RESUMEN
Human activities have led to the contamination of all environmental compartments worldwide, including bird species. In birds, both the environment and maternal transfer lead to high inter-brood variability in contamination levels of pollutants, whereas intra-brood variability is generally low. However, most existing studies focused on heavy metals or persistent compounds and none, to our knowledge, addressed the variability in contamination levels of multiple pesticides and the factors influencing it. In this study, the number of pesticides detected (of 104 compounds searched) and the sum of their concentrations in the blood of 55 Montagu's harrier (Circus pygargus) nestlings from 22 nests sampled in 2021 were used as metrics of contamination levels. We investigated the effect of organic farming at the size of male's home range (i.e., 14 km2) and chicks' sex and hatching order on contamination levels. We did not find a difference between inter-brood and intra-brood variability in pesticide contamination levels, suggesting a different exposure of siblings through food items. While chicks' sex or rank did not affect their contamination level, we found that the percentage of organic farming around the nests significantly decreased the number of pesticides detected, although it did not decrease the total concentrations. This finding highlights the potential role of organic farming in reducing the exposure of birds to a pesticide cocktail.
Asunto(s)
Monitoreo del Ambiente , Contaminantes Ambientales , Agricultura Orgánica , Plaguicidas , Animales , Agricultura Orgánica/métodos , Monitoreo del Ambiente/métodos , Falconiformes , Masculino , FemeninoRESUMEN
Neonicotinoids (neonics) are the most widely used insecticides worldwide and are considered to be of low risk to non-target organisms such as vertebrates. Further, they are reported to be rapidly excreted and metabolized, reducing their potential toxicity. Nevertheless, growing evidence of adverse effects of neonics on farmland bird species raise questions about the purported harmless nature of these pesticides. We attempted to search for pesticide residues in species of different trophic levels and at different life stages, by using multiple bird monitoring programs on a Long-Term Socio-Ecological Research (LTSER) platform. Three passerine birds-the blackbird (Turdus merula), cirl bunting (Emberiza cirlus), and common nightingale (Luscinia megarhynchos)-that feed on seeds and invertebrates were monitored during their reproductive period, and the grey partridge (Perdix perdix) that feeds on seeds was monitored during its wintering period. We also monitored chicks of an apex predator-the Montagu's harrier (Circus pygargus)-that preys mostly upon common voles but also upon insects. We found that the birds' blood samples showed presence of residues of five neonics: three banned since 2018 in France-clothianidin, thiacloprid, and thiamethoxam-and two-dinotefuran and nitenpyram-used for veterinary purposes only. While none of these neonics was detected in blackbirds, all were present in grey partridges. Clothianidin was detected in all species, except blackbirds. Concentrations of the three banned neonics were similar or higher than concentrations found in birds monitored elsewhere before the ban. These findings raise questions about the persistence of neonics within the environment and the mode of exposure to wild fauna. Future investigations on the sublethal effects of these neonics on life-history traits of these farmland birds may help in providing a better understanding of the effects of exposure of bird populations to these insecticides, and also to the consequent effect on human health.
Asunto(s)
Insecticidas , Pájaros Cantores , Animales , Humanos , Granjas , Neonicotinoides/toxicidad , Tiazoles , Nitrocompuestos , CodornizRESUMEN
En nuestro programa de FIV y técnicas relacionadas se empleó clomifeno 50 mg diarios del 2o. al 6o. día del ciclo en 20 pacientes y 20 ciclos (17 casos de FIV y 3 de FIGT). Además se utilizaron menotropinas en 2 esquemas diferentes: Además se utilizaron menotropinas en 2 esquemas diferentes: a) 2 amp. en días alternos (12 casos) y b) 1 amp. diarias em forma continua (8 casos). La pacientes con el esquema de administración en días continuos requierieron en total una dosis menor de menotropinas y tuvieron niveles más altos de estradiol sin significancia estadística, y mayor número de folículos. Se realizaron 16 laparoscopias para captura ovular y se obtuvieron 53 oocitos (30.2% maduros). Diez oocitos fueron de pacientes de GIFT, del resto se fertilizaron 16 y se segmentaron 8. Sólo una paciente de FIV con el esquema de días alternos tuvo embarazo y aborto del 1er. trimestre