Main research line

My main line of research focus on biological conservation. to understand the factors regulating populations within ecosystems, mainly the importance of intra- and interspecific interactions on population dynamics. To attain this goal I use both, native species (key and/or endangered species), invasive species and genetically modified organisms. With a multidisciplinary approach, which includes theoretical, experimental and field studies, I use complementary tools as mathematical modelling to test effects when experimentation is difficult, or stable isotopes to identify trophic relationships. The final goal is to understand the function of these key species from a theoretical approach, but also with an applied perspective to the management and conservation of ecosystems, to ameliorate national policies or international treaties.

 

I can split my main  research line in three different aspects in which I have worked along my career:


The conservation of species of high conservation and social concern

The European rabbit is one of the most important vertebrate prey species in southwestern Europe Mediterranean ecosystems, and several predator species depend on high rabbit densities. It is also a very important small game species in these ecosystem. However, in the last 60 years wild rabbit populations have undergone a sharp decrease caused mainly by the appearance of the viral diseases, mixomatosis and rabbit haemorrhagic disease. Management of their populations has been necessary and has to take into account both social requests.

 

Moreover, the rabbit is a prolific species which has been distributed all over the world by man for food and hunting. In many areas it ha become a real pest, multiplying "like rabbits". This will link with my third research line, invasion biology.


The Allee effect

The conservation of endangered species or species at low densities is the goal of my research focusing on Allee effects. The Allee effect is a dynamical process occurring in populations when individuals suffer a decrease in fitness at low densities. If the fitness is reduced, per capita population growth rates may decline as a consequence and extinction risk is increased.

Social species are particularly susceptible to Allee effects as individuals rely on cooperation to increase their fitness. The value of rarity fuels the disproportionate exploitation of rare species, rendering them even rarer and thus more desirable, ultimately leading them into an extinction vortex. We have described this Allee effect as the Anthropogenic Allee effect. Some dynamical processes affecting survival, such as natural predation can also create predation-driven Allee effects.


Invasion biology

I have been interested in the effects of invasion of different taxa, including rabbits, rodents, and recently, ants. My main current lines are the study of the effects of the Argentine ant on the ecosystem, and more general, how native communities determine the success and impact of biological invasions. I search for the effects of the Argentine ant in the whole ecosystem, focusing not only in the effects on the ant community, but also in ant predators, or other species sharing the ecosystems (birds, plants, etc) and deepening  into the mechanisms leading to such effects. The mechanisms leading to the invasion of native communities: biotic resistance, enemy release, and biotic facilitation, and their relative importance will improve our understanding of biological invasions.