Archive for April, 2010
AFTER Silent Spring, Britain now faces the silent summer. Fifty years after Rachel Carson’s seminal book about humanity’s impact on nature, Sir David Attenborough has warned that Britain’s wildlife could be on the edge of the next great environmental disaster.
He has written the foreword to a new book, Silent Summer, in which 40 leading British ecologists detail how factors such as pesticides, population growth and intensive farming are destroying the plants, insects and animals on which the rest of the country’s wildlife depends.
The book describes the decline of 75% of butterfly species, the near disappearance of many moths and similar reverses for bees, flies and snails.
Attenborough warns that such organisms make up the foundations of Britain’s ecosystems. “We tend to focus on the bigger animals and ignore the smaller ones — but small creatures like these are the basis of our entire ecosystems and they are disappearing faster than ever. That loss is transforming our wildlife and countryside,” he said.
More light has been shed on orchids that trick male bees into pollinating them by mimicking female insects.
The bees, lured by a pheromone-packed scent, attempt to mate with the flowers, but unwittingly carry away pollen after their visit.
Now, scientists working in the south of France have found how the flowers’ false advertising could help new species of orchids to arise.
The research is published in the journal BMC Evolutionary Biology.
Lead scientist Dr Nicolas Vereecken, from the Free University of Brussels (Universite Libre de Bruxelles), said: “This pollination strategy is only known in orchids.
“For flowers to attract insects by imititating the female mating signals instead of advertising nectar or oil or pollen is very peculiar.”
The floral odour that the flowers produced, he said, was key.
ETA, research paper: Hybrid floral novelty drives pollinator shift in sexually deceptive orchids. Nicolas J Vereecken, Salvatore Cozzolino and Florian P Schiestl. BMC Evolutionary Biology 2010, 10:103.
Recent years have seen an unusual rise in the number of bees about in the cold winter months, and scientists are now beginning to find out why.
While most bees are hibernating, the buff-tailed bumblebee, Bombus terrestris, is out taking advantage of exotic winter-flowering plants in our gardens and parks, according to scientists from Queen Mary, University of London.
The study, published in the journal PLoS ONE, suggests this unique species raises an extra generation of workers to collect nectar from such plants as strawberry trees and holly-like Mahonia, which flower during the colder months.
[Originating PloS One paper]