Sentences with phrase «wild bee numbers»

But not all altered landscapes are equal for bees: modern agriculture has taken a severe toll on wild bee numbers.

Not exact matches

Of the hundred principal crops that make up most of the world's food supply, only 15 percent are pollinated by domestic bees (mostly honey bees, bumble bees and alfalfa leafcutter bees), while at least 80 percent are pollinated by wild bees and other wildlife (as there are an estimated 25 000 bee species, the total number of pollinators probably exceeds 40 000 species).

Claire Kremen, a conservation biologist at the University of California, Berkeley (and Harmon - Threatt's mentor), has shown that the diversity of pollinators drops with increasing distance from wild habitat, as does the number of visits by wild bees to flowering crops.

Several small studies have already raised the possibility that the substantial number of viruses and parasites plaguing commercial honeybees and bumblebees are spreading to wild bees that visit the same flowers (SN: 8/16/08, p. 10).

In response, USDA Chief Scientist Catherine Woteki told GAO that it would be «physically and fiscally impossible» to track the roughly 4000 North American species of wild and native bees But she said it would be «informative» to monitor a smaller number of «sentinel species,» each of which could serve as a proxy for multiple bee species.

A recent study published in the journal Science found that in a span of 120 years, Illinois lost half its wild bee species, largely because of diminished numbers of wild flowering plants.

Wild bees could become more important because of the decline in numbers of honey bees due to colony collapse disorder, which has resulted in the loss of more than 10 million hives in the past decade.

In the hopes of increasing local bee numbers, University of Buffalo architecture students created this intriguing wild urban bee habitat.

The results show that numbers of wild bees likely declined by 23 % between 2008 and 2013 in key agricultural regions in California, the Midwest, in Great Plains states and in the Mississippi river valley.

In 2014, President Obama issued a memorandum calling for an assessment of the state of honey and wild bees across the US, in the face of an increasing number of threats such as colony collapse disorder.

Unfortunately the numbers of wild bees available in the areas in which they are grown have declined.

Wild bees in the US have declined in many farming areas according to the first national effort to map their numbers.

The study suggests that between 2008 and 2013, the numbers of wild bees went down across almost a quarter of the US.