Organochlorine pesticides and polychlorinated biphenyls in common kestrel eggs from the Canary Islands: Spatiotemporal variations and effects on eggshell and reproduction.

Organochlorine (OC) pesticides were widely used on the Canary Islands (Spain) for intensive crop production and against plagues of African locust. A previous study performed in 1988-1994 showed a high concentration of p,p'-DDE in the eggs of common kestrels (Falco tinnunculus) from the island of Tenerife. The present study shows OC pesticide and polychlorinated biphenyl (PCBs) levels in 40 unhatched common kestrel eggs collected from southern Tenerife between 2009 and 2016. The protoporphyrin IX in eggshells has also been analysed in order to explore the use of this pigment as a biomarker. Egg biometry, status of embryo development, eggshell thickness and mass of extractable lipids of each egg were recorded. Surrounding land use and reproductive parameters (hatching and fledging rates) were obtained for each nest. The most abundant compound was p,p'-DDE (15.0 µg/g d.w), followed by PCBs (0.46 µg/g d.w.). The decline in p,p'-DDE levels in southern Tenerife (with 23.6 µg/g d.w. in 1988-1994) was 36.4%. p,p'-DDE levels were positively associated with the surface of active and abandoned cropland in a 200 m-radius around the nest and with proximity to urban areas. PCB levels were associated with proximity to roads. Shell thickness was negatively affected by the p,p'-DDE concentration. The concentration of protoporphyrin IX in the eggshell was negatively associated with the concentration of hexachlorobenzene in the egg content. Despite the total ban on the use of p,p'-DDT in Spain since 1986, p,p'-DDE levels remain elevated in those areas in which that use was formerly intensive.

Low-quality birds do not display high-quality signals: The cysteine-pheomelanin mechanism of honesty.

The mechanisms that make that the costs of producing high-quality signals are unaffordable to low-quality signalers are a current issue in animal communication. The size of the melanin-based bib of male house sparrows Passer domesticus honestly signals quality. We induced the development of new bibs while treating males with buthionine-sulfoximine (BSO), a substance that depletes the levels of the antioxidant glutathione (GSH) and the amino acid cysteine, two elements that switch melanogenesis from eumelanin to pheomelanin. Final bib size is negatively related to pheomelanin levels in the bib feathers. BSO reduced cysteine and GSH levels in all birds, but improved phenotypes (bibs larger than controls) were only expressed by high-quality birds (BSO birds with largest bibs initially). Negative associations between final bib size and cysteine levels in erythrocytes, and between pheomelanin and cysteine levels, were observed in high-quality birds only. These findings suggest that a mechanism uncoupling pheomelanin and cysteine levels may have evolved in low-quality birds to avoid producing bibs of size not corresponding to their quality and greater relative costs. Indeed, greater oxidative stress in cells was not observed in low-quality birds. This may represent the first mechanism maintaining signal honesty without producing greater relative costs on low-quality signalers.

Levels of organochlorine pesticides and polychlorinated biphenyls in the critically endangered Iberian lynx and other sympatric carnivores in Spain.

Accumulation of organochlorine compounds is well studied in aquatic food chains whereas little information is available from terrestrial food chains. This study presents data of organochlorine levels in tissue and plasma samples of 15 critically endangered Iberian lynx (Lynx pardinus) and other 55 wild carnivores belonging to five species from three natural areas of Spain (Doñana National Park, Sierra Morena and Lozoya River) and explores their relationship with species diet. The Iberian lynx, with a diet based on the consumption of rabbit, had lower PCB levels (geometric means, plasma: <0.01 ng mL(-1), liver: 0.4ngg(-1) wet weight, fat: 87 ng g(-1)lipid weight) than other carnivores with more anthropic and opportunistic foraging behavior, such as the red fox (Vulpes vulpes; plasma: 1.11 ng mL(-1), liver: 459 ng g(-1), fat: 1984 ng g(-1)), or with diets including reptiles at higher proportion, such as the Egyptian mongoose (Herpestes ichneumon; plasma: 7.15 ng mL(-1), liver: 216 ng g(-1), fat: 540 ng g(-1)), or the common genet (Genetta genetta; liver: 466 ng g(-1), fat: 3854 ng g(-1)). Chlorinated pesticides showed interspecific variations similar to PCBs. Organochlorine levels have declined since the 80s in carnivores from Doñana National Park, but PCB levels are still of concern in Eurasian otters (Lutra lutra; liver: 3873-5426 ng g(-1)) from the industrialized region of Madrid.