Is lone cow the very last of Knysna’s iconic elephants
Source: CXPress
FINDINGS announced by SANParks scientists during a press conference on Wednesday February 6, that a female elephant lives alone in the Knysna forest, has resulted in strong opinions from the public and scientists alike – Fran Kirsten reports.
SANParks scientist Lizette Moolman explained that the findings of a team of scientists (recently published in a scientific article titled And Then There Was One, following a rigorous camera trap survey, using 72 passive infrared-triggered cameras, 24/7 from July 2016 to October 2017 in the 185km² Knysna elephant range) confirmed that only one elephant exists.
“Because elephants move along defined pathways, we placed our cameras on these paths and covered the elephant range evenly, with spaces between camera traps no larger than the smallest range recorded for elephants.
“An elephant would not reside in a gap area, between camera trap locations, for the duration of the survey. The cameras were all active for 15 months, and during this time the same female elephant was identified in 140 captures, always by herself. No other elephants were photographically captured.”
Moolman emphasised that SANParks had decided upon releasing the information to the public out of concern for this lonely cow.
“The many hours of footage shows her roaming by herself – extremely abnormal behaviour. We carried out this survey to gather reliable and consistent information on the Knysna elephant behaviour and numbers, to enable well-informed decision making, and not to try and prove previous investigators wrong.”
However, Gareth Patterson – award-winning wildlife expert and author of Secret Elephants, which details his eight-year odyssey to uncover truths about the Knysna’s pachyderms – took to social media to voice his disagreement with the survey’s outcome.
“My long years of fieldwork on these special elephants has proved that they brought themselves back from the brink [of extinction]. Additionally I undertook two DNA censuses. The results on the first in 2007 indicated the presence of five (relatively young adult) females.
“Results of the second (2009) came up with the same five females, plus a sixth that we missed the first time round. Field work additionally indicated the presence of three bulls and of calves,” he wrote.
Patterson’s conclusions were reached by performing DNA tests on dung collected and measurements of hind foot diameters.
Asked how Patterson’s DNA tests could now be incorrect, Moolman responded: “Various scientific study findings have been published since the Knysna DNA genotyping survey was undertaken that showed that dung must be a few hours to 24 hours old in order for genotyping to work.
“Therefore to ‘estimate’ a population size in this manner, you must use very fresh dung and you need quit a number of samples. So one will have to physically track an elephant, disturbing it in the process, to get enough reliable samples.
“Dung samples used in the DNA study were collected from dung piles that were more than four days old, as reported in the 2007 publication. Since this study result was published, other researchers who did studies elsewhere, reported that dung needs to be much fresher (less than 20-24 hours old) to get a reliable DNA reading. DNA studies conducted on dung older than a day lead to overestimations of populations.
Moolman explained and showed video clips of the female cow walking backwards over her own footprints – a habit that could explain how Patterson’s team may have been led to believe that there was more than one elephant moving in that area.
Although Patterson disagrees with the number of elephants still roaming the forest, he expressed his concern for the Knysna elephants saying that they are a tiny endangered population. “But if I believed that only one of these elephants exists, I would be the very first person to say. ‘How could we have allowed this to happen?’ and I am not saying this.
“What I would strongly recommend scientists to do though, is to undertake a comparison DNA census to determine the current numbers of the Knysna elephants.”
Moolman said since the elephant moves across four different landowners’ properties, it is not a SANParks decision alone on whether to bring in more elephants.
“SANParks has conducted numerous meetings and workshops with stakeholders groups. Some of these workshops specifically dealt with identifying, discussing and risk-analysing possible management options for the Knysna elephant.
“Whether there are one or two or three elephants, we can safely say that there is a problem, and that is that the Knysna elephant is under threat,” said Moolman.
If various parties, on different sides of the number debate, can agree to disagree about the number and reach common ground that there is a problem, then the conversation can progress to a next more constructive level,“ concluded Moolman.
The tales that Skeleton tell
This mounted skeleton of a male elephant discovered near the Garden of Eden in 1983 can be seen at Diepwalle’s Legends of the Forest Museum. It is speculated that the animal died 10 years prior to discovery of its remains.
SANParks scientist Lizette Moolman explained the difficulty in ascertaining if this elephant was related to the existing lone cow roaming the forest. “Blood and tissue always provides the highest quality DNA for reliable testing, which could be problematic depending on the type of remains. If, for example, bone marrow could be extracted, family links may be assessed.”