Estimating nest-switching in free-ranging wild birds: an assessment of the most common methodologies, illustrated in the White Stork (Ciconia ciconia)

Reliable estimates of nest-switching are required to study avian mating systems and manage wild populations, yet different estimation methods have rarely been integrated or assessed. Through a literature review and case study, we reveal that three common methods for assessing nest-switching blend different components, producing a wide range of estimates. Careful component definition and reporting are essential to properly estimate this behaviour

Genetic Introgression and Morphological Variation in Naked-Back Bats (Chiroptera: Mormoopidae: Pteronotus Species) along Their Contact Zone in Central America

Two sibling bare-backed bat species (Pteronotus fulvus and P. gymnonotus) have been traditionally differentiated by their size. However, intermediate specimens between the two species have been found in sympatric populations along southern Mexico and it has been suggested that they may be the outcome of a hybridization process between the two species. We used one mitochondrial (COI), three nuclear markers (PRKCL, STAT5A and RAG2) and 13 microsatellites to explore the evolutionary relationships between these two species and elucidate whether the intermediate morphotypes correspond to hybrid individuals. These markers have been analyzed in sympatric and allopatric populations of the two species plus the closely related species Pteronotus davyi. We confirmed the species-level differentiation of the three lineages (P. fulvus, P. davyi and P. gymnonotus), but the phylogenetic hypotheses suggested by the nuclear and mitochondrial markers were discordant. We confirm that the discordance between markers is due to genetic introgression through the mitochondrial capture of P. fulvus in P. gymnonotus populations. Such introgression was found in all P. gymnonotus specimens across its sympatric distribution range (Mexico to Costa Rica) and is related to expansion/retraction species distribution pulses associated with changes in forest distribution during the Quaternary climate cycles. Microsatellite analyses showed contemporary genetic contact between the two sympatric species and 3.0% of the samples studied were identified as hybrids. In conclusion, we found a historical and asymmetric genetic introgression (through mitochondrial capture) of P. fulvus into P. gymnonotus in Mexico and Central America and a limited contemporary gene exchange between the two species. However, no relationship was found between hybridization and the intermediate-sized specimens from southern Mexico, which might likely result from a clinal variation with latitude. These results confirm the need for caution when using forearm size to identify these species in the field and when differentiating them in the laboratory based on mitochondrial DNA alone

Evolved Saccharomyces cerevisiae strains to reduce ethyl carbamate in Sherry wines

Urea is the main precursor of ethyl carbamate in fortified wines, which is in turn mostly produced by Saccharomyces cerevisiae due to the arginine catabolism during alcoholic fermentation. Due to its potential safety risks, efforts have been taken to reduce ethyl carbamate content by reducing the urea produced. However, most of them have been made through genetic manipulation, and their use in the food industry is therefore limited by legal constraints. In the present study, the adaptive laboratory evolution technique had been used to improve this trait in a diploid wine yeast already used at industrial level to obtain Sherry base wine. For this purpose, the genetic variability of the yeast population was increased by sexual reproduction and subsequently canavanine, a toxic arginine analogue, was applied as selective pressure to select yeast variants with lower urea production. Finally, an evolved variant that showed 62% lower urea content than the parental strain, also displaying an enhanced fermentative performance, was selected. The base Sherry wine obtained at industrial level not only showed a lower urea and ethyl carbamate content, but also an improvement in the aromatic profile, being fruitier and fresher than that obtained with the parental strain mainly due to an increase in ester content

Prisoners in Their Habitat? Generalist Dispersal by Habitat Specialists: A Case Study in Southern Water Vole (Arvicola sapidus)

Habitat specialists inhabiting scarce and scattered habitat patches pose interesting questions related to dispersal such as how specialized terrestrial mammals do to colonize distant patches crossing hostile matrices. We assess dispersal patterns of the southern water vole (Arvicola sapidus), a habitat specialist whose habitat patches are distributed through less than 2% of the study area (overall 600 km2) and whose populations form a dynamic metapopulational network. We predict that individuals will require a high ability to move through the inhospitable matrix in order to avoid genetic and demographic isolations. Genotypes (N = 142) for 10 microsatellites and sequences of the whole mitochondrial Control Region (N = 47) from seven localities revealed a weak but significant genetic structure partially explained by geographic distance. None of the landscape models had a significant effect on genetic structure over that of the Euclidean distance alone and no evidence for efficient barriers to dispersal was found. Contemporary gene flow was not severely limited for A. sapidus as shown by high migration rates estimates (>10%) between non-neighbouring areas. Sex-biased dispersal tests did not support differences in dispersal rates, as shown by similar average axial parent-offspring distances, in close agreement with capture-mark-recapture estimates. As predicted, our results do not support any preferences of the species for specific landscape attributes on their dispersal pathways. Here, we combine field and molecular data to illustrate how a habitat specialist mammal might disperse like a habitat generalist, acquiring specific long-distance dispersal strategies as an adaptation to patchy, naturally fragmented, heterogeneous and unstable habitats

Del individuo a la especie: filogeografía y genética del paisaje de la rata de agua (Arvicola sapidus)

