1987] 
Peeters & Crewe — Ophthalmopone berthoudi 
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tunnels were sometimes intimately associated with the ant nests, and 
we suggest that the ants modify abandoned termite tunnels and use 
them as nests. 
Since adults and brood were frequently carried between nests, we 
soon determined that a single colony occupies more than one nest 
site (= polydomy). Colony units were made up of 2-7 nests, and 
these nests were separated by distances varying from 30 cm to 75 m. 
None of the nests were connected underground, even those with 
entrances very close to each other. 
Individual nests contained variable numbers of adults (mean = 
186 ± 151 s.d., range = 20 - 840, n = 34) and brood. Four colonies 
had all their component nests excavated, and the following esti- 
mates of total population were obtained (mean = 517): 
January 1981: 3 nests, 453 adults (84, 142, 227). 
April 1981: 3 nests, 838 adults (445, 75, 318). 
December 1981: 2 nests, 311 adults (261, 50). 
February 1982: 5 nests, 464 adults (168, 124, 72, 80, 20). 
Patterns of activity 
The ants were observed outside their nests throughout the year, 
although the level of above ground activity decreased during the dry 
winter months. A subjective impression was that foragers then spent 
more time away on single hunting expeditions, and that they 
returned with fewer termites. This is probably linked to decreased 
termite availability; the dry soils and the low temperatures at night 
lead to a reduction in the nocturnal activity of the termites. 
Diurnal patterns of activity varied during the year. The ants 
remained outside the nests throughout the day during winter, but 
during the rest of the year, above ground activities stopped during 
the middle of the day. The biphasic summer pattern (04h30-10h00; 
17h00-sunset) appeared to be regulated by soil temperatures. 
Indeed, foragers returning to their nests towards the end of the 
morning period of activity repeatedly climbed up short grass stems. 
They remained there for short periods before they ventured on the 
ground again and ran across to the next plant. When the ground 
surface became very hot (50° C), the ants stayed inside their nests. 
On cool, cloudy or rainy summer days, foraging continued for 
longer periods and even for the whole day. 
