Foraging habitat selection by gull–billed tern (Gelochelidon nilotica) in Central Spain (Castilla–La Mancha)

The gull–billed tern breeds in temporary lakes in Castilla–La Mancha in Central Spain but depends on surrounding land habitats to feed its chicks. It is therefore vital to know the type of environments it selects to capture prey to feed nestlings. The aim of this study was to evaluate the use of habitats for hunting by adult gull–billed tern. Of 66 lakes monitored between 1996 and 2016, we found the gull–billed tern used 12 for breeding. Each lake was used during this period for 1–14 breeding seasons. We selected circular areas around the three wetlands where the species bred in 2013 and 2014. Within these circles, we sampled a total of 60 random points and recorded 125 gull–billed tern contacts (including between 1 and 39 birds). We estimated the same environmental variables at contact and random points, including land use and the distance to the nearest wetland, the nearest colony and to several types of anthropic uses (paved roads, houses, and cities). To evaluate habitat selection we calculated the Manly selection index for soil use variables, and fitted linear mixed models to evaluate differences in the distance variables. Land uses selected for foraging by the gull–billed tern were mainly cereal crops, whereas vineyards were avoided. The birds foraged on average up to 2 km from the colonies and tended to avoid proximity of towns and paved roads, suggesting that the species is sensitive to human disturbance. Vineyards are the main land use in this region and the intensity is increasing. Our results suggest vineyards should be limited in areas around these wetlands so that gull–billed terns may forage in their preferred sites

Foraging habitat selection by gull–billed tern (Gelochelidon nilotica) in Central Spain (Castilla–La Mancha)

Selección del hábitat alimentario de la pagaza piconegra (Gelochelidon nilotica) en el centro de España (Castilla–La Mancha) La pagaza piconegra se reproduce en lagos temporales de Castilla–La Mancha, pero depende de los hábitats terrestres de los alrededores para alimentar a los pollos. Por consiguiente, es fundamental conocer el tipo de ambientes que selecciona para capturar presas con las que alimentarlos. La finalidad de este estudio fue evaluar la utilización que los adultos de la pagaza piconegra hacen de los hábitats para la caza. De los 66 lagos estudiados entre 1996 y 2016, constatamos que la pagaza se reproducía en 12. Durante este período, cada lago se utilizó para 1–14 temporadas de cría. Seleccionamos las zonas circulares alrededor de los tres humedales en los que la especie crio en 2013 y 2014. Dentro de estos círculos, muestreamos 60 puntos aleatorios y registramos 125 contactos con pagazas piconegras (incluidas entre 1 y 39 aves). Estimamos las mismas variables ambientales en los puntos de contacto y los aleatorios, con inclusión del uso de la tierra y la distancia al humedal más cercano, a la colonia más cercana y a varios tipos de usos antrópicos (carreteras asfaltadas, viviendas y ciudades). Para evaluar la selección del hábitat, calculamos el índice de selección de Manly para las variables de uso del suelo y utilizamos modelos lineales mixtos para evaluar las diferencias entre las variables de distancia. El principal uso de la tierra que la pagaza piconegra seleccionó para la alimentación fue el cultivo de cereales, mientras que evitó los viñedos. De media, las aves se alejaron para alimentarse hasta 2 km de las colonias y tendieron a evitar la proximidad de ciudades y carreteras asfaltadas, lo que sugiere que la especie es sensible a las perturbaciones antrópicas. Los viñedos constituyen el principal uso de la tierra en esta región y su intensidad está aumentando. Nuestros resultados sugieren que los viñedos se deberían limitar en zonas cercanas a estos humedales, para que la pagaza piconegra pueda alimentarse en sus lugares preferidos.The gull–billed tern breeds in temporary lakes in Castilla–La Mancha in Central Spain but depends on surrounding land habitats to feed its chicks. It is therefore vital to know the type of environments it selects to capture prey to feed nestlings. The aim of this study was to evaluate the use of habitats for hunting by adult gull–billed tern. Of 66 lakes monitored between 1996 and 2016, we found the gull–billed tern used 12 for breeding. Each lake was used during this period for 1–14 breeding seasons. We selected circular areas around the three wetlands where the species bred in 2013 and 2014. Within these circles, we sampled a total of 60 random points and recorded 125 gull–billed tern contacts (including between 1 and 39 birds). We estimated the same environmental variables at contact and random points, including land use and the distance to the nearest wetland, the nearest colony and to several types of anthropic uses (paved roads, houses, and cities). To evaluate habitat selection we calculated the Manly selection index for soil use variables, and fitted linear mixed models to evaluate differences in the distance variables. Land uses selected for foraging by the gull–billed tern were mainly cereal crops, whereas vineyards were avoided. The birds foraged on average up to 2 km from the colonies and tended to avoid proximity of towns and paved roads, suggesting that the species is sensitive to human disturbance. Vineyards are the main land use in this region and the intensity is increasing. Our results suggest vineyards should be limited in areas around these wetlands so that gull–billed terns may forage in their preferred sites.Selección del hábitat alimentario de la pagaza piconegra (Gelochelidon nilotica) en el centro de España (Castilla–La Mancha) La pagaza piconegra se reproduce en lagos temporales de Castilla–La Mancha, pero depende de los hábitats terrestres de los alrededores para alimentar a los pollos. Por consiguiente, es fundamental conocer el tipo de ambientes que selecciona para capturar presas con las que alimentarlos. La finalidad de este estudio fue evaluar la utilización que los adultos de la pagaza piconegra hacen de los hábitats para la caza. De los 66 lagos estudiados entre 1996 y 2016, constatamos que la pagaza se reproducía en 12. Durante este período, cada lago se utilizó para 1–14 temporadas de cría. Seleccionamos las zonas circulares alrededor de los tres humedales en los que la especie crio en 2013 y 2014. Dentro de estos círculos, muestreamos 60 puntos aleatorios y registramos 125 contactos con pagazas piconegras (incluidas entre 1 y 39 aves). Estimamos las mismas variables ambientales en los puntos de contacto y los aleatorios, con inclusión del uso de la tierra y la distancia al humedal más cercano, a la colonia más cercana y a varios tipos de usos antrópicos (carreteras asfaltadas, viviendas y ciudades). Para evaluar la selección del hábitat, calculamos el índice de selección de Manly para las variables de uso del suelo y utilizamos modelos lineales mixtos para evaluar las diferencias entre las variables de distancia. El principal uso de la tierra que la pagaza piconegra seleccionó para la alimentación fue el cultivo de cereales, mientras que evitó los viñedos. De media, las aves se alejaron para alimentarse hasta 2 km de las colonias y tendieron a evitar la proximidad de ciudades y carreteras asfaltadas, lo que sugiere que la especie es sensible a las perturbaciones antrópicas. Los viñedos constituyen el principal uso de la tierra en esta región y su intensidad está aumentando. Nuestros resultados sugieren que los viñedos se deberían limitar en zonas cercanas a estos humedales, para que la pagaza piconegra pueda alimentarse en sus lugares preferidos

