Moonlight Gliders is a beautifully shot and reported piece on mating season for Montana's flying squirrels. Among the amazing facts shared by Alexander V. Badyaev: they can glide while carrying rather large pine cones in their mouths.
Another lab research finding that challenged the basic aerodynamics of gliding was the flying squirrel's ability to carry heavy objects in flight without compromising height or trajectory. In the lab, the squirrels are routinely observed generating lift forces up to six times their body weight, a feat that makes it possible for them to take flight with such things as stolen peanut-butter sandwiches—or, under more natural conditions, enormous pine cones. Indeed, even advanced stages of pregnancy seem to have little impact on the squirrels' flying capabilities.
• Moonlight Gliders (Biographic)