SYDNEY: Birds with multiple versions of their colour patterns evolved into new species more quickly than those with uniform plumage, Australian researchers revealed in a significant genetic study published Thursday.

The University of Melbourne research, published in “Nature”, found that birds with more than one version of its markings such as the Gouldian finch, which can have a red, black or yellow head, “rapidly” evolved into new species.

The study proves a theory in evolutionary biology first proposed 60 years ago and helps shed light on the processes that create biodiversity, according to lead researcher Devi Stuart-Fox.

“We’re trying to figure out how and why new species evolve... the triggers and catalysts,” she said.

“Why will some populations evolve into new species while others just stay the same for millions and millions and millions of years?” Though they look different, the finches in the study coexist within a single population and Stuart-Fox said the study found they evolved into genetically new species much faster than uniformly-coloured birds.

“This is the first time that we’ve been able to show that it actually speeds up speciation rates or rates of evolution,” she added.

Hawks, eagles, owls and nightjars were the focus of the Melbourne study but birds are not the only animals with so-called “colour polymorphic” species -- it was also a feature of fish, lizards, butterflies and snails.

The different colour versions often varied in things like physiology and behaviour and Stuart-Fox said their inclusion within a single population “might allow (it) to exist in a broader range of environments”.

Some researchers were examining whether and how colour polymorphism contributed to species’ resilience and adaptability to external factors such as habitat loss and climate change, she added.