A peregrine falcon in a hunting dive reaches a terminal velocity of about 320 km/h (200 mph), which makes it the fastest animal alive.

That figure is not a guess from a single enthusiast with a stopwatch. A peer-reviewed aerodynamics study notes that peregrines exceed 320 km/h in a full stoop, though its own filmed dives took place past a 60 m dam — short enough that the falcons never reached terminal velocity, but long enough to capture the changing wing shape on high-speed cameras. The record claim sits higher still: a captive falcon named Frightful was reportedly clocked at 389 km/h (242 mph) in 1999 after release from a light aircraft.

For comparison, the Guinness World for the fastest speed in an Formula 1 car is 372.56 km/h (231.51mph). These cars need a long straight and lots of horsepower. The falcon gets there with body mass, gravity, and a folded silhouette, then has to land a precise strike at the end of it. The car only has to keep going straight.

The dive has a name: the stoop. The record speed belongs only to the dive, and the dive depends on shape. Robin Mills, a biologist who has modelled the manoeuvre, describes it this way: “Within the blink of an eye, it dives down – first flapping forcefully and then folding its wings to decrease drag. It basically appears to drop out of the sky.” All of this is in service of the strike at the bottom — the stoop is how the falcon turns altitude into a killing blow.

The peregrine delivers the blow with its feet, used as a blunt weapon rather than as the gripping talons most people picture. The popular image of a clenched fist is roughly right but not exact. The Birds of Stanford essays note that “High-speed cinematographic studies, however, have shown that they strike their prey from above with all four toes fully extended.” The foot may be open at the instant of contact, not closed, though the strike itself remains a percussive hit rather than a grab.

The impact does much of the killing. Peregrines and their close relatives carry only modest talons, so they cannot rely on the crushing grip that some larger raptors use. Instead, as Fowler and colleagues describe in their study of raptor anatomy, “For immobilisation, Falconini rely more strongly on strike impact and breaking the necks of their prey, having evolved a ‘tooth’ on the beak to aid in doing so.” The dive does the work, and the notched beak finishes what the blow starts.

The speed record hides something. A car at 320 km/h is being asked to follow a known line on a known surface. The falcon is being asked to intercept a small, frightened, swerving target in open air, and to do it while its own anatomy works against it. The peregrine’s sharpest vision sits off to the side of its eye, not straight ahead. Tucker and colleagues put the problem plainly: “When diving at prey straight ahead from great distances at high speeds, a peregrine has a conflict between vision and aerodynamics.”

To see the prey clearly, the bird “must turn its head approximately 40 ° to one side” to fix the target on the most acute part of its eye, but a turned head adds drag and slows the dive. Wild peregrines solve this not by turning the head but by curving the whole approach. Tucker’s team observed birds tracking distant prey along a curved path resembling a logarithmic spiral, which keeps the target pinned on that sideways high-acuity vision while the head stays streamlined. It is the aerial equivalent of taking the racing line rather than the shortest one.

The precision goes deeper than the path. A 2018 simulation by Mills and colleagues at Groningen and Oxford modelled the attack and found the diving falcon steers using the same proportional-navigation logic that guides missiles. The same work is careful about what high speed actually buys. The simulations suggest that when prey moves erratically, high-altitude stoops raise catch success compared with low-altitude attacks, but only if the falcon’s guidance law is finely tuned and its vision and control are precise. Speed without that control is just a fast miss. This is a modelling result rather than a field measurement, so it is best read as a clue to how the real birds manage it, not the last word.

The body comes equipped for the rest. Bony tubercles inside the nostrils are thought to limit the air rushing in at speed, and a translucent third eyelid sweeps across the eye to protect it while still letting the falcon see, a built-in visor for a pilot who cannot afford to blink at the wrong moment.

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It might sound strange but a swarm of bees deciding where to live is perhaps one of the cleanest examples of a crowd making a good choice without anyone in charge.

There is no leader, no vote-counter, no bee that surveys the options and issues a verdict. The queen, despite the title, has no say in it. And yet a few hundred bees, working only with their own senses and a dance, settle on a new home that is more often than not the best one available.

