TheImprovement ofTropical and Subtropical Rangelands

PASTORAL REGIMES 0' MAURITANIA 223
Finally, while theoretically the need to water stock adequately
is the only potential limitation upon migrations, in practice habit
plays a large role in determining where a tribe will graze. lI It is
the return year after year to an area with well-known watering and
gruing potentials that permits the delineation of tribal territories,
and only dire necessity will force a tribe to move to an area outside
its normal orbit.
In the most southerly parts of Mauritania, the fact that cattle
and sheep form the basic component of the herds, coupled with
the importance of cereal cultivation, keeps the extent and duration
of pastoral movements small.1° When the rains begin, the herders
commonly make a short movement southward to pick up the rainfall
at the earliest possible moment 20 and then follow the advance of the
rains northward. Once the rainy season is over, the tribes return
to their traditional summer wells, where they occupy a restricted
area in close proximity to the watering point. Although the return
is usually completed by October or November, some groups, for
example the Ladem of the Hawd,21 spend the cool, dry season at
some intermediate point in the tribal territory.
Further north, the mixture of pastoral and agricultural forms
becomes more complex. Some tribes are strictly camel herders, with
little or no interest in agriculture. For example, the Ahel Noh spend
the cool, dry season in the southern part of their area, the dry, hot
season in an intermediate zone of sand dunes, and the rainy season
on the edge of the Dar in the north. 22 The location of the dry, hotseason
pastures in a zone intermediate between the pastures of the
other two seasons is quite unusual, but actually represents merely an
adaptation to peculiar locally favorable resourcett-in this case, the
water resources collected at shallow depths beneath the dunes.
Most tribes, however, poaess mixed herds. Those tribes herding
sheep and camels divide the herds, with the sheep (and small herds
of cattle, if these are owned) moving in restricted orbits in close
proximity to the permanent watering points and agricultural centers
of the section. Most of the family remains with the sheep and cattle
herds. However, the camels, accompanied by shepherds and the
young men, move in a completely different orbit and make use ofthis
animal's superior mobility to range far into the interior. Whereas the
herds of sheep follow a more fixed and definite route determined by
the location of permanent watering points, the camel herders range
more widely, visiting those places on their accustomed itinerary that