Reintroduint la marmota alpina als Pirineus

Malgrat la manca de planificació i de seguiment, la reintroducció de la marmota alpina als Pirienus ha estat un èxit. Tot i així, les poblacions reintroduïdes a Andorra, la Cerdanya i el Ripollès tenen molt poca diversitat genètica, un aspecte crucial per adaptar-se al nou ambient. Només el temps dirà si aquest aspecte les perjudica al adaptar-se a les noves condicions que genera el canvi climàtic.Pese a la falta de planificación y seguimiento, la reintroducción de la marmota alpina en los Pirineos ha sido un éxito. Sin embargo, las poblaciones reintroducidas en Andorra, la Cerdanya y el Ripollès tienen muy poca diversidad genética, un aspecto crucial para adaptarse al nuevo ambiente. El tiempo dirá si este aspecto las perjudica al adaptarse a las nuevas condiciones que genera el cambio climático.Despite a lack of planning and monitoring, the reintroduction of the alpine marmot in the Pyrenees has been a success. However, reintroduced populations of Andorra, La Cerdanya and El Ripollès have low genetic diversity. Only time will tell whether this inconvenience will influence their adaptation to the new conditions climate change is generating

Selecció sexual: per què els mascles lluiten i les femelles trien?

The struggle to reproduce is a key part of the existence of any organism. For sexually reproductive species, reproduction is more difficult because they need to find another individual willing to mate. Charles Darwin was the first to study mating systems from an evolutionary point of view and he laid the first stone of sexual selection theory. More than one century was needed to convince the scientific community of its validity, but it has become one of the most active areas in the field of evolutionary biology. According to the theory, the traits that give individuals higher reproductive output, though they often compromise their survival, may be selected by two different mechanisms. First, individuals of the same sex compete with each other to copulate with the other sex, so any character that makes them good competitors should be selected. Second, the individuals of a given sex, usually the females, are able to choose which individual they prefer to mate with, so they can select attractive traits in the eyes of the other sex. From this perspective, sexual selection theory has explained why males usually fight and females are the choosy sex. In addition, it has increased understanding of a great variety of extravagant behaviours in the context of sex: furtive mating, cross-dressing lovers, nuptial gifts and sexual suicide. Everything counts in the struggle for reproduction!La lluita per aconseguir reproduir-se és una part essencial de l’existència de qualsevol organisme. Per als animals sexuats, l’afer es veu complicat per la necessitat de trobar un altre individu disposat a aparellar-se. Charles Darwin va ser el primer que va estudiar els sistemes d’aparellament des d’una òptica evolutiva i va posar la primera pedra de la teoria de la selecció sexual. Tot i que va caldre més d’un segle per convèncer els científics de la seva validesa, ha esdevingut una de les àrees més fecundes en el camp de la biologia evolutiva. Segons la teoria, els caràcters que confereixen als individus més possibilitats de deixar descendència, malgrat que puguin comprometre la seva supervivència, seran seleccionats per dos mecanismes diferents. Per una banda, els individus d’un mateix sexe competiran entre si per aconseguir aparellar-se amb l’altre sexe, de manera que se seleccionaran caràcters que els facin bons competidors. Per altra banda, els individus d’un sexe, generalment les femelles, podran elegir quin individu els fa més el pes per aparellar-s’hi, de manera que es podran seleccionar trets que per alguna raó fan els individus més atractius a ulls de l’altre sexe. Sota aquesta perspectiva, la teoria de la selecció sexual ha mirat d’explicar perquè són els mascles els que normalment lluiten i perquè les femelles les que majoritàriament són més exigents a l’hora d’escollir parella. A més, ha permès entendre una gran varietat de comportaments extravagants en el context del sexe: còpules furtives, amants transvestits, regals nupcials o suïcidis sexuals. Tot s’hi val en la lluita per la reproducció

Bons o mals dispersors d'aglans? : cada ratolí dispersa en funció de la seva "personalitat"

El comportament i les pautes alimentàries de cada ratolí repercuteixen en la formació dels boscos, sigui per la reacció àvida o no que aquests tenen al menjar, en funció de la percepció de depredadors en l'entorn més pròxim; o bé per la reserva o consum d'aglans i la posterior germinació d'aquests si queden guardats al cau i no es consumeixen. Dos experiments amb animals salvatges del grup SGR: BEEMed Biodiversitat i Evolució en Ecosistemes Mediterranis del departament de Biologia Animal, de Biologia Vegetal i d'Ecologia de la UAB han classificat la personalitat dels ratolins amb la finalitat, a més, de contribuir a l'estudi de la formació dels boscos en un context de canvi climàtic.El comportamiento y las pautas alimenticias de cada ratón repercuten en la formación de los bosques, sea por la reacción ávida o no que estos tienen a la comida, en función de la percepción de depredadores en el entorno más próximo; o bien por la reserva o consumo de bellotas y la posterior germinación de estos si quedan guardados en la madriguera y no se consumen. Dos experimentos con animales salvajes del grupo SGR: BEEMed Biodiversitat i Evolució en Ecosistemes Mediterranis del departamento de Biologia Animal, Biologia Vegetal y Ecologia de la UAB han clasificado la personalidad de los ratones con el fin, además, de contribuir al estudio de la formación de bosques en un contexto de cambio climático

