Rhinos and frogs are rarely mentioned in the same sentence unless you are talking about that chance encounter with a frog that wandered into the humid shower of your Big 5 Safari accommodation where you hoped to photograph some rhinos. The two might also be mentioned together when you talk about Asia’s Rhinoceros Frog (scientific name: Limnonectes plicatellus). In 2023 we started mentioning frogs and rhinos together; our Experiential Conservation Safari which usually focuses on the Big 5 and other large mammals introduced frogging evenings with our Project Director (Dr Fortunate Phaka AKA Doctor P) taking conservation interns out to watering holes to look for and learn about frogs. This seems a bit odd but there’s good reasoning behind it. Doctor P specialises in frog conservation research and knows that frogs provide a conservation service that rhinos do not provide. Rhinos and other members of the Big 5 are umbrella species as their conservation and the conservation of the habitats they need to survive benefits many other animals that also need those habitats to survive, frogs included. While the rhino’s “conservation umbrella” offers many other species protection, it is missing an early-warning system for harmful changes to the environment. This is where frogs jump in. Frogs are one of a group of organisms that scientists like Doctor P can use to understand the state of the environment and for this purpose they are aptly called biological indicators or bioindicators.

Compared to our beloved Big 5, frogs are more sensitive to physical, chemical and climatic changes in the environment. Changes in frog population composition can warn us about environmental stresses long before they affect the larger animals. On this year’s frogging evening there was a noticeably lower number of frogs compared to 2023 and no evidence of breeding in the form of tadpoles of the winter breeders, granted that frog activity in winter when we are usually on safari is limited. This low frog activity was caused by lower-than-average rainfall in the Waterberg region which meant some waterbodies dried up and the remainder were likely to have higher concentrations of dissolved minerals. The water also had a slightly foul smell and plenty of dead snails (another group of bioindicators) as further evidence that water quality was decreasing as a result of lower annual rain. Noticeable changes in frog activity can alert reserve managers to non-desirable changes in environmental conditions and managers can implement mitigation measures before they affect the larger animals which are less abundant compared to frogs and more expensive to heal. Frogs are also a great pest control for those mosquitoes buzzing around your ears when you hoped for the nighttime sounds of the African bush to lull you to sleep. Next time you find a frog in the shower of you favourite Big 5 lodge, give it a high 4 (they only have 4 fingers on their forelimbs, not 5) for keeping those pesky mosquitoes in check.