For the first time, bees have been placed on the U.S. Fish and Wildlife Services’ Endangered Species List.
Seven different species of yellow-faced bees native to Hawaii were added to the list Friday.
For years, we’ve heard of bee numbers declining, with scientists at times evoking the word “disappearing.” But the placement of the yellow-faced species on the Endangered Species List is a stark, public alarm bell.
Sean O’Donnell, PhD, professor in Drexel’s College of Arts and Sciences, is an expert on tropical insect ecology, focusing on bees, wasps and ants. He explains here what the addition of bees to the list means and where the prolific pollinators might go from here.
Landing on the Endangered Species List Might Actually Be Good
I see listing as a good thing. Not because of what it represents — species in decline due to human activities — but because it brings recognition and resources for protection. It’s good for insects in general (and bees and pollinators in particular) to get this kind of attention and recognition.
One good reason to list these bees is their ecological connection, as pollinators, to Hawaiian native plants. Protecting the bees will likely help with conservation of the native flora and fauna.
If Bees Do Die Off, There’s No One to Pick Up the Slack
It’s unlikely other insects would replace the bees if they were lost, at least in the short-term. Even if bees were out-competing other insects for flower access, replacement insects would be unlikely to offer the kind of effective — often specialized — pollination services that bees provide.
The social Honey bees we are most familiar with are generalists, visiting hundreds of species of flowers, but they are unusual among bees. Most species of bees are solitary nesters — meaning they don’t live in hives or colonies — and most kinds of bees are relatively specialized, visiting flowers of one or just a few species of plants.
These bee-plant relationships are important and close. In many cases, when bees are lost, the flowers simply go un-pollinated.
For the Most Part, Humans are Behind Bee Die-Offs
Bee declines are a complex issue. There are many diverse species of bees with different seasonalities, flower sources and nest site needs. Risk factors may often be species-specific, however, a few widespread human actions are impacting many kinds of bees. Habitat destruction is a big problem. Loss of flower resources, heavy insecticide use and some kinds of genetically modified crops are also issues. Climate change’s negative effects are likely increasing and may accelerate bee declines, for example by affecting bee and flower seasonality.
Then there are pathogens — diseases —being moved around by humans and introduced into new areas. It is not clear to what extent pathogens can jump, or transfer, among bee species, but this may be happening in some cases.
We May Not Have Reached the Point of No Return, Though
Many insect populations are resilient. Even if their numbers fall to low levels, their fast reproduction can allow the populations to bounce back quickly if conditions improve.
However, some solitary nesting bees, like the endangered Hawaiian bees, have low reproductive rates. Females raise only a few offspring in each nest, investing a lot (for example, a large mass of pollen) in each offspring. Insects with heavy parental investment and low numbers of offspring can have slower population recovery rates and remain threatened with extinction longer. And, obviously, we can’t bring back extinct species.
Media interested in speaking with O’Donnell should contact Frank Otto at 215.571.4244 or fmo26@drexel.edu.
