Albert Bertolero

Climatic shifts may increase the extinction risk of populations, especially when they are already suffering from other anthropogenic impacts. Our ability to predict the consequences of climate change on endangered species is limited by our scarce knowledge of the effects of climate variability on the population dynamics of most organisms and by the...

The presence of the Mediterranean pond turtle Mauremys leprosa in the Ebre Delta (Catalonia, north-east Spain) is well documented after the late 1970s, when the first reptile distribution lists were published. Owing to the fact that the species was considered scarce, a reintroduction programme based on the release of individuals at sites with poten...

Although reintroduction programmes are often implemented for recovering animal populations, projects seldom monitor the long-term survival of released animals. In addition, although many releases may occur in the same area, little is known about how the survival of successive release batches is affected by the presence of conspecifics and density d...

This study examines blood mercury (Hg) concentrations in Calonectris spp. shearwaters from three colonies along the Atlantic and Mediterranean waters of the Iberian Peninsula (southwestern Europe), investigating their relationship with foraging ecology through GPS tracking and stable isotopes (δ15N and δ13C) data during the breeding season. Hg leve...

Invasive species constitute a growing threat to diversity because of their role as competitors, predators or disease vectors. In Spain, aquatic ecosystems have been markedly affected by the colonization of numerous alien species, including crustaceans, fishes, amphibians and reptiles. However, there's little information about the status of most of...

Four native chelonians species occur in Spain, three of which are severely threatened. In recent surveys, 25 species of alien turtles and tortoises were reported, some of which had established breeding populations and interfered with native species. In this study, we used ecological niche models to evaluate which regions are more vulnerable to colo...

The evolutionary theory of life histories predicts that there is a trade-off between survival and reproduction: since adult survival in long-lived organisms is high, then breeding investment is more variable and more dependent on conditions (e.g. food availability and individual experience). Clutch features influence fitness prospects, but how a be...

Perfluoroalkyl substances (PFAS) are known to bioaccumulate and trigger adverse effects in marine birds. This study develops an extraction and analytical methodology for the target/untargeted analysis of PFAS in eggs of Yellow-legged gull (Larus michahellis) and Audouin's gull (Larus audouinii) and blood of Greater flamingo (Phoenicopterus roseus),...

This study used photo identification “ capturerecapture” to monitor a population of ocellated lizards (Timon lepidus Daudin, 1802), providing the first data on the demography of this species in the wild. The monitoring was conducted over a period of six years in a valley of the Var River in southeast France, with an average rate of 25 visits per ye...

Fecha de aceptación: 15 de diciembre de 2021.

The Ebro Delta is a wetland of international importance for waterbird conservation but severally affected by intensive agriculture, toxic waste discharges from a past chloro-alkali industry and affluence of tourism. The discharge of contaminants associated to these activities pose waterbirds breeding in the Ebro Delta at risk. The aim of this study...

Direct consequences of biological invasions on biodiversity and the environment have been largely documented. Yet collateral indirect effects mediated by changes in agri-environmental policies aimed at combating invasions remain little explored. Here we assessed the effects of recent changes in water management in rice farming, which are aimed at b...

Age drives differences in fitness components typically due to lower performances of younger and senescent individuals, and changes in breeding age structure influence population dynamics and persistence. However, determining age and age structure is challenging in most species, where distinctive age features are lacking and available methods requir...

Large-scale climatic indices are extensively used as predictors of ecological processes, but the mechanisms and the spatio-temporal scales at which climatic indices influence these processes are often speculative. Here, we use long-term data to evaluate how a measure of individual breeding investment (the egg volume) of three long-lived and long-di...

The only wetland in Europe colonized successfully by the apple snail Pomacea maculata Perry, 1810, is the Ebro Delta (Spain). After ten years it has become widespread there, despite significant eradication attempts. In spite of its great negative ecological and economic impacts, its incorporation into food webs can result in an abundant potential r...

Gull eggs are excellent bioindicators of environmental pollution as reflect the contamination levels of coastal areas, especially of persistent and bioacumulative compounds such as perfluoroalkyl substances (PFAS). This study aims to evaluate the geographical distribution and 10-year temporal trends (2009–2018) of 17 PFAS in eggs of two gull specie...

