Two species of bottlenose dolphin in Eastern AustraliaThese are two older illustrations I recently r

Two species of bottlenose dolphin in Eastern Australia

These are two older illustrations I recently revamped. I really like how they turned out so I decided to make a little infographic. The distribution and ecological interaction between these two species is very interesting. In many places, two types of Common bottlenose dolphin exist:

• The coastal / inshore type, which inhabits small ranges in (very) shallow water
• The oceanic / offshore type, which inhabits very large ranges in deep water

The oceanic type can appear quite close to shore in places where the seafloor quickly drops (here the coastal type is often absent), but in most areas with extended shallows the coastal type will make its home. However, once you enter the range of the Indo-pacific bottlenose dolphin, the coastal type disappears. Indo-pacific bottlenoses completely fill their coastal niche, and only oceanic-type Common bottlenoses remain. This situation is very noticeable in Australia, which these illustrations are based on.

It’s interesting to note though that coastal Common bottlenose dolphins from warmer waters can look incredibly similar to Indo-pacific bottlenoses: including a longer beak, large fins and spotted undersides (which are usually seen as Indo-pacific-specific traits). Curiously, spotting is actually absent on Indo-pacific bottlenose dolphins from the southern half of Australia.