|
Motivation behind the Survey The geographic distribution of Giant Bullfrogs (Pyxicephalus adspersus) remains poorly described compared to the large majority of frogs in South Africa. The primary reason for this is that Giant Bullfrogs spend most of the year in aestivation (i.e. a type of dormancy) buried underground, and following the first heavy rains in spring they spend only a very brief period above ground engaged in breeding and feeding. In other words, there are only very brief windows of opportunity during which the presence of Giant Bullfrogs may be recorded at different localities within this species complete distributional range. The geographic distribution of a species constitutes an important piece of information about that animal. Besides its natural history value, proper knowledge of a species distribution is fundamental for e.g. conservation planning, phylogenetic investigations, predictive distribution modelling, and zoo-cartographic work. Now that the World Conservation Union (IUCN) has listed the Giant Bullfrog as Near-Threatened in southern Africa, a precise and accurate description of the geographic distribution of these frogs (at least in South Africa) is a crucial prerequisite for the formulation of an effective conservation management strategy for this species. To date, distribution maps that have been compiled for the Giant Bullfrog have been fraught with imprecision and inaccuracy. Whilst the former stems from sparse locality records, the latter is a consequence of the misidentification of specimens, from which locality records have been taken, as a result of confusion regarding the taxonomy of members in the genus Pyxicephalus. The most recent and probably the most comprehensive assessment of the geographic distribution of Giant Bullfrogs in South Africa has been accomplished by the Southern African Frog Atlas Project (SAFAP), but unfortunately not even SAFAPs distribution map for the Giant Bullfrog is adequate for the purposes of formulating an effective conservation management strategy for this species. Due to the difficulties involved in predicting when and where Giant Bullfrogs will emerge, and in having to check all parts of the country during those brief "windows of opportunity" when Giant Bullfrogs are out-and-about, it was evident that the public would have to to be called upon for assistance. Thus the "Giant Bullfrog Survey" was devised.
About the Survey Members of the public are urged to please take at least a close-up photograph of the side of any bullfrogs that they encounter, since this will permit the only means of distinguishing between the two bullfrog species that are currently recognized in South Africa. When the distance between the bullfrog's eye and it's ear is noticeably greater than the diameter of it's ear, the bullfrog will be identified as the Giant/Highveld Bullfrog (Pyxicephalus adspersus). When the distance between the bullfrog's eye and it's ear is less than or equal to the diameter of it's ear, the bullfrog will be identified as the African/Bushveld Bullfrog (Pyxicephalus edulis).
Awards
Alternatively you can complete the online entry form. Your photographs and/or entry forms can be e-mailed to: cayetman@zoology.up.ac.za, or posted to: Bullfrog Survey, CFES, Room 2-1, Geography Building, University of Pretoria, 0002.
Rules and regulations
|