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Richard Bartz via Wikimedia Commons // CC BY-2.5
Richard Bartz via Wikimedia Commons // CC BY-2.5

Why Worker Bees Don’t Have Babies

Richard Bartz via Wikimedia Commons // CC BY-2.5
Richard Bartz via Wikimedia Commons // CC BY-2.5

Honeybees are great. They’re important pollinators, industrious honey-makers, and they’re darn cute (just look at that fuzzy body!). But you don’t get to be as successful as they are without making some brutal choices. Those efficient, humming colonies of theirs are ruled by rigid, hierarchical laws that determine who can eat, who can leave, and who can reproduce. Exactly how those laws were enforced has long been a subject of great interest to scientists, and now one team of researchers say they’ve figured out how exactly the queen keeps her workers’ fertility in check. They published their findings in the journal Nature Communications

An individual bee’s behavior (bee-havior?) is subject to all kinds of influences, whether it be the waggle dance of a returning forager, the electrical messages put out by a flower, or the many chemical signals drifting through hive air. One notable signal is queen mandibular pheromone, or QMP. QMP is an astonishingly versatile compound. It tells drone bees when the queen is ready to mate, induces the colony to swarm, and can destroy the ovaries of worker bees to keep them from getting busy. Pretty impressive, right? 

Previous studies in fruit flies had found a link between the flies’ egg production and a cellular pathway called the Notch. To find out if the same pathway had any involvement in honeybees' egg shutdown, evolutionary biologists at New Zealand’s University of Otago treated some workers with a chemical that suppressed any Notch activity and left other workers’ Notch signaling intact. Then all the bees were exposed to typical levels of QMP. The researchers killed the bees, then examined their ovaries to see what had happened. 

Sure enough, the ovaries of bees with normal Notch function were damaged by the QMP. But before their deaths, the blocked-Notch bees had been humming along just fine; many of their ovaries contained fully developed eggs.

Additional tests on the bees confirmed a strong bond between Notch and QMP. When worker bees were left to their own devices and not exposed to a queen or her pheromones, their Notch receptors gradually degenerated. Without a queen, the workers' fertility was unfettered.

The researchers were surprised to see just how early in the reproductive process Notch could make a difference. Speaking in a press statement, co-author Peter Dearden said they’re still not sure if the pheromone attacks the ovary directly or works through the brain.

"However it is acting, the outcome is that Notch signaling's fundamental role in the ovary has been modified and transformed in honeybees into social control of worker bees' reproduction," he said. 

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Animals
Pigeons Are Secretly Brilliant Birds That Understand Space and Time, Study Finds
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Of all the birds in the world, the pigeon draws the most ire. Despite their reputation as brainless “rats with wings,” though, they’re actually pretty brilliant (and beautiful) animals. A new study adds more evidence that the family of birds known as pigeons are some of the smartest birds around, as Quartz alerts us.

In addition to being able to distinguish English vocabulary from nonsense words, spot cancer, and tell a Monet from a Picasso, pigeons can understand abstract concepts like space and time, according to the new study published in Current Biology. Their brains just do it in a slightly different way than humans’ do.

Researchers at the University of Iowa set up an experiment where they showed pigeons a computer screen featuring a static horizontal line. The birds were supposed to evaluate the length of the line (either 6 centimeters or 24 centimeters) or the amount of time they saw it (either 2 or 8 seconds). The birds perceived "the longer lines to have longer duration, and lines longer in duration to also be longer in length," according to a press release. This suggests that the concepts are processed in the same region of the brain—as they are in the brains of humans and other primates.

But that abstract thinking doesn’t occur in the same way in bird brains as it does in ours. In humans, perceiving space and time is linked to a region of the brain called the parietal cortex, which the pigeon brains lack entirely. So their brains have to have some other way of processing the concepts.

The study didn’t determine how, exactly, pigeons achieve this cognitive feat, but it’s clear that some other aspect of the central nervous system must be controlling it. That also opens up the possibility that other non-mammal animals can perceive space and time, too, expanding how we think of other animals’ cognitive capabilities.

[h/t Quartz]

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The Queen's Racing Pigeons Are in Danger, Due to an Increase in Peregrine Falcons
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Queen Elizabeth is famous for her love of corgis and horses, but her pet pigeons don't get as much press. The monarch owns nearly 200 racing pigeons, which she houses in a luxury loft at her country estate, Sandringham House, in Norfolk, England. But thanks to a recent boom in the region’s peregrine falcon population, the Queen’s swift birds may no longer be able to safely soar around the countryside, according to The Telegraph.

Once endangered, recent conservation efforts have boosted the peregrine falcon’s numbers. In certain parts of England, like Norfolk and the city of Salisbury in Wiltshire, the creatures can even find shelter inside boxes installed at local churches and cathedrals, which are designed to protect potential eggs.

There’s just one problem: Peregrine falcons are birds of prey, and local pigeon racers claim these nesting nooks are located along racing routes. Due to this unfortunate coincidence, some pigeons are failing to return to their owners.

Pigeon racing enthusiasts are upset, but Richard Salt of Salisbury Cathedral says it's simply a case of nature taking its course. "It's all just part of the natural process,” Salt told The Telegraph. "The peregrines came here on their own account—we didn't put a sign out saying 'room for peregrines to let.' Obviously we feel quite sorry for the pigeons, but the peregrines would be there anyway."

In the meantime, the Queen might want to keep a close eye on her birds (or hire someone who will), or consider taking advantage of Sandringham House's vast open spaces for a little indoor fly-time.

[h/t The Telegraph]

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