Saturday, December 12, 2009

Africa wildlife series: The Nile Crocodile

Kenya wildlife safaris: The Nile crocodile

Among many reptile species in Africa, the crocodiles have somehow stolen the arena by being the most vocal and other adaptations. Unlike other reptiles they do not shed their skin and instead grow with it. These dinosaur-like creatures are usually spotted while basking in the early morning sun and late afternoon on the river banks. In the middle of the day when temperatures are higher they lie in the shallow waters sometimes with half of the body partially submerged. It is their way of warming up or cooling behavior.

Being creatures of the water, they are great swimmers and divers. Their respiratory system has a tissue flap that seals off while under water. These enable them to open the mouth and not choke underwater. In addition, crocodile's nostrils close while diving and the same case happens with the external ears. Most reptiles do not have the external ears. Their vision under the water is very good and is facilitated by the nictitating membrane (transparent third eye membrane). This keeps water out of the eye hence no vision interference.

What's more, the tail acts as a oars that helps them maneuver while in the water. They use the tail also for feeding whereby they can disorient schools of fish with strong strokes and catch them. Crocodiles never stay far away from the water. Incase the pool or swamp dries they too die. Their preference is the permanent rivers but on occasions they can be spotted in seasonal rivers especially during the heavy rains whereby they avoid the strong currents. Immediately when the rain subsides they return to their territories.

On land, the crocs can walk fairly fast, up to about 28 miles an hour. Although the back legs are webbed, this does note interfere with their walking on land. Despite this, they do not wader too far from the water. Though they are termed as hunters, their hunting method mostly lying low and wait for their victims to come to drink. Then they thrash forward and grab them, drag and drown them under the water. Their teeth are especially formatted to seize and hold the prey. With crocodiles you can see the two front teeth of the lower jaw.

These lizard-like reptiles live in big groups and can be up to several hundreds. Usually the big males are in charge but it is more of domination than organized social leadership. There is no known coordinated group activity apart from feeding together.
There feeding method is by tearing chunks from the victim and this may sometimes include spinning of the whole body while holding tight with the teeth.

The crocodile (Nile crocodile) reach sexual maturity at the age of 8-12 years. Then they can mate, and after about 60 days the female is ready for laying eggs. She digs a hole and lays her eggs there. She can lay between 20-90 eggs. The eggs are heavily calcified and chicken-egg sized. Inside the buried egg, the temperatures rise to over 90 degrees.

After about 90 days later the hatchlings calls for the mother through hissing and she digs them out. Then she moves them to the water. This is a critical stage as most of them are predated on. Among the predators includes birds of prey,( eagles, hawks, vultures..), monitor lizards, among others. Usually when the mother senses danger to her young ones she can put them inside the mouth (gular pouch) for protection. The few survivors are free from the mother after two years and ready to face the world alone.

Note that crocodiles have no sweat glands. They lose heat through their mouths cavities. During your Kenya safari, you will see them sun-bathing with the mouth open and sometimes panting like dogs. Their color ranges from dark green, to a black-grayish but with a lighter belly. The body is covered with scales and they never shed them.

Their diet varies from small to large animals and in Kenya they have been known to catch birds. Their ectothermic metabolism is very efficient in that the huge crocs can stay for several months without food.

Crocodile have been known to attack and kill people. There are many cases of cows being attacked when they come to drink. Though CITES have classified them endangered, the populations in Kenya and Tanzania are very healthy.
It is their habitat that is in constant danger from intrusion, pollution and fishermen's nets.

Natural Track Safaris
Kenya safari Desk

Africa Wildlife series: A thing or two about Elephants

One of the dominant wildlife in the main Kenya wildlife safari parks.

