Sunbirds are another common feeder on aloe flower nectar at Mpala, but with a much less destructive foraging strategy than white-bellied go-away birds (Corythaixoides leucogaster). Using their slender recurved bills and long brush-tipped bifurcated tongues, sunbirds extract nectar via capillary action, leaving the flowers completely intact. Like sunbirds, hummingbirds fill a similar ecological niche and have independently evolved similar bill/tongue morphologies and reduced body size— an example of convergent evolution between New World and Old World nectarivorous birds. Plants that are pollinated by these nectar-feeding birds have also evolved similar morphologies, most notably long tubular flowers. However, differences between both pollinator systems exist. Many sunbird-pollinated plants are characterized sturdy bracts which sunbirds perch on, while hummingbird-pollinated plants are often more delicately positioned. This may explain why sunbirds and hummingbirds have different flight patterns and feeding postures. Sunbirds simply perch when drinking nectar, while hummingbirds hover with great accuracy to reach the precariously-positioned flowers.
All photographed after pursuit [3]
