As you may know, the African clawed frog is entirely aquatic but may travel overland in search of water, but only when forced to do so – when its habitat dries out or poison is introduced to its pond. Many years ago I kept an adult pair that would lie out on a rock which protruded above the water, directly under an incandescent bulb. This only occurred in winter, when the water temperature in their tank averaged 66 F, so I thought they might be seeking warmth. However, others I’ve kept at that temperature have not left the water, despite being provided with a basking light as well.
The second observation involves a female clawed frog that laid eggs in absence of a male. That in itself is unusual, as most frogs utilize amplexus (the male grasps the female just behind the front legs or, in Xenopus, just above the rear legs) to induce egg laying. Odder still, however, was the fact that a male placed in the tank with the eggs (and without the female) on the following day fertilized the eggs. He was in breeding condition, as evidenced by the rough “nuptial pads” along his forearms, and perhaps was responding to pheromones or scents in the water, but still should have (according to me, not him, it seems!) required a female to stimulate sperm release. I have spoken with a number of herpetologists about this, and none can recall a similar incident.
Further information on this frog’s mating behavior and ability to travel overland is available at:
http://animaldiversity.ummz.umich.edu/site/accounts/information/Xenopus_laevis.html