, the mother dwarf crocodile creates a compost heap, which works as an incubator to supply the eggs with warmth. One time a year, the female will breed, laying 10 to 20 eggs at a time. The mother guards the nest viciously until the hatching begins after a period of 85-105 days.

When the babies hatch, their mother escorts them into the water, ensuring their safety. Some babies may even stay with their mother for a period of a few weeks. Baby crocs stay in touch with their mom, even though she allows them the freedom to leave. From a distance, a strange twangy sound can be heard from the baby crocodiles. This sound is a form of communication from the tiny crocodiles, apparently to keep their mother informed of their location.

The African dwarf crocodile stay in shallower swamp waters, however they can swim quite well. They rely strictly on their tails for power, as do the larger crocodiles. Walking and even galloping on land is no problem for the crocs, to maintain speed even on dry ground. The dwarf crocodile is a solitary animal. Other reptiles have two chambers in the heart while crocodiles have four. Remaining in the burrows during the daylight hours, the smaller crocs come out to eat at night.

They hunt in the water, sliding along the banks in search for food. When the dry season rolls around, at least for the crocs living in the savanna areas, spending longer amounts of time in the burrows is common.

The dwarf crocodile species is vulnerable to changes in habitat and to the hunting habits of man. The crocs are often killed for food and due to this, they are categorized as a vulnerable species in the wild. In some places, the crocs are more abundant and higher in numbers, however they are diminishing in numbers in regions such as Gambia. Breeding programs exist in zoos to push the numbers of this species back up into safer numbers.

The International Union for Conservation of Nature lists the dwarf crocodile as "vulnerable". The population is decreasing, showing an obvious threat of extinction in Gambia and Liberia because of the hunting activities of local residents and the habitat destruction of the area. The smaller size makes the crocodile an easy target, along with the non-aggressive nature of the crocodiles, they are easier to capture and transport.

The international trade of the species is controlled and captive breeding is considered to keep the species at full numbers. Monitoring systems are being created at high priority status to clearly record the status of the West African dwarf crocodile as well.

The Common Knowledge About Nile Crocodiles

Length and weight:

Mature Nile crocodiles average 4 to 5 meters in length with exceptionally large specimens reaching 6 meters. Large adults can weigh over 1000 kg.

Habitat:

Crocodiles are found in most game reserves throughout Africa, taking preference to rivers, lakes and wetlands.

Diet and Feeding:

Their diet varies quite considerably depending on its age or size. Hatchlings prey mainly on insects, frogs, small fish and crabs. As they grow larger they then start preying off larger fish like catfish as well as birds.

Adults over 3 meters in length prey on birds, fish, various antelope species, monitor lizards, snakes, other predators including lions, leopards, hyenas, wild dogs as well as other crocodiles. Crocodiles are opportunistic predators and help clean water sources by feeding off any carrion they may find.

Animals caught by crocodiles are normally dragged under water, causing suffocation. Larger prey species, too large to be dragged under water often die from a loss of blood and shock as a result of a number of different crocodiles gripping and tearing off flesh at the same time.

When feeding off large prey, the crocodile, using its powerful jaws and gripping teeth, thrashes the prey around until small enough pieces to swallow are torn off.
Crocodiles feeding on the same animal under water grab hold of the prey with a tight grip and then spin their bodies in order to break pieces of flesh off.

Reproduction:

Nile crocodiles are sexually mature at about 12 – 14 years. Fertilization is internal with mating taking place in the water. When the female is ready to lay eggs, she then looks for a suitable nest site with sufficient cover.

A hole is excavated in a sand bank above the flood-line and after depositing a clutch of between 20 and 80 eggs she then fills the hole up with sand again.

The female is highly protective over her nest and defends the eggs from being eaten by predators such as monitor lizards, water mongoose, baboons and monkeys. During this period she does not eat but will on occasion drink water.

The eggs incubate for 3 months and on hatching the young make high-pitched cheeping sounds, which attracts the mothers' attention to the nest. The female then digs open the nest and using her jaws, she gently cracks open any unhatched eggs, once done she then carefully carries the hatchlings in her mouth to the river. The young crocodiles stay with their mother for about 2 months before leaving on their own.

What Is The Difference Between Alligators And Crocodiles

Alligators and crocodiles are both crocodilians; but from different families. There are three separate families of crocodilians: Aligatoridae include alligators and caimans, Crocodylidae include crocodiles and Gavialidae include only the gharial. This is only the difference in classification; there are many physical differences between the two animals.

Alligators are found in only two places in the world; the southeastern United States and in China. The Chinese alligator is classified as Critically Endangered by the IUCN. It is found in small bodies of water on the lower Yangtze River. Habitat destruction is the biggest culprit as more and more Chinese land is converted for agricultural uses – we really are insatiable in the West aren't we? There is hope for them; there are over 10,000 Chinese alligators in zoos and sanctuaries. This is probably enough to maintain genetic diversity. Crocodiles are found in Africa, Asia, North and South America and Australia.

Alligators, in general have a more pointed and stronger jaw that assists them in crunching through the hard shells of turtles that are plentiful in their habitat in the United States. Crocodiles have a weaker jaw. Their jaws are also different. Only the top teeth are visible on an alligator with a closed mouth; their top jaw completely covers their lower jaw whereas crocodiles have jaws that allow their teeth to fit nicely between each other; meaning top and bottom teeth are both visible.

Two more interesting features distinguish alligator from crocodile. Small sensory organs on the skin of both animals are thought to detect changes in pressure, allowing them to locate prey easier. Alligators only have them in the area around their head, whereas crocodiles have them covering most of their body. The second feature is salivary like glands in the tongue that secrete salt. Both alligators and crocodiles have these organs, but they are only active in crocodiles. This is why crocodiles are able to live in ocean and fresh water while alligators live only in fresh water.

As with many things in life, there are exceptions to the rule. The Indian Mugger crocodile actually has a snout resembling an alligator, but is a crocodile in all other ways.