The number of bees recorded has fallen sharply since the 1990s, according to a global analysis of the populations of these insects. Details of this work are published in the journal A land.
Bees have received a lot of attention for several years. And for good reason, the threats weighing on these insects which play a crucial role in our ecosystems are numerous and dangerous. These include the loss of their natural habitats due to agriculture, resource extraction and urban development. They are also affected by air pollution and the misuse of pesticides. Finally, climate change is also a problem, with many bees unable to migrate to colder areas.
Drastic drop in the number of species observed
These threats therefore lead to a decline in bee populations, but to what extent? As part of a study, Argentine researchers examined the number and nature of sightings of these insects reported in recent decades in the Global Biodiversity Information Center (GBIF). It is indeed an online platform on which everyone can record their observations.
These results showed that 25% fewer bee species were reported on GBIF between 2006 and 2015 compared to the records available before 1990. These data are all the more worrying as the number of records has increased. increased by around 55% since the early 2000s. In other words, this decline is not due to a lack of observations.
“Thanks to citizen science and the ability to share data, records are increasing exponentially, but the number of species reported in these records is decreasing“, Summarizes Eduardo Zattara, of the University of Comahue (Argentina) and main author of the study. “It’s not a cataclysm yet, but what we can say is that wild bees aren’t really on the rise.“.
Species that have become too rare, or even completely extinct
The study also points out that these declines are not evenly distributed among bee families. Overall, the observations of so-called “rare” bees have decreased more sharply than the more common ones. As an example, records of Melittidae, a family of bees found in Africa, have dropped to 41% since the 1990s, while the Halictidae, the second most common family, have decreased by 17% during the same period.
Of course, one cannot draw definitive conclusions by referring only to this database, important as it is. This does not necessarily mean, for example, that all the species “missing from radar” have become extinct, but that they have become rare enough that no one can regularly find them in the wild. Yet even taking into account the degree of uncertainty, the trend observed in this study is quite clear and matches other previous reports.
Finally, remember that if attention is often paid to bees (and rightly so), let us not forget that bumblebees are also in danger. According to a study published in the journal Science last February, the number of areas frequented by bumblebees would have decreased by 46% in North America and 17% in Europe in just a few decades.