Chelonians are among the most threatened animal groups because due to life history strategy, they are extremely vulnerable to human pressure. At the ""Mediterranean workshop to develop tortoise conservation strategies"" scientists, conservation associations, environmental managers, IUCN advisers and CITES inspectors met in 2019 in Spain. The aims w...

Chelonians are among the animal groups with the poorest conservation status. Since tortoises are long‐lived species that need very long time to reach sexual maturity, they are extremely vulnerable to human pressure. Despite their endangered status, there are no common strategies for the devel opment of conservation actions. At the “Mediterranean wo...

Social interactions, through influence on behavioural processes, can play an important role in populations’ resilience (i.e. ability to cope with perturbations). However little is known about the effects of perturbations on the strength of social cohesion in wild populations. Long-term associations between individuals may reflect the existence of s...

The processes underlying macroecological gradients in body size are widely debated, in part because their intraspecific variability remains poorly described even in well-studied taxa such as vertebrates. In this study, we investigated how climate, habitat, genetic lineage and sex explain body size variations in French populations of the European po...

Abstract. Population characteristics of the Hermann's tortoise Testudo hermanni hermanni Gmelin in the Albera Mountains (Reptilia: Tes-tudinidae). During 2019, the population of the Hermann's tortoise in the Albera Mountains (Girona, Catalonia) has been censed using the capture-mark-recapture method. The total sampled area was 95.7 ha. Furthermore,...

Turtles and tortoises (chelonians) have been integral components of global ecosystems for about 220 million years and have played important roles in human culture for at least 400,000 years. The chelonian shell is a remarkable evolutionary adaptation, facilitating success in terrestrial, freshwater and marine ecosystems. Today, more than half of th...

El censo de la mayor población de collalba negra que se conoce en Cataluña, la asentada en el sur de la provincia de Tarragona, detecta densidades especialmente bajas de esta especie y confirma la preocupación por su futuro. Revista Quercus nº412 p42 https://www.revistaquercus.es/noticia/7697/nacional/se-censa-la-poblacion-catalana-mas-importante-...

Phalangeal reduction is a common and widespread phenomenon among tortoises that has been associated with the adaptation to terrestrial life. While reduced manual digit 1 appears characteristic in almost all Testudo species, it is uncertain why the metacarpal I and distal carpal of the same digit are completely missing in some individuals of Hermann...

Understanding the behaviour of a population under perturbations is crucial and can help to mitigate the effects of global change. Sociality can influence the dynamics of behavioural processes and plays an important role on populations’ resilience. However little is known about the effects of perturbations on the social cohesion of group-living anim...

We examined how coastal mercury contamination varied spatially and temporally across the Iberian Peninsula by measuring mercury concentrations in the eggs of the sentinel biomonitor yellow-legged gull (Larus michahellis). Samples were collected from eight colonies that ranged from the Atlantic across the south and northern areas of the Mediterranea...

The Common Sandpiper Actitis hypoleucos is a common autumn migrant in the Ebro Delta in Spain, although it is uncommon in winter. Autumn migration was studied in this locality from 2007 to 2014. There is an earlier migration passage of adults (median date 22 Jul) than juveniles (10 Sep), with 50 days between the age medians. Nine of 10 birds recapt...

We present a review and analysis of the conservation status and International Union for Conservation of Nature (IUCN) threat categories of all 360 currently recognized species of extant and recently extinct turtles and tortoises (Order Testudines). Our analysis is based on the 2018 IUCN Red List status of 251 listed species, augmented by provisiona...

We used 454-sequencing to identify and characterize 32 microsatellite loci for the Western Hermann’s tortoise (Testudo hermanni hermanni) for which primer sequences, characteristics, and multiplexes are provided. These markers have been tested for one continental (Var) and one insular (Corsica) French population as well as for the Eastern Hermann’s...

El còlit negre (Oenanthe leucura) viu únicament al nord d’Àfrica i a la península Ibèrica. La població catalana constitueix el límit NE de la seva distribució mundial, on des de principi del segle XXI hi ha hagut diferents extincions locals que han suposat una disminució de l’àrea ocupada. Actualment la major àrea de distribució a Catalunya es conc...

1. Since 2009, the apple snail Pomacea maculata has become a new invader in rice fields and wetlands in Europe, thus far invading only the Ebro Delta (northeastern Spain). It is considered a highly invasive and damaging species, resulting in large economic losses worldwide. 2. Despite the great negative impact of the invasive apple snail in the ag...

The objective of the present project is to monitor the chemical contamination caused by Persistent Organic Pollutants and mercury (Hg) using seagull eggs (Larus michahellis) as bioindicators of environmental contamination. During the period 2013-15 an annual sampling of seagull eggs has been carried out in the National Park of Atlantic Islands of G...

The aim of the present work was to comparatively assess the occurrence and impact of persistent organic pollutants (POPs) in nine natural and national parks from Spain and Portugal using gull eggs (Larus michahellis and L. audouinii) as bioindicators of environmental contamination. Sampling was performed during the breeding season of 2016. Compound...

Predators are an important ecological and evolutionary force shaping prey population dynamics. Ecologists have extensively assessed the lethal effects of invasive predators on prey populations. However, the role of non-lethal effects, such as physiological stress or behavioural responses like dispersal, has been comparatively overlooked and their p...

Translocations to restore populations of endangered species are an important conservation tool, but a reliable diagnosis is needed to assess their success. We used capture-recapture modeling to analyze the adult apparent survival of released and resident tortoises in two translocation projects in Spain monitored for 14 and 29 years. We tested if lo...

La variación del número de dedos y falanges de las extremidades anteriores es un fenómeno común en tortugas, aunque la variación en el grado de desarrollo difiere en género e incluso a nivel de especie. Se ha estudiado la variación en el número de dedos y falanges de las extremidades de la población de tortuga mediterránea (Testudo hermanni hermann...

Recent European policies on the ban of fishing discards and the closure of open-air landfills are expected to reduce predictable and abundant food resources for generalist seabirds. In order to forecast the consequences of this reduction on seabird breeding investment it is important to understand whether diverse anthropogenic foraging resources ac...

Many chelonians have colourful dots, patches and stripes throughout their body that are made up, at least in part, of carotenoids. Therefore, turtles are very suitable models to study the evolution and functionality of carotenoid-based colouration. Recent studies suggested a close link between colouration and immune system in these taxa. However, m...

Studying colonisation is crucial to understand metapopulations, evolutionary ecology and species resilience to global change. Unfortunately, few empirical data are available because field monitoring that includes empty patches at large spatiotemporal scales is required. We examine the colonisation dynamics of a long-lived seabird over 34 years in t...

Injuries have the potential to influence individual behaviour, reproduction and/or survival. One of the least frequently observed and least known injuries in birds is sublingual fistulation, which has only been reported in four species to date. Audouin's Gull Larus audouinii is now added to this list. Based on periodical re-sightings of darvic-ring...

The Menorca Biosphere Reserve is a figure created by the UNESCO to conciliate and promote the development of the island's natural environment, aiming to apply the concept of sustainable development. Menorca was declared as a Biosphere Reserve in 1993, and it is located in the centre of the occidental Mediterranean Sea. UNESCO's directives establish...

Many bird families, including the Rallidae, are characterised by a lack of plumage sexual dimorphism and reduced sexual size dimorphism. In such cases, biometry may still allow the sex of captured birds to be determined. We investigated this possibility in the purple swamphen, a species for which biometric and moult data from southern Europe are sc...

In this communication we present some of the results of the benthic diatom community study. Diatom samples were obtained from 17 sites distributed across the two coastal lagoons, both before (2011) and one and two years after habitat restoration actions were taken to restore (2012 and 2013)

Conditions during early life, including maternal cohort effects, can influence the future fitness of individuals. This may be particularly true for long-distance migrating birds, because, apart from conditions experienced by cohorts during rearing, conditions during early-life in regions far from breeding grounds may also influence their population...

El criterio fundamental para considerar que una especie es alóctona en el territorio español se basa en la constatación de que la coloniza-ción no ha sido natural, sino de origen antró-pico. Según este criterio, debemos considerar como poblaciones alóctonas la mayoría de las tratadas en este volumen, con algunas excepcio-nes como Testudo graeca en...

Freshwater turtle species are still poorly understood, and many species are in decline due to unsustainable trade as well as human alteration and degradation of freshwater ecosystems. Mauremys leprosa is a freshwater chelonian endemic to the Mediterranean Basin. Whereas the fossil record demonstrates that this species used to be distributed to well...

The ability to control infections is a key trait for migrants that must be balanced against other costly features of the migratory life. In this study we explored the links between migration and disease ecology by examining natural variation in parasite exposure and immunity in several populations of Lesser Black-backed Gulls (Larus fuscus) with di...

Ce travail analyse le régime alimentaire de la Sterne hansel dans 11 colonies localisées en région Méditerranéenne à partir de travaux publiés et de données originales du delta de l’Èbre (NE Espagne). Nous avons utilisé le coefficient de corrélation de Spearman et l’analyse factorielle des correspondances pour déterminer s’il y a des relations entr...

The Mediterranean tortoise is a species common in Menorca, but virtually disappeared in Catalonia. We present a first attempt to characterize visually the different populations by testing quantitative differences of the colour pattern among reference populations, two from Menorca (Cala Tirant and Barranc d’es Bec) and one from Catalonia (Albera). T...

The Hermann’s tortoise benefits from a positive image which gives this species significant sympathetic importance. The popularity of this species (notably as a pet) may lead us to believe that it should benefit from a certain level of protection. Yet, its populations are constantly decreasing, and the reduction of favourable habitat has triggered i...

Small and peripheral populations are typically vulnerable to local extinction processes but important for the metapopulation dynamics of species. The Slender-billed gull (Chroicocephalus genei) is a long-lived species breeding in unstable ephemeral coastal habitats. Their Western Mediterranean populations are relatively small and represent the edge...

Dispersal is a key process for the population dynamics of spatially structured populations (at local and metapopulation levels), so the understanding of the mechanisms underlying the movement of individuals in space and time is important for evolutionary and ecological studies. Here we analyzed, for the first time, a long-term (1992–2009) multi-sit...

One of the main breeding populations of Redshanks in Spain is in the delta of the Ebro in Catalonia. The breed-ing biology of this population has not previously been studied. Between 1996 and 1999, the number and size of eggs, laying dates and nest-site selection, as well as the number of pairs were recorded. Number and size of the eggs were simila...

The primary moult of Curlew Sandpiper Calidris ferruginea was studied at a staging area in the south of Europe. The duration of primary moult was estimated as 73 days (9 August to 21 October), a shorter period than those reported in the wintering areas. Birds in moult showed a lower speed of fat accumulation than non moulters. An increase in the pr...

The Hermann’s tortoise is considered an endangered species in Spain, since only one autochthonous population remains in Catalonia (Alberes). The other populations are the result of reintroductions carried out recently (Catalonia and Valence) or in the past (Balearic Islands). The conservation status of the Albera population is the most critical, wi...

Assessing population trends is a basic prerequisite to carrying out adequate conservation strategies. Selecting an appropriate method to monitor animal populations can be challenging, particularly for low-detection species such as reptiles. This study compares 3 detection-corrected abundance methods (capturerecapture, distance sampling, and N-mixtu...

Resum A Menorca la tortuga mediterrània Testudo hermanni hermanni és una espè-cie comuna que es distribueix per quasi tota l'illa. Els estudis anteriors sobre la seva distribució van ser realitzats entre els anys 1970 i 1994. Entre 2003 i 2006 es va prospectar la major part de Menorca amb la finalitat de determinar-ne la distribució actual. A parti...

This study is aimed to evaluate the presence and distribution of Perfluorinated Compounds (PFCs) in Yellow-legged gull eggs (Larus michahellis) collected from 8 National or Natural Parks from the Iberian Peninsula. In each colony, 12 eggs were randomly collected and pooled from 3 areas of the colony and analyzed using liquid-solid extraction and li...

Hermann's Tortoise, Testudo hermanni (Family Testudinidae), is a medium-sized terrestrial species (average carapace length ca. 130 to 180 mm), widespread in the European Medi-terranean region. Currently two subspecies are distinguished: T. h. hermanni in Western Europe and T. h. boettgeri in Eastern Europe, the border between them being the Po Vall...

Chelonian trouble: threats and future Challenge for its Conservation. – Among the 324 spe- cies of chelonians currently known, approximately one-quarter are currently threatened with extinc- tion. The factors leading to the disappearance of these species have been directly linked to human activity. Major threats include the increasing commercial tr...

En Menorca se encuentran poblaciones de tortuga mediterránea Testudo hermanni hermanni en buen estado de conservación, que hasta hace poco habían sido poco estudiadas. Los estudios realizados a partir de 2003 han permitido conocer diferentes aspectos de su distribución, genética y demografía. Entre los diferentes resultados obtenidos se ha podido d...