Jesús Domínguez

Spatial and temporal patterns of polycyclic aromatic hydrocarbons (PAHs) in eggs of a coastal bird from northwestern Iberia after a major oil spill.

This study investigated the spatial and temporal patterns of polycyclic aromatic hydrocarbons (PAHs) in kentish plover (Charadrius alexandrinus) eggs after a major oil spill (Prestige, November 2002) in northwest Iberia. We analysed a total of 77 eggs from 10 breeding localities of the Iberian Atlantic coast, 9 located along the Galician coast (NW Spain) and one in the Ria de Aveiro (Portugal). General linear mixed models did not show a significant effect of the area on the total PAH levels and on each compound, probably due to the spread of pollution caused by the Prestige ship and the industrial and harbour pollutions of the Ria de Aveiro (Portugal). In contrast, the PAH levels were significantly affected by year. The PAH levels decreased from 2004 to 2006 but strongly increase and showed a different pattern of PAH accumulation in 2007. These results may be due to tetra- and pentacyclic compounds from forest fires that occurred during summer 2006.

Rural abandoned landscapes and bird assemblages: winners and losers in the rewilding of a marginal mountain area (NW Spain)

Abstract In many regions of Europe, large-scale socio-economic changes have led to the abandonment of rural activities and a gradual takeover of natural vegetation. It is important to assess the relative positive and negative effects of land abandonment on particular areas where the low-intensity farming is no longer socially or economically viable in order to quantify the potential conservation costs and benefits of a rewilding as a land-use management policy. During the period 2000–2010, we studied the land-use/land-cover changes in an abandoned mountain landscape (Galicia, NW Spain) and evaluated the effects on breeding bird occurrence and distribution. For this purpose, we analysed remotely sensed data-derived maps in combination with data obtained from bird censuses carried out in 2000 and 2010 at both landscape and census plot scale. The results revealed a gradient of change from bare ground and open shrubland to closed shrubland and woodland. Thirteen shrubland and forest bird species showed a significant increase (including species of conservation concern such as Turtle Dove, Dartford Warbler and Western Bonelli’s Warbler), while four ecotone and open-habitat species (e.g. Red-backed Shrike) showed a significant negative trend. In conclusion, rewilding appears to have overall positive effects on biodiversity and should be considered by policy makers as alternative land-use strategy in marginal mountain areas, particularly if they have been historically affected by wildfires. Fire management aimed at favouring the creation of small burned areas in progressively closed landscapes derived from rewilding may be a complementary alternative to maintain open habitats in these areas.

Sleeping and vigilance in Black-tailed Godwit

Abstract. I studied the influence of position within the flock of the bird on the sleep-vigilance trade-off in individual Black-tailed Godwits Limosa limosa roosting at high tide. The peeking rate, the percentage of time during which its eyes were open and mean duration of peeks were highest in peripheral birds. The duration of the sleep posture, defined as the amount of time an individual sits or stands with its bill tucked beneath its scapulars, did not differ significantly between central and peripheral birds. The rate of agonistic encounters was minimal, in both peripheral and central birds. These observations suggest different benefits for both positions in the flock, mainly anti-predatory in the case of central birds and thermoregulatory in the case of peripheral birds.

Modelling habitat use by Iberian hare Lepus granatensis and European wild rabbit Oryctolagus cuniculus in a mountainous area in northwestern Spain

We developed broad-scale habitat use models for the distribution of the Iberian hare Lepus granatensis Rosenhaeur, 1856 and the relative abundance of the European wild rabbit Oryctolagus cuniculus (Linnaeus, 1758) in a mountainous area in north-western Spain, the Baixa Limia Site of Community Importance (SCI). For the Iberian hare, the most parsimonious model included average altitude, average slope, scrub-pasture area and length of border between scrublands and forests. Four variables were consequential, 2 of them with a positive sign for the presence of the hare (average altitude and scrubland area) and 2 with a negative one (average slope and length of border between scrubland and forest). For the European wild rabbit the most parsimonious General Linear model obtained included average altitude and scrub-forest edge. Only 2 predictors were consequential, both with a negative sign on the relative abundance of wild rabbits: the average altitude and length of border between scrubland and forest. The models obtained indicated the need of management actions to favour open habitats with suitable vegetation structure, avoiding extensive reforestation. A revision of the current hunting plans in the protected area of Baixa Limia is required.

Factors Affecting Plumage Oiling Levels in a Kentish Plover Charadrius alexandrinus Population after a Major Oil Spill

Abstract. The oil tanker Prestige, with a 77000-tonne cargo of heavy fuel oil, was badly damaged on 13 November 2002 off the Galician coast (NW Spain), where it leaked about 63 000 tonnes of oil. During the winter of 2002 and spring of 2003, we studied the degree of oil contamination in the plumage of the Kentish Plover Charadrius alexandrinus. Using the Generalized Estimated Equations (GEE), we evaluated the hypothesis that the presence of oiled birds in the breeding period could be influenced by 1) the location of the beach (estuarine versus non-estuarine), 2) the presence of an intertidal area in the lagoon associated with the beach, 3) the distance from the initial spill location and 4) the month. The worst affected body parts were the abdomen, and, to a lesser extent, the breast. The location of the beach was the only predictor included in the final model. The beaches with the highest average scores of oiled birds were those located on the non-estuarine coast. The other two predictors with significant parameters in the univariate analysis were the distance from the initial spill location and the month.

