Different colour, same species #2

The last blog attempted to illustrate the (I thought) interesting fact that sometimes birds that look different can be the same species. Apparently the two colour morphs of the Brown Falcon were not different enough to excite anyone about the fact that this was so.

So let’s try again. Crimson Rosellas (Platycercus elegans), pictured left, are widespread through south eastern Australia commonly found in the more forested areas. They feed on a variety of seeds, nectar, berries and nuts as well as invertebrates and their larvae.

En-route whilst driving to Adelaide recently I spotted a Yellow Rosella (pictured right). The scientific name for this parrot is also Platycercus elegans i.e. the same species but clearly a different colour. Scientifically the birds are divided into races – the Crimson Rosella (race: elegans) and the Yellow Rosella (race: flaveolus). To confuse the situation more whilst cycling north through Burra I came across Adelaide Rosellas, pictured below, again Platycercus elegans but the race subadelaidae. Adelaide Rosellas are thought to be the hybrids of Crimson and Yellow Rosellas that are known to mate where their distributions overlap.

Given the definition of a species is that individuals can mate and produce viable, fertile offspring (and clearly this is happening), the three birds are the same species but of different races. The definition of race is very ambiguous.

In the case of the two Brown Falcons from the previous blog, the colour differences are called morphs (not races). The definition of a morph is that the different populations co-exist in the same habitat and can randomly mate with each other. I am not sure how this relates/differs from race.

Clearly I need to consult someone with a greater knowledge of taxonomy. My head hurts!