Africa: Research in the Serengeti
Landcare Research wildlife ecologists regularly travel to diverse parts of the globe so when researchers from the Serengeti Biodiversity Programme asked for assistance, Lincoln-based Wendy Ruscoe and Andrea Byrom were only too happy to help.
They spent a month in Tanzania assisting the Serengeti Biodiversity Programme, a 40-year programme focusing on the factors that affect all species in the Serengeti ecosystem and how the protected area affects human populations surrounding the park.
Serengeti researchers had been trapping rodents for 10 years but they wanted extra assistance to ensure the trapping techniques were correct. Drs Ruscoe and Byrom were able to also provide assistance on field techniques including labelling individual animals correctly and matching that with written data, preparing samples for genetic identification, collecting specimens, as well as identifying, measuring and handling rodents in the field.
‘What we found is that just like our rodent populations, theirs go up and down every year. But we wanted to know if this was a cyclic population or if it’s an ‘eruptive species’ based on some sort of a resource. Ultimately, we were able to link the periodic large rodent population increases to extended short rainfall seasons,’ Dr Ruscoe says.
There are two rainfall seasons in the Serengeti – short rains (November–December) and long rains (February–May) – and if the short rains are larger than usual this allows more grass growth over summer providing more seed and other food for rodents. Once rodent numbers increase, the next year we see carnivores that are rodent specialists, such as the black shouldered kite, increasing in numbers as well.
Although this is a natural system and animal numbers fluctuate over time, there can be significant impacts on people living around the park.
Dr Ruscoe says that once the rodent numbers erupt, they also erupt in the villages surrounding the park, which causes crop losses and disease. So, being able to predict when there are going to be spikes in rodent numbers allows managers to predict potential outbreaks and transmission of disease.
These findings will be published in the next Serengeti book, SERENGETI IV: Biodiversity.