One of the world's most elusive songbirds may never have existed
"The Liberian Greenbul has gained almost 'mythical' status since it was sighted in the '80s"
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.
"We can't say definitively that the Liberian Greenbul is the same bird as the Iceterine Greenbul but we have presented enough evidence that makes any other explanation seem highly unlikely.
"The genetic work was performed independently by scientists here in Aberdeen and in Dresden to make sure there could be no error - we both came to the same conclusion."
The Liberian Greenbul, which is recorded as having distinctive white spots, has long been one of the world's most poorly known bird species and was listed as Critically Endangered up until 2016.
It has been seen on nine occasions between 1981 and 1984 in the Cavalla Forest in Eastern Liberia.
Cavalla is recognised as an important bird and biodiversity area by BirdLife International, not only for the Liberian Greenbul, but for other threatened species
The only known specimen of the elusive bird was collected there in January 1984 and described as "new to science".
Liberia's civil wars prevented any serious attempt by ornithologists to find any more individuals for another 25 years.
Targeted searches were made in two known areas of sightings in 2010 and 2013, but failed to find any sign of the bird.
It meant the Liberian Greenbul had never been seen since the only known bird was shot.
Experts at the University of Aberdeen have now compared DNA from that specimen with that of the Icterine Greenbul and others.
The study, published in the Journal of Ornithology, found no significant genetic difference between the two species.
Instead, scientists believe it is most likely an unusual plumage variant of the Icterine Greenbul, possibly caused by nutritional deficiency while the feathers were growing.
The Aberdeen study was carried out in collaboration with scientists from the Zoological Research Museum Alexander Koenig in Bonn, Germany, Senckenberg Natural History Collections in Dresden, the University of Cambridge and BirdLife International.