There was a research project in the mid 80's in Denali National Park where
Golden eagles killed and carried off 14 Dall sheep lambs in a 10 day period.
Once the lambs got to be about 2 weeks old they passed the size threshold
and the eagles moved to other prey. I no longer remember the weights of the
lambs that were measured but I remember being impressed that the eagles
could carry something that heavy. I got to watch 2 days of this and it was
clear that birds took advantage of the steep mountain habitat by being able
to drop a bit at first before getting any soaring and wing lift. The Eagle
nests were on the opposite side of the valley, and they only carried the
lambs about half way (about 3,000 meters) to a couple of rocky outcrops
where they ripped up the prey and took food back and forth to the nest in
their crop. The ravens had a party on what the eagles would leave behind
and I heard that one of the researchers saw a wolverine climb all the up to
site to scavenge and there was an all out battle between the wolverine and
an eagle.

Rob Sandelin
Naturalist, Writer, Teacher
Snohomish