By Michele Hofmeyr and Graeme EllisFor six weeks in June and July this year, the biodiversity survey team was busy in the south of the Kruger National Park (KNP) looking at all the smaller creatures that are not often seen.
Six Weeks and 1900 Traps Reveal Myriad Creepy Crawlies
At these special survey areas or “Golden Sites” as they have been named by scientists from Scientific Services in Skukuza, the team looked at birds, small mammals, reptiles, frogs and insects. Each golden site comprised a number of trapping sites across the landscape and each site was surveyed for five days.
To date, 11 sites, consisting of 38 trap sites, have been surveyed in the south of the park. The survey team consisted of the biodiversity survey co-ordinator Graeme Ellis, a game guard and volunteers from abroad. To catch lizards, snakes and insects, the team put in special pitfall traps. These are buckets sunken to ground-level and connected by plastic drift fences to guide the creature into the waiting bucket. These traps also play an equally important role in catching various crawling, ground-dwelling insects and other invertebrates. The team checked the buckets twice a day during the five working days at each site and found 45 specimens including two snakes, several skinks, geckos, sandveld lizards, rain frogs and toads. The traps also caught giant stick insects, scorpions, baboon spiders and solifuges (sun spiders).
All larger specimens were photographed and released back in the area where they were caught. Insect specimens were brought back to the laboratory in Skukuza for positive identification and added to the specimen collection housed in the herbarium for later use in further research projects. Once the survey was completed at a site, the buckets and drift fences were removed and set up again at the next site.During the six survey weeks, 1900 traps were set to catch the rats and mice active in the grass at night. At each golden site 10 rodent traps were each baited with a mixture of peanut butter, oats, oil and syrup.
From these traps the team also caught many ants, which were attracted to the sweet oat mix. The species, gender and weight of each rodent trapped was recorded and added to the database before being released back into the veld. 129 rodents were caught from 14 different species.
These ranged from a tree squirrel weighing 169g to a pygmy mouse weighing a mere 1.5g. To provide the sweet bait for the rodents, altogether eight kilogrammes of oats, seven kilogrammes of peanut butter, one litre of oil and one litre of syrup was used. The team also walked 19.2km of bird surveys which involved 32 hours of bird watching where the team identified birds they saw and heard. These surveys were carried out at first light in order to incorporate the "dawn chorus" and approximately 100 species of birds were encountered. The team was pleased with the variety of species encountered during this survey, bearing in mind that it is a winter season survey, where one would expect fewer smaller creatures to be active.
A summer biodiversity survey will be done during December 2007 and January 2008 to see what moves about in the veld as it gets hotter in the park. KNP is embarking on a long-term biodiversity monitoring programme which means that these chosen sites are permanent and will be returned to for future monitoring.