Used in falconry since the Middle Ages, goshawks have a telltale white stripe over their eyes that gives them an especially fierce countenance. Goshawks inhabit dense forests on six continents, taking advantage of cover to ambush prey from small animals to other birds. Their short wings and long, rudder-like tails make them supremely adapted to maneuvering through the tree canopy.



“They rely on surprise,” Karpanty said. “They live in dense, older forest. They sit and wait and then go into a quick dive after prey. They can tuck their wings to get through narrow gaps in the forest.”



Goshawks are at the top of the food chain wherever they are found. Having good numbers of apex predators is a sign of a healthy or intact ecosystem.



Karpanty donned rappelling gear to climb 40 feet into abandoned nests after nesting season to see what Henst’s goshawks were eating. They used a slingshot to fire a fishing line over a sturdy branch to rig the climbing ropes.



“I practiced climbing a lot at gyms. I was young, childless at the time and fearless!” Karpanty said. “My guides were really good with the slingshot.”



Not surprisingly, she found the skeletal remains of several kinds of small lemur at the bottom of the nests.

The conventional method of tracking birds by using radio telemetry was impractical in the rugged terrain, she said.



“We radio-tagged some birds but were unsuccessful in tracking them,” Karpanty said. “You have to do everything by foot so we’d lose the birds all the time. From our radio-transmitter data alone, we couldn’t know the extent of their range.”



