A Sheep in Wolf's Coat
Mis-identification of Plain-Pouched hornbill (Aceros subrificollis)

R.K. Birjit Singh *

It was indeed a great moment of pride and excitement for all the birders and members of Indian Bird Conservation Network (IBCN) to received a sudden call from E. Budha, a young and dynamic wild life activist, an active birder, secretary, Wild Life Protection Committee (UWLPC), Sekmaijing of his recent sighting of a hornbill species( Uchek Langmeidong), a female Plain-pouched hornbill (Aceros subrificollis) which had never been sighted in the Indian sub-continent and at the same time never been reported correctly regarding its identification over the years.

While looking through the photograph mailed by him, I was not ready to convinced myself regarding the correct identification of the species, rather the hornbill species seems to be Wreathed Hornbill (Rhyticeros undulatus). Obviously, it is very difficult to distinguish between a Plain-pouched hornbill and a Wreathed hornbill, particularly in the off-field condition and when compared with the actual photograph and illustration pictures drawn in the book. It is easy to get frustrated birding when you see a new species but can't identify it properly.

All previous records from northern Myanmar, India and Sumatra were the result of misidentifications. The striking identification character of a female Plain-pouched hornbill is the presence of blue-pouch just below the bill. As no blue coloration could be seen in the pouch below the bill of the species, I told Budha to send me another photograph of the species captured from different angle.

Next day, he come to my residence with all the photographs and video clips, he got through and told me that he had seen the blue-pouched with his necked eye before capturing the species in his camera. While going through the photographs and video clips, I found no reason to ascertain the species as Plain-Pouched hornbill which is vulnerable as per Red List of the Threatened Species of IUCN.

In a humor gesture, I told Budha that lens aberration cannot change blue colour pouch to yellow specifically and vice –versa. Chromatic aberration manifests itself as "fringes" of color along boundaries that separate dark and bright parts of the image, because each color in the optical spectrum cannot be focused at a single common point.

Since the focal length f of a lens is dependent on the refractive index n, different wavelengths of light will be focused on different positions. Later on, I come to know that, I was the last person contacted by him with the photographs regarding the correct identification of the species. And it seems that most of them already given their opinion as Plain-Pouched hornbill. Armed with so many opinions as the species claimed by him, Budha was not ready to accept my observation. Simply he smiled and left my home.

His lovely smile haunted and made me spend a sleepless night scanning every dot and pixel of the photographs provided by him and reviewing, checking and consulting many reference books on the hornbills of the world. At last I found a darn up mark in the pouch which is probably the black stripe in the pouch of the male wreathed hornbill but I was not sure.

As no option has been left, I started contacting some of the top hornbill specialist of the country and abroad by sending mails and photographs to Dr. Raju Kasambe of BNHS, Dr. Ranjit Manakadn, Dr. Vibhu Prakash, Tim O'Brien, Wildlife Conservation Society, Mpala Research Centre, Kenya, Dr. Chution Savini, Srinakharinwirot University, Bangkok and Christine Sheppard , chair of the SSC Hornbill Specialist Group,IUCN and Laboratory of Ornithology, Cornel university.

While I was eagerly waiting for reply from the top hornbill experts regarding the correct identification of the species, local English daily, the Sangai Express reported about the sighting of the hornbill species with the caption, "Crusade on to save rare bird species", on the 24th April,2014, confirming the species as Plain-Pouched hornbill.

Hurriedly, while checking through my mail, I found reply from most of the experts confirming the species as Wreathed Hornbill (Rhyticeros undulatus) locally known as Langmeidong mei-ngou which is protected under Schedule I of the Wild Life Protection Act, 1972. Interestingly, the darn up mark in the pouch as I have already mentioned above turns out to be the black stripe in the pouch of the male wreathed hornbill. As the species was a juvenile, a second year (male) bird with short casque and less serrated basal half of the beak and no prominent mark on the gular pouch made me confused while confirming as Wreathed Hornbill.

I think, Budha was in hurry for reporting his new sighting to the media before establishing the correct identity of the species. Of course media is a vital tool for conveying the message of conservation but we birders should have a good patient while birding otherwise message will go wrong and in vain. Thus the species turns out to be a sheep in wolf's coat.

No one has reported the species in Manipur after the British colonial period except by Anwaruddin Choudhury in the year 2009 as reported in FORKTAIL 25 (2009): 71–89, a British journal of ornithology of the oriental region but without any documentary evidence of the bird. So, kudos to E. Budha as he is probably the first one to capture digitally the hornbill species in Manipur.