Lizards, endemic island plants and extinctions


Seed dispersal by lizards is an insular phenomenon. In the Canary Islands, many fleshy-fruited plants depend on lizards for their successful dispersal and recruitment. We are now working in a project directed by Alfredo Valido to analyze the movement ecology of Canarian endemic Gallotia lizards and its consequences for plant dispersal and recruitment. We study the reproductive ecology of orijama plants Neochamaelea pulverulenta, an endemic Cneoraceae in the islands, whose seeds are exclusively dispersed by the lizards. We combine studies of fine- and medium-scale genetic structure with data and models of foraging movements of the lizards, monitoring with radio-tracking methods. So far the results are superb, and we now have detailed data on movement patterns of Gallotia galloti in Teno Bajo (Tenerife)- our main study site- and G. stehlini (in the photo) in Barranco de Veneguera (Gran Canaria). We have also seeds samples from two 1.2 ha plots in the two sites as well as leaf samples from >2000 plants to assess seed dispersal patterns with genetic methods, similar to those that we’ve been using with Prunus mahaleb and Frangula alnus. We are interested in assessing the potential effects of previous extinctions of other giant lizard species (e.g., G. goliath) that were very good dispersers of orijama. These were up to 1.3 m long and able to disperse even the largest fruits and seeds of orijama, which now remain undispersed on the plants; only the smaller fruits and seeds remain dispersed by the extant smaller lizards.

Author: Pedro Jordano

Fazendo ciéncia e soltando pipa... I'm an evolutionary ecologist, working on how ecological interactions, e.g. mutualisms, shape complex ecological systems. Sevilla, España · ebd10.ebd.csic.es

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