Although cities have their own fauna, the reality is that one could reasonably think that for animals of all kinds the urban environment is far behind the countryside in diversity and quality of life: there is a lot of asphalt, noise, pollutants… well yes, but no, because there is a place where bees have found a true residential paradise: a cemetery in IthacaNew York.
Where you see a cemetery, the bees see paradise. It turns out that a laboratory technique called Rachel Fordyce had a trick to get to your work at Cornell University without paying for parking: park on the other side and take a walk through the East Lawn Cemetery. In spring 2022 he arrived at his post with a jar full of bees that he had found along the way: that was the beginning of it all.
The bees inside were Andrena regularis, known as the “common mining bee,” a wild, solitary species that nests underground. That is, it does not have a queen and it does not build hives either. Each female digs her own tunnel, lays her eggs, supplies them with food, and seals them. And under the ground of the Ithaca cemetery there are millions, more specifically 5.56 million in just over 6,000 square meterswhich come out every spring to pollinate the surrounding apple trees.
Why is it important. Because it is the largest population of wild bees with a nest in the ground ever documented and very far of the secondof 1.6 million individuals of a different species in Arizona. And their work is essential: pollinators in general are responsible for the production of approximately 75% of the world’s food crops. according to the FAO.
As explains Bryan Danforthprofessor of entomology at Cornell University, they must be protected: “If we don’t preserve nesting sites and someone paves them, we could instantly lose 5.5 million bees that are important pollinators.” The most striking thing of all is that this enormous population was there, in the midst of civilization and next to one of the most prestigious universities in the world.
Context. Contrary to popular belief, the most common way of life for bees is solitary and with a nest on the ground: approximately 75% of the bees on the planet live like this. Those bees that produce honey and live in hives may be the most famous, but they are an absolute minority. Solitary wild bees are not as well known, but their pollination work is key in nature and in food. Thus, this enormous population lives independently but concentrated in that place because the substrate conditions are optimal.
The bad news is that pollinators are in decline: according to the report of the Intergovernmental Platform on Biodiversity and Ecosystem Servicesmore than 40% of pollinating insect species are threatened. In this scenario, finding such a large population in a city shows that there are more refuges for biodiversity than we thought and we must find them before they disappear (and if possible, avoid it).
In detail. We knew about the presence of Andrena regularis in that cemetery since 1935, but it was not until 2021 when the scientific community began to intuit what was underground. To estimate the population, the team installed mesh traps at 10 points in the cemetery between March 30 and May 16, 2023. The result was extraordinary: as explains the press release from the New York university, is the equivalent of 200 honey bee hives on just 0.6 hectares of land and more than triple the population of Manhattan.
Yes, but. The study has important limitations, such as that the population data is from a single spring (2023) and that the figure is a statistical estimate and not a real inventory, so we do not know if the population is rising, falling, remaining stable or how climate change affects it, which is advancing the flowering of apple trees and therefore altering the life calendar of the bees. And although it is the largest aggregation of wild nesting bees documented to date, its presence in a cemetery suggests that there may be others whose existence we are unaware of.
In Xataka | We have a serious problem with the extinction of bees. The United Kingdom wants to solve it with bricks
Cover | Marisol Benitez, Chad Madden and Damien TUPINIER
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