Bowhunting wounds and cripples a large percentage of deer.
"For a variety of reasons - the arrow's inherent rainbow-shaped trajectory, an animal's ability to hear the snap of the string and react (referred to as 'jumping the string'), and a hunter's excitement and nervousness when seeing an animal ('buck fever') - even experienced archers fail to retrieve approximately half of the animals they shoot." -- Mike Markarian, "Bowhunting: Culling or Crippling?" The Animals' Agenda, Vol. 16, No. 1.

A former bowhunter and author noted "the impossibility of accurately placing shots with archery equipment" and concluded that "broadhead [arrows] are absolutely inadequate" for killing animals humanely. -- Adrien Benke, The Bowhunting

Alternative, B. Todd Press, San Antonio, Texas, 1989.
A large number of studies published by wildlife agencies and in wildlife journals from 1947 to 1989 revealed crippling rates of 38 to 68 percent, with an average of 50 percent. This is far higher than the wound rate from rifle hunting, which itself is too high. Some of the studies:

R.L. Croft, 1963: 44 percent wounded
G.A. Boydston & H.G. Gore, 1987: 50 percent wounded
J.D. Cada, 1988: 51 percent wounded
L.P. Hansen & G.S. Olson, 1989: 52 percent wounded
L.E. Garland, 1972: 63 percent wounded
M.K. Causey et al., 1978: 50 percent wounded
A.N. Moen, 1989: 68 percent wounded
R.W. Aho, 1984: 58 percent wounded