Eisentraut, M. (1930) - Beitrag zur Eidechsenfauna der Pityusen und Columbreten. - Mitteilungen aus dem Zoologischen Museum in Berlin, 16: 397-410.  Romero, J.M.L. (2012) - Estudian una nueva subespecie de lagartija en es Vaixell. - Diario de Ibiza, 23-02-2012. Pérez-Mellado, V. & Pérez-Cembranos, A. & Rodríguez, V. & Buadxes, J.M. & Brown, R.P. & Böhme, W. & Terrasa, B. & Castro, J.A. & Picornell, A. & Ramon, C. (2017) - The legacy of translocations among populations of the Ibizan Wall Lizard, Podarcis pityusensis (Squamata: Lacertidae). - Biological Journal of the Linnean Society, 121 (1): 82-94.  × The Ibizan wall lizard, Podarcis pityusensis, was the subject of several documented translocations by the German
vertebrate zoologist Martin Eisentraut, in 1930. He aimed to initiate long-term experiments into the evolution of
melanism and other morphological traits and accordingly he designed introductions into five islets that (he believed)
contained no lizards. In this study, we analyzed the genetic and morphological characteristics of individuals we
found there. We found no lizards on two of the islets, namely Escull de Tramuntana and Galera, but for the first
time, detected a large population on a third islet, Es Vaixell. Eisentraut founded the Es Vaixell population with nonmelanistic
Ibizan specimens, but the present day population of Es Vaixell was found to be fully melanistic. Genetic
markers support a strong similarity between Es Vaixell and its neighbour islet, Na Gorra, and indicate that, in all
likelihood, the individuals introduced by Eisentraut have left no descendants. It is likely that Es Vaixell already
contained lizards prior to this introduction. Analyses of microsatellite DNA placed individuals from a fourth islet,
Dau Gran, with those of one of its source islet, Escull Vermell. They are also morphologically close to individuals
from Escull Vermell. This suggests that selection pressures could have favoured the Escull Vermell phenotype following
introduction. For reasons we discuss, the translocations have revealed less than Eisentraut would have originally
hoped for. Although evolutionary processes are normally time-consuming, these translocations do provide some
potential insights into the rapid evolution of lizard morphology following colonization. Cirer, A.M. & Berg, M.P. van den (2025) - Estimation of lizard density in Podarcis pityusensis island populations over time, with special attention to the correct naming of the islets. - L@CERTIDAE (Eidechsen Online), 2025 [1]: 1-187. × In this study we compile data regarding lizard densities of the island populations of the Ibiza wall lizard, Podarcis
pityusensis, which can serve as a baseline for future research and control of the invasive snakes, and in particular the
horseshoe whip snake Hemorrhois hippocrepis, in the Pityusic Islands. Special attention has been given to the correct
official spelling of 96 locations of which 89 are real rocks, islets and islands. For each island a short description, toponymy,
faunal and floral aspects and some herpetological history is given, and a lizard density value was assigned. The results are
very disturbing, with two confirmed- and three most likely extinct island populations of Podarcis pityusensis, and we call
for coordinated action. Pérez-Mellado, V. & Pérez-Cembranos, A. (2026) - A Large Lizard in a Small Islet: Abundance, Body Growth, and Diet of Podarcis pityusensis from Es Vaixell (Balearic Islands, Spain). - Animals, 16 (9): 1314. DOI: 10.3390/ani16091314. × The islet of Vaixell, off the west coast of Ibiza (Balearic Islands, Spain), is home to a native population of the Pityusic wall lizard, Podarcis pityusensis, with the largest body size recorded for the species. These lizards live in extreme environmental conditions on an islet with a small surface area covered by very sparse vegetation. The sex ratio is balanced, and a very high incidence of missing toes and autotomized tails is observed, indicating strong intraspecific competition involving both males and females. The body growth rate, adjusted using the Gompertz model, is intense and, apparently, juvenile lizards quickly reach relatively large body sizes. This fast body growth is probably a strategy against predation pressure from conspecifics. In P. pityusensis from Vaixell, the peak growth acceleration is prenatal and practically coincides with the moment of hatching. The diet consists mainly of aggregated prey, such as ants, with the inclusion of marine subsidies, such as halophyllous and littoral isopods, and a lower consumption of plant matter compared to other insular populations of lizards from the Balearic Islands. The lizards of Vaixell are an excellent example of the adaptive response of a lacertid lizard to the extreme conditions on the small coastal islets of the Mediterranean, with very small available areas, high population density, but a small population size, of about 50 to 100 lizards, which also reach a remarkable longevity.
|
