Sunday, May 26, 2013

Evolutionary Explanations of each Animal

One our class assignments includes analyzing our field notes and field guides then explaining the behavior of animals we saw...


Burchell Zebras:

The zebra’s most prominent characteristic is its stripes. Each zebra has a different stripe pattern (like fingerprints) and can identify each other by memorizing each other’s patterns. In particular, baby zebra’s memorize their mother’s stripe pattern so that they can identify her easily amongst the herd. A zebra’s stripes also serve as a camouflage technique from predators— because many predators lack an advanced color vision, the black and white stripes break up the image and create a pseudo shadow appearance. This can help the zebra remain unspotted and gives it a greater chance of survival.

Their mane stands erect and is short and neatly chopped. The exact purpose of this is unknown; however, when the zebra is sick, its main will droop to one side. This sign of poor health could deter others from mating with a weak zebra and make the gene pool stronger. 

Zebras live in family groups where it is typical to find a couple males, females, and a baby. On our 4th day of safariing, in the afternoon, we saw a stallion who put himself in between us and his herd and was “displaying” himself. Stallions are very defensive over their family groups. By threatening potential threats and alerting his group to dangers, they are safer from predators.

Baby zebra’s can nurse for up to a year and remain with their mother during this time for protection until they have grown enough to fend for themselves.

Savannah Giraffes

The splotches of brown on gold on a giraffe’s coat provides excellent camouflage. It breaks up the landscape when looking from afar and looks like shadows created from tree branches. This decreases the giraffe’s chance of being spotted by predators.

Their long neck allows them to feed high up on trees where other animals cannot reach. They are also the first to spot danger because they are so high up. Giraffes spread their legs apart in order to reach their neck to ground. This is how they drink and reach low lying leaves. To avoid competing with each other, females graze lower on trees while males graze higher up.

A giraffes horns are used for protection. When fighting, they use their long neck like a baseball bat to whack their opponent. During one of the drives, the other car saw 2 giraffes fighting. I unfortunately was not with them, but they told us that the stronger giraffe was using its neck to repeatedly pound its victim. Before developing, baby giraffes Male giraffes are larger overall and have bigger horns than females. Before developing, babies have shaggy horns, but due to fights, males often wear off the hair on their horns. Females, on the other hand, are smaller overall and have slender horns with hair on the top. This difference between genders has developed because males are territorial and require larger horns to defend their ground.

Giraffes are one of the only animals able to eat from the acacia tree. In order to get around the acacia’s thorns, giraffes have evolved a long, hardened, dexterous tongue that can easily eat around them.

There is no set social structure for giraffes; however, mothers with young will congregate together for extra protection. This increases their young’s chance of survival because other vulnerable babies are around that the predator can choose from.

On our walking tour, the giraffes were not threatened by us; however, if they are threatened, they will move straight towards the predator. Predators often have chasing instincts, so moving towards them throws them off guard. We also examined their dung on the walking tour and discovered that one can identify the sex of a giraffe by looking at their dung. Females’ dung is pointed on one side and flat on the other while males’ dung is flat on both sides.

Often while driving, we’d see warthogs trotting through the grass. At one point, we saw several babies emerge out of a burrow and follow their mother. As they run, it is difficult for young warthogs to follow because the grass is taller than them. Therefore, their tail that stands straight up while running is a following signal.

They live in ground holes that are initially created by aardvarks digging into termite mounds. The warthog then scrapes the hole out even more, creating a burrow in which they can raise their young and hide from predators. When getting in their burrow, they always back in with their tusk facing the outside. In this position, a predator who tries to attack the warthog will likely run head-on into sharp tusk that can injure it.

To eat, they kneel down and are able to eat roots and short grasses that many other herbivores do not eat. This prevents competition.

On day 7 in the afternoon, we saw a warthog with its hair standing up. This is called pilo erection and is a fear response. They look bigger and more threatening when their hair is sticking up; therefore, it can possibly deter predators from attacking.


Hippos thrive in the water during the day and move onto land to graze at night. This allows them to spend their time conserving energy and affords them the luxury of having to eat less grass. During the day, they secrete a sun-screen like chemical that protects their sensitive skin from the sun.

