This study examined how habitat and resource conditions influence the foraging behaviour and ecology of the Pale (Pallid) Flycatcher Agricola pallidus and Marico Flycatcher Bradornis mariquensis, two perch-and-pounce insectivores that swoop on prey from elevated perches. These species were studied in the early 1980s at the Nylsvley Nature Reserve in Limpopo Province, South Africa, where Marico Flycatchers occupied fine-leafed, spinescent Vachellia (Acacia) tortilis-dominated woodland, while Pale Flycatchers were confined to Burkea africana-dominated mesophyll woodland. These two woodland types correspond to two contrasting savanna types across Africa more broadly: arid-eutrophic, fine-leafed savannas and mesic/moist-dystrophic, broad-leafed woodlands. Their juxtaposition at the Nylsvley Reserve provided an opportunity to explore the factors affecting the habitat preferences and foraging behaviour of these two species. Acacia woodlands had higher invertebrate abundance, at least on the ground, and lower groundcover than Burkea woodlands in both seasons, although the difference was less during the dry season. Throughout the year, Marico Flycatchers consistently foraged at a faster rate, pouncing more frequently and more successfully on prey than did Pale Flycatchers. They also spent less time searching from each perch and gave up sooner if they found nothing. The average time difference between successful and unsuccessful searches was only a few seconds for both species, however. Presumably because they occupied a less productive woodland, Pale Flycatchers had considerably larger home ranges and occurred at lower densities overall, and so experienced fewer intraspecific and interspecific interactions. In contrast, Marico Flycatchers faced more competition both intra- and interspecifically, especially in the dry season when prey was scarce; they lost most of their conflicts, all with larger birds. Habitat separation between these two flycatcher species is apparently maintained by the differences in habitat structure, resource availability and occasional interspecific interactions, in which Marico Flycatchers dominated Pale Flycatchers.
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