Canyon Coal successfully relocates Bullfrogs at Phalanndwa

The releasing of froglets into the relocation pan

Over 4 000 Giant Bullfrog froglets and 2 adults have been efficaciously relocated to a new pan (endorheic wetland system) at Canyon Coal’s Phalanndwa Colliery near Delmas, in Mpumalanga. The relocation was undertaken owing to an expansion of the mining area at Phalanndwa Colliery.

Canyon Coal Compliance Officer Arjen Nell says, “Based on the number of Bullfrogs successfully relocated and the preservation of the genetics into account, the relocation can be regarded as a success. The froglets relocated to the new pan are expected to thrive as the habitat is deemed highly suitable for this species.” 

The Relocation Process

Three field surveys were conducted to determine the presence of Bullfrogs in the vicinity of the pan which was proposed to be mined. They were undertaken by a terrestrial ecologist, herpetologist, and a wetland ecologist. They were done to determine the presence of any Bullfrogs on-site, including the presence of adults, froglets, tadpoles, as well as any signs such as burrows.

The relocation process in the field consisted of: A site discussion on how the animals must be handled and the measures that should be taken to ensure the successful relocation. The field office needed to be set up to ensure that work was conducted in an orderly fashion. The work undertaken at the office included a workstation for field records, filling crates with water and allocation of field apparatus (nets, buckets, crates, etc.). The relocation process required the capturing of all Bullfrogs observed (including adults, froglets and tadpoles), up until the base of the bucket was covered.

“Care was taken to ensure that the froglets were not injuring one another. Individual adult frogs were placed in the buckets to ensure their safety. The froglets were transferred from the buckets to the crates to ensure that they had sufficient space before being relocated to the new pan,” Arjen notes.

A sample of 50 individuals were measured, weighed, and photographed. Measurements taken included:  

1) Photographing of the dorsal and ventral sides of the individuals,

2) Age Class (Froglet/Sub Adult/Adult)

3) Snout to Ventral Length

4) Mass

5) Sex (in adults)

The number of froglets was determined by placing them one by one into an empty crate. The crates were loaded into a vehicle and transported to the relocation pan and the relocations were performed continuously to ensure that the stress on the frogs was reduced.

“At the end of the relocation process the frogs were released at the edge of the relocation pan between foliage to ensure that they did not become prey before being accustomed to their new environment,” Arjen concludes.