Hippos are vegetarian (excluding a few rare exceptions) and come ashore to graze during the night.

On day 8, we saw 2 hippos (one male and one female) in a lake. One lifted its head out the water, opened its mouth, and made grunting sounds. This is threatening behavior and used to defend its territory. In this pond, there was only one female, but typically they have a harem structure with one male and multiple females.


Their brown coat with white stripes serves as camouflage by creating pseudo shadows and hiding them from prey.

A noticeable characteristic of the males are their large horns (they have the largest horns of any African antelope). These are used for defense as well as for mating.

A two-toned coat acts as camouflage to predators by blending into the environment and creating a three dimensional shadow appearance. This helps them avoid being spotted by predators.

Impala are mixed eaters and eat both grass and trees. Often they will be found in conjunction with other herbivores such as giraffes, zebras, wilderbeast, or warthogs. Each animal is a different height and has different “eating zones.” This allows them to stay together for safety, but not compete against each other for food.

Impala maintain safety in numbers by staying in large herds. It is a lottery for them as to who will get picked off next; but by doing this, the weak get picked off and the strong survive, increasing the genetic gene pool. November is the peak of the new babies birth. All impala females have young within 2 days of each other. When an entire herd of say, 30, has young, it is expected that a few will fall prey. However, the 5 or so that do is a small price to pay for the 25 that will survive.

During mating season, there are three different social structures for impala: a harem herd, bachelor herd, and a solitary male. Harem herds consist of 20+ females and one dominant male. When a male grows up enough to mate, he is rejected from the herd. From there, he joins a bachelor herd that consists of males of different ages. There he will wait until he is strong enough to defeat the dominant male of a harem herd. Males often practice fighting and are ranked within the bachelor herds. On day 2 we saw 2 males thrashing (butting heads) to assert which one is more dominant. When a male decides to challenge, he becomes solitary and selects a territory to defend. This leaves it venerable to predators, but is necessary to mate. When females cross his path, it will then challenge the dominant male in the hopes of winning the females over. This method of mating increases genetic diversity.

Metatarsal glands on the back of their ankles releases a musky smelling chemical when running. Pre-orbital glands on their face secrete chemicals as well and impala rub their faces on things to mark their territory. These chemicals are used to find mates and prove their status as a male.

On our walking tour, a male impala was grunting. This behavior either means he is getting ready to challenge a male or herding his females to safety.

A circle on their butt acts as a following signal. While running through the bush, young waterbuck can easily see where they are going and follow.

When approached, they stand stock still and stare. Predators detect movement, so by doing this, they are trying to blend in with the environment.

A brown coat is used for camouflage and blending in with their surroundings. Because of their tiny size, they use concealment as a survival strategy. They have a very square build compared to the steenbok’s lean build. They are able to maneuver quickly throughout the bush felt and hide from predators.  

These are pair bonding animals and will either be in groups of a female and male or be alone. Pair bonding saves them the energy of finding a new mate and allows them to focus more on survival. When one is spotted, it is almost certain that its mate is nearby; however, the two do not stand near each other for survival purposes.

Vervet Monkeys
On day 2, these animals made an alarm call when we approached and hid in their trees on the river bank. Eventually, they determined we were not a threat and ventured out of hiding. They stick together in groups and alert each other to threats. Looking out for each other helps them survive. 


Buffalo use olfactory senses to smell threats. When we approached on foot (Day 2), the herd got a whiff of our scent and took off in a stampede. Being able to sense predators before they are close enough to kill gives them an advantage. Additionally, stampeding poses a danger of being trampled to any animal who attempts to take one down. When alerted to a threat, they access it and depending on the situation, either flight or fight.  

Males have a “part” in the middle of their head called a “boss” that is actually a thick, hardened bone. This protects their skull in fights.

They group in large herd that can contain around 100 buffalo. Because they are social animals; this allows them more access to mates. Young buffalo also learn faster and become independent sooner. This helps them survive by outgrowing their vulnerable stage quickly.

