Diana Chin/Lentink Lab
When it comes to hopping between branches, tiny parrots try only as hard as they need to. The finding comes from high-speed video taken to measure how Pacific parrotlets (Forpus coelestis) shift momentum from takeoff to landing.
Bird flight is though to have started with jumping and gliding. When traveling short distances, parrotlets get most of their oomph from their legs, probably because it’s a more efficient way to accelerate than pushing against air with their wings. Still, small wingbeats do help support some of the birds' bodyweight. The farther the trip, the more that wings contribute to keeping the birds in the air. The birds also optimize their takeoff angles to apply as little mechanical energy as possible, Diana Chin and David Lentink of Stanford University report May 17 in Science Advances.
The researchers also found that one partial wingbeat can support 15 to 30 percent of a parrotlet’s weight — on par with feathered, flightless dinosaurs like Archaeopteryx. With a bit of mathematical modeling, they determined that one such flap in flight could have extended Archaeopteryx’s jumping range by 20 percent, perhaps giving the dinos an edge in foraging for food.
Chin says the simulation provides a potential explanation for how feathered dinosaurs and early birds refined their tree hopping skills, ultimately giving rise to foraging flights of modern parrotlets and other birds.
High-speed video cameras reveal the momentum shifts that parrotlets undergo on flights or hops between branches as they forage for food. Diana Chin, Lentink Lab
Editor's note: This post was updated on May 24, 2017, to correct that the researchers measured rather than modeled the percentage of support that a parrotlet gets from a partial wingbeat.