I am an Englishman that has braved the heat and moved to South Africa for its wealth of biodiversity. Cormac Price recently joined me as a fellow post-graduate student at the University of KwaZulu-Natal, some 18 months after I first arrived. My project is slowly nearing completion with my final data all collected, as I go through the inevitable horrible process of number crunching to produce the thesis that will probably define my next few positions. Having talked to Cormac about some of the stories from my field work, he told me that I should write an article for BioWeb.ie. After a few drinks at the pub watching Ireland narrowly lose to France (I was supporting you guys), I agreed.
My Masters project is investigating how home range and movement patterns are affected by variations in climate, as well as food and water resources. The study species? South Africa’s biggest and baddest tortoise species; Leopard Tortoise (Stigmochelys pardalis). I hope I didn’t big up the species too much before revealing.
Despite growing up in England, I have had a passion for tortoises as long as I can remember. Once I was offered the chance of studying one of the world’s infamous tortoise species, my decision to come here was made. Leopard Tortoises are one of 14 tortoise species in South Africa; a country which can be considered the biodiversity hotspot for Testudinids.
Despite being based in Pietermaritzburg in the province of KwaZulu-Natal, my study sites are in the middle of the Great Karoo; a semi-arid desert similar to those in Nevada/California or Spain. Living in the Karoo throughout my study was not possible, and so on six occasions I have made the 13+ hour drive to my study site from my Pietermaritzburg accommodation.
My budget allowed for the purchase of 10 GPS transmitters. These would collect data every two hours, night and day, for a minimum period of 12 months. With the help of an assistant, the transmitters were attached to adult Leopard Tortoises in late 2014. However, to collect the data, a basestation receiver would have to be in the vicinity of the tortoises to download the data. As the tortoises were spread over several locations, it was unfortunately not possible to simply leave the basestation to collect the data every day. As I soon found out, tortoises move MUCH further than people might give them credit for.
The first trip back to my study sites after deploying the transmitters was some eight weeks later. Most of my two and a half weeks was carried out doing other project-related surveys; for example, 20 transects, each 2km in distance. Throughout the field trip, I would move the basestation to a different location – a different hill (or Kopjie, as they are called). 7 of the 10 tortoises clocked in, with the previously collected data successfully downloaded. I wasn’t worried about the other three, as I expected future field trips to yield better results.
The second trip was much the same, though one of the missing tortoises was easily found, as expected. I began to get worried about the remaining two, but I wasn’t sweating too much at this point. By September, it was time for my third field trip. The same 8 were easily found again, but I knew I needed to do something about the missing two tortoises this time. Their transmitters had 9 months worth of data on them. Losing two of the subjects of my research would mean a considerable loss of time, energy, finance and effort.
After hours of driving around the sites, one tortoise was found purely by chance. This tortoise had travelled a huge distance away from its original location. Looking back at the data now, I can see its daily movements. First the tortoise moved some 3.5km westwards up to the mountains over the course of about three weeks. After that, the individual made a strange, yet direct 7km trek southeast. If this doesn’t impress you, I can’t even stress how many fences, ravines and roads the tortoise would have been required to cross…
Considering this, I was desperate to find the last tortoise, which remained evasive. I ended up contacting a nearby flying school; AIFA. Here, Chief Flying Instructor Mr Ronny Johnson offered to assist with the search. Within 15 minutes of turning up at the airport, I was in a small plane, which was being flown by a pilot-in-training with the basestation duct-taped to the side of the plane. I can’t imagine this would happen in Europe, but hey, T.I.A (This is Africa).
A weak signal was received nearly immediately. However, the signal was too weak to download any data. We circled that area for approximately one hour before turning back. Two days later, after some changes to the settings by Victor Hugo (producer of transmitters for my study), I was up in the sky once more. The settings were now as such that only the last GPS point would be downloaded by the basestation. I assumed it would be easy sailing, but one hour passed with no signal at all. I decided to tell the pilot to head back, and just like in a Hollywood blockbuster (albeit less dramatic), the signal was received and a data point was downloaded.
We landed, and then my team drove towards the destination. I was somewhat disappointed that the GPS point was a location where I had previously left the basestation. Perhaps the GPS coordinate was incorrect? Regardless, my team and I searched the local area on foot. Eventually, just prior to giving up, the tortoise was located, alive and well. Nine months of valuable data was then downloaded!
As a way of saying “Thank You”, I offered the flying school the chance to name the tortoise. They ran a competition through their monthly newsletter and allowed me to pick the winner. There were several decent suggestions, but Captain Skyhawk won, due to the fact that the small aircraft was a Cessna Skyhawk. On my final 2015 visit to the study site, I caught up with Captain Skyhawk for perhaps one final time, where we took the following photo.
Thanks for reading,