The older dominant males are the primary ones who mate with the females of the herd. When searching for a mate, the male partakes in “flemming.” The male tastes the hormones in females’ urine and can tell if they are in estrus or not. If they are, they will mate.


These tiny brown antelope are able to bound through the bush quickly and are less noticeable to predators because they are so small.

Steenbok are pair bonders and will pair for life unless something happens to their partner. This allows them to spend less energy trying to find mates and more energy on surviving.

Hares, in contrast to rabbits, are born with their eyes open and with hair. This increases their survival because they are not as reliant on their mother when born.

The size of an elephant helps protect it from predators. They can weigh around 3-4 tons, making it very difficult for anything but a large pride of lions to successfully kill it.

Elephants particularly like marulla trees. They will strip the tree of its nutritious bark by scraping it off with their tusk, eat its fruits (during feb), and push it down to eat their leaves.

We saw 2 male elephants on day 6 that had mud all over them. Elephants cover themselves in mud and then rub against trees to remove ticks and parasites. One of these males put his ears back and shook his head. This behavior means he was agitated.

Elephants will only mate when a female is in estrus and a male is in musk. Often it is the mature, dominant males that go into musk when a female is in estrus. They secrete a chemical in their temporal gland that increases their testosterone, sex drive, travel more, and makes them spend less time eating and drinking. Musk is therefore very taxing on males. When ready to breed, they move as far away from their birth place as possible to increase genetic variation. Once mated, females gestate for about 22 months and typically give birth around the end of summer (feb/mar).

On day 2, we also saw a male elephant that was about 12-13 years old. He stayed close to the herd, yet was quite out of range of them. This is because the females are beginning to kick him out. In order to have genetic variation, males must leave their family herds in order to find mates with different genes.

The same day, we saw a herd of elephant mothers with babies. One of the mothers trumpeted at us and even bluffed a charge at the other vehicle. This protective behavior is critical for their babies to survive. A protective mother can deter a predator from attacking because it’s not worth the risks. Once determining we were not a threat, the female mother kept a watchful eye and occasionally raised her trunk in the air. This is how she smells us and determines if we are dangerous or not. The baby with her looked to be about 2 years old. It was still trying to suckle but the mother was preventing it. When the dominant female turned or moved, the others followed. This leadership helps the herd maneuver safely throughout the bush.

We examined elephant dung on our walking tour; because elephants only digest 40% of what they eat, there were many pieces of undigested fruit, seeds, and grass. The undigested material is useful for many animals to utilize.

At the elephant whisperers, they demonstrated just how smart elephants are. They can remember roughly 80 commands and have astonishing memories. In the wild, the matriarch remembers where they have eaten for years. This allows her to guide her herd to new grazing areas. If the leader is killed, the herd will be thrown into chaos and may starve.

White Rhino

As the 2nd largest land mammal in the world, they have virtually no predators (besides humans). A large horn protruding from their nose helps them to defend themselves. If something threatens them, they will charge blindly towards the threat. Bad eye sight makes them even more dangerous because they are unpredictable and will unknowingly run you over.

White rhinos eat grass which allows them to coexist with the black rhino that feeds on trees.

To mark their territory, they kick their dung around. This deters other males from entering their area and gives the marker more access to females.

A rhino horn is valuable in India because many believe a myth that it can cure cancer and other diseases. A kg of rhino horn powder sells for $80,000 and a whole horn can sell for ½ million. Poachers therefore hunt the rhino for their horns and as a result has endangered it. The reservation injects poison into their horn in an attempt to prevent this.

On day 8, we spotted 2 male rhinos grazing. They have to constantly eat in order to maintain their massage body weight.

A sloping back is conducive for long distance running, and other features, such as their coat, allow them to be camouflaged from predators.

Wilderbeast secrete a pheromone that relay to other wilderbeast information such as its age, dominance, gender, territory, etc. This helps males find a mate and size up competitors. It also tells males which females are in estrus and ready to mate. We saw a male rubbings his scent onto things and leading his herd off. This is how they mark their territory and tell others that this is his land.