The elephant is one of the most interesting and beautiful creatures on earth. During our Tanzania and Kenya holidays we meet this creature in numerous numbers. It is the largest animal on land with some bulls growing up to about thirteen feet tall. They can weigh up to seven tones for the bulls- about the weight of a truck.
Elephants are unique in that they smell, eat, and wash themselves using their long flexible trunks. In addition they have elongated teeth made of ivory that aid them in getting food. They do use them also to lift heavy objects including pushing down trees. These teeth are called tusks.
African Elephants in Samburu,Kenya
The most obvious characteristic of elephants, besides their massive size, is their trunk. The trunk is nothing more than an elongation of their nose and upper lip. Besides being used for breathing and smelling it is also used as an appendage, much like an arm or hand. Elephants are capable of pulling up to 11.5 liters (3 gallons) of water into the trunk to be sprayed into the mouth for drinking or onto the back for bathing. As seen on most Kenya safaris, they use their two finger-like projections that are at the tip to manipulate small objects and to pluck grasses.
Elephants eat grass, small branches, and bark from trees. They especially like leaves from the top branches. They get the leaves by pushing down the trees with their large heads and bodies. Then they get the bark by scraping it with their sharp tusks.
Most elephants live in the grasslands of Africa and in the forests of Asia. They live in groups called herds. The herd is typically composed of up to ten females and their young. All of the females in the herd are directly related to the matriarch, who is typically the oldest and largest female. Males beyond the age of maturity are with the herd only during mating. A herd is a group that may have ten or more elephants. It is usually led by a female elephant. Herds have been known to travel ten miles or even farther to look for food and water. When elephants travel, they walk very quietly in single file. Young elephants are led by the older elephants with their tails. They stay close to their mothers at all times. The entire herd will protect the young ones if there's any sign of danger.
Elephants love water and are very good swimmers. When they get hot, they swim in lakes or rivers, or give themselves showers using their long trunks. An elephant can also cool off by rolling in a shady bed of mud.
Young elephants stay with their families for many years. It's not unusual for a herd of elephants to live together all of their lives. They are also capable of making low frequency sounds that are below the human range of hearing; this allows wandering individuals within the herd as well as several different herds to stay in direct contact over distances of many miles.
Did you know that?
  • · Elephants stomp when they walk.
  • · Elephants sleep standing up.
  • · Sometimes baby elephants lie down to sleep.
  • · Elephants bathe. Sometimes they spray dirt on themselves or bathe in mud to get the parasites off.
  • · They cool off by fanning their ears. This cools the blood in their ears. That blood goes to the rest of their body and cools off the elephant.
  • · They poop 80 pounds in one day.
  • · Elephants weigh about 10,000 pounds. It would take 250 students to add up to 10,000 pounds.
  • · Only grown up ladies and their babies live in the herds.
  • · The bull elephants leave the herd when they are 12 years old.
  • · They fight with their tusks.
  • · They eat grass and bark.
  • · During the wet season they eat things low to the ground.
  • · During the dry season they use their trunk to gather food from trees and bushes.
  • · They suck up water into their trunks and shoot it into their mouths.
  • · Elephants need lots of room to roam and eat.
  • · They can run 24mph for short distances.
  • · Elephants perform greeting ceremonies when a member of the group returns after a long time away. The welcoming animals spin around, flap their ears, and trumpet.
  • · The blue whale weighs as much as thirty elephants, and is as long as three greyhound buses.
  • · What do bats' wings, elephants' ears, flamingos' legs, rabbit's ears, goats' horns and human skin all have in common? They radiate heat to provide cooling.
  • · Female elephants produce one calf every five years.
  • · Genuine ivory does not only come from elephants. It can come from the tusk of a boar or walrus.
  • · Mice, whales, elephants, giraffes, and humans all have seven neck vertebras.
  • · African elephants have larger bodies, bigger ears, less bumpy foreheads, and longer tusks than Asian elephants.
  • · African elephants only have four teeth to chew their food with. However, each tooth is 12 inches long, and their tusks are elongated teeth that grow throughout their lives, like fingernails.
  • · At birth an Asian elephant weighs around 440 pounds (200 kilograms) and an African elephant weighs 581 pounds (264 kilograms). By adulthood both types of elephants will weigh close to 4 tons.
  • · Elephant tusks grow throughout an elephant's life and can weigh more than 200 pounds. Among Asian elephants, only the males have tusks. Both sexes of African elephants have tusks.
  • · Elephants and short tailed shrews get by on only two hours of sleep a day.
  • · Elephants are covered with hair. Although it is not apparent from a distance, at close range, one can discern a thin coat of light hairs covering practically every part of an elephant's body.
  • · Elephants communicate in sound waves below the frequency that humans can hear.
  • · Elephants have been known to remain standing after they die.
  • · Heart and liver: The elephant heart weights about 22kg and circulates about 450 liters of blood. Inner "cleaning" is performed by a 77kg liver.
  • · Water and trunk: To drink its 11 litres of water at a time, the elephant uses its trunk which weighs about 113kgs.
  • · Tongue: Helping the swallowing process is a 12kg elephant tongue.
  • · Food and intestines: The approximately 250kg food eaten every day passes through 18m of intestines. Eventually processed into about 100kg of elephant dung per day.
  • · Digestion: Elephants only digest about 40% of what they eat, and therefore, they need to spend two-thirds of every day eating.
  • · Gas: An elephant 'releases' 2000 litres of methane gas per day!
  • · Skin: Its skin weighs 450-750 kg.
  • · Tail: The tail weighs about 11 kgs.
  • · Fighting: The longest recorded fight between two elephants was recorded at 10 hours and 56 minutes.
  • · Gestation: An elephant's gestation (conception to birth) is 23 months.
  • · Call: It is estimated that an area of fifty square kilometers is filled with particular elephant "call" in infrasound. This might increase to about three hundred square kilometers at dusk due to lower temperatures.
  • · Eyes: An elephant’s eyes are very small in relation to its head. The eye contains very few photoreceptors and they cannot see very well further than a few hundred feet.
  • · Speed: A herd ambles at about 4 miles per hour and can charge at more than 25 miles per hour.
  • · No jumping: Elephants cannot run or jump. They can however walk very fast and climb.
  • · Swimming: They can swim considerable distances. In deep water they hold their trunks above the water like periscopes.
  • · Trunk: An elephant’s trunk is the most versatile of all mammalian creations being used as a nose, arm, hand and multipurpose tool. It is powerful enough to kill a lion with a single swipe, yet the finger-like lobes at the end are adept enough to pluck a feather from the ground.
  • · Trunk muscles: The trunk is boneless, and is composed of an estimated 40 000 muscles.
  • · Tusks: Elephant’s tusks are elongated upper incisor teeth, which grow continuously throughout the elephant’s life. They are not always an exact match, as this depends on which side they favor much like left and right-handed humans.
  • · Ears: An elephant’s ears are covered with lots of veins, which form distinct and unique patterns which can be used to identify individuals - much like human fingerprints. Elephant's ears are packed with blood vessels, and when flapped, they quickly lower the animal’s body temperature. This swiftly circulating blood is cooled by about 15 degrees Fahrenheit while in the elephant’s ear.
Natural Track Safaris
Kenya safari desk