Coexistence of predators in time: Effects of season and prey availability on species activity within a Mediterranean carnivore guild

The degree of coexistence among predators can determine the structure of ecological communities. Niche partitioning is a common strategy applied by species to enhance their coexistence. Diet, habitat, or time use can be responsible for segregation among carnivore species, the latter factor being the least studied in Mediterranean ecosystems. Terrestrial medium‐sized carnivores (i.e., mesocarnivores) carry out important functions in ecosystems, and identifying their interactions is essential for their conservation. In this study, we explore the activity of a terrestrial mesocarnivore guild in order to determine seasonal differences in daily activity patterns of competitors and prey. We also investigate how the abundance of a common mesocarnivore prey in the region, small mammals, influences the activity of predators. During a year, camera trap devices (n = 18) were installed in Montseny Natural Park (Catalan Pre‐Coastal Range, North‐East Iberian Peninsula), a region that hosts five mesocarnivore species. Camera trapping detections were used to estimate their daily activity patterns and corresponding overlaps. We also surveyed small mammal plots (n = 5) in order to calculate prey abundance and test its effect on the relative activity of each carnivore species. Despite all target mesocarnivores are mainly nocturnal, the activity overlap among them varies according to species particularities and season. Red fox (Vulpes vulpes) appears as a generalist species in terms of time use, whereas stone marten (Martes foina) and genet (Genetta genetta) show the most similar activity patterns and both of them seem to be positively influenced by small mammal abundance. Overall, the diversity found in the way mesocarnivore species use time could facilitate their coexistence. Despite activity pattern similarities among carnivore species should not be directly translated to negative interactions, they can have a strong influence in habitat and resource‐limited ecosystems. Therefore, activity overlaps should be taken into account when discussing wildlife management actions

Intraspecific variation in digit reduction in Testudo : the case of the Hermann's tortoise

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's tortoise (Testudo hermanni hermanni). To clarify this issue, we investigated the number of manual claws in six populations of Hermann's tortoise (one from the Ebro Delta in the Iberian Peninsula and five from Minorca Island), their age, sex, genetic lineage, and the substrate type that they inhabit. The number of claws was ascertained based on direct counts (n > 1500 individuals) and by X-rays (n = 32 individuals), obtaining three different phalangeal formulae: (1-2-2-2-1, D-2-2-2-1, 0-2-2-2-1). Thus, claw counts through both methodologies (direct count and X-ray) further confirm that the observed claws serve as a good proxy to assess the actual number of digits. Our results show no loss of phalanges, metacarpal and carpal bones in digit 1 associated with age, sex, or substrate, contrary to some previous authors who hypothesized a relationship between this loss and sexual dimorphism. Therefore, variations in the number of manual digits and the loss of metacarpal I and distal carpal in digit 1 in Hermann's tortoise are related to population and genetic lineage. More detailed comparisons with other Testudo hermanni populations from elsewhere in Europe would be required to understand the evolutionary significance concerning the intrapopulation variability in the number of digits remaining

Coexistence of predators in time : Effects of season and prey availability on species activity within a Mediterranean carnivore guild

The degree of coexistence among predators can determine the structure of ecological communities. Niche partitioning is a common strategy applied by species to enhance their coexistence. Diet, habitat, or time use can be responsible for segregation among carnivore species, the latter factor being the least studied in Mediterranean ecosystems. Terrestrial medium-sized carnivores (i.e., mesocarnivores) carry out important functions in ecosystems, and identifying their interactions is essential for their conservation. In this study, we explore the activity of a terrestrial mesocarnivore guild in order to determine seasonal differences in daily activity patterns of competitors and prey. We also investigate how the abundance of a common mesocarnivore prey in the region, small mammals, influences the activity of predators. During a year, camera trap devices (n = 18) were installed in Montseny Natural Park (Catalan Pre-Coastal Range, North-East Iberian Peninsula), a region that hosts five mesocarnivore species. Camera trapping detections were used to estimate their daily activity patterns and corresponding overlaps. We also surveyed small mammal plots (n = 5) in order to calculate prey abundance and test its effect on the relative activity of each carnivore species. Despite all target mesocarnivores are mainly nocturnal, the activity overlap among them varies according to species particularities and season. Red fox (Vulpes vulpes) appears as a generalist species in terms of time use, whereas stone marten (Martes foina) and genet (Genetta genetta) show the most similar activity patterns and both of them seem to be positively influenced by small mammal abundance. Overall, the diversity found in the way mesocarnivore species use time could facilitate their coexistence. Despite activity pattern similarities among carnivore species should not be directly translated to negative interactions, they can have a strong influence in habitat and resource-limited ecosystems. Therefore, activity overlaps should be taken into account when discussing wildlife management actions

