% Global Loss
per decade

10 million sp.
Annual Loss

30 million sp.
Annual Loss

Source

2-3%

20,000-30,000

60,000-90,000

Wilson
(1989, 1993)

0.8-5.2%

8,000-52,000

24,000-156,000

Reid
(1992)

8.3%

83,000

250,000

Raven
(1988)

0.6-5%

6,000-50,000

18,000-150,000

Mace
(1994)