The Owl Prowl

19 Jul 2017
POSTED BY Alvin Thomas

When two ornithologists stumbled upon an unknown breed of owl in Oman, their find prompted keen birdwatcher Dr Christopher Clarke to take on a quest of his own to spot the new species.

March 2013 was a significant month in the history of the Sultanate’s wildlife.

Ornithologists Magnus Robb and René Pop had just travelled to Oman from the UK to obtain sound recordings of the Pallid Scops Owl Otus brucei, in the foothills of Jebel al Akhdar.

After several exhausting nights, just when they had finally established a rapport with the Scops Owl, they heard the distant hooting of another kind of owl. What caught their attention was a sound different from any known call of a Middle Eastern owl.

They managed to get sound recordings of this unknown owl, and during a further three trips to the same area, took photographs and made more sound recordings.

It was clear to Robb that he had found a new species, which he aptly named the Omani Owl Strix omanensis.

This discovery created a stir among birders and biologists around the world – a bird around the size of a Barn Owl the discovery of which was extraordinary. Even more controversial was that it was a bird named only using sound recordings and photographs.

Normally, for a species to be recorded as new to science, it needs to be caught, killed, preserved, and taken to a museum, where it will be compared with specimens of similar species. 

If it is found to be different, it will be named, and the newly-collected specimen will be known as the “type specimen”. This means that this would be the specimen upon which a new species is described.  However, the naming of the Omani Owl did not follow this rule, nor was the story of its nomenclature over.

Magnus Robb compared his photographs of the Omani Owl with a dusty and decrepit specimen of an owl in the ancient archives of the British Museum of Natural History, and was baffled to find that they were identical.

The museum specimen was of an owl called Hume’s Owl, Strix butleri, which was obtained in 1878 by Lieutenant-Colonel Edward Arthur Butler. The Lieutenant-Colonel had received the specimen by canoe from a certain Mr Nash who was posted at the Telegraph Station in Ormara, on the Makran Coast of what is now southern Pakistan.

Butler sent the specimen to an ornithologist called Allan Octavian Hume.  Hume described the species in the Journal of Ornithology for India and its dependencies, and gave the owl an English name after himself, and a Latin name after the Lieutenant-Colonel from whom he had received it. Hume’s Owl was therefore described on the basis of this single specimen.

Since the 1880s, Hume’s Owls have been recorded in Jordan, Saudi Arabia, Sudan, Yemen and southern Oman, yet none were ever again recorded north of the Persian and Oman Gulfs.

All were similar to each other and had the same call. Magnus Robb also knew about Hume’s Owl and its call but the owl he heard in Jabal al Akhdar had a different hoot, and even looked different from photographs of Hume’s Owls.

And to make matters more confusing, blood samples of an Omani Owl were collected in 2015 that showed this owl to have different DNA compared to Hume’s Owls. But why was the Omani Owl the same as the type specimen of Hume’s Owl?

Scientists then realised that for more than a century they had been making a mistake. All owls recorded as Hume’s Owl based on the 1878 specimen, were in fact a different species of owl from that specimen but the Omani Owl and the 1878 specimen were the same. On examination of the source of the 1878 specimen, it was apparent that Mr Nash collected species from localities outside the coastal town of Ormara.

It is even possible the 1878 specimen could have come from Oman, especially given that parts of the Makran coast of Pakistan were governed by Oman at the time the specimen was collected, and there would have been trade links between the two places.

As a result, in 2015, a revision was made to the taxonomy of Hume’s and Omani Owl. Omani Owl Strix omanensis became Omani Owl Strix butleri. And Hume’s Owl Strix butleri became Desert Owl or Desert Tawny Owl Strix hadorami.

The intriguing story of the Omani Owl made me wonder whether this particular owl was known to local people, and if so, what was the name they had given it?

Also, I wanted to see and hear it for myself. After all, how often have you had the chance to observe a new species of science less than two hours’ drive away?

I managed to obtain the GPS co-ordinates of four of the locations where the owl had been found from the internet, and since they were all within an area of 2km by 1 km, I considered my chances of finding it to be high.

Find out how Christopher got on in his quest, in part two, in next week’s edition of Y

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