Giraffes

Towering over what is known as the Big Five, and all other mammals in the vast plains of Africa, is the giraffe.  But, their numbers are in near precipitous decline in most parts of Africa.  Two months ago, my wife and I had the opportunity to travel to Tanzania to view many animals in their native habitat; it was an amazing experience.  One of the things that drew me to an African safari was to see the large land animals in their natural setting as many are decreasing at remarkable rates.  It was not until we got back that I had a chance to read the October 2019 issue of National Geographic, which on its cover featured a photo of the last male White Rhino on the planet, but had an article on giraffes to know that their numbers are also in decline.

Masai Giraffe, Tarangerie National Park

Giraffe populations may not be as dire as that of the Rhino, but education and action is needed to avoid that problem.  To show the problem with poaching, Sudan, as the Rhino was named, was under  24/7 armed protective custody.  Sudan was 45 years, at his death in 2018 at a conservancy in Kenyna, but 90 to 100 years in comparable rhino age, was put to sleep due to a variety of ailments.  He was old for a rhino.  He is survived by his daughter and granddaughter.  He was found in a zoo in the Czech Republic, which was a good thing because he was protected.  He was eventually moved to an African conservancy.  The fate of the rhinos and elephants is generally well understood I was surprised to read in the same issue that giraffes may well face the same fate.

Those giraffes, tall and stately whose Ossicones on the top of the head provide a sharp contrast to the length of their legs and neck,  that we saw roaming the Serengeti and Tarangerie Tanzanian National Parks are also threatened. Giraffes are only found in Africa, and up until very recently it was thought they were all in one species.  That, however, has turned out not to be the case, there exist four main species of giraffes, with two of those having subspecies.  In some respects, there are seven species, if each subspecies is taken as a species.  All live south of the Sahara.  Threats to giraffes are similar to that of the other large African mammals--habitat fragmentation, deforestation, war and poaching.  While giraffes are very tall and have long legs, they cannot jump, so fences that are installed severely reduce their habitat.

Acacia Tree branch with places (brown balls) for ants to nest
to prevent giraffes from eating vegetation

As we look at a giraffe I think we all see a very tall animal which, with its long neck, can reach the acacia tree leaves, even though surrounded by many thorns.  Their long tongues, up to 20" in length are particularly agile to reach around the thorns of the acacia.  Interestingly, as acacia trees age and grow taller once the canopy is out of reach of the giraffe, they start to lose their thorns.  The magnificence of nature and its adaptability

The tongue is just one part of the unique anatomy of the giraffe.  Due to its size, both height and weight the giraffe has unique organs and structures.  For example, the left ventricle of the heart has thicker and more muscular walls to pump blood to the head and then around the body.  Sticking with the circulatory system, arteries above the heart are not only more muscular to pump blood against gravity, and the veins contain valves which close when the head is lowered to prevent backflow of blood.  Per National Geographic, a network of "elastic vessels expands when the head is lowered to prevent blood from flooding the brain, and constricts when the head is raised , to prevent quick depletion."

Reaching for food

The structural system also has unique features, such as a joint at the base of the skull to allow the head to be in a near vertical position.  Their seven neck vertebrae contain ball and socket connections, similar to the human shoulder, which allow their nose to reach their lower backs.  Because the neck is so long, a strong, and powerful elastic ligament in the neck reduces the muscle effort required to hold the head up.  Their leg bones thicken, by narrowing the marrow cavity, as they age to hold the massive body on such narrow legs. Their skin acts like compression leggings to aid circulation and help regulate blood pressure.  The Masai Giraffes which we saw in Tanzania will have a height of 19 feet, and a male may weigh up to 4275 pounds. Given their proportions of a mature giraffe, I could probably walk under its belly without my head touching it, and if not me, I know my mother-in-law could.

All four species of giraffe have different spots.  The unique color pattern of the spots is thought to contain sweat glands and more blood vessels to release heat from the body.   Spots on animals, as we learned on safari, may becoming darker due to climate change. Masai Giraffes  have the darkest spots of the four specie groups.

Thorns on a young acacia tree branch

Of the four species only the Southern Giraffe has had a growing population such that hunting of the animal is allowed in some circumstances. The Masai giraffe population has fallen to 35,000 from over 110,000, the once most populous of the four species, just thirty years ago.  Two of the three subspecies of the Northern Giraffe are the most threatened mainly due to being in the war torn countries of west Africa, think also Islamic extremists who terrorize populations.

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Man's seeming indifference to the beautiful animals of Africa results in a loss not just to the local country, the continent, but the whole world.  We saw many giraffes on our trek at two of the three parks visited.  Giraffes are not present in the Ngorongoro crater, due to the steep descent of the ridge leading from the top of the crater ridge to the crater floor.  They are present in the conservation area which extends out beyond the crater ridge and floor.  As I looked at the giraffe on our trip, I viewed them as rather common, and I certainly did not think of any particular specifics to the anatomy to allow this tall animal to function.  The wonders of nature and its ability to adapt never cease. I will no longer view the giraffe as rather common as I now recognize the perils they face.

Masai Giraffe near Silale Swamp

Main Source:  "Girafffes" by Joshua Foer, in National Geographic October 2019.
Photos by Author, October 2019

On a very windy day, the dust is blowing over
the Serengeti Plain

Images by author, October 2019