Giraffe

Giraffes are wonders of the animal kingdom, they currently hold the record as the tallest animals alive. Giraffes lead a solemn life, mostly neck-wrestling and reproducing.

Their beautiful lifestyle is being interrupted by their main predators, which are not any wild animal, but humans. Giraffes are hunted for both their body for meat and for their coveted pelts. Habitat destruction and scattering are also threats to giraffe populations.

Giraffes live in a variety of areas, mostly warm and dry. There are 11 species of giraffe that are recognized by the scientific community, but seven of these species are extinct. All living giraffes were once considered to be part of the same species, but in 2016, they were reclassified into four separate species based on analysis of genomic DNA. Differences in DNA sequences were assumed to indicate genetic isolation.

Anatomy
Giraffes are the tallest animal in the world, reaching up to 18 feet high. Male giraffes are often larger than females. Male giraffes weigh between 2,400 and 3,000 pounds. Female giraffes weigh between 1,600 and 2,600 pounds and grow to be 16 feet tall.

Giraffes have small "horns" on top of their heads that grow to be about five inches long. The horns are used to protect the giraffes' heads in fights with other males, even though neck stretching is the main male dominance ritual. 

Reproduction


Female giraffes conceive after their fifth year of life. Female giraffes associate in groups of about a dozen members. The males usually stick by themselves or join small groups of other males. Reproduction is polygamous with giraffes. The males go around impregnating all the fertile females in the herd. The males know if the female is in estrus by licking the female's urine.

An average giraffe female will have ten calves (giraffe young) in her lifetime, but usually they only have one calf at a time (twins are a rarity). Gestation lasts between 14 and 15 months. Newborns are born at least six feet high, and 150 lbs. The mother gives birth standing up, usually while walking. The welcoming the baby gets into the world is a six foot plunge to the ground. The embryonic sack usually bursts with the landing.

After birth, the calves are already highly developed. So they are able to immediately stand up and after only about an hour they start nursing. Within a few hours the baby can run. Only about 25-50% of baby giraffes reach adulthood because the fall prey to lions, leopards, and hyenas. Male calves are weaned after 15 months, and females are weaned a little later.

Most giraffe males are sexually confused, engaging in "inappropriate behavior" with other males. They usually start out by necking, a common ritual between males in which the twist their necks together. The behavior appears to be competition for the right of the estrus female, but frequently ends in homosexual mounting. The females are less confused, and only about 1% of females exhibiting such behavior.

Ecology
Giraffes can rest standing, but they usually lie down with their legs folded underneath them. The neck is vertical except during short periods of sleep, usually about five minutes long, when the head is rested on the "rump". When giraffes walk they swing their legs on the same side of the body at almost the same time. Their maximum galloping speed is 31-37 mph.

Giraffes form scattered herds about their habitats. Since they are such a tall and rather defenseless animal, giraffes band together into loose groups for protection against predators such as hyenas and lions. Home ranges for giraffes are large, about 46 square miles.

Bulls (grown male giraffes) are non-territorial, and grow together in "overlapping" home ranges. Each individual giraffe knows its status in the hierarchy, which leads to an overall sense of peace between the herds. Young males develop an elaborate ritual called necking to determine dominance. The necks are slowly intertwined, pushing from one side to the other, like arm-wrestling in humans. This ritual apparently determines the places in the hierarchy with the male giraffe.

Extinction Problems
Giraffes have been living peaceful lives until quite recently. A few key factors have contributed to this. Firstly, the hunting as mentioned before by humans. They are also dying due to a lack of habitat. As the world grows bigger, many animals homes do the opposite. 

Another factor has been the outbreak of a virus called "Rinderpest". This virus attacks cloved mammals and is letal when caught. Rinderpest is caught by any contact of the host, the incubation perioud is less than two weeks, and the only immediate symptoms are a slight fever. Thankfully, Rinderpest has been mostly "eraticated" from the giraffe's habitat.

Related References

 * Giraffe: Giraffa camelopardalis Nature-Wildlife Online
 * Mammals: Giraffe San Diego Zoo
 * Giraffe Extinction American Zoo
 * Rinderpest Animal Disease Data