Wednesday, August 5, 2015

Snakes & Palm Oil Plantations in Colombia

The most commonly encountered snake in oil palm plantations
was Ninia atrata.
Rainforest in the tropics is frequent cut to make way for the African oil palms, Elaeis guineensis. The plant is most often grown for cooking oil but has recently attracted the attention of the alternative energy industry as a source of biofuel. While the plant is native to sub-Saharan Africa, it has now spread to tropical Asia and the Neotropics.
Lynch (2015) analyzes the snake species found during student field trips to Colombian oil palm plantations between 2006-2013. They visited 30 palm plantations varying in size from 0.02-20,000 hectares. These include small privately held palm trees groves as well as large commercial plantations. Success-rates varied with less success in the dry season and greater success in the wet season. Thirty-five snake species were found. Widespread lowland species (Boa constrictor, Clelia clelia, Corallus hortulanus, Imantodes cenchoa, Leptophis ahaetulla, Ninia atrata, Oxyrhopus petola, Tantilla melanocephala, and the species pairs of Bothrops asper or B. atrox, Epicrates cenchria or E. maurus, and Leptodeira annulata or L. septentrionalis). Seven other species (Chironius carinatus, Erythrolamprus bizona, Lampropeltis cf. triangulum, Mastigodryas boddaertii, M. pleei, Sibon nebulata, and Typhlops reticulatus) occur across the regions sampled but do not occupy all lowlands of Colombia. All of these except Imantodes cenchoa, Lampropeltis cf. triangulum, and Sibon nebulata were captured in at least one plantation. Of the 35 species of snakes captured in palm trees, fourteen were diurnal activity or crepuscular, the remaining 21 species are exclusively nocturnal.
To date, there are no reliable data on population sizes of any snake species in Colombia. In point of fact, the impression of collectors is that densities are very low. This impressions is contradicted by our work in palm plantations. Collecting in natural habitats by other researchers has produced success rates equivalent or superior to our work in palm trees.
The Colombian African palm oil industry could be a major factor in conserving snakes. Snake mortality from rural workers exceeds 100 million/year and no fewer than 50,000 snakes die/year due to traffic. However, to be a partner in snake conservation will require two changes in the industry: (1) all waste be fronds need to be piled into mounds on the plantation and allowed to decompose slowly. This provides refuges for snakes, easy access to prey, and reduces human encounters, Secondly, stop converting parcels of secondary forest into more monoculture of palms. Leaving patches of secondary forest and scrub increases microhabitats and the prey base.

Citation
Lynch, J. D. (2015). The role of plantations of the African palm (Elaeis guineensis Jacq.) in the conservation of snakes in Colombia. Caldasia, 37(1), 169-182.

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