In the 1980’s, researchers from West Africa discovered a distinctive songbird dubbed the Liberian Greenbul (Phyllastrephus leucolepis) in the Cavalla Forest. It was purportedly spotted nine different times between 1981 and 1984, but it was never seen in the wild again after researchers collected the first specimen for science.
Image Credit: Till Toepfer via University of Aberdeen
The mystery continues to elude animal conservationists to this day, and because no one has found another over 30 years later, the circumstances are raising some pressing questions about the species.
In fact, for a group of researchers led by Prof. Martin Collinson from the University of Aberdeen, the circumstances were pertinent enough to call the species’ existence into question entirely. They underscore their concerns in a new study published in the Journal of Ornithology.
One of the only cosmetic variations between the Liberian Greenbul and the common Icterine Greenbul are some white patches that appear in the bird’s plumage. Apart from that, you’d be hard-pressed to spot any others.
Nevertheless, looks alone can be deceiving.
The researchers went a step further and used genetic analyses to compare the Liberian Greenbul specimen's DNA with that of the Icterine Greenbul and other greenbul variants.
Related: Do songbirds get their songs from their genes?
Perhaps unsurprisingly, they discovered similar genetics between the Liberian and Icterine Greenbuls. On the other hand, there were significant genetic differences when compared to other Greenbul species. The implications of these findings cannot be ignored.
“The Liberian Greenbul has gained almost ‘mythical’ status since it was sighted in the ‘80s,” said Professor Collinson.
“We can’t say definitively that the Liberian Greenbul is the same bird as the Icterine 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.”
Related: Is climate change is killing desert songbirds?
As it would seem from the analysis results, there’s justifiable cause to consider that the Liberian Greenbul never actually existed. What's more is that the specimen scientists are holding right this moment could instead be an Icterine Greenbul.
So why the distinct white patches then? According to the researchers, it might have been related to a nutritional deficiency during feather development. Still, this is just a theory and has yet to be confirmed.
Because we know so little about the Liberian Greenbul and the ecosystem where experts found it, this is a complicated mystery to crack. No one can be entirely sure that the Liberian Greenbul never existed, but there’s substantial scientific evidence to insinuate it.
Source: University of Aberdeen