Ecologist Reports

Ecologist Report – May 2010

Rainfall and Temperatures

Temperatures

The average maximum temperature for this month was 29°C and the average minimum temperature 13°C. The average maximum temperature for May 2010 is lower than May 2009 and falls within the range of temperatures that have been experienced during the previous years which gives the indication that temperatures are not increasing. The highest temperature recorded for May was 36°C and the lowest was 6°C.

Rainfall

As expected with the onset of winter there has been no major rainfall experienced during May, with a total of 7 mm recorded during the month. The total of 7 mm received during the month, brings the total rainfall received during 2010 to 274.5 mm. The total for this wet season (September 2009 to August 2010) has increased to 837 mm.

Field

Maintenance

Maintenance work has been undertaken throughout the Reserve, with odd jobs being completed in many sectors. Repair works were done to the wetland which began to leak as a result of the resident hippo creating an access and exit point in the wall of the wetland. This break in the wall was filled with gravel and compacted and vegetation was placed on top to discourage the hippo from creating a new access and exit point.

With regards to erosion reclamation, no major activities were undertaken during the month, as we still await the delivery of gabion wire. The rocks required to fill the gabions have been collected and placed on site to ensure that the construction of the gabions is efficient and effective. A small amount of routine maintenance work was undertaken on another gabion structure on Tamboti Open area. Here we once again lowered the height of the gabion to allow water to flow over the gabion, preventing water from flowing around the structure and undermining it.

Roads

Very little work was done on road maintenance during the month, as all efforts were concentrated on the removal of alien plant species along the Sabie River and several of the dry riverbeds. As we are now in our winter season, the lack of rainfall provides and excellent opportunity to undertake routine maintenance on the properties road network, before the rains return. Routine maintenance involves the opening of mitre drains and the repairing of their associated humps, as well as the filling of potholes and the removal of obstructions such as rocks. This is very important as is facilitates the removal of water from the roads surface.

Routine road maintenance was undertaken on Bonsela, Chawkleys and Ivory Access during May.

Vegetation and Water

With the lack or rainfall that accompanies the winter season, most tree and grass species are beginning the dormant phase. Trees are losing their leaves and grasses are storing their nutrients in their roots. These are both strategies to save water and nutrients during a very low rainfall period, allowing for rapid growth when spring and the resulting rainfall events arrive. As a result, the vegetation throughout the property is starting to appear dull and dry, creating excellent conditions for game viewing.

Water levels in the large waterholes within the Reserve remain high, due to low levels of evaporation as a result of overcast and cloudy days experienced during the month. Thus water is readily available to support the wide variety of animals located in the area. Most of the small natural pans and mud pools have now started showing signs of drying or have completely dried up, forcing animals to move to the waterholes and Sabie River in search of valuable drinking water. Water is essential as all of the animals within the Reserve depend on it for their survival, either by being directly dependent on it for drinking and pest removal purposes or by being dependent on the prey attracted to the water.

Animals

Birds

Temperatures have remained relatively warm during the beginning of the winter period, and as a result we still catch an occasional glimpse of some of the migrant species which should have migrated northwards during the onset of winter. These include species such as Eurasian (Coracias garrulus) and Purple Rollers (Coracias naevia). There have also been numerous sightings of predatory bird species, including Bateleurs (Terathopius ecaudatus), Whitebacked Vultures (Gyps africanus), Martial Eagles (Polemaetus bellicosus) and Little Banded Goshawks (Accipiter badius).

In addition, Black (Ciconia nigra) and Saddlebilled storks (Ephippiorhynchus senegalensis) are becoming a common occurrence along the Sabie River as the water level has begun to subside due to the lack of rainfall associated with the dry season. This creates a perfect habitat for these birds to catch prey items such as fish, frogs and small crustaceans.

Reptiles

Winter is now here and nearly all the reptiles have taken refuge and found a shelter to hibernate and spend the winter, making the chance of seeing these fascinating creatures rather unlikely. As reptiles are cold blooded, they rely on environmental conditions to regulate their body temperature and since temperatures in winter are low, they are forced to spend this period dormant, awaiting the warmer temperatures of spring.

There were however a few reptile sightings during the month which included:

- Tree agama (Acanthocerus atricollis)
- Nile crocodile (Crocodylus niloticus)
- Giant plated lizards (Gerrhosaurus validus)
- Flap-neck chameleon (Chamaeleo dilepis)

Special Sighting

Charleston Pride males bring down a male buffalo

One early Wednesday morning the three males of the Charleston Pride took down an adult buffalo bull, a few kilometres outside 1933. The Charleston Pride usually consists of nine members, three males, four females and two cubs of about 7 months old. Only the adult males present at the kill, as the females and cubs were on a neighbouring property at the time. The males did not hesitate to feed and made short work of the buffalo, reducing it to skin and bones after just four days. This was surprising as they spent much of their time sleeping, belly up, in the shade of the surrounding Tamboti trees.

On the fifth day, we arrived at the kill, to find that our Lions had left and were replaced by a small clan of spotted Hyena. Hyenas are apex predators and bring down more prey than Lion, but when their numbers are high and there is an opportunity, they will not hesitate to scavenge a kill from another predator. They must have located the kill during the night and successfully chased the Lions from the kill, allowing them to feed in peace on the few scraps that remained.

Mammals

Lion

Lion sightings have once again been incredible over the past month, with these majestic creatures being located almost every single day. The Charleston Pride is still strong and healthy and consists of the three pride males, four females and the two cubs aged four and seven months. The pride spends most of its time as one unit, but occasionally the males will break away to patrol their territory, protecting it from rival males who would be a threat to the prides young cubs. During this period the females will then be left to look after the cubs, protecting them from danger, such as buffalo and other predators, and provide food for the rapidly growing cubs.

During May we managed to locate several of the Charleston pride’s kills, these included an adult male buffalo, an adult female blue wildebeest and several impala of varying ages.

The southern prides spent most of the month on the neighboring properties, and we only had sightings of the entire pride on a few occasions during the month. The pride continues to move between several properties in the southern Sabi Sand Wildtuin, an extensive territory. The pride has decreased in size and now consists of one pride male, three adult females, two sub-adult males and one sub-adult female, a small fraction of the seventeen member strong pride of January 2009. Whether the pride has split is unknown, but pride splits are not an uncommon occurrence within the Southern Pride and other large lion prides of the Kruger National Park.

Leopard

Leopards have been an illusive quarry during the past month, with only a few sightings of these magnificent cats. On the occasions that we did view leopard, we had some incredible sightings, these include a large male leopard in a tree with a kill, a mating pair disappearing into a rocky outcrop and our dominant male, the Sandriver male, patrolling his territory.

Predation by Leopards was below average during the month, with only four impala kills being located. Three had been placed in trees to prevent them from being stolen by other predators, while the other was left on the ground and stolen by a spotted hyena.