There are 3 currently-recognised subspecies of Asian elephant, Elephas maximus:
The physical differences between them are a matter of degree and are expressed as gradual changes across the range:
The elephants of north-east Borneo present an interesting case.
Genetically distinct from all other living populations, they may have been isolated there for hundreds of thousands of years, since Borneo was connected to the mainland during the ice ages.
However, there is circumstantial evidence that people imported them from Java a long time ago. Since elephants are extinct on Java, the Borneo population may represent the last surviving relict of the ‘Javanese’ subspecies.
Borneo elephants have been described as a separate subspecies, Elephas maximus borneensis. They are said to be pygmies, perhaps an example of ‘island dwarfing’.
A Natural History Museum-led expedition in 2008 investigated this claim by measuring the height of elephants in the field using a laser rangefinder technique.
Our results suggest that Borneo elephants are not significantly smaller than those of mainland south-east Asia. Our research on their status continues.