New research suggests that climate change-related changes in flower diversity is having an unexpected effect on bumblebees.
The phenomenon appears to be causing a decrease in the length of alpine bumblebees' tongues, leaving the vital insects poorly suited to eat and pollinate the region's crops, the American Association for the Advancement of Science reported. The new findings highlight the crucial need to fight climate change in order to preserve these types of mutually beneficial ecological partnerships.
Long-tongued bumblebees have adapted to feasting on the nectar from deep flowers with long corolla tubes, but these bumblebees have exhibited a serious population decline.
To make their findings, a team of researchers looked at a number of high-altitude sites in Colorado that are typical habitats for two species of long-tongued alpine bumblebees. The team analyzed bumblebee specimens collected between 1966 and 1980 as well as samples acquired between 2012 and 2014, They paid special attention to changes in the tongues and found that the average length had gotten shorter over time.
In order to identify a possible mechanism behind the change, the researchers looked at archived bee specimens and field surveys of bumble bees and host plants. They determined that the shorter tongues were not linked to a decrease in body size, competition from other insects and animals, or a co-evolution of flowers in the region.
The scientists concluded that the bees' tongues were getting shorter because of warmer summers that reduced the number of deep flowers that act as the bees' preferred food source. This phenomenon forced the bumblebees to act as general foragers, feasting on a much wider variety of flowers, including much shorter ones than they had before.
"The pattern seen here may predict future effects of climate change in other systems," the researchers said.
The findings demonstrate how climate change can dramatically decouple mutualisms between bees and plants.
The research was published in a recent edition of the journal Science.
