Aspen and its environs are atwitter with feathered friends this time of year; their dulcet calls are hard to miss, of course, but dive deeper into avian culture, and you’ll unearth a slew of intriguing facts. Find the figures given here, and much more to consider, in the recent book Birds of Aspen and the Roaring Fork Valley, by Rebecca Weiss, with photography by Mark Fuller.

155 
species of birds covered in Weiss and Fuller’s book
 

8 x 42 
the binocular magnification configuration preferred by birders

10 
calories required daily by a mountain chickadee

60 miles per hour that the Wilson snipe can fly, thanks to massive flight muscles that make up a quarter of its body mass 

2.5 
miles that the distinctive bugle of the sandhill crane can carry

1 
egg laid by a band-tailed pigeon in its nest each spring

2,000 mosquitoes consumed by a common nighthawk during a single feeding session

200+ miles per hour that a peregrine falcon can reach while diving on prey

1,250 beats per minute of a broad-tailed hummingbird’s heart rate during flight

30,000  piñon nuts cached annually by a Clark’s nutcracker

45 days it takes a nestling red crossbill to develop its unique, fully crossed bill

400 pounds per square inch of crushing power in a golden eagle’s talons (10 times the grip strength of an adult human’s hand)

Flock to It

The Aspen Center for Environmental Studies offers birding opportunities throughout the summer, including weekly morning outings with Weiss at Hallam Lake and Rock Bottom Ranch; occasional mornings at North Star Nature Preserve (in cooperation with Pitkin County Open Space and Trails); and several Birding by Habitat classes led by Weiss and Fuller. aspennature.org

Roaring Fork Audubon offers field trips from May to August (some led by Fuller) in the Roaring Fork and Crystal River valleys and beyond, including several that venture farther away. roaringforkaudubon.org