Rinkhals table mountain…really?

In 2010  research was initiated  to determine if the rinkhals, Hemachatus haemachatus, could still be found in the greater Cape Town area.

The project unexpectedly received nationwide publicity as it called for public assistance in locating this elusive species in the Cape.  Positive feedback was soon forthcoming and in a matter of months the project received a number of records confirming the existence of the rinkhals in the eastern part of the City of Cape Town, while sightings from the Cape peninsula itself remained unconfirmed.

On the 24/11/2011, it appeared that this had all changed. Historically, the rinkhals was once common in the lowlands of Cape Town and had been recorded regularly by naturalists in the late 1960’s and the early 1970’s but never a rinkhals Table Mountain.

This interested me… a lot! The rinkhals is known to occur from sea level to 2 500 metres throughout much of the country, but had only ever been recorded in the low-lying areas of the Cape? And in Gauteng, despite extensive urban expansion the rinkhals is still one of the most regularly encountered snakes, so why has such a resilient species become so rare in the Cape?

Rinkhals sightings were flooding in, many from areas on Table Mountain, some of which detailed the species accurately down to incidents of venom spraying. But, without photographic proof , these records remained unconfirmed – until the day we received the following photographs (so we thought).

 

The banding on this snakes body had a striking resemblance to a juvenile rinkhals. I was convinced. My dream had come true. Immediately I began planning a trip to the area where it was spotted on Table Mountain to survey the area.

I contacted my good friend Elroy Arendse, who introduced me to this species,  and he burst my bubble when he told me he’d once seen similar markings on a juvenile Cape cobra from an area nearby. I felt deflated. Had I ‘seen’ rinkhals in this picture because that is what I so badly wanted it to be? Was it possible that a Cape cobra to have such rinkhals-like markings? I frantically started searching the internet for comparative pictures of both Cape cobra and rinkhals juveniles.

After my fruitless search, I contacted experts Prof. Graham Alexander and Johan Marais who re-inspired me they both identified the snake as being, undoubtedly, a rinkhals.

The Reality

Even though the experts had confirmed it as a rinkhals, something about its location, it’s head and overall body shape and Elroy’s nearby sighting left enough uncertainty to warrant further investigation.

Elroy forwarded comparative pictures of his juveniles.

Of course I hoped it was a rinkhals but had to be sure. So I contacted Prof. Graham Alexander again and asked him to take a closer look but he reiterated that he believed it was a rinkhals. However, after I explained the reasoning behind the doubt, he concluded that the pictures were not clear enough.

Johan Marais was then also contacted again. He kindly inspected the pictures once again and noticed something in the distinctive in the head shape. When I look closely, I see it now too. I think I always saw it but I hoped that one of the experts could tell me otherwise. But it wasn’t to be. The snake in the picture was not a rinkhals, but a Cape cobra, Naja nivea.

Although this was somewhat disappointing, it did make sense – Cape cobras are relatively common at that particular site and the rocky mouintain slope is not known to be typical habitat for a young frog loving snake. Interestingly though, was that it was found basking in temperatures of a mere 10 degrees Celsius. The rinkhals is  known to be active in cool weather and has the ability to maintain its body temperature in these conditions, but Cape cobras are usually only active in temperatures from the upper 20’s according to research conducted by Dr Tony Phelps. (Which just to added to the initial confusion).

In the end a great deal was learned and served as  a good reminder of just how meticulous we have to be with every rinkhals record we receive and just how easily snakes can be misidentified with confidence, even by experts.

I’d love to hear about your experiences. Have you ever seen a rinkhals or misidentified a snake? Do you find snake identification easy or difficult. Feel free to interact in the comments section below.