“Wolf”
Wolf densities for the past three years have been the lowest in Denali since 1987.
Gray Wolf (Canis lupus)
Denali National Park, Alaska
07/23/2013
Canon 7D
Canon 100-400mm lens @ 310mm
1/160 sec @ f5.6
iso 400
© Teklanika Photography 2013
Teklanika Nature Photography 
Do they know why the populations are down?
There are many factors that have contributed to the current density, but it is widely agreed that the main reason for the low numbers is loss of breeding wolves due to the the recent opening of a previously closed wolf trapping / hunting area at the northeast corner of the park. More info can be found here – http://www.nps.gov/dena/naturescience/upload/wolfbuffer2010gn.pdf
That’s really unfortunate.