After its existence was confirmed in 2016, a new endemic species of owl has been described from Príncipe Island in the Gulf of Guinea.
Príncipe Scops Owl joins seven other bird species endemic to to the island. It is one of two owls endemic to the Democratic Republic of São Tomé and Príncipe, with the São Tomé Scops Owl only found on the island of São Tomé.
Researchers have suspected the existence of Príncipe Scops Owl since 1998 but it seems local people may have encountered the bird as long ago at 1928. Its binomial name, Otus bikegila, is a nod to parrot-trapper turned park ranger Ceciliano do Bom Jesus, known affectionately as Bikegila.
The researchers said: "The discovery of Príncipe Scops Owl was only possible thanks to the local knowledge shared by Bikegila and by his unflinching efforts to solve this long-time mystery. As such, the name is also meant as an acknowledgment to all locally-based field assistants who are crucial in advancing the knowledge on the biodiversity of the world."
In the description of the new paper in ZooKeys, the team led by Martin Melo, Bárbara Freitas and Angelica Crottini described the owl's morphology, genetics and vocalisations. It occurs in rufous and grey-brown morphs but its rapidly repeated tuu note was what proved crucial in its discovery, with birds often heard duetting just after dusk.
Results of an island-wide survey for the species have been published in Bird Conservation, revealing that the owl is only found in the relic old-growth forest on the south side of Príncipe. It prefers lower elevations, further limiting its range, which amounts to just 15 sq km.
However, in that small area a remarkable density of 1,000-1,500 birds is estimated to survive. Because of its tiny range, some of which is due to be impacted by the construction of a hydroelectric dam, it has been recommended for Critically Endangered status on the IUCN Red List.
Further monitoring will take place using tried-and-tested autonomous sound recording equipment to work out the species' population trends.
The researchers said: "On a positive note, the area of occurrence of Príncipe Scops Owl is fully included within the Príncipe Obô Natural Park, which will hopefully help secure its protection."
They added: "Although it may seem odd for a bird species to remain undiscovered for science for so long on such a small island, this is by no means an isolated case when it comes to owls."
"The discovery of a new bird species is always an occasion to celebrate," they said, but added: "In this age of human-driven extinction, a major global effort should be undertaken to document what may soon not be anymore."
The team put the discovery down as an example of how "curiosity-driven endeavour is more likely to succeed when coupled with local ecological knowledge, the participation of keen amateur naturalists, and persistence".
Other Otus species that have eluded scientists for decades include Anjouan Scops Owl and Flores Scops Owl, both rediscovered in the 1990s after no firm reports since the late 19th century.
References
- Martim Melo et al. 2022. A new species of scops-owl (Aves, Strigiformes, Strigidae, Otus) from Príncipe Island (Gulf of Guinea, Africa) and novel insights into the systematic affinities within Otus, ZooKeys. DOI: 10.3897/zookeys.1126.87635
- Bárbara Freitas et al. 2022. The recently discovered Principe Scops-owl is highly threatened: distribution, habitat associations, and population estimates, Bird Conservation International. DOI: 10.1017/S0959270922000429
