#animals

idea

The giraffe is an animal leaving in the African savana and woodlands. They weigh 1.2T and measure between 4 and 5m (females are smaller)

They are even toed ungulates, which means their hooves evolved from their third and fourth toe. The giraffes legs are composed of three segments, the longest one accounting for 1/2 the length of their legs being the giraffe's metatarsal and metacarpal bones, meaning that what looks like their knees are in fact their ankles and wrists.

They are ruminants. Their jugular veins are contracting when lowering their heads to drink in order to prevent blood from rushing to their brain. They are believed to drink following a pump like mechanism, filling part of their neck with water which flows down their stomach when lifting back their head.

They mainly eat acacia leaves, and adapted to the acacia thorns by having a long (45 cm) tongue, and their upper teeth move back, the front top of their mouth being soft and flexible to grasp on leaves but not thorns.

It is unclear why the giraffe evolved a long neck (2m)[1]. Its neck is made of elongated vertebrae, whereas birds with long necks usually have more vertebrae. The two main explanations being that (i) it would give them an advantage to access higher food sources, but the trees they are eating from are not that high, or (ii) it provides them an advantage in fights for mating, but females don't mate and have a long neck.

Giraffes are susceptible to extinction.

links

natural selection - it is not certain why the giraffe evolved their long necks.

references

ZeFrank / Giraffes is a fun introduction to the giraffe

[1]: Necks‐for‐sex or competing browsers? A critique of ideas on the evolution of giraffe