Play Tree & Scat Dog Visit to Rolf Ritter's Farm

One of the projects we are currently undertaking is to investigate which physical and environmental characteristics influence the selection of cheetahs scent marking trees, locally known as play trees. In 2005, a camera survey was started at a number of play trees, both on CCF land and neighbouring farms as part of developing census techniques for free ranging cheetahs. Identifying potential locations for camera placement is crucial for increasing the probability of cheetah captures.

Namibian cheetahs are known to frequent play trees for territorial marking and social interactions. Play trees, once present in a habitat, can provide valuable census data on known individuals occupying a particular home-range. However, there are instances where play trees are difficult to identify, or are absent in a given habitat. CCF quantified key characteristics around play trees including visitation rates by cheetahs, prey abundance, habitat type and presence of con-specific predators on its farms and the land of a local farmer, Mr Ralf Ritter.

In January 2013 three of CCF’s staff members, accompanied by Tiger, a CCF scat detection springer spaniel dog,  visited a number of play trees on Mr Ritter's farm for scat sample collection, taking pictures of the trees themselves as well as some extra measurements. The scat samples are used to analyse cheetahs’ diet and study biomedical aspects. 

Stephanus helping to take measurements of play trees

We travelled for almost half a day to reach our destination. The weather was hot and dry and our morale kept us going. As always, we were made to feel very welcome on the farm. Our sniffing friend was the centre of attention for the day. On the farm there were 2 large great Danes amongst other pets whose bark were loud as thunder and looked mean enough to send chills down your spine. However, to our surprise Tiger did not seem to be threatened and all he wanted was to sniff - sniff. He was moved to his safety pen to rest and cool down for a few hours before work commenced.    

Mr. Ritter assigned one of his skilled guides, Stephanus, to help us find the best routes to the trees. We hit the ground running that afternoon and covered 50% of the target play trees. A GPS device helped to check that we actually measured the exact same tree that was used in the original study. Fortunately Matti, CCF’s senior ecology researcher, recognized all the trees and could ensure that we were looking at the right one. Once we arrived at a play tree, Len, our dog trainer, would first take Tiger to explore around the tree to look for any signs of cheetah scat. Unfortunately, since the area had heavy rains the day before we arrived on the farm, we did not find any cheetah scat or tracks this time around.  

Len with Tiger searching for cheetah scat

One of the problems with using only a single scat dog, is that they cannot work continuously in the heat and humidity. Nonetheless, we were able to visit, measure and photograph 10 different play trees that were up to 30km apart in a two day period. Mr. Ritter also told us that it seemed to him as if the number of leopards on his farm has increased, while the number of cheetahs has decreased. CCF intends to expand this project to other areas of the country in the near future.

A typical cheetah play tree

"I" is for Impala

CCF has carried out a number of camera trapping surveys, and also maintains a network of cameras positioned for ongoing monitoring of the wildlife on our land.  While we are mainly focussed on cheetahs, there are many other species out there, and the cameras will trigger no matter what passes them by.  In this series of weekly blog entries, I will use these pictures to illustrate some of the wealth of animal life in Namibia - one species per week.  I hope you will enjoy seeing a little more of our world here in the bush.

This time I have the chance to talk about a rare visitor to CCF.  Given that Namibia (aside from the far NW) is not part of their range, we were rather surprised to spot Common Impala on our camera traps.  There have been just enough sightings to convince us that they seem to have settled, but we think it's probably quite a small group.  We've no real idea where they originated, but given that the species has been introduced to numerous game farms in Namibia, it's probably safe to assume that they escaped from one of those.

The IUCN lists Impala as Least Concern, since their population is large (approx. 2 million) and stable.  More usually they are found much further east ranging from Kenya in the north to Botswana, and north-western South Africa in the south, and all the way across to the Indian Ocean.  A numerically smaller sub-species, the Black-Faced Impala is resident in Namibia's Etosha National Park.

A mixed browser and grazer, the impala can usually be found in areas with both woodland and open grasslands.  They seem to prefer grass in the wet season, and bushes in the dry season, although many exceptions occur.  Impala are about 150cm (59") long and stand 90cm (35") at the shoulder, with gracefully curving horns on males only. Unique to impalas are scent glands on the fetlocks thought to aid lost members of a herd by laying 'trail markers' as the group moves. 

Males can be extremely aggressive to each-other while competing for females, and deaths do occur.  Courtship displays also involve both long and high jumps, with members of a herd often becoming so involved in what they are doing that they become oblivious to everything else.  Barring accidents impala will live to around 15 years, although 50% of calves are lost to carnivores within a few weeks of birth.

Why We Care About Cheetah Scat...

Four years ago two wild male cheetahs, named Hifi and Sam, took up residence near the Cheetah Conservation Fund (CCF) making our captive females part of their territory. Since Sam’s death two years ago, Hifi has remained on his own but still managed to keep his territory around our headquarters. Hifi is currently equipped with a satellite collar but is also regularly sighted on CCF’s property and our camera traps.  But some of the most important evidence he leaves behind is his scat (feces). Scat is crucial to our conservancy and collecting it allows us the unique opportunity of a long-term study on a wild cheetah.

The types of questions that we can answer by using Hifi’s scat are:

• Prey (what he ate): through identification of the hair that is present in the scat. Every prey species has a unique scale pattern on the hair which can be used to identify what Hifi ate.

• Reproductive hormones: testosterone levels (for females: estrogen and progesterone). These can be compared to the hormone level variations of animals in captivity.

• Stress level indicators: cortisol levels. Cortisol is a hormone that is in part influencedby stress levels. Stress levels are believed to affect gastritis incidence. Analysis of cortisol has therefore been included in the gastritis study of captive cheetahs at CCF. CCF’s cheetahs have a very low incidence of gastritis compared to captive cheetahs living in zoos; therefore, CCF’s cheetahs are used as a baseline in the study. However, having cortisol levels of wild cheetahs available for comparison is an excellent opportunity to provide further comparative analysis in this research. 

• Parasitology: egg count of intestinal parasites. To assess their health. 

• Genetic make-up. In order to identify the individual who dropped the scat, genetic markers are tested on the scat. This shows if it was Hifi, or if it was a different cat altogether. Since the sample will be used for genetics, it is crucial to pick up the scat with a lot of care to avoid contamination (the genetic material will be amplified, therefore the slightest contamination can falsify results).

The samples are collected on a daily basis on our “scat walk” by interns, volunteers or staff to ensure that the scat is found while it is still fresh. Although older scat samples can yield results, fresh scat has a higher success rate. Also, the scat needs to be less than 24 hours old so that it can be accurately placed on a time graph.

During the past four years we have collected over 800 scat samples. We have obtained the genetic identification on about 100 samples, and are ready to do additional genetic work on the other 700 samples, as well as the hormone work on the entire sample set, as soon as funding becomes available. This unique sample collection will give us long-term information on behavior, health status, and diet of a wild cheetah. We are very excited to see what we find out!