At one point, we saw a solitary wilderbeast with several impala. The wilderbeast was likely staying with them for protection while they were within his territory.

When walking through the bush, a wilderbeast spotted up, snorted, and moved away from us. It snorted to alert the females to predators. This protective behavior can save the lives of member of the herd.

One baboon can weight up to 90 lbs. In a group, there is one big male who is in charge. They have an oligarchy structure in which all males are ranked above all females.

They are very intelligent and cause damage to homes because they can break in easily. As a result, many are shot.


Dwarf Mongoose

Jackals are scavengers and feed off of the leftovers from lions and other large predators. They are also pair bonders and spend less time and energy searching for mates.

Hyenas live in a matriarchal society where every single woman is more dominant than even the highest ranking male. It is difficult to determine their gender because females are physically bigger and have a “pseudo penis” that consists of enlarged genitals.

On day 4 we saw 3 hyena pups. They raise their young in old warthog or aardvark dens, but the puppies will modify it to create little chambers in which they can tuck themselves away. They stay in this den for about 1-2 years. The pups we saw were probably about a year old and were just getting ready to leave the den.

A slanted back allows them to run long distances. To catch prey, they chase them until they are exhausted and cannot run anymore. From there the hyenas move in for the kill. They do not have retractable claws, so they cannot climb; however, their claws provide traction for running.

We saw a carcass of a giraffe that had been chewed up by a hyena. Hyenas are the only animals that can crunch bone with their teeth. By opening up the bone, other animals can therefore get inside.

We examined the dung of a hyena on our walking tour; it was very chalky and white. This is a result of their diet that includes a lot of bone. The calcium turns their dung white.

On day 7 in the afternoon, we saw a hyena resting in a puddle of water. They do this to cool themselves down on a hot day.

Nile Crocodile
We saw a couple crocs throughout the trip that were swimming in lakes. Crocodiles feed on turtles, fish, and other small animals. They can live alongside hippos because they do not compete against each other; however, if a croc comes too close, the hippo would overpower it and could bite it in half.

We first saw a leopard sitting on a man-made watering hole. It jumped in, but after a few minutes it hopped out and casually laid in the grass. Resting during the day is typical of leopards because they are conserving their energy for hunting during the night. These big cats have spots that help it blend in with its surroundings and stalk up on prey without them noticing. They are also built for strength and power—necessary to take down larger prey.

We saw another leopard during the afternoon drive on day 7. As it walked it sprayed urine on trees. This is how they mark their territory. On of its eyes were injured and it kept licking its paw, so we suspect that was injured as well. These injuries were likely from a fight with the larger male leopard that controls that territory. The smaller leopard was in his territory because he was looking for a female that was in that area a couple years ago.

On day 8, we saw the same leopard we had seen on day 7. Birds made alarm calls at it to alert others that a predator is in the area.


Lion’s social structure consists of one male and several related females. Once a lion grows to adulthood, he is forced out of the group and becomes solitary. He then waits until he grows strong enough to challenge the alpha male of a new pride. This system increases genetic diversity. One example of how lions are drawn to others with different genes was seen the first night. Two female lions slept on the fence line for 6 months because they were trying to get to the male on the other side. Likewise the male (seen the following night) was also on the fence line hoping to get across and mate with those who had “fresh genes.”

On day 7 in the afternoon, we saw a pair of male cheetahs laying down. They require a lot of resting to conserve their energy for running. The cheetahs then got up and started walking, panting as they went. They pant to cool themselves down.

The thin frame, large lungs, and muscular legs of a cheetah are all physical factors that contribute to its speed. It uses its speed to chase down prey.

To prevent competition with lions and leopards, cheetahs often hunt during the day. Even still, however, they often fall prey to lions.

Honey Badgers

A honey badger’s aggression; loose skin; and fearlessness allows it to defend itself from predators and be a successful carnivore.

As part of the weasel and mongoose family, it preys on small animals and scavenges for eggs and leftovers.

One of their favorite things to eat is honey. They will crack open a bee hive and despite being stung by the whole swarm, will sit there and eat.

No comments:

Post a Comment