The natural habitats of Colombia, its forests, rivers, and grasslands, are global conservation priorities because of the richness and endemism of their fauna and flora (McNeely et al., 1990; Myers et al., 2000; Olson & Dinerstein, 1998; Stattersfield et al., 1998). The ecosystem function of these natural habitats benefits millions of Colombians who depend on their water, wood, bushmeat, and medicinal plants (Rodríguez & Ponce, 1999). Over several centuries, the advance of the agricultural frontier has fragmented these ecosystems resulting in the extirpation of endemic species, natural disasters, and a general decline in environmental quality, particularly in the Andes and the Caribbean region (Cavelier & Etter, 1995; Cavelier et al., 1998; Etter & van Wyngarden, 2000). Over the last decade, however, incentives for agricultural production in Colombia have decreased. The output of annual crops fell at an average annual rate of 3.2%, agricultural production lost 4% of its relative importance in the GDP, and agricultural imports have increased almost 10-fold (Jaramillo, 2001; Robledo, 1999; Vásquez, 1997). Nonetheless, the fragmentation of natural ecosystems persists partly because of the expansion of other legal economic activities—perennial crops, cattle ranching, mining, and timber exploitation—as well as that of illicit crops whose exponential growth has paralleled the escalation of armed conflict (Álvarez, 2001, 2003).