IsoLampro

The introduction of alien species is one of the most serious problems that currently affect biodiversity, especially in island ecosystems. The California kingsnake (Lampropeltis californiae), native from United States and Mexico, is an invasive species on the island of Gran Canaria (Canary Islands, Spain) introduced from individuals of the pet trade. Although only 30% of the analysed snakes presented gastrointestinal contents (GIC), the analysis has revealed that its main impact is the consumption of endemic reptiles - Gran Canaria giant lizard (Gallotia stehlini), Gran Canaria skink (Chalcides sexlineatus) and Boettger's wall gecko (Tarentola boettgeri).

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In Gran Canaria, California kingsnake has a discontinuous distribution with three established populations: (1) a main center (MC), with a greater number of individuals, located in the east of the island and situated in an area characterized by irrigation crops of fruit trees and watercress (Nasturtium officinalis) and an dispersed building; (2) a secondary center (SC) in the northwest, with a lower density and a smaller range, located in a special conservation area (ES7010011 Amagro), with natural vegetation of the basement floor, characterized by the sweet tabaiba (Euphorbia balsamifera) and other endemism such as Euphorbia canariensis; and (3) a third center (TC), the latest declared  and located in the south of the island.

 

The overall objective of this project is to determine the trophic ecology of the California kingsnake populations through the development of an innovative method, stable isotopes analysis (SIA). Stable isotopes are a tool to investigate issues such as the ecological niche, the position within the food chains and diet. Specifically, the SIA will allow  to determine if there are variations of the trophic niche associated with the locality, sex and the ontogeny. The results of this project will provide a tool for the evaluation of the impact of the California kingsnake in the control of the invasion process.

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Methodology

The public enterprise Gesplan S.A., which maintains a capture programme for California kingsnake in Gran Canaria will provide all euthanized snakes. The place and date of capture will be recorded. Each snake will be measured (snout-vent length), weighed and dissected. Also, muscle samples of the tail of juveniles  and adults  of the three locationswill be collected. These samples will be lyophilized, homogenized, weighed and pressed into tin capsules in the Laboratory of Molecular Biology of the University Institute EcoAqua, University of Las Palmas (IU-EcoAqua, ULPGC). The samples will be sent to the Stable Isotope Laboratory of the Biological Station of Doñana (EBD, CSIC - Sevilla, Spain) for carbon and nitrogen stable isotopes analysis.