Published online by Cambridge University Press: 27 March 2009
Studies on night-enclosed eland, oryx, buffalo and cattle in south eastern Kenya showed that the animals spent only a short time each day in the shade; the mean duration was not more than 2 h/day for any species.
All four species actively sought shade in the middle of the day. The time spent in the shade by the three indigenous species was significantly related to activity times and environmental heat load; that of cattle was not.
In general the time spent in the shade by the four species could be related to characteristics of their coat.
The captive animals at Galana spend less time in the shade than their free-living counterparts. This is thought to be partly due to the need of wild animals to reduce their total body water turnover rate and for captive animals to spend more time feeding during the day.
The inter-individual distances (IID) maintained by eland, oryx and cattle and the synchronization of the activity of these three species and buffalo were also studied.
Eland maintained the largest mean IID (13·7 m) while those for oryx (6·5 m) and cattle (4·0 m) were considerably less. Calculations showed that herds of 250 eland might occupy an area of approximately 5 ha, oryx 1 ha and cattle would occupy 0·5 ha. The IID of all three species were significantly related to activity and the IIDs of eland and oryx were significantly related to meteorological factors. The differences in the IIDs of the three species were thought to be due to differences in feeding strategies and the length of time for which cattle have been domesticated.
For all species feeding was well synchronized, but walking, idling and shade behaviour were not. Although only one activity was well synchronized it was the most time consuming one. The lack of synchrony in other activities did not pose a great problem in the management of the relatively small herds being studied. Lack of synchrony, however, might cause a problem if the size of the herds were substantially increased.