Manuel Máñez

Bioaccumulation and biomagnification of emerging and classical flame retardants in bird eggs of 14 species from Doñana Natural Space and surrounding areas (South-western Spain)

The occurrence of classical (polybrominated diphenyl ethers, PBDEs) and emerging FRs (dechloranes, hexabromobenzene (HBB), pentabromoethyl benzene (PBEB) and decabromodiphenyl ethane (DBDPE)) in unborn eggs of 14 different species from Doñana Natural Space and surrounding areas was studied. PBDEs, Dec-602, Dec-603 and DP were detected in all the species, whereas HBB, PBEB, DBDPE and Dec-604 were not detected in any sample. ΣPBDE and ΣDechlorane levels ranged from 1.40 to 90.7, and from 0.77 to 260 ng/g lw, respectively. BDE-209 was the most abundant BDE congener in almost all the species, whereas Dec-602 was the predominant among dechloranes. In general, levels of PBDEs and dechloranes were similar and even higher for dechloranes, probably indicating the increasing use of dechloranes as a result of legal restrictions on PBDEs. In both cases, the most contaminated specie was the white stork. Using stable isotope characterization, differences among species and possible biomagnification processes were also evaluated. PBDE levels increased as the trophic position increased, showing biomagnification capacity. The same behavior was observed for Dec-602 and Dec-603; however, DP levels were not linearly correlated with trophic level. These results show that more attention should be given to emerging FRs such as dechloranes since they show similar environmental behavior as PBDEs.

Long-Term Population Trends of Colonial Wading Birds Breeding in Doñana (Sw Spain) in Relation to Environmental and Anthropogenic Factors

Summary. Breeding season counts of nine species of colonial wading birds (Nycticorax nycticorax, Ardeola ralloides, Bubulcus ibis, Egretta garzetta, Ardea cinerea, Ardea purpurea, Ciconia ciconia, Plegadis falcinellus and Platalea leucorodia) nesting at Doñana during 1984–2010 were analysed. The aim of the study was to assess the size and trends of populations and to analyse their environmental and anthropogenic determinants. We used the TRIM programme to test for long-term trends, and Generalised Additive Models to assess the effect of local rainfall, the surface area of ricefields surrounding Doñana and rainfall in the Sahel on breeding population size. All species showed positive population trends, mainly from 1996 onwards. The number of active colonies increased over time, and up to 17,297 nests from the nine studied species were recorded in one year (2010). Low precipitation (< 500 mm) in the previous autumn and winter was associated with reductions in the numbers of breeders, since rainfall determines the flooding extent in the natural marshes of Doñana. The area of ricefields positively influenced the breeding numbers of five species. Only four of these species are considered to be increasing in Europe and increases in Doñana coincide with management changes that have improved nesting and feeding habitat and reduced human disturbance. In addition to large-scale man-made habitat changes, breeding population sizes for the studied species were strongly influenced by high annual variation in rainfall, typical of Mediterranean habitats, therefore making them likely to be affected by climate change.

Formation and growth of a heronry in a managed wetland in Doñana, southwest Spain

Capsule A newly created wetland has been beneficial for the breeding of five heron species and for the settlement and expansion of Glossy Ibises in the region. Aim To determine whether created wetland would lead to the establishment of a heron and ibis breeding colony, and if so, to determine its effects on the distribution of these species in the wider region. Methods Number of pairs breeding at the new wetland and in the region were estimated annually from 1996 to 2008. We investigated whether the growth of the new colony was explained by redistribution of breeding pairs within the region. Results Purple Herons, Squacco Herons and Glossy Ibises colonised the new wetland in 1996. Black‐crowned Night Herons settled in 1998, while Cattle and Little Egrets were the last species to establish in the mixed colony in 2001. The population increase was particularly marked for Glossy Ibises (which had bred in Doñana only sporadically through the 20th century). Our findings suggest that simple redistribution of pairs does not explain the formation and growth of the new colony. Since the first year of establishment numbers of Glossy Ibises and Purple Herons have shown a significant growth trend at both the new colony and in Doñana. Conclusion The creation and management of a new wetland has been successful for the conservation of heron and egret species and promoted the expansion of the Glossy Ibis population across the western Mediterranean region.

Temporal trends in classical and alternative flame retardants in bird eggs from Doñana Natural Space and surrounding areas (south-western Spain) between 1999 and 2013

Several halogenated flame retardants were detected in black kite, white stork and greater flamingo unborn eggs from Doñana Natural Space (Spain) collected in 1999, 2003, 2011 and 2013. The main components of Penta-BDE commercial mixture (BDE-47, -99 and -100) showed a decrease in the studied time interval, concurring with the ban of this mixture in the European Union (EU) in 2006. On the other hand, BDE-209, the main component of Deca-BDE mixture showed a clear trend in black kites but further monitoring is needed since its production ceased at the end of 2013. Besides, even if Dechlorane Plus (DP) was proposed by the EU as an alternative to BDE-209 no time trends were observed. Furthermore, total concentrations of PBDEs (classical FRs) are still higher than concentrations of hexabromocyclododecane (HBCD) and alternative FRs halogenated norbornenes (HNs), which are theoretically substitutes of the already banned PBDEs.

Endangered Waterbirds at Doñana Natural Space

Taking into account data obtained primarily from 1996 to 2008, this paper reviews the importance of Donana Natural Space for seven species of waterbird declared “Endangered”: the highest category of threat from a legal perspective in Spain. Marbled teal, ferruginous duck, white-headed duck, bittern, squacco heron, and red-knobbed coot all breed, while black stork has a wintering population. Only the winter population of the black stork showed a significant trend, positive in this case. The wetlands of Donana Natural Space represent the first or second most important areas of Spain for all the breeding species except white-headed duck.

Using UAVs to Map Aquatic Bird Colonies

In this chapter, we present the results of several flight campaigns carried out in 2015 and 2016 using multirotor Unmanned Airborne Vehicles (UAVs) over Slender-billed Gull (Chroicocephalus genei) colonies in the Donana Nature Space, south west Spain. The images were taken at different times during the breeding season. The requirements for the flight campaigns were to acquire sufficient visible and nadir pictures at 5 cm pixel resolution and to cover the entire nesting colony with maximum overlap. Although we carried out the flights under clear skies, low wind speed was not always possible, causing a few blurred pictures. After georeferencing and mosaicking the set of raw pictures, we adopted photo-interpretation as the first technique to identify and delineate birds, either lying, standing or flying. A nest position was assigned when the clear pattern of a lying birds was recognised. We then selected a set of breeding individuals (nests) to train a supervised classification in semi-automatic nest delineation. We applied two different algorithms and tested their accuracy in identifying gulls with an independent set of manually delineated individuals. We chose the best method according to the accuracy results and applied it to the whole colony. We found major issues for nest identification and delineation for nests under tree and shrub canopies. The different campaigns and flight characteristics were useful to improve bird identification accuracy. As a result, we provided estimates of the number of breeding pairs per year to managers and cross-checked these with estimates from the ground monitoring and colony sampling. As an added value, the spatial coordinates of nests can be used for spatial analysis and investigate nest aggregation, density and distribution in order to reveal spatial relationships with environmental factors such as distance to colony edges, distance to colony centroid, distance to predators, etc.