Applied Animal Behaviour Science, 37 ( 1993 ) 197-209 0168-1591/93/$06.00 © 1993 - Elsevier Science Publishers B.V. All rights reserved 197 Differences in behaviour of free-ranging cattle in the tropical climate Jan Langbein *'a, Martin Nichelmann b alnstitut J~r Zoo- und Wildtierforschung im Forschungsverbund Berlin e. E, Alfred-Kowalke-Strasse 17, 0-1136 Berlin, Germany blnstitut fur Verhaltensbiologie und Zoologie, FB Biologie, Humboldt-Universitiit zu Berlin, Invalidenstr. 43, 0-1040 Berlin, Germany (Accepted 29 March 1993 ) Abstract The pasture behaviour of Holstein Friesian and Siboney de Cuba (5/8 Holstein Friesian× 3/8 Cuban Zebu) lactating cows was studied during the dry season and the rainy season in the tropical climate of Cuba. Grazing, total activity, standing and lying, time spent in the sun and time spent in the shade were recorded from 08:00 to 18:00 h at 5-min intervals. In the rainy season, the Holstein Friesian cattle spent less time grazing and in activity, but spent longer in the shade than Siboney de Cuba, i.e. a higher thermal load was imposed on the purebred taurine cattle as compared with the Siboney de Cuba. However, no differences between the two breeds were observed in the dry season. The results indicate that the heat tolerance of Siboney de Cuba is superior to that of Holstein Friesian during the rainy season. In the rainy season mixed group series, the behaviour of Siboney de Cuba followed (was masked by ) the behavioural changes shown by Holstein Friesians, i.e. a new herd be- haviour was determined by purebred taurine cattle. Key words: Cattle; Grazing; Lying; Temperature Introduction Cattle breeds of the zebuine type living in tropical regions of the world dif- fer from the taurine cattle, typical of the moderate latitudes, by their lower metabolic rate (Chikamune and Shimizu, 1983; World Meteorological Orga- nization (WMO), 1989 ) which is related to their lower production. In order to compensate for these milk and beef yield deficits in tropical regions ani- mals oftaurine breeds increasingly have been introduced in the past 40 years into areas with autochthonous zebuine cattle (Johnson, 1980; WMO, 1989 ). The introduction of European breeds into tropical regions does, however, usually result in a profound impairment of their performance owing to their insufficient ability to adapt to extreme environmental conditions. Ambient *Corresponding author.