Woodchucks (groundhogs) are one of the few true hibernators among Pennsylvania mammals.  During hibernation, they lose 30-50% of their body weight, and their heartbeats slow, to as few as 15 per minute.
Pennsylvania’s bats also hibernate, with the exception of the red bat, hoary bat, and silver-haired bat, all of whom migrate south each winter.
Migration is derived from the Latin migrare, to go from one place to another.  It is triggered in North American birds by the change of the photoperiod in the spring and fall, causing the birds to store extra fat that will provide energy reserves for their long migration flights.
Some Pennsylvania birds do not migrate and over-winter right here in our state.  Others travel only a few hundred miles south.  Still others pass southward throughout the Northeast south and the Gulf of Mexico. 

The gray catbird and the Baltimore oriole travel to Central America and the West Indies.  Long-distance migrants, including nighthawks and barn swallows, are known to fly as far as Argentina!
Did you know…that most small birds fly at speeds below 50 miles per hour?  The house sparrow is the record slowest at 16 mph.  Ducks and geese fly within the 50 – 70 mph range, and loons can achieve speeds up to 100 mph!  The peregrine falcon holds the record for fastest at 237 miles per hour!
Animal Facts
Okay animal fact lovers, here are some facts that you might not have known...
Photo by Dan "Gypsy" Meharry