i would consider a buck droping dead of natural causes, something like the buck is walking/running along and has a heart attack. or he is so old his hip gives out and he goes under,weather something eats him or not.

i would say the buck would have to fail or be unable to live or endure under his own power. if he becomes too slow or lose his senses and the preditors get him, well it isnt because of the ability of the preditor but because of the disibility of the buck.

for the sake of the discussion lets say a buck that gets so old his body giving out and it leads to his demise.

but how many dandy bucks are found each year dead with not a scratch on them? got to be at least a few intact bucks are found every year that just seemingly dropped dead(old deer, dying of old age as suspect)!