One of the most elusive species of songbird may be so rarely seen because it never actually existed, according to researchers.

The Liberian Greenbul was first recorded as being spotted in a forest during the early 1980s, but has escaped the search of experts for decades.

Now University of Aberdeen scientists believe the bird is actually a common Iceterine Greenbul, but with an unusual plumage variant caused by poor nutrition. Professor Martin Collinson said: "The Liberian Greenbul has gained almost 'mythical' status since it was sighted in the '80s."