Andes

Pervasive genomic signatures of local adaptation to altitude across highland specialist Andean hummingbird populations

Populations along steep environmental gradients are subject to differentiating selection that can result in local adaptation, despite countervailing gene flow and genetic drift. In montane systems, where species are often restricted to narrow ranges …

Social Investment and Smallholder Coca Cultivation in Colombia

Colombia is the largest supplier of coca leaf in the world, and fields smaller than one-hectare account for more than 60 per cent of cultivation. Despite the obvious relevance of smallholding growers to the strategies to control illicit crops, there …

Parallel molecular evolution in pathways, genes, and sites in high-elevation hummingbirds revealed by comparative transcriptomics

High-elevation organisms experience shared environmental challenges that include low oxygen availability, cold temperatures, and intense ultraviolet radiation. Consequently, repeated evolution of the same genetic mechanisms may occur across …

On the Evolution and Diversification of Andean Hummingbirds

At first look, the harsh physical conditions of the Andes should impose serious physiological constraints on hummingbirds, but instead, they have a wide distribution and are abundant at high altitudes. Several studies suggest highland species are …

Spatial autocorrelation reduces model precision and predictive power in deforestation analyses

Generalized linear models are often used to identify covariates of landscape processes and to model land‐use change. Generalized linear models however, overlook the spatial component of land‐use data, and its effects on statistical inference. Spatial …

A Bayesian Spatial Model Highlights Distinct Dynamics in Deforestation from Coca and Pastures in an Andean Biodiversity Hotspot

The loss of tropical forests has continued in recent decades despite wide recognition of their importance to maintaining biodiversity. Here, we examine the conversion of forests to pastures and coca crops (illicit activity) on the San Lucas Mountain …

Illicit Crops and Armed Conflict as Constraints on Biodiversity Conservation in the Andes Region

Coca, once grown for local consumption in the Andes, is now produced for external markets, often in areas with armed conflict. Internationally financed eradication campaigns force traffickers and growers to constantly relocate, making drug-related activities a principal cause of forest loss. The impact on biodiversity is known only in general terms, and this article presents the first regional analysis to identify areas of special concern, using bird data as proxy. The aim of conserving all species may be significantly constrained in the Santa Marta and Perijá mountains, Darién, some parts of the Central Andes in Colombia, and between the middle Marañón and middle Huallaga valleys in Peru. Solutions to the problem must address the root causes: international drug markets, long-lasting armed conflict, and lack of alternative income for the rural poor.

Forests in the Time of Violence: Conservation Implications of the Colombian War

Forest remnants in the Colombian Amazon, Andes, and Chocó are the last repositories of a highly diverse and endemic biota. Historical changes in the Colombian landscape have been dramatic, but the magnitude and rate of change has increased over the …

Forests in the Time of Violence; Conservation Implications of the Colombian War

Forest remnants in the Colombian Amazon, Andes, and Chocó are the last repositories of a highly diverse and endemic biota. Historical changes in the Colombian landscape have been dramatic, but the magnitude and rate of change has increased over the last half century, while conflict has consumed the capacity of Colombian society to respond to environmental threats. Academic experts in the study of the Colombian conflict have explored the social, political, and economic implications of the war. However, the environmental consequences of conflict are documented only when groups in conflict target salient economic resources. This paper presents the first analysis of the geographic distribution of forest remnants in relation to armed conflict in Colombia. Results show that guerrillas and/or paramilitaries range throughout areas of human encroachment into remnant forests. The policies promoted by Colombia's irregular armed forces range from “gunpoint conservation” rarely applied by guerrillas, to the rapid conversion of forests and crops to cattle ranches and coca (Erythroxylum sp.) plantations, following paramilitary occupation. Because the rates and extent of fragmentation are linked to such land use practices, armed groups may play a crucial role in determining the fate of Colombia's forests and their endemic biota.

Illicit Crops and Bird Conservation Priorities in Colombia

Over the last 5 years the amount of land in Colombia planted in illicit crops, such as coca and poppy, has grown an average of 21% per year and may account for half the total area deforested in 1998. I conducted a geographic analysis of the distribution of illicit crops relative to standing forests and areas of conservation priority for birds. Municipalities where illicit crops have been detected were overlaid on a forest‐cover map of Colombia and two types of conservation priorities for birds were plotted: distributions of threatened species and minimum‐area sets for conservation of all species. The sites of the highest conservation priority affected by illicit crops were in the southern Andes, the northern West Andes and adjacent Darién lowlands, the Sierra Nevada de Santa Marta, Serranía del Perijá, and the Serranía de San Lucas. The largest forested areas threatened by illicit crops were in Amazonia and the Amazonian foothills of the East Andes, sites of low conservation priority. Given current trends in the expansion of illicit crops and the narrow endemicity of some bird species, the conversion of forests for illicit‐crop cultivation may result in the extirpation of several bird species from affected regions. To impede this, those involved in illicit‐crop eradication and alternative development should give high priority to the protection of existing forest reserves and parks from the planting of illicit crops. Such efforts should also extend to areas proposed for conservation based on the diversity of threatened and endemic birds that are currently unprotected. The conservation of threatened and endemic birds in Colombian forests may hinge on successfully curbing incentives for deforestation, including the international trade in illicit drugs.