17 Aug Game On! Game transects with Welgevonden Research
Imagine you are watching a beautiful herd of wildebeest peacefully grazing on one of the Southern plains. You can see the bull standing off to the side guarding his harem, clusters of cows accompanied by last season’s calves and yearlings play fighting and frolicking care-free in the afternoon sun.
This herd tells us a story, a story about success. Success in breeding, success in fecundity and, if we watch the herd over time, success in survival. By examining these traits in herds, and observing multiple herds, we can draw meaningful conclusions about the populations on the Reserve.
Population demography is a powerful ecological tool. By measuring and calculating elements that are common to all populations such as the size, density, fecundity, mortality, sex ratio and age structures we can tell a lot about the status of the population. Is it stable, or is it increasing or decreasing? Better yet, if there are any problems, we can pinpoint where these potential issues lie.
For example, if your wildebeest herd, and others across the reserve, are showing a low ratio of cows to calves compared to the previous year, it is indicative that the fecundity of the population has dropped. If this were to persist over time, the low recruitment of young to adult stages would result in a decline in the population.
If we were to monitor the herd monthly and noted that in December the number of calves was high, but in subsequent months these numbers dwindled – we could conclude that calf mortality is high.
All these observations give us empirical data to understand the impacts on prey populations. This combined with predator kill observations helps us to understand the predator-prey dynamics of the Reserve. Of course, with the power of identifying problems comes the opportunity to implement solutions.
Every month the Biomonitoring Officers at Welgevonden Research conduct game transects throughout the Reserve to capture this data. They drive slowly along the transects and record every single animal and herd they encounter. Each individual’s age and sex is captured and a GPS location of the herd/animal is taken. Body condition is also recorded for the popular prey species such as impala, wildebeest and zebra. The data is recorded on the CyberTracker app which allows Research Ecologist, Jonathan Swart, to remotely access the data for analysis.
Because herd locations are recorded, Jonathan is also able to look at animal distribution patterns over time and see where the animals are spending most of their time. This, in combination with data from vegetation surveys (eg. the map above), allows him to assess the grazing dynamics on the Reserve.
Analyzed data collected on these game transects inform many management decisions and are critical for the maintenance of the predator-prey balance on the Reserve.