Identification of distinct evolutionary units in allopatric populations of Hypostomus cf. wuchereri Günther, 1864 (Siluriformes: Loricariidae): karyotypic evidence

Few chromosomal reports are available for the endemic fish fauna from coastal basins in northeastern Brazil, and regional biodiversity remains partially or completely unknown. This is particularly true for Loricariidae, the most diverse family of armored catfishes. In the present work, allopatric populations of Hypostomus cf. wuchereri (Siluriformes: Loricariidae) from two basins in Bahia (northeastern Brazil) were cytogenetically analyzed. Both populations shared 2n = 76 chromosomes, a karyotype formula of 10m+18sm+48st/a (FN = 104) and single terminal GC-rich NORs on the second metacentric pair. Nevertheless, microstructural differences were detected by C-banding, fluorochrome staining and chromosomal digestion with restriction enzymes (Alu I, Bam HI, Hae III, and Dde I). The population from Una River (Recôncavo Sul basin) showed conspicuous heterochromatin blocks and a remarkable heterogeneity of base composition (presence of interspersed AT/GC-rich and exclusively AT- or GC-rich sites), while the population from Mutum river (Contas River basin) presented interstitial AT-rich C-bands and terminal GC/AT-rich heterochromatin. Each enzyme yielded a specific band profile per population which allowed us characterizing up to five heterochromatin families in each population. Based on the present data, we infer that these populations have been evolving independently, as favored by their geographic isolation, probably representing cryptic species

Sperm cryopreservation: effects on chromatin structure.

Cryopreservation is a technique that can keep sperm alive indefinitely, enabling the conservation of male fertility. It involves the cooling of semen samples and their storage at -196°C in liquid nitrogen. At this temperature all metabolic processes are arrested. Sperm cryopreservation is of fundamental importance for patients undergoing medical or surgical treatments that could induce sterility, such as cancer patients about to undergo genotoxic chemotherapy or radiotherapy, as it offers these patients not only the hope of future fertility but also psychological support in dealing with the various stages of the treatment protocols.Despite its importance for assisted reproduction technology (ART) and its success in terms of babies born, this procedure can cause cell damage and impaired sperm function. Various studies have evaluated the impact of cryopreservation on chromatin structure, albeit with contradictory results. Some, but not all, authors found significant sperm DNA damage after cryopreservation. However, studies attempting to explain the mechanisms involved in the aetiology of cryopreservation-induced DNA damage are still limited. Some reported an increase in sperm with activated caspases after cryopreservation, while others found an increase in the percentage of oxidative DNA damage. There is still little - and contradictory - information on the mechanism of the generation of DNA fragmentation after cryopreservation. More studies are needed to establish the true importance of such damage, especially to improve the results of ART