Analysing citizen science data to address the demographic expansion of the Eurasian Magpie (Pica pica) in southern Spain

Citizen science platforms such as eBird provide essential spatiotemporal information and big data for the study of birds. The analysis of an extensive 20-year dataset of the distribution of the Eurasian Magpie Pica pica showed that the species is steadily expanding within urbanised areas in the south of the Iberian Peninsula. The occurrence of the species in the eBird checklists in the study area has an average exponential growth rate greater than 20%. The area occupied by the species has multiplied by 40 in the last 20 years, going from 25 to almost 1000 km2. In order to test potential negative impacts of this demographic expansion on potential Magpie prey species, such as other birds, a seasonal study of the Magpie’s diet through pellet analysis showed that its stable diet consists of insects, snails and seeds, while other birds or food from anthropogenic sources does not constitute a significant part of its diet. The combined use of new open-science big data technologies together with classical monitoring and laboratory study offers indispensable tools for the assessment of species distribution and potential spatial management

Kentish Plover (Charadrius alexandrinus) and Little Tern (Sternula albifrons) prefer shells for nesting: A field experiment

Shorebird populations are declining worldwide, mainly due to human disturbances and loss of coastal wetlands. However, supratidal habitats as saltpans could play a role in buffering human impact. Saltpans have shown to be important as feeding or breeding sites of some shorebird species. A potential conservation strategy to increase shorebird populations in saltpans is to manipulate the cues that birds use to select optimal breeding habitat. Here it is hypothesized that shorebirds are attracted to bivalve shells due to the advantages they offer. Following this hypothesis, we supplemented a restored saltpan in 2019 and 2021 with bivalve shells, expecting an increase in the number of breeding birds’ nests. More than 75% of Kentish Plover (Charadrius alexandrinus) and Little Tern (Sternula albifrons) nests were found in patches with shells in both years. The best model for both species indicates that the presence of shells is the factor that most correlates with the location of nests. The probability of choosing one place over another to settle their nest increases in areas with an abundance of shells, double in the case of the Kentish Plover and triple in the case of the Little Tern. The result of this study may constitute a valuable tool for attracting birds to restored saltpans and could contribute to the success of expensive restoration projects where time is usually a constraint

Quail eggs in artificial nests change their coloration when exposed to ambient conditions: implication for studies on nest predation

Quail eggs have been widely used in field experiments, mainly to study factors associated with the risk of nest predation. Some shortcomings of using quail eggs in this type of study have been previously addressed (e.g., these eggs might be too big for some predators of eggs of small birds). Here, we show experimental evidence of another shortcoming of the use of these eggs in field experiments. Quail eggs exposed to sunlight rapidly faded in colour after three days, both in the visible and UV spectra, and this change was related to the amount of solar radiation received. This caused changes in the camouflage of the eggs, which may be perceived by predators with different visual systems (dichromatic, trichromatic, and tetrachromatic (for both violet- and UV-sensitive species)). Therefore, the results of field studies of nest predation using quail eggs might be questioned in those cases in which the camouflage has been altered due to the rapid changes in coloration, as this can affect the resulting predation rates. We recommend that researchers planning to use quail eggs should perform a prospective assessment of changes in coloration of eggs exposed to environmental conditions in the nest sites used by the target species.This study was funded by grant CGL2017-83518-P from Ministerio de Economia, Industria y Competitividad, Spain, with EU-ERDF financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Guía visual de la fauna y flora marina del intermareal de La Caleta y roquedos intermareales asociados

Primera guía visual de las especies de animales (25 especies) y macroalgas (25 especies) más habituales y/o curiosas de los roquedos del intermareal de La Caleta (Cádiz) y roquedos intermareales asociados .Fundación Biodiversidad del Ministerio para la Transición ecológica, CEIMA

Nueva guía visual de la fauna y flora marina del intermareal de La Caleta y roquedos intermareales asociados.

Nueva guía visual de las especies de animales (54 especies) y macroalgas (52 especies) más habituales y/o curiosas de los roquedos del intermareal de La Caleta (Cádiz) y roquedos intermareales asociados. Se incluyen mas del doble de las especies que aparecían en la guía publicada en 2019. Dos de las especies de animales añadidas fueron recientemente descritas como nuevas para la Ciencia a partir de material encontrado en La Caleta (en parte).Universidad de Cádiz Ministerio de Ciencia e Innovación Fundación Española de Ciencia y Tecnología (FECYT) Campus de Excelencia Internacional del MAR (CEIMAR)108 pagina

Introducción al muestreo de aguas superficiales para el análisis de contaminantes

Vídeo docente que recoge la explicación de objetivos del muestreo ambiental, el tipo de contaminantes que se puede estudiar y el recipiente en el que deben almacenarse las muestras para cada contaminante, así como el procedimiento a seguir en la toma de cada una de las muestras. Estas actividades se desarrollan en la asignatura de Métodos en Oceanografía del Grado en Ciencias del Mar de la Universidad de Cádiz.El muestreo es la etapa del análisis químico medioambiental más crítica, ya que cualquier error cometido durante la misma no puede solucionarse con posterioridad. En este vídeo se expone a los alumnos cuales son los objetivos de un muestreo ambiental, algunos de los contaminantes que son de interés en las aguas naturales y cómo realizar un muestreo que minimice los errores debidos a contaminación de las muestras o perdida de analito. Esta actividad forma parte de los contenidos prácticos de la asignatura de Métodos en Oceanografía del Grado de Ciencias del Mar de la Universidad de CádizVídeo de 13 minutos de duració