Nature is inspiring the design of the next generation of drones, or flying robots, that could eventually be used for everything from military surveillance to search and rescue.
In the journal Bioinspiration and Biomimetics, 14 research teams reveal their latest experimental drones.
They include a robot with bird-like grasping appendages, and some that form a robo-swarm or flock.
The developments are inspired by birds, bats, insects and even flying snakes.
Aerial robotics expert Prof David Lentink, from Stanford University in California, says that this sort of bio-inspiration is pushing drone technology forward, because evolution has solved challenges that drone engineers are just beginning to address.
“There is no drone that can avoid a wind turbine,” he told BBC News. “And it is very difficult for drones to fly in urban environments,” where there are vast numbers of obstacles to navigate, and turbulent airflow to cope with.
Even the humble pigeon, Prof Lentink said, “flies where drones still can’t”.
Some advances published in the journal directly demonstrate how these challenges can be overcome.