Maths formula proves giraffes can swim, but not very well

Two scientists — a Canadian and a Britisher — have in a new mathematical study proved that giraffes can swim but added that the species wouldn't be very good at it.

According to Donald Henderson, of the Royal Tyrell Museum of Palaeontology in Canada and Darren Naish of the University of Portsmouth in Britain, most large animals are extremely good swimmers, but so far nobody has seen or heard of giraffe swimming or wading.

Using a digital giraffe in digital water, both decided to investigate whether or not giraffes could swim.

The results of their study, which appear in the Journal of Theoretical Biology, found that giraffes could actually swim based on numerous calculations of weight, mass, size, shape, lung capacity, centre of gravity and rotational dynamics.

Naish said: "Many previous studies have claimed that giraffes cannot swim and that they avoid water like the plague, even in an emergency, but we wanted to put the theory to the test in proper controlled experiments."

In their study, both authors found that a full-sized adult giraffe would become buoyant in 2.8 metres of water. Giraffes can wade across bodies of water that are shallower.

Henderson said: "The idea that giraffes are poor waders or will not cross rivers is untrue and there are no obvious reasons why giraffes might be more prone to sinking than other animals."

But after becoming buoyant, they said a giraffe would be unstable in the water due to its long, heavy legs, short body, and long neck.

The unusual shape of the giraffe means that it floats in a peculiar manner, with the long front limbs pulling the body downwards. This forces the neck to be held horizontally and mostly underneath the water surface, so the animal would have to hold its head upwards at an uncomfortable angle.

Giraffes have other handicaps in the water. Horses tend to swim by trotting in the water, similar to the way they move on land.

But giraffes move on land in an unusual way, moving their neck up and down in time with their limbs, and this important neck movement is not possible in the water.

This means that giraffes are probably very poor swimmers.

Giraffes also have 13% more surface area than a horse, mostly because of their longer legs, leading to greater drag.

A further complication is that larger animals have slower muscle contractions, making it difficult for a giraffe to paddle fast enough to move forward.

The Telegraph quoted Naish as saying: "Our models show that while it's feasible for a giraffe to swim, it is much harder than it is for a horse. It is fair to say that giraffes might be hesitant to enter the water knowing that they are at a decided disadvantage compared to being on solid ground."