By Ryan CrossMay. 17, 2017 , 2:00 PM
If you’ve ever watched a bird hop from branch to branch in search of food, you’ve caught a glimpse at how prehistoric flying dinosaurs foraged among forest trees. That’s what researchers are saying after they trained four Pacific parrotlets (Forpus coelestis)—small, pastel-colored parrots about 13 centimeters long—to jump and fly for millet seed rewards. The researchers designed a cage decked out with perches that doubled as sensors to measure the birds’ leg forces, and surrounded the cages with high-speed cameras to study the birds’ wing beats as they moved between branches. For short jumps, the parrotlets primarily used their legs as their main source of momentum for takeoff, using their wings only for “controlled collision,” where their legs absorb the impact with the branch. During long jumps, the parrotlets mostly relied on the forces generated from wing flapping. Using their models of hopping and flapping from parrotlet data, the researchers estimated how four birdlike dinosaurs may have used their early winglike arms. Archaeopteryx and Microraptor—feathered dinosaurs that likely flew or glided between trees—would have had the most success at boosting the range of their long jumps by 20%. The larger and heavier feathered dinosaurs Protarchaeopteryx and Caudipteryx would not have been able to generate enough force from a wing beat to support their body weight or significantly increase their long jumps. The scientists surmise that Archaeopteryx developed an edge over other tree-foraging competitors by using their jumping and wing flapping to minimize energy expenditure while foraging for food in their trees. Thus, long jump Olympians of the Archaeopteryx world may have spurred the evolution of flight.