A note before going further: we are writers reading the work of biologists, not animal-behaviour researchers ourselves. The findings here come from a small number of careful field experiments, and the temptation to read bee democracy as a lesson for human democracy is one to hold lightly. This is reflection on what the research describes, not a claim that crowds of people work the same way.

The swarm that shouldn’t work

The setup looks like a recipe for chaos. When a hive becomes overcrowded in early summer, two-thirds of the worker bees leave with the old queen and cluster on a nearby branch, a temporary camp with no roof and no plan. From there, several hundred scout bees, often the oldest in the colony, fly off to find somewhere permanent. They might inspect 10 to 20 candidate cavities scattered across the surrounding countryside.

No single scout visits every option. No scout can compare all the sites and pick a winner. By any obvious logic, a group of individuals each holding a fragment of the picture should struggle to agree on anything, let alone the right thing. What’s striking isn’t that bees manage to choose at all — it’s that they keep choosing the best of the available options, through a mechanism stranger and simpler than a committee.

What scouts actually do

A scout that likes a cavity comes back and dances. The waggle dance encodes direction and distance, and crucially, it encodes enthusiasm. Cornell biologist Thomas Seeley puts the mechanism plainly: “A scout adjusts how long she dances according to the goodness of the site.” 

This is the part that looks like campaigning. A bee returning from a good site lobbies harder, and her advertising recruits more visitors, who in turn come back and dance for the same place. What keeps the system from being hijacked by an over-eager scout is that the bees appear to grade honestly.

The quorum, not the consensus

The popular picture of bee democracy gets one thing slightly wrong. The swarm does not wait for agreement. It waits for a threshold.

As scouts visit and re-advertise the leading candidate, their numbers at that cavity build. Once roughly 15 scouts are present at one site at the same time, that site has effectively won. The bees are not polling the whole crowd for a majority. They are sensing local density, the moment when enough of them are gathered in one place.

Seeley and P. Kirk Visscher tested this directly by scattering scouts among identical boxes instead of letting them concentrate; spreading the bees out delayed the signal to leave, which is what you would expect if the trigger is a quorum at a single spot rather than a tally across all sites.

Once the quorum is reached, the scouts switch from advertising to mobilising. They produce piping signals that prime the rest of the swarm to warm their flight muscles to around 35°C, the temperature a bee needs to fly. Then a buzz-run signal tears through the cluster, and the whole swarm lifts off at once and heads for the chosen home. The decision and the departure are two separate acts, and the second only happens when the first is sealed.

Why the crowd gets it right

The honest test of any decision rule is whether it lands on the best option, not just a tolerable one. Seeley and Susannah Buhrman ran that test on Appledore Island, off the coast of Maine. They offered swarms one excellent nest box among four mediocre ones, and in each trial, one or more of the poor sites happened to be discovered hours before the good one. Even with that head start working against the right answer, the swarms picked the excellent site in four of the five trials.

What makes the rule work is that quality and persistence are coupled. A better site draws longer dances, longer dances draw more scouts, more scouts reach quorum faster. The early lead a mediocre site might enjoy gets overtaken because its dancers give up sooner. No individual bee weighs the options; the weighing emerges from the population, in the bookkeeping of who keeps dancing and who stops.

Perhaps what the swarm reveals most clearly is that good collective choices carry a cost, and the cost is time. The whole process, from clustering on the branch to lifting off toward a new home, can stretch across two or three days, spent hanging exposed with little shelter and finite reserves. The colony could probably decide faster by lowering the quorum or trusting the first site found, but it doesn’t. Those hours and that energy seem to be the price of getting the answer right. 

The post When a honeybee colony outgrows its hive it makes a genuinely democratic decision: scout bees fly out, inspect possible new homes, and ‘campaign’ for their favourite with waggle dances, lobbying harder for better sites — and only once enough scouts have converged on the same spot does the whole swarm lift off together, almost always choosing well appeared first on Space Daily.

