Poisoning, both intentional and unintentional, is a direct cause of mortality
in many crane species (e.g., Khachar et al. 1991, Van Ee 1981, Tyson 1987, Vernon
1987, White 1987, Zhmud 1988, Tarboton 1989, Urban and Gichuki 1991, Johnson 1992b,
Wang Y. 1991). Grey Crowned, Blue, Demoiselle, and Wattled Cranes are the most
widely affected species. Although poisoning is widely reported, precise information
on the cause and extent of poisoning, and the poison involved, is often lacking.
Intentional poisoning of cranes is usually undertaken by farmers to prevent crop
depredation and damage. Unintentional poisoning of cranes usually occurs as a
result of ingestion of or exposure to various pesticides. Consumption of tainted
seeds, grains, insects, and fish, and the bioaccumulation of toxic substances,
may affect cranes either by directly killing them or by reducing their reproductive
capacity.
Previous Section--Threats: Direct Exploitation Return to Contents Next Section--Threats: Other Anthropogenic Threats