Reptiles de los niveles Epipaleolítico, Mesolítico y Neolítico de Cova Fosca (Ares del Maestrat, Castellón, España)

Cuatro taxones de reptiles han sido determinados en los niveles del Epipaleolítico, del Mesolítico y del Neolítico Antiguo y Medio del yacimiento de Cova Fosca: cf. Mauremys leprosa, Timon lepidus, Zamenis scalaris y Vipera latastei. Al menos una parte de los restos es- tudiados muestra trazas de digestión y evocan la acción de un depredador de tipo mamífero en el que el hombre no puede ser excluido. El conjunto de reptiles permite inferir la existencia de un clima mediterráneo y de un paisaje con vegetación aclarada y un punto de agua.

Nuevas citas de los galápagos chinos Mauremys reevesii (Gray, 1831) y Mauremys sinensis (Gray, 1834) (Testudines, Geoemydidae) en España

El comercio de quelonios acuáticos como animales de compañía y su eventual liberación o escape ha conllevado la detección de especies exóticas naturalizadas o formando poblaciones invasoras en ecosistemas acuáticos. La importación de Mauremys spp. exóticos implica una nueva amenaza para la conservación de los ecosistemas acuáticos, debido a su capacidad de hibridarse con la especie nativa Mauremys leprosa. En este trabajo se documentan 16 nuevos registros de ejemplares asilvestrados de los galápagos asiáticos Mauremys reevesii y Mauremys sinensis en Andalucía (sur de España). La mayor parte de ellos (13) corresponden a ambientes acuáticos artificiales asociados a áreas urbanas y el resto se encontraron en espacios naturales protegidos con poblaciones naturales de M. leprosa. Estas nuevas citas ponen de manifiesto que los nuevos taxones comercializados reproducen el patrón de venta-abandono-naturalización-invasión ya acaecido con otras especies exóticas de galápagos. El número de ejemplares de Mauremys exóticos importados en España (más de 100.000 desde 2006) sugiere que el número real de ejemplares asilvestrados podría ser bastante mayor al documentado en los trabajos publicados.

Niche differentiation among genetic lineages in the Mediterranean Pond turtle, Mauremys leprosa, across its geographical range

Ecological niche modelling provides a useful tool to measure niche properties such as niche breadth, niche overlap and niche conservatism among genetic lineages, with relevant implications for conservation. The Mediterranean pond turtle Mauremys leprosa occurs on both sides of the Strait of Gibraltar over most Iberia and the Maghreb Region of north-western Africa, where it shows a complex genetic structure as the result of Pleistocene climatic oscillations and the particular geographical features of this region. We analyzed the overlap of the climate niche of genetic lineages and sublineages of Mauremys leprosa, based on confirmed records across the known geographical range of the species. We also compared the accuracy of environmental niche models obtained by splitting the two lineages into subunits and lumping across lineages. Results revealed an overall niche overlap between the two main lineages and among most sublineages, indicating no relationship between genetic variation and niche divergence. Likewise, the environmental niche modelling revealed an extensive geographical overlap of climatic suitability between the two lineages. However, some ecological differentiation occurs for some sublineage pairs, in particular involving a sublineage whose occurrence corresponds to a particular morphotype – the Sahara blue-eyed pond turtle – which occupies very isolated habitats along the Draa basin in Morocco. These populations are currently threatened by fragmentation of habitats, drought and water salinization. This study will help assessing more effectively the impacts of ongoing climate change on Mauremys leprosa that along with local human activities are likely to increase in the southernmost limit of its distribution.

Habitat overlap and body condition in aquatic turtles: are there additive effects between invasive and native species?

Trachemys scripta (Reptilia, Emydidae) is among the most widespread invasive reptiles in the world. In general, it is assumed that this species has negative effects on native aquatic turtles based on experiments conducted under controlled conditions. Here, we analysed a 7‒year time series (2013‒2019) of data from captures of three species of turtles (two natives and one alien) from natural populations in the northeastern Iberian Peninsula. We evaluated (i) the interspecific spatial overlap and (ii) the correlation between the scaled mass index (SMI) of the native turtles and the abundance of T. scripta, including an interaction effect between the species. The analyses revealed that T. scripta has relatively low spatial overlap with Emys orbicularis but high overlap with Mauremys leprosa. Overall, the abundance of T. scripta was not associated with significant variations in the SMI of the native species, although for the female E. orbicularis, we detected a negative trend. The analyses also indicated that the abundance of T. scripta does not have an additive effect on the SMI of other turtles, even if there is a negative effect between native species. These findings suggested that the impact of T. scripta on other turtles could be density-dependent.