Global warming caused functional mismatch in a bumble bee pollination mutualism

Our planet is witnessing a number of strange events due to global warming. We have already heard researchers talk about how global warming is altering behavior of different tiny marine organisms, prompting walruses to gather at the Alaskan shore and changing the circulation of oceans. Now, a research team is saying that climate change is responsible for shrinking the tongues of bumblebees.

In a paper published in the journal Science this Thursday, scientists have revealed that climate change is causing the tongues of some bumblebees to shrink. What’s more significant is that according to scientists writing the paper, in the past four decades or so, the tongues of two alpine bumblebee species have shrunk by almost 25%.

It may sound bizarre to some, but the study authors believe that this shrinking of bumblebee tongues might actually have significant implications for both the creatures and flowers pollinated by them.

For bees, the size of the tongue is extremely important as it is the primary deciding factor when it comes to picking the flower they will be visiting for nectar. According to experts, bees boasting longer tongues possess the ability to amass nectar from flowers boasting long corollas. For those who don’t know: the term “corolla” is used for the cylindrical shape petals of a flower form to protect the nectar inside.

Medium-length tongues in bees indicate that the creatures are capable of pollinating a range of flower species. However, long-tongued bees are usually regarded as the specialists. They pollinate only the flowers boasting deep corollas and this turns out to be a really beneficial bargain for both the planet and the bee.

The arrangement allows long-tongued bees to amass nectar from flowers that are not accessible to insects with smaller tongues, which automatically reduces the competition these bees need face when collecting nectar. The flowers, on the other hand, get pollinated by bees which are only pollinating flowers belonging to the same category. This in turn increases the chances of fertilization for the flowers.

The researchers conducting this new study, however, found that global warming is causing flowers of all shapes and sizes to decrease in numbers in the mountains. This has made the process of finding food more difficult for the bees. Due to the unavailability of ample flowers, the bees are struggling to remain so specialized. The study authors are saying that the tongues of the bees are shrinking gradually so that they can visit flowers of all sizes for collecting nectar.