A new owl species from Indonesia is formally described
A new species of owl discovered in Lombok, Indonesia, has been formally described by scientists.
The Rinjani Scops owl (Otus jolandae) was discovered by two separate researchers just days apart in September 2003.
The "common" owl is the first endemic bird species recorded on the island of Lombok.
The first study of the species, by an international team of scientists, is published in the journal PLoS One.
Lead researcher George Sangster, from Stockholm University's Department of Zoology in Stockholm, Sweden, described his first encounter with the new species.
"I found the new owl on 3 September 2003, and Ben King found it independently at a different location on 7 September 2003."
Wise old birds
"I was on Lombok to collect sound recordings of the local population of a species of nightjar. On the first night I arrived on Lombok, we heard the vocalisations of an owl that [I was] not familiar with."
Coincidentally researcher Ben King, from the Ornithology Department, American Museum of Natural History in New York, USA, was in Lombok at the same time, recording the same nightjar species even though the researchers had never met.
Mr King commented, "My experience was similar to George's. While I was tape-recording the nightjar, I heard a song that sounded like an owl, but unlike any I'd heard in years of field work in Indonesia."
Initially Mr Sangster was not certain whether it was a previously known species from Java and Bali that for some reason had been overlooked on Lombok.
This explanation was quickly ruled out when he played back the sound recordings of the owl.
"When we first heard them, the owls were very vocal, and either involved in a duet (of male and female) or a duel (between two males).
Because we were not sure which species this was, we made recordings and played it back.
Owls are territorial, so when their sound is played back in their territory, the owl usually comes to investigates the 'intruder'."
The owls responded strongly to the recordings and approached the researchers, meaning they had a clear view of the owls.
This meant that the volcalisations were indeed their song, a crucial piece of information according to researchers.
The Rinjani Scops owls initially looked very similar to the Moluccan Scops owl, a species of owl that was reported to occur on Lombok.
However, their whistles sounded completely different from the "raven-like croak" of the Moluccan Scops Owl.
The researchers only realised that they had in fact discovered a new species when they checked the taxonomic literature and examined their recordings more closely.
Previously no endemic species of birds from the island of Lombok were known.
To verify their findings the scientists studied plumage differences in museums, took measurements of various body parts and analysed the songs.
They used playback in the field to determine which species are present on Lombok and Sumbawa, before using DNA data to compare all relevant species.Further finds
Mr Sangster explained that there may be further undiscovered bird species in Indonesia.
"Several species have already been announced in the scientific literature but await formal description. There are probably several other species of Scops owls in Indonesia that remain overlooked, even if they are already named.
Until recently, many species of owls were included as 'subspecies' of highly variable, widespread species. Step-by-step, we are learning that this is not always correct, and that some of those are better considered as species."
Mr Sangster was most surprised by how common this new species was. The researchers found the owls at several locations and often heard multiple individuals calling from different directions.
He suggested how this discovery can have long-reaching implications for study.
"In the past, ornithologists and birdwatchers have largely ignored the island because, unlike Java, Bali, Flores and other islands in the region, no bird species were unique to it," he told BBC Nature.
"Our study underscores that even after 150 years of scientific study we still do not know all birds in the Indo-Malayan region. In fact, Indonesia is a treasure trove for taxonomists."