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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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Red mud as makeup in the Egyptian vultures

Red mud as makeup in the Egyptian vultures

It is well-established that plumage colours are important for avian visual communication and are used to signal social information. Yet, little is known about the ability of birds to modify the expression of plumage colours with exogenous materials after feather development, a phenomenon also known as avian cosmetics. The deliberate staining of feathers with red soil in a social signalling context has so far only been described in the Bearded vulture. Here, for the first time feather painting behaviour is described in the Egyptian vulture, another Old-World scavenger. Egyptian vultures are considered endangered worldwide, but 60 breeding pairs and a total population of about 300 individuals still occur on Fuerteventura (Canary Islands, Spain). Two bowls were presented to the birds visiting the main feeding station: one with red soil dissolved in water and one containing only water. A remarkable response was observed with 18 different birds painting themselves with red soil to different degrees and only one bird took a bath in the bowl containing water only. These observations of multiple birds taking mud baths in the wild are the first ever filmed. The exact function of this behaviour is not yet clear, as no evidence was found for a status signalling function as has been suggested for the behaviour in the Bearded vulture. However, little is still known about Egyptian vulture group dynamics and patterns of social relationship within their society and it is possible that the behaviour serves a different social function in this species. This work adds a new and unusual behaviour to the already impressive behavioural repertoire of Egyptian vultures and opens exciting new opportunities to test alternative hypotheses for the evolution of avian cosmetics or non-vocal communication in birds in general. informacion[at]ebd.csic.es: van Overveld et al (2017) Cosmetic coloration in Egyptian vultures: Mud bathing as a tool for social communication? Ecology doi:10.1002/ecy.1840


http://onlinelibrary.wiley.com/doi/10.1002/ecy.1840/full