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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] 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
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“Planned obsolescence” in the plumage of larks

"Planned obsolescence" in the plumage of larks

Larks (Alaudidae) present a heavily worn plumage for the most part of the annual cycle, to the point that identification field guides typically depict lark species in both fresh and worn plumages. The ephemeral nature of lark feathers is even more strange knowing that larks are among the few passerines undergoing a single annual molt. Contrarily, a majority of songbirds moult feathers twice a year. Larks are dull-colored ground-dwelling birds living in open areas, thus occupying a niche where abrasion by air and soil particles is maximal. Authors observed that lark feathers have unmelanized fringes and are prone to breakage. Larks may have turned need into a virtue: they possibly cannot avoid a premature damage of their fragile plumage, and instead of incurring the cost of molting repeatedly, they gain the advantage of a form of crypsis known as disruptive camouflage. When feathers break, they create a serrated random pattern, cancelling out the effect of smooth lines more easily detected by predators. informacion[at] Negro et al (2019) Adaptive plumage wear for increased crypsis in the plumage of Palearctic larks (Alaudidae). Ecology