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Honeybee colonies have increased exponentially in the Mediterranean Basin

Evidence for pollinator declines largely originates from mid-latitude regions in North America and Europe. Geographical heterogeneity in pollinator trends combined with geographical biases in pollinator studies can produce distorted extrapolations and limit understanding of pollinator responses to environmental changes. In contrast with the declines experienced in some well-investigated European and North American regions, honeybees seem to have increased recently in some areas of the Mediterranean Basin. The Mediterranean Basin is home to approximately 3300 wild bee species, or approximately 87% of those occurring in the whole western Palaearctic region. Because honeybees can have negative impacts on wild bees, it was hypothesized that a biome-wide alteration in bee pollinator assemblages may be underway in the Mediterranean Basin involving a reduction in the relative number of wild bees. This hypothesis was tested using published quantitative data on bee pollinators of wild and cultivated plants from studies conducted between 1963 and 2017 in 13 countries from the European, African and Asian shores of the Mediterranean Sea. The density of honeybee colonies increased exponentially and wild bees were gradually replaced by honeybees in flowers of wild and cultivated plants. The proportion of wild bees at flowers was four times greater than that of honeybees at the beginning of the period, the proportions of both groups becoming roughly similar 50 years later. The Mediterranean Basin is a world biodiversity hotspot for wild bees and wild bee-pollinated plants, and the ubiquitous rise of honeybees to dominance as pollinators could in the long run undermine the diversity of plants and wild bees in the region. informacion[at]ebd.csic.es: Herrera (2020) Gradual replacement of wild bees by honeybees in flowers of the Mediterranean Basin over the last 50 years. Proc Royal Society B 287(1921). Doi 10.1098/rspb.2019.2657


https://royalsocietypublishing.org/doi/10.1098/rspb.2019.2657
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Insecticides in wild bird eggs

Insecticides in wild bird eggs

Recent studies demonstrated that the common pyrethroid insecticides are present in aquatic biota tissues. In this study, 123 samples of unhatched eggs of 16 wild bird species collected from 2010 to 2012 in Doñana National and Natural Park were analysed to determine 13 pyrethroids. This study represents the first time that pyrethroids are detected in tissues of terrestrial biota, 93% of these samples being positive to those pollutants. Levels of total pyrethroids ranged from not detected to 324 ng g?1 lw. Species with diets based on anthropogenic food showed higher levels of pyrethroids and lower values of ?15N. Finally, the isomers of pyrethroids were characterized and some isomeric- and enantiomeric-specific accumulations were discerned. In particular, tetramethrin and cyhalothrin showed an enantiomeric-selective accumulation of one enantiomer, highlighting the need to assess toxicological effects of each enantiomer separately to be able to make a correct risk assessment of pyrethroids in birds. Attempts have been made to find relationships between pyrethroid levels and parameters such as stable isotopes and feeding habits. These relations suggested anthropogenic factors (most probably food from garbage dumps and agricultural runoff) as the main source of high levels of pyrethroid contamination in the sampled avian species. Because of that awareness campaigns for the local population as a way to decrease pyrethroid contamination in this area are suggested. Corcellas et al (2017) Pyrethroid insecticides in wild bird eggs from a World Heritage Listed Park: A case study in Doñana National Park (Spain). Environm Pollution 228, 321–330, DOI 10.1016/j.envpol.2017.05.035


http://www.sciencedirect.com/science/article/pii/S0269749117304487