AG magazine (in print)
Online magazine (pdf)
Online articles (html)
Literature- and poster projects
of the real lizards, family Lacertidae
Podarcis carbonelli berlengensis VIVENTE, 1985
Amado, A. (2007) -
Amaral, M.C.F. do (2009) -
The lizard Podarcis carbonelli is an endangered species endemic to the Iberian Peninsula. One location where this species occurs is at the Berlengas Natural Preserve, an Atlantic archipelago off the coast of Portugal. These island populations are geographically separated from nearby mainland populations. The fundamental question is, are these insular individuals distinct from the mainland populations? Four localities were chose for comparison: two island populations and two nearby coastal populations. We assessed this question using three distinct approaches: molecular, morphological and physiological approach. We sequenced the 12S RNA, the mtDNA Control Region and the 7th intron of the !-fibrinogen gene and determined genetic diversity values as well as several parameters of population structure and differentiation. Individuals from these populations were also measured for several biometric characters and their blood lactate concentration was sampled. There was no genetic variation in both the mtDNA regions analyzed. The nuclear intron revealed high levels of genetic variation, with islands having in general lower values than the mainland regions. The four populations sampled had low levels of divergence; the populations of Berlenga and Peniche were the most distinct and the populations of Farilhão and Baleal were the most similar from the four populations sampled. Morphometric analyses revealed a different pattern of similarity among populations with the population of Farilhão being the only population statistically distinct from all other populations based on mass and SVL. Furthermore, island populations were in general more similar to each other than to mainland populations, with the exception of Berlenga males which in size are more similar to the Peniche males. The analysis of the blood lactate concentration revealed that the population of Peniche has significantly lower blood lactate levels than the populations of Farilhão and Berlenga. The lack of genetic differentiation found in the populations under study is most likely due to the recent divergence of these populations. Furthermore, the genetically most different populations (Berlenga and Peniche) are not the most distinct in terms of morphology, particularly the males. This suggests that genetic drift, the most likely mechanism behind the genetic differentiation seen, is not responsible for the morphological differences observed. The morphological differences seen can be attributed to: a possible difference in age of the individuals in each population; mechanisms of natural selection that are favoring specific phenotypes in each of the populations, or phenotypic plasticity. The differences in blood lactate levels found between the population of Peniche and the island populations can be attributed to differences in predatory pressure or home range size. It is suggested that the island populations are closely monitored due to their likely isolation, low mtDNA diversity and possible higher predatory pressure than initially predicted.
Araujo, A.P.R. de (1990) -
Baptista, R. & do Amaral, J. (2006) -
Deschandol, F. (2011) -
Ferreira, M. & Proenca, V. & Antunes, P. & Barbault, R. & Vicente, L. (2004) -
Ferreira, M. & Proenca, V. & Perraud, B. & Luz, A.C. & Vicente, L. (2004) -
Ferreira, M. & Proenca, V. & Vicente, L. (2004) -
Ferreira, M. & Proenca, V. & Vicente, L. (2005) -
Ferreira, M. & Vicente, L. (2001) -
Figueirinhas, C. & Amaral, J.P,do & Ferreira, M. & Proenca, V. & Luz, A.C. & Hasse, A. & Sousa, J. & Vicente, L. (2006) -
Harris, D.J. & Sá-Sousa, P. (2001) -
Wall lizards (Podarcis) are the dominant reptile group across most of southern Europe. Their taxonomy is complex because most species exhibit substantial intraspecific morphological polymorphisms. We have estimated the phylogeny of the particularly diverse western Iberian forms using partial cytochrome oxidase and cytochrome b mitochondrial DNA sequence data and have compared this against morphological variation. Of the two currently recognized species in the area-Podarcis hispanica and P. bocagei-neither is monophyletic, and extremely high genetic diversity between newly identified forms (up to 15% cytochrome b divergences) indicates that both are species complexes. Podarcis b. bocagei is genetically distinct from P. (b.) carbonelli which appears to be a separate species using both mtDNA and protein electrophoretic data. The insular form previously assigned to P. b. berlengensis, and sometimes argued to deserve species status is not genetically distinct from P. (b.) carbonelli using the mtDNA sequences. P. hispanica can be separated into at least four highly divergent groups, two in western Iberia, one in eastern Iberia and one in North Africa.
Luz, A.C. & Monasterio, C. & Vicente, L. (2004) -
Luz, A.C. & Monasterio, C. & Vicente, L. (2006) -
A study in comparative morphology between two different populations of Podarcis carbonelli berlengensis on the Berlenga´s Archipelago was conducted and showed significantly differences between them. The lizards foun d on the island of Farilháo Grande are larger, have relatively longer limbs and are more melanistic than the indiciduals living on the island of Berlenga Grande. Differences related to the head shape, scalation and chromatic pattern were also found. Such differences could be assigned to different selective pressures, founder effect or genetic drift.
Malkmus, R. (2002) -
Malkmus, R. (2011) -
Within a 500 m margin along the more than 2,000 km long coastline of Continental Portugal, its coastal islands and atlantic archipelagos (Azores, Madeira, Selvagens) 21 amphibian and 40 reptile taxa (including 5 marine turtles) were recorded; three of them are insular endemisms (Tarentola bischoffi, Podarcis carbonelli berlengensis, and the polytypic Teira dugesii). The extreme maritim-atlantic component of the coastal climate plays a relevant part as biogeographic factor: parallel to the coast eurosiberian and montane species penetrate deep into the mediterranean region (Lissotriton helveticus, Alytes obstetricans, Anguis fragilis, Lacerta schreiberi, Podarcis carbonelli) and reach there the southernmost limit of their distribution area; on the other hand some thermophilous taxa (Pleurodeles waltl, Pelobates cultripes, Pelodytes sp., Podarcis hispanica) reach along the coast in the eurosiberian region their northernmost limit. In the last 30 years the coastal ecosystems were overrun by an excessive urbanisation, caused by inland immigration and tourism. Consequently in many coast sectors the herpetofauna are endangered, often extincted by urban and suburban development with fragmentation, degradation and destruction of habitats. Namely ca. 40 % of the coastal region are protected areas, but the effectiveness of this protection is threatened by many special permissions for building projects and an insufficient supervision of the nature reserves.
