Figure 8.9 Migration of a satellite-tracked radio-tagged Short-toed Eagle Circaetus gallicus from France to Niger, showing the daily distances flown and the nightly stopping places. From Meyburg et al. (1998).

known from previous observations to move around over large areas, concentrating temporarily in areas of abundant food (Newton 1979). In effect, the individuals tracked were on migration for most of the time between leaving the nesting area in one year and returning there the next, as they followed the rain-belts in southern Africa in search of termites and other prey (Meyburg et al. 2004b).

Among various raptors, no consistent difference was apparent between the duration of autumn and spring journeys, either from the mean values calculated for different populations or using the values for those individuals of each species tracked on both outward and return journeys (Figure 8.10, Table 8.3). In some populations (or individuals) the autumn journey took longer, in others the spring journey. The biggest divergence was recorded in a White-tailed Eagle Haliaetus albicilla which took markedly different routes at the two seasons, so that the autumn journey lasted 57 days (39 km per day) and the spring journey 67 days


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