Movement and microhabitat use of a terrestrial amphibian (Bufo marinus) ona tropical island: Seasonal variation and environmental correlates

We sampled movements and microhabitat use of cane toads (Bufo marinus), as well as environmental variables (soil moisture, air temperature, and relati ve humidity), monthly for 16 months. Toads emerged significantly more often at: night during the wet months (February-May) compared to the dry months (September-December). Distance moved per night increased with soil moisture initially, but asymptoted at 0.4-0.5 ml/g dry wt Minimum convex polygon ar eas fitted to toad locations were significantly larger during January-April (wet) than September-December (dry). Toads used daily shelters similar to those described for other terrestrial amphibians, but there were significan t differences between months in the types of shelter used. Reek crevices we re used as shelters throughout the year, but toads sheltered in hollow tree s mainly in the drier months and in dense vegetation in the wetter months. When emerging at night toads remained under canopy cover in the drier month s, but increasingly moved in the open grass as conditions became wetter. Oc casionally toads returned to the same shelter site after activity at night, but the frequency of homing was not greater than expected from a random mo del. Seasonal patterns in movement and microhabitat use were primarily rela ted to soil moisture, rather than air temperature or relative humidity, and compared to their native range in South and Central America, toads were mo re active and moved further at night.