Mass transfer during lactation of an ice-breeding pinniped, the grey seal (Halichoerus grypus), in Nova Scotia, Canada

The land planarian Microplana termitophaga is one of three invertebrate predators feeding at the open chimneys of the mound of the termite Odontotermes transvaalensis in Harare. This paper records over 4000 field observations of the mound and reports on the planarians over three rainy seasons from 1990 to 1993. Microplana termitophaga is crepuscular with a large early morning and a smaller evening activity peak. Rainfall appears to be of over-riding importance; activity is confined to the rainy season, occurring once the cumulative rainfall reaches 150-250 mm and being suspended during longish dry spells. Activity is also favoured by ambient relative humidity above 70%, light intensity below 50,000 lux (but not total darkness) and ambient temperature between 13 and 23C. Planarians on sun-exposed, but not on shaded, mounds disappeared after a drought. Dispersal occurs during prolonged wet weather.
Microplana termitophaga occurs with two predatory spider species and a commensal phorid fly and they all utilize the same termites. These four species exhibit temporal separation, probably related to their specific micro-climatic needs.