Welcome to my blog

This is where I post various musings about wildlife and ecology, observations of interesting species (often invertebrates)
and bits of research that grab my attention. As well as blogging, I undertake professional ecological & wildlife surveys
covering invertebrates, plants, birds, reptiles, amphibians and some mammals, plus habitat assessment and management
. I don't work on planning applications/for developers. The pages on the right will tell you more about my work,
main interests and key projects, and you can follow my academic work here.

Wednesday, 22 August 2012

Rubber-necking the rare Rothschild Giraffe

The giraffe (Giraffa camelopardalis) is of course a familiar and unmistakeable animal - it is however much less common than often imagined. It is split into a number of subspecies (up to nine, depending where taxonomic boundaries are placed) and even the most common, the Maasai giraffe G. c. tippelskirchi numbers no more than around 40,000 individuals in the wild. Several subspecies number no more than a few hundred, one of which, the Rothschild giraffe G. c. rothschildi has an estimated wild population of less than 650 (all in protected areas of East Africa) with almost as many kept in zoos around the world (including Marwell's conservation programme where I took these photos, although I have seen them wild in the Lake Baringo area of Kenya - it is sometimes known as the Baringo giraffe). They are readily identifiable from the coat colour/pattern, especially the pale 'socks' due to a lack of pattern on the lower leg.

Rothschild giraffes at Marwell - a surreal sight in southern England!
Given the small population size, and ongoing threats such as habitat loss (e.g. encroachment by human settlements), widespread poaching, and possibly hybridisation, this subspecies was added as Endangered on the IUCN Red List in 2010. It is also a poorly understood subspecies with no major research being undertaken on it prior to the ongoing Rothschild's Giraffe Project which aims to look at the behaviour and ecology of wild populations, in particular, ecological/habitat requirements, group dynamics, factors affecting behaviour, social structure, herd formation and relatedness, and from all of this, knowledge about how to formulate effective conservation plans (if you'd like to donate to the project, you can do so here).

Like all giraffes, both sexes have short blunt horns called ossicones (formed from ossified cartilage and fused to the skull) - these contain blood vessels and may be involved in temperature regulation. Males compete by engaging in 'necking' behaviour - this starts by rubbing and pushing, and can develop into full-blown contests as males swing their heads at each other and try to land blows with the ossicones. If you ever get the chance to see this, it's amazing - like a huge game of conkers.

Their necks are of course their best-known feature - with just the usual seven cervical vertebrae, each is about 30cm long and they have ball-and-socket articulations for flexibility. Proportionally, newborn young have short necks with most of the elongation happens after birth, otherwise giving birth would be problematic. When upright, the neck is supported by the nuchal ligament and large muscles which create the small hump seen at the base above the shoulders. When bending down to drink or graze (which also means splaying or bending the legs), the network of veins and arteries called the 'rete mirabile', plus valves in the jugular veins, prevent excessive blood flow to the brain. These are just some of the circulatory adaptations that allow the giraffe to function with such as long neck - its heart rate (about 150 beats/minute) is high for a large animal, its heart weighs around 11kg or more generating blood pressure about twice that in humans, and the skin of the lower legs is thick and tight to prevent too much blood pooling there.

Rothschild giraffe bending down to graze - note the splayed front legs.
I could go on about the bizarre anatony of the giraffe, but I won't - instead, why not have a look at the excellent 'Inside Nature's Giants' TV programme (videos are on Youtube) based on dissections by specialists in their field. It's amazing I can assure you!

No comments:

Post a Comment