Picture a single society running from the Italian Riviera to the Atlantic edge of Spain, its members numbering in the billions, none of them ever raising a weapon against another. That is not a thought experiment about humans; it is a population of ants.

In 2002, three researchers at the University of Lausanne reported that a single network of Argentine ant nests stretched at least 6,000 kilometres along the Mediterranean and Atlantic coasts of southern Europe. Tatiana Giraud, Jes S. Pedersen and Laurent Keller documented a main supercolony of millions of nests and billions of workers — a cooperative unit they described as astonishing in scale.

What makes the European supercolony so strange is not just its size — it is the peace. In their native South America, Argentine ants behave like most ants: neighbouring colonies fight, and a colony stays small, on the order of a few metres to a few kilometres across.

These ones do something different. Workers pulled from nests hundreds of kilometres apart, with no shared recent ancestry to speak of, meet and groom and pass food rather than tear each other apart.

The Lausanne team put numbers to it by collecting ants from sites along the coast and staging encounters between them. Workers from the same supercolony showed no aggression toward one another, even when separated by huge distances and genetic differentiation between sampling sites. Mix workers from two different supercolonies, though, and the result is lethal. The truce holds inside the network and stops hard at its edge.

The European finding raises a question that sounds philosophical but turns out to be biological: at what point does a sprawling web of cooperating individuals stop being a population and become a single society? Biologist Mark Moffett took it up. His answer turns on growth. Moffett wrote that “this capacity for unrestricted growth is the defining characteristic of supercolonies.” A normal ant colony has a ceiling; a supercolony does not.

That capacity for essentially unlimited scale shows up in only a handful of ant species and in one other animal: us. The comparison is what gives the European supercolony its claim to be the second-largest cooperative society on the planet. The Lausanne team had already reached for similar language, describing the network as one that “effectively forms the largest cooperative unit ever recorded.”

And it grew larger still. A later study traced the connections beyond Europe. Behavioural tests and chemical analyses showed that the biggest European, Californian and Japanese supercolonies recognise one another as nestmates, linking them into one intercontinental society. Ellen Van Wilgenburg, Candice Torres and Neil Tsutsui concluded that the intercontinental network is the “most populous known animal society.”

The supercolony was not engineered. It is a by-product of human shipping, which carried a South American ant around the world and, on the working hypothesis, narrowed its recognition system down to a single shared signal somewhere along the way.

In its home range the same species stays small and quarrelsome. Dropped into Europe with its old border disputes erased, it kept doing the one thing ants do well, cooperating, and simply never ran out of relatives to cooperate with.

Why the peace holds so widely is not fully understood. The same team that mapped the intercontinental network was candid about the gap, noting that the global supercolony’s persistence looked like apparent evolutionary stasis — surprising because introduced populations often evolve rapidly. 

The post A single ‘supercolony’ of Argentine ants is thought to stretch some 6,000 km along the coasts of southern Europe, from Italy to Spain — billions of workers across millions of nests that treat one another as kin and refuse to fight, making it one of the largest cooperative societies on Earth, second only to our own appeared first on Space Daily.

The number that anchors everything is about 600 volts. That is the peak discharge an electric eel can deliver, several times the roughly 120 volts of a North American wall socket. The figure is stranger than it looks: no single part of the eel produces anything close to that. The voltage is assembled, cell by cell, out of thousands of much smaller contributions.

Despite its name, the electric eel is a type of  knifefish, and as much as four-fifths of its roughly two-metre body is given over to one job: making electricity. 

Each of the specialised cells, called electrocytes, produces only a tiny voltage on its own. A single electrocyte fires at around 150 millivolts, about a seventh of a volt. Stack thousands of them in series and fire them at once, and the small jolts sum the way cells in a battery do. The cells are linked in series to build voltage and in parallel to build current, channelling the combined output toward a target.

The comparison to a battery is more than loose metaphor. The arrangement has long been likened to Alessandro Volta’s voltaic pile of 1799, the first synthetic battery, which stacked metal discs to do what the eel does with living tissue.