Tesis Univ. Granada. Departamento de Biología Animal y Ecología. Leída el 15 de septiembre de 200

Data from: Sex determination in the wild: a field application of loop-mediated isothermal amplification successfully determines sex across three raptor species

PCR-based methods are the most common technique for sex determination of birds. Although these methods are fast, easy and accurate, they still require special facilities that preclude their application outdoors. Consequently, there is a time lag between sampling and obtaining results that impedes researchers to take decisions in situ and in real time considering individuals’ sex. We present an outdoor technique for sex determination of birds based on the amplification of the duplicated sex-chromosome-specific gene Chromo-Helicase-DNA binding protein using a loop-mediated isothermal amplification (LAMP). We tested our method on Griffon Vulture (Gyps fulvus), Egyptian Vulture (Neophron percnopterus) and Black Kite (Milvus migrans) (family Accipitridae). We introduce the first fieldwork procedure for sex determination of animals in the wild, successfully applied to raptor species of three different subfamilies using the same specific LAMP primers. This molecular technique can be deployed directly in sampling areas because it only needs a voltage inverter to adapt a thermo-block to a car lighter and results can be obtained by the unaided eye based on colour change within the reaction tubes. Primers and reagents are prepared in advance to facilitate their storage at room temperature. We provide detailed guidelines how to implement this procedure, which is simpler (no electrophoresis required), cheaper and faster (results in c. 90 min) than PCR-based laboratory methods. Our successful cross-species application across three different raptor subfamilies posits our set of markers as a promising tool for molecular sexing of other raptor families and our field protocol extensible to all bird species

Alignment of partial sequences of the CHD gene located in the Z-chromosome of Gyps fulvus, Milvus migrans and Neophron percnopterus

DNA sequences of the CHD-Z fragments of Gyps fulvus, Milvus migrans and Neophron percnopterus used for design of LAMP primers suitable for sex determination. These sequences were obtained after Sanger sequencing of the CHD-Z fragments obtained by PCR using 2550F and 2718R primers (Fridolfsson & Ellegren 1999

Data from: Habitat use, but not gene flow, is influenced by human activities in two ecotypes of Egyptian fruit bat (Rousettus aegyptiacus)

Understanding the ecological, behavioral and evolutionary response of organisms to changing environments is of primary importance in a human-altered world. It is crucial to elucidate how human activities alter gene flow and what are the consequences for the genetic structure of a species. We studied two lineages of the Egyptian fruit bat (Rousettus aegyptiacus) throughout the contact zone between mesic and arid ecozones in the Middle East to evaluate the species' response to the growing proportion of human-altered habitats in the desert. We integrated population genetics, morphometrics and movement ecology to analyze population structure, morphological variation and habitat use from GPS- or radio-tagged individuals from both desert and Mediterranean areas. We classified the spatial distribution and environmental stratification by describing physical-geographical conditions and land cover. We analyzed this information to estimate patch occupancy and used an isolation by resistance approach to model gene flow patterns. Our results suggest that lineages from desert and Mediterranean habitats, despite their admixture, are isolated by environment and by adaptation supporting their classification as ecotypes. We found a positive effect of human-altered habitats on patch occupancy and habitat use of fruit bats by increasing the availability of roosting and foraging areas. While this commensalism promotes the distribution of fruit bats throughout the Middle East, gene flow between colonies has not been altered by human activities. This discrepancy between habitat use and gene flow patterns may, therefore, be explained by the breeding system of the species and modifications of natal dispersal patterns

Extra-pair paternity in the socially monogamous white stork (Ciconia ciconia) is fairly common and independent of local density

Although many birds are socially monogamous, most (>75%) studied species are not strictly genetically monogamous, especially under high breeding density. We used molecular tools to reevaluate the reproductive strategy of the socially monogamous white stork (Ciconia ciconia) and examined local density effects. DNA samples of nestlings (Germany, Spain) were genotyped and assigned relationships using a two-program maximum likelihood classification. Relationships were successfully classified in 79.2% of German (n = 120) and 84.8% of Spanish (n = 59) nests. For each population respectively, 76.8% (n = 73) and 66.0% (n = 33) of nests contained only full-siblings, 10.5% (n = 10) and 18.0% (n = 9) had half-siblings (at least one nestling with a different parent), 3.2% (n = 3) and 10.0% (n = 5) had unrelated nestlings (at least two nestlings, each with different parents), and 9.5% (n = 9) and 6.0% (n = 3) had "not full-siblings" (could not differentiate between latter two cases). These deviations from strict monogamy place the white stork in the 59(th) percentile for extra-pair paternity among studied bird species. Although high breeding density generally increases extra-pair paternity, we found no significant association with this species' mating strategies. Thus although genetic monogamy is indeed prominent in the white stork, extra-pair paternity is fairly common compared to other bird species and cannot be explained by breeding density.publishe

Genotypes, colonies and geographic location of Rousettus aegyptiacus

Genotypes (n=223) from 26 sampling sites of Egyptian fruit bat (Rousettus aegyptiacus) in the Middle East using 18 microsatellites. Lat/Long coordinates (decimal degrees) of each sampling site are also provided