Analysis Reveals Massive Drop in Bee Species
Mon, November 29, 2021

Analysis Reveals Massive Drop in Bee Species

An analysis of bee collections and observations shows a decline in bee diversity in the last three decades, indicating that the drop is a global process. The number of bee species began to plummet around the 1990s after enduring several decades of high diversity in collections / Photo by: Carly & Art via Wikimedia Commons


An analysis of bee collections and observations shows a decline in bee diversity in the last three decades, indicating that the drop is a global process. The number of bee species began to plummet around the 1990s after enduring several decades of high diversity in collections.

"This is the first study suggesting that bee decline is a global process and that the most significant changes have occurred in recent years," said bee evolutionary ecologist Margarita López-Uribe.

The new work, which is currently under peer review, looked into the global trends in bee diversity through the database of the Global Biodiversity Information Facility—the most comprehensive dataset of insect collection records worldwide.

Fewer Bee Species Are Buzzing

The global bee situation remains unclear. Some studies say the number of the bee population has dropped, but these results are limited to the regions where the research was conducted. Fortunately, the number of bee observations rose in recent decades, possibly due to an increased number of documentations and studies.

The new analysis indicates there are fewer bee species than in the 1950s. Back then, collectors added about 22,000 bee records a year, with about 1,900 species annually to bring the global total of collection for a whole decade to 5,600 species.

About 6,700 species would've been observed in the wild following correction for sampling efforts. But in the 2010s, that observation dropped to an average of 860 species a year from an average of over 37,000—leading to an estimated drop of merely 3,400 species.

Earlier studies on bees indicate a drop in their population, but the evidence was limited to those in Europe and North America. For instance, the number of western honeybees has been dropping in the said regions but has increased in others like Asia, Africa, and South America.

However, the new study reveals nearly every continent observed a decline in a number of bee species, most of which occurred in the 1990s. Bi-weekly magazine Science News says an exception is Australia ad nearby islands, where the average number of species rose from about 300 to 500 in the 2000s before dropping back to 300 a decade later.

The results of this analysis are evidence that bee diversity losses are "part of a larger, worldwide trend," rather than a regional issue, according to researcher Eduardo Zattara.

Biologist Natapot Warrit of Chulalongkorn University in Bangkok said he hopes that the study would encourage researchers in Asia to look into and share data on bees, considering how the dataset in the recent study is missing important insect collections from the region. Still, he commended that the results provide an "invaluable" overview of the global bee situation.

Causes of Bee Decline

Despite their small size, bees play a big role when it comes to sustaining the environment. Bees pollinate food crops, wherein they move pollen from one plant to another to fertilize the plants so that they can bear fruit, vegetables, or seeds.

With their ability to pollinate, the extinction of bees can tip the balance of the Earth's ecosystem and eventually affect global food supplies. This is the reason why the Royal Geographical Society of London declared the buzzing little creatures as the most important living beings on Earth.

But that's not the only list they were added to, as wildlife experts and scientists also classified bees as an endangered species. This listing comes as nearly 90% of the bee population has disappeared in the last few years.

Entomology researcher Philip Donkersley provides the top causes of declines not only in bee species but also in insect diversity and abundance.

• Invasive species

Experts noted invasive species, parasites, and pathogens as the culprits for the decline of honeybee colonies worldwide. For instance, Asian Hornets are causing great concern as they spread in Europe and prey on honeybees—with a single hornet capable of destroying an entire hive.

Meanwhile, bees were able to coexist with pathogens like fungal and bacterial disease before. But the recent increase lost of bees to these diseases may be due to their increased exposure to pesticides, which damages their immune system.


Insecticides are a clear threat to bees because of their chemical composition, although herbicides may be more of a problem since farmers use them more. Herbicides target a variety of wild plants bees need as a food source.

While insecticides and herbicides are likely to be among the main causes of the species' decline, Donkersley noted that chemicals used by city authorities and civilian gardeners may also be harmful to bees and other insects.

• Climate change

Increasing global temperatures make it difficult for certain bee species to thrive since some can only survive in certain temperature ranges. Warming habitats may force some species to live at higher altitudes, where it's cooler, even if their living space becomes limited.

• Habitat loss

Habitat loss comes as farmers convert land for agricultural purposes, a process highly associated with biodiversity and pollination decline. Cultivating land for farming destroys the space bees use to nest, takes away the food bees feed on, and even poses wider impacts on other species like wild birds, mammals, and amphibians.

Saving the bees

Many of the causes of bee decline are interrelated, and this complexity makes it difficult to address the issue. But that doesn't mean the problem is unsolvable, and humans can still provide a solution to it considering they are largely responsible for the two most prominent causes of bee decline: pesticides and habitat loss.

According to environmental organization Greenpeace, "common sense actions restore and protect the world’s bees." Simple ways to do so include:

• Banning the use of the most dangerous pesticides.
• Protecting the health of bees and other pollinators through habitat preservation.
• Restoring ecological agriculture.

Greenpeace also suggests practicing ecological farming—a new policy trend that can stabilize human food production while preserving wild habitats and protecting bees. Through ecological farming, farmers can resist insect damage by avoiding large monocrops and preserving ecosystem diversity.

"By restoring bee populations and healthier bees, ecological agriculture improves pollination, which in turn improves crop yields," the organization says.