Bumble bee tongues are shrinking, which may affect the global bee population, researchers suggest.
A new study was conducted in which Nicole E. Miller-Struttmann, a biologist at SUNNY, and her colleagues analysed data from 1960 to 2014. Struttmann found that the decline in bumble bee population was not due to a decrease in body size, co-evolution with flowers, or rivalry with other intruders.
It is actually a result of very high temperatures during the summer, which lower the numbers of the deep flowers that the bees like. The bees are now forced to find food in other species of flowers, many of which are shallow flowers.
In order to feed themselves from the deeper flowers, the bees used their long tongues. Since the number of deep flowers is decreasing, the bumble bees’ tongues are shrinking in order to adapt to the shallow flowers.
According to scientists, 2014 is one of the hottest years that they have recorded so far and 2015 will actually manage to top it. If temperatures during the summer rise 5 degrees Fahrenheit (3 degrees Celsius) above average, that will hinder flower growth, scientists say.
Only four summers were hot enough to damage the flowers, between 1960 and 1985. Ever since 1958, about 50 percent of the summers have been too hot for the flowers to grow in large numbers.
“Declines in flowering [affect] the majority of the mountain landscape; in these extensive habitats, millions of flowers were lost. Thus, even with gains of a few thousand flowers on the summit, total food resources for alpine bumble bees on Pennsylvania Mountain have fallen by 60% since the 1970s,” researchers say.
As a result, the bumble bees now have to compete with the short-tongued bees that have actually grown in number.
These problems appeared not only in Colorado, where the study was conducted, but in other places as well.
Managed bee populations decreased by more than 40 percent between 2014 and 2015, and in 2013 the bumble bee population dropped by 35 percent.
Experts say that about 75 percent of the domestic produce – especially tomatoes, apples, almonds, and strawberries – will be affected by the declining bumble bee population.
Nicole E. Miller-Struttmann says that the bubble bees are safe for now, because evolution has helped them keep up with the warmer summers. “I am an optimist, so I see the glass as half full. But we have to stop tipping it over (so to speak)!” Struttmann added.