Snakes of Arunachal Pradesh

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Hello!

I just got back from a visit to the Namdapha Tiger Reserve in Arunachal Pradesh, N.E.India. I had gone there for a survey of birds (funded by the OBC), reptiles and butterflies. I was accompanied by Ashok Captain, Vidya Athreya and Ambrish Kumar. I am going back again in December for the second part of the survey on birds. Since it gets quite cold there, I dont expect to see any reptiles then. So I have given below some notes on the snakes recorded during this visit. I'll post the bird and butterflies report after the second half in January.

If I might sermonise here a bit : I have often heard from professionals that collection of specimens is absolutely essential for proper identification of animals such as snakes, frogs, butterflies etc. As a matter of necessity and a personal distaste of killing animals unnecessarily, several of us have been endeavouring during the last decade to prove to ourselves and to others that killing is not really necessary for identification for many studies. It is no doubt much harder work but we can confidently claim from experience that at least 95% of the snakes and butterflies encountered, including such terrors like the various Lycaenids and Hesperiids can be accurately identified without having to kill them. All it requires is some patience, a field note book and a butterfly net fashioned out of an old badminton racket. The net is very useful for catching butterflies as well as snakes (and many other animals) in a manner which is safe for all concerned. The animals can be released unharmed after being closely examined for identification. A good camera with a macro lens would improve things considerably particularly when you want to prove to our "seasoned brethren" that the identification is indeed correct. It improves matters enormously if you can take your sketches and/or close-up photographs to compare with an already existing museum collection such as the BNHS or the ZSI. The people there will first tell you that it isn't possible to identify animals that-a-way but you can get them around to your way of thinking if you persevere long enough without giving in to their attempts to proselytise :-)

However, since the idea is to release the captured animals as soon as possible and in the same area, it would be of enormous help to have field guides which have identification keys which are not based on the structure of the bones or the arrangement of teeth (as in the case of snakes) but on characteristics which are identifiable, at least with a good lens. We are trying to adapt Smith's key for snakes (in the Fauna of British India series) for use in the field. I would appreciate suggestions from others and exchange of notes if possible in this regard.

There are a few field guides for identifying Indian butterflies but none yet for snakes ...... however, I have heard that one is in the offing (not yet sure if it is going to be a coffee table book or a field guide though!)

SNAKES OF NAMDAPHA TIGER RESERVE

(by Ramana M Athreya and Ashok Captain)

We visited Namdapha Tiger Reserve (NTR) and its environs including the settlements at Miao, Vijoynagar and Gandhigram between the 27th of September and 17th October. NTR is in south-eastern Arunachal on the Burmese border. The 3 settlements mentioned are all on the banks of the river Noa Dehing which flows from the Burmese mountains and cuts across the reserve before joining the Brahmaputra. The park head-quarters is at Miao (200m altitude) which is on the Assam side of NTR. Gandhigram (1150m) and Vijoynagar (1280m) are on the far side of NTR and are surrounded by Burmese mountains on three sides, the international border being only a few km from the two places. The settlements at Gandhigram and Vijoynagar can be accessed on foot by walking along the Noa Dehing Valley on the river bank or along the remnants of a road which exists only on paper. The airforce operates several civilian/ration helicopter sorties a month which may be availed by outsiders after obtaining special permits from the district administration. The sortie operates only during fair weather and so the flooded Noa Dehing ensures that the places cannot be accessed throughout the monsoon between April and September, which, unfortunately, happens to be the best season for reptiles and invertebrates.

The snakes listed below were all identified with the key given by M.A.Smith in the Fauna of British India volume on Serpentes. The names are as given in Smith and have doubtless been changed of late. Since Smith is the only definitive/comprehensive work to date, we have stuck to those names.

We had to spend a couple of days at Miao to obtain the various permits to visit the other two places. Our request to trap snakes in the wild for closer examination for identification (and subsequent release) was turned down by the Department. So we decided to utilise those two days to familiarise ourselves with some of the snakes of the region by identifying the pickled specimens in the Forest Department museum.

A first glance at the labels on the bottles gave us the impression that Arunachal was over-flowing with banded Kraits (Bungarus fasciatus). A closer examination indicated that all snakes with bands had been labelled banded kraits while those without were usually either vipers, cobras or king cobras. As it happenned we did come across a single actual banded krait in the whole collection!!!

In fact one of the "banded kraits" turned out to be a rare wolf snake, Lycodon laoensis, hitherto known only from south east asia!!! We subsequently found out that a Zoological Survey of India party had indeed collected one specimen of this snake from Namdapha some time before that, which happens to be the first record for India. So the specimen in the collection may be the only other record of this species from India. We managed to identify and label about 15 specimens. There is much more to be done there.

If you are a snake buff, it may be well worth your while to examine the collected specimens at Arunachal Pradesh Forest Dept. museums - you may come up with some astonishing discoveries! And the Forest Dept. staff are only too happy to let you try your hand at identifying the snakes.

The snakes identified at Miao (most of them collected by the forest staff in the surrounding grounds) are given below. The full counts of the Lycodon laoensis have been listed here.