Lack of genetic structure in Kentish Plover Charadrius alexandrinus from the Iberian coast. What’s wrong with the endangered north-western population?

Coastal wader species are sensitive to anthropogenic activity and habitat change along the coastal edge, which has been responsible for the decline in the populations of these birds. Correct management requires knowledge of the pattern and scale of genetic variation within and among populations as well as the relationships between population dynamics and genetic structure. We investigated these factors in the Kentish Plover Charadrius alexandrinus from the Iberian coast to determine the degree of vulnerability of the endangered north-western population. We analysed the genetic structure and gene flow using a 631-bp fragment of the mitochondrial (mtDNA) control region and eight microsatellite markers in 113 unrelated individuals from 31 Iberian beaches. The results do not support the recent decline hypothesis because there was no evidence of a bottleneck, but they do support a population expansion along the Atlantic coast. We found no genetic structure or isolation-by-distance, in agreement with results recently observed on a continental scale. However, explanations for high continental gene flow, such as temporary breeding habitats and high breeding dispersal, do not seem to apply to the Galician population. Galician Kentish Plovers breed solely on beaches, a suitable and more predictable habitat during the breeding period than ephemeral inland wetlands, and female movements during the breeding period are uncommon, mainly due to the extremely low hatching success. This study suggests a demographic connectivity between Portuguese and Galician populations that is referred to as source-sink population dynamics, in which individuals dispersing from Portugal support the Galician coastal population. This dispersal pattern highlights the importance of supranational management plans to protect endangered species.

Long-term population trends of breeding Kentish Plovers Charadrius alexandrinus in north-west Spain under the effects of a major oil spill

The Kentish Plover Charadrius alexandrinus is the only wader that nests on the beaches of Galicia, north-west Spain. In November 2002, much of that habitat was heavily affected by the Prestige oil spill, considered one of the largest spills ever experienced in Europe. We used a 23-year dataset (1988–2010) tracking the abundance and distribution of Kentish Plover breeding pairs along the Galician coast to evaluate population trends and identify the underlying effects of an oil spill. A TRIM linear trend model classified the population trend as a moderate increase; the main trend exhibited a decline in the population from 2002 to 2004 (the second reproductive period after the catastrophe), followed by a moderate increase to the present. The results showed that the variation in annual population trends can be explained by considering the characteristics and location of breeding beaches. In the most parsimonious model, three covariates were significant: the beach position: inner (located in the interior part of the estuaries), or outer (exposed to the open sea), the beach length, and the location of the stretch of coastline in relation to the Prestige wreck. The variation was obvious both with regard to population size and habitat use, with an increase in the number of birds and breeding locations and changes in distribution along the entire Galician Coast after 2004. The birds reacted to the catastrophe by avoiding the most affected areas and moving to new breeding beaches, suggesting that conservation plans must take into account the correct management of currently unoccupied beaches that could provide potential habitat for the species.

The contribution of Earth observation technologies to the reporting obligations of the Habitats Directive and Natura 2000 network in a protected wetland

Background Wetlands are highly productive systems that supply a host of ecosystem services and benefits. Nonetheless, wetlands have been drained and filled to provide sites for building houses and roads and for establishing farmland, with an estimated worldwide loss of 64–71% of wetland systems since 1900. In Europe, the Natura 2000 network is the cornerstone of current conservation strategies. Every six years, Member States must report on implementation of the European Habitats Directive. The present study aims to illustrate how Earth observation (EO) technologies can contribute to the reporting obligations of the Habitats Directive and Natura 2000 network in relation to wetland ecosystems. Methods We analysed the habitat changes that occurred in a protected wetland (in NW Spain), 13 years after its designation as Natura 2000 site (i.e., between 2003 and 2016). For this purpose, we analysed optical multispectral bands and water-related and vegetation indices derived from data acquired by Landsat 7 TM, ETM+ and Landsat 8 OLI sensors. To quantify the uncertainty arising from the algorithm used in the classification procedure and its impact on the change analysis, we compared the habitat change estimates obtained using 10 different classification algorithms and two ensemble classification approaches (majority and weighted vote). Results The habitat maps derived from the ensemble approaches showed an overall accuracy of 94% for the 2003 data (Kappa index of 0.93) and of 95% for the 2016 data (Kappa index of 0.94). The change analysis revealed important temporal dynamics between 2003 and 2016 for the habitat classes identified in the study area. However, these changes depended on the classification algorithm used. The habitat maps obtained from the two ensemble classification approaches showed a reduction in habitat classes dominated by salt marshes and meadows (24.6–26.5%), natural and semi-natural grasslands (25.9–26.5%) or sand dunes (20.7–20.9%) and an increase in forest (31–34%) and reed bed (60.7–67.2%) in the study area. Discussion This study illustrates how EO–based approaches might be particularly useful to help (1) managers to reach decisions in relation to conservation, (2) Member States to comply with the requirements of the European Habitats Directive (92/43/EEC), and (3) the European Commission to monitor the conservation status of the natural habitat types of community interest listed in Annex I of the Directive. Nonetheless, the uncertainty arising from the large variety of classification methods used may prevent local managers from basing their decisions on EO data. Our results shed light on how different classification algorithms may provide very different quantitative estimates, especially for water-dependent habitats. Our findings confirm the need to account for this uncertainty by applying ensemble classification approaches, which improve the accuracy and stability of remote sensing image classification.