Nunes, S.F. & Mota-Ferreira, M. & Sampaio, M. & Andrade, J. & Oliveira, N. & Rebelo, R. & Rocha, R. (2021) -
Invasive species are a major threat to island biodiversity, and their eradications have substantially contributed to the conservation of island endemics. However, the consequences of eradications on the trophic ecology of native taxa are largely unexplored. Here, we used the eradication of invasive black rats Rattus rattus and European rabbits Oryctolagus cuniculus from the Berlenga Island, in the western coast of Portugal, as a whole-ecosystem experiment to investigate the effects of the eradication of invasive mammals on the trophic niche and body dimensions of the island-restricted Berlenga wall lizard Podarcis carbonelli berlengensis over a 2-year period. Our results suggest an expansion of the isotopic niche and an intensification of the sexual dimorphism of the lizard following mammal eradication. Additionally, we found considerable variability in isotopic niche across the island and detected evidence of sex-specific and season-modulated nutritional requirements of this threatened reptile. Our findings support that the eradication of 2 of the planet’s most problematic invasive vertebrates led to changes in the lizard trophic niche and sexual dimorphism in just 2 years. This suggests that the ecological pressures—for example, prey availability and habitat structure—to which lizards are exposed have substantially changed post-eradication. Our study emphasizes the scientific value of island eradications as experiments to address a wide range of ecological questions and adds to the increasing body of evidence supporting substantial conservation gains associated with these restoration interventions.
Oefinger, B. & Oefinger, P. (2013) -
Sá-Sousa, P. (2009) -
Sá-Sousa, P. & Almeida, A.P. & Rosa, H. & Vicente, L. & Crespo, E.G. (2000) -
Six biometric characters and 15 electrophoretic loci of three known subspecies of Podarcis bocagei were studied. Contrary to biometric indications, Podarcis bocagei berlengensis showed a closer genetic relationship with Podarcis bocagei carbonelli than with the nominal subspecies. The biometric results were confounded by the relative large size of P. b. berlengensis. Post-glacial colonization from two different areas might explain the greater genetic differentiation between the P. b. bocagei and P. b. carbonelli populations (Nei`s D - 0.158 - near the species threshold). It might also explain the known colonization of these two lizards through the islands off the west coast of the Iberian penninsula and their present distributions to the north of (Galicia; Northern Portugal) and to the south of the valley of river Douro (central Portugal, western and Sistema Central), respectively.
Vicente, L. & Barbault, R. (2001) -
This study explores the dynamics of a lacertid population in an island environment. The research was conducted on the island of Berlenga, off the Portuguese West Coast. The data collected were compared to previously existing data obtained from mainland areas. The study is interesting for two reasons: first: because it allows observation of Podarcis bocagei berlengensis, an endemic form subjewcted to insular constraints and, second, because the study shows that the knowledge of population dynamics is crucial to the formation of scientifically rooted conservation strategies. Comparison of the population characteristics of Podarcis bocagei berlengensis with those of the mainland species, Podarcis muralis supports the idea that species that are subjected to insular constraints are likely “K-strategist” traits: greater life expectancy, lower rates of population renewal, and very high population densities. The recruitment rate for Podarcis bocagei berlengensis was found to be lower than that of Podarcis muralis, the density of the Podarcis bocagei berlengensis population was higher than the densities of the Podarcis muralis populations, the mortality of eggs was significantyl lower for the island population, and the mortality of adult Podarcis bocagei berlengensis was consistently lower and more constant than the mortality of adult Podarcis muralis. All of these population characteristics indicate that, since its introduction to the island, the population has evoilved to develop some traits of the “K-strategy”. The data also acts as an alarm, providing humans with a way to determine if the population dynamics of Podarcis bocagei berlengensis are being dangerously affected by external factors. It has been noted that the large density decreases seen between 1985 ans 1987 are most likely related to the correlated increases in the yellow-legged-gull populations during the same period. This observation suggests that there is a serious conservation problem that must be addressed on the island of Berlenga. The future of the Podarcis bocagei berlengensis population is unsure unless effective control of the yellow-legged-gull breeding population is achieved.
Vicente, L. & Ferreira, M. & Perraud, B. & Antunes, P. & Barbault, R. (2001) -
Vicente, L.A. (1985) -
Vicente, L.A. (1989) -
Vicente, L.A. & Araujo, P.R. & Barbault, R. (1995) -
De nombreux travaux ont été publiés sur le régime alimentaire de lézards insectivores. Très peu cependant font explicitement référence au spectre des proies disponibles, ce qui limite singulièrement leur portée écologique. On étudie ici l`écologie trophique de deux populations de Lacertidés insulaires, Podarcis bocagei berlengensis et Lacerta lepida, en reliant les spectres de proies consommées aux ressources effectivement disponibles. Il apparaît que les deux espèces sont caractérisées par un opportunisme alimentaire marqué, bien qu`il existe une certaine sélection des proies fonction de la facilité de capture. Leur importante différence de taille permet de réduire le chevauchement des niches alimentaires et favorise la coexistence de ces deux espèces dont l`abondance est probablement réglée par une forte compétition intraspécifique.