Researchers have since built the principle back the other way. A team at the University of Fribourg, working with stacked ion-selective hydrogels to mimic the eel’s total of up to 600 volts, assembled an artificial version that generated 110 volts when thousands of its cells were triggered together.

For most of the time we have known about the eel, the assumption was that it shocked prey underwater and left it at that. Then Kenneth Catania filmed something different.

The Vanderbilt biologist documented and filmed eels rising out of the water to press their chin against a partially submerged threat. The contact point matters: the current exits through the chin into the target and returns to the eel’s tail, completing the circuit through the animal it is attacking rather than dissipating into the surrounding water.

The measurements showed both voltage and current to the target rising the higher the eel climbed. Catania read the behaviour as a defensive move, a way to drive a shock home with maximum effect. This, he wrote, lets the eels deliver shocks “with a maximum amount of power to partially submerged land animals that invade their territory”. He also proposed that the manoeuvre could have arisen in steps, with “each stage” providing “a successive advantage, suggesting how it may have evolved.”

The discovery did more than describe new behaviour — it rehabilitated an old story. 

In 1800, the naturalist Alexander von Humboldt described eels in a South American pool attacking horses, with two horses stunned and drowned in the first five minutes of the skirmish. For roughly two centuries afterward, no scientific reports of any such leaping attack appeared, and the tale was treated with skepticism. Catania felt the same pull of disbelief. “The first time I read von Humboldt’s tale, I thought it was completely bizarre,” he said. “Why would the eels attack the horses instead of swimming away?”

The filmed leaps offered an answer. Catania argued that the behaviour, most likely a dry-season defence when crowded eels are cornered in shrinking pools, fit Humboldt’s description closely enough that “it seems reasonable to suggest” the naturalist had watched a similar eel behaviour on 19 March 1800. The hedge is his own, and it stays a careful inference rather than proof. Other researchers found the work persuasive all the same. In the view of James Albert, a University of Louisiana at Lafayette biologist who studies how electric fish evolved their use of electricity, the results “are literally rewriting the book on what we know about electric behaviors of the electric eel.”

The post The electric eel can generate a jolt of around 600 volts — several times the shock from a household socket — by stacking thousands of specialised cells together like tiny batteries, and rather than only zapping prey underwater, it has been filmed rearing up out of the water to press its chin directly against a larger attacker appeared first on Space Daily.

When researchers at the Australian National University played recordings of superb lyrebird mimicry to grey shrike-thrushes, the shrike-thrushes responded to the fakes much as they would to one of their own. As lead author Anastasia Dalziell put it, “Surprisingly, strike-thrushes approached the speaker broadcasting mimicked songs as well as the shrike-thrushes’ own song.”

The superb lyrebird (Menura novaehollandiae) is a large ground-dwelling songbird of the forests of south-eastern Australia, and most of what it sings is borrowed. The bulk of a male’s song is imitation, drawn overwhelmingly from other forest birds. During the breeding season a male will mimic roughly 20 to 25 species.

Dalziell and Robert Magrath measured how close the copies actually were in a study titled “Fooling the Experts.” The acoustic match for grey shrike-thrush song was tight enough that the model species could not reliably tell the imitation from the real thing. “Grey shrike-thrushes sing a complex and beautiful song, but lyrebirds can accurately mimic them all the same,” Dalziell said.

Two cautions belong here. This was a playback experiment measuring acoustic similarity for one model species, not a blanket finding that every lyrebird copy is indistinguishable. The shrike-thrushes also did better at discriminating when given other contextual cues, so “fooled” sits closer to “often fooled” than to “always fooled.”

The chainsaws and car alarms that made the bird globally famous come with their own footnote. The celebrated imitations of saws and drills trace largely to captive birds, including a male named Chook at Adelaide Zoo who died in 2011. Wild lyrebirds overwhelmingly mimic natural forest sounds. 

Look closely and it get’s more interesting. A male does not simply replay everything he knows at maximum length. In the “Fooling the Experts” analysis, the lyrebirds abridged the songs they copied, trimming repeