Annual Aerial Census
A four-day animal census coveringan area of approximately 61,000 hectares was conducted from September 18th toSeptember 21st.
The helicopter used counting bars and a data collection systemto record animal observations, assigning each a latitude and longitudeposition. The data was recorded on a laptop with customized software. The census employed East/West/Eastflight strips, covering the region at an average altitude of 150 feet. The default animal sex setting was female, with males recorded using the"m" key. The census recorded demographics of white rhinos, including age and sex. The number of times off-road and riverbed driving was used was also recorded.
The four days were divided into three counting sessions of approximately two hours each, interspaced with refuelling stops. The first session had overcast conditions but sufficient light penetration. Session two and three saw brighter conditions with intermittent cloud shadows. The following three days had open skies with bright conditions and little wind, with temperatures ranging from the lower 20s to mid-30s.
However, animal observations were difficult in the dense Acacia nigrescens (Knob thorn) tree flower canopy in thesouth of the reserve, which obstructed visibility. The late rains from the past summer caused soil moisture levels to remain high, and many tree species retained their foliage through late winter, making it difficult to observe animals standing in the shade during the warmer part of the day.
Wildlife populations are influenced by various factors, with climatic cycles being the most significant. In large open systems, the balance of the ecosystem isself-regulated by the carnivores who control herbivore numbers. When herbivore populations rise, carnivores adapt accordingly. However, declining herbivore numbers lead to more competition at kills, leading to predator mortalities.This results in a positive shift in herbivore populations, and the cyclerepeats. Accurately interpreting observations and comprehending the influences at play is essential to understanding the impact on wildlife populations and the interrelatedness of the system.
From 2000 to current, the census technique has been standardised and is deemed to be the most accurate. Navigation is improved due to the on-screen flight grids and the aircraft position been constantly available on the computer screen for the pilots' reference. The data collection method, which is computer based provides a visible record of previous observation records, eliminating any potential double counts in subsequent grids.
Thank you to those involved:
Mr Mike Pingo | Helicopter pilot.
Mr Colin Rowles | Data capture/observer.
Dr Mike Peel | Observer.
Mr Sean Fairhead | Observer.
Field ranger, Mr Light Manyike provided the logistic supportand transported helicopter fuel and crew refreshments to various predeterminedlocation across the reserve.