1. Typhlops diardi (Diard's blind snake)
2. Elaphe radiata (Copperhead racer)
3. Elaphe porphyracea
4. Ptyas korros (Indo-chinese rat snake)
5. Lycodon laoensis

Scales in 17:17:15 rows, smooth and with an apical pit; long loreal not touching the eye or the internasals; 1 preocular reaching the top of the head and touching the frontal; 2 postoculars; 2+2/3 temporals; 9 supralabials with the 3rd, 4th and 5th touching the eye; 9 or 10 infralabials; 197 ventrals; a divided anal and 70 divided caudals;

6. Dryophis prasinus (Short nosed vine snake - 3 specimens)
7. Boiga multimaculatus (Large spotted cat snake - 3 specimens)
8. Bungarus niger (Black krait)
9. Callophis macclellandi (MacClelland's coral snake)
10. Naja kaouthia (Monocellate cobra)
11. Trimeresurus monticola (Mountain pit-viper)

As I mentioned before, since we did not get permission from the department to catch snakes in the sanctuary, we confined our snake activities to the villages of Gandhigram and Vijoynagar which are outside the sanctuary. With the help of the local Lisu tribals we got 13 snakes in a matter of 3 days (I couldn't believe my eyes!!!). They were all keyed out, photographed and released back into the places where they were caught. I can post the shield/scale counts if any one is interested. The snakes included

1. Elaphe taeniura (Striped Racer)

2. Elaphe frenata

3. Natrix himalayana (Himalayan keelback)

4. Natrix khasiensis (read the following mail)

5. Psammodynastes pulverulentus (Mock viper)

6. Natrix piscator (Checkered keelback - 3 specimens)

7. Trimeresurus monticola (Mountain pit-viper)

8. Trimeresurus jerdoni (Jerdon's pit-viper)

9. Trimeresurus stejnegeri/popieorum (Green pit-viper)

This is in continuation of my previous mail on snakes of Arunachal Pradesh : An examination of BNHS specimens in connection with some snakes that we saw in Arunachal indicates that the characters mentioned by Smith in the Fauna of British India for Natrix Khasiensis may be in slight error (the postocular count)

Ashok Captain and I obtained 3 individuals of a Natrix species which could have been either N.khasiensis or N.modesta. The difference between the two species as given in the key by Smith in the Fauna of British India series was :

labials black with white centres ....... khasiensis

labials whitish with dark margins ...... modesta

Smith has done a great job on the book but he indulges in these occasional streaks of meanness by slipping in key differences of that sort!

The colouration of the snakes was more like khasiensis .... but colour is not always to be relied upon. The only other differences between khasiensis and modesta are in their ventral and caudal counts and in the number of postoculars. All the snakes had 3 postoculars (as for modesta; Smith mentions 1 or 2 for khasiensis) but the ventral count was more equivocal (our specimens had ventral counts of 143, 145 and 146 whereas Smith lists 145-155 for khasiensis and 148-168 for modesta; however he mentions that modesta is a very variable species). The caudal counts for the species are 94-110 for khasiensis and 110-132 for modesta. However he mentions that the tails of many specimens of modesta are missing and the counts may be incomplete. And the first two specimens we obtained had missing tails (!!!) and so we couldn't count the caudals. However the third one had a count of 99 which put it among khasiensis.

One thing we were certain about - all the 3 snakes were the same species. There was an exact matching in their colouration and all the scale/shield counts that we could check (except for the missing tails). While Khasiensis appeared to be more appropriate, the one major reason against it was the different postocular count.

So we took our notes and got several good mug shots, released the snakes back into the wild and came to check the specimens in the BNHS collection. Fortunately we found several specimens of N.khasiensis collected from Burma and Khasi hills in Meghalaya including the co-types collected by Col. Wall!! Unfortunately the collection lacks any specimen of N.modesta.

We were pleasantly surprised to note that of the two co-types, one had 3 and another had 2 postoculars; of the other 13 specimens, 11 had 3 postoculars while only 2 had 2 postoculars. However, we also noticed that in the specimens with 3 postoculars, the lowest one was quite tiny (but distinct) and may conceivably be labelled a post-subocular.

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So :

either the 1 or 2 postoculars mentioned for Khasiensis in Smith is a typo/oversight and ought to be 2 or 3 postoculars

OR

Smith has forgotten to mention the extra post-subocular in addition to the "1 or 2 postoculars"

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So our three specimens belong to Natrix khasiensis, hitherto known only from the Khasi hills of Meghalaya in India. These records constitute a range extension into Arunachal Pradesh ..... though not a surprising one since they are also known from Burma and Burma was only a few km from Gandhigram.

But I'd like to see a specimen of N.modesta before being 100 per cent certain that what we saw were indeed Khasiensis. Would any one in the US/UK be able to help us in this regard by checking out which museum has specimens of N.modesta. I could mail you a good photograph of the snake for a superficial checking out apart from the scale/shield counts.

As I mentioned in my previous mail .... one can identify snakes, even toughies, without having to kill them!

Thank you

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Ramana M Athreya
National Centre for Radio Astrophysics
(Tata Institute for Fundamental Research)
P.O.Bag 3, Pune University Campus,
Pune : 411 007. India.

email : ramana@gmrt.ernet.in
Phone : (+91 212) 357107, 351384
Fax : (+91 212) 355149
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