Mate choice for neutral and MHC genetic characteristics in Alpine marmots : different targets in different contexts?

We warmly thank all students and Earthwatch volunteers involved in catching the marmots and the authorities of the Vanoise National Park for granting us permission to work in the Grande Sassière Nature Reserve. We thank M. Harrington for English editing and Dr. E. Rajon for helpful discussions on the manuscript. This work was supported by the "Agence Nationale de la Recherche" (ANR, project ANR-08-BLAN-0214-03, ANR-13-JSV7-0005), the "Centre National de la Recherche Scientifique" (CNRS), the "FR41 BioEnvironnement et Santé de l'Université de Lyon" and the "Earthwatch Institute", the scholarship for postgraduate studies "Obra Social Fundació La Caixa" and Vetagro-Sup.Sexual selection through female mate choice for genetic characteristics has been suggested to be an important evolutionary force maintaining genetic variation in animal populations. However, the genetic targets of female mate choice are not clearly identified and whether female mate choice is based on neutral genetic characteristics or on particular functional loci remains an open question. Here, we investigated the genetic targets of female mate choice in Alpine marmots (Marmota marmota), a socially monogamous mammal where extra-pair paternity (EPP) occurs. We used 16 microsatellites to describe neutral genetic characteristics and two MHC loci belonging to MHC class I and II as functional genetic characteristics. Our results reveal that (1) neutral and MHC genetic characteristics convey different information in this species, (2) social pairs show a higher MHC class II dissimilarity than expected under random mate choice, and (3) the occurrence of EPP increases when social pairs present a high neutral genetic similarity or dissimilarity but also when they present low MHC class II dissimilarity. Thus, female mate choice is based on both neutral and MHC genetic characteristics, and the genetic characteristics targeted seem to be context dependent (i.e., the genes involved in social mate choice and genetic mate choice differ). We emphasize the need for empirical studies of mate choice in the wild using both neutral and MHC genetic characteristics because whether neutral and functional genetic characteristics convey similar information is not universal

Evidence of high individual variability in seed management by scatter-hoarding rodents : does 'personality' matter?

We analysed the individual variation in behaviour by scatter-hoarding rodents. The perceived predation risk was manipulated to assess the consistency of behaviour. Individual differences explained more than 80% of total behavioural variance. Rodents showed an extraordinary consistency in their individual behaviour. We highlight the relevance of individual behaviour in scatter-hoarding animals

Escriure Biologia a la Universitat

Podeu consultar la versió anglesa al recurs relacionat.Guia que ajuda els destinataris (professorat i alumnat) a comunicar-se, sobretot per escrit, en la seva disciplina acadèmica; biologia en aquest cas

DNA metabarcoding Passerine bird feces at tree-line uncovers little intra- and inter-species dietary overlap

High-elevation insectivorous birds are currently confronted with the reality of a changing climate, land use shifts, and the decline of many prey groups. The diet dynamics among many imperiled animals in this group are still unresolved. Examining the diets of tree-line Passerine birds to the species level of the prey allows for stronger population predictions. This study uses DNA metabarcoding to identify prey arthropods from adult Passerine bird feces at and slightly below tree-line in a Pyrenean forest. Our objective was to quantify the intra-and inter-species richness and overlap of Passerine bird diet over time and space. The results showed that adult Passerine diets have high inter- and intra-species dietary variability and low inter- and intra-species dietary overlap. The lack of association between dietary richness and open space, season, and elevation and lack of differences between dietary overlap and open space and elevation suggest high-elevation Passerine birds have very high dietary flexibility. The results also showed that aphids known to be pests to conifers, and other conifer pests, were prevalent in the birds' diets. The Passerine diets and high rate of rare dietary items are mainly in line with other recent DNA metabarcoding studies. Implications for the long-term projections relative to tree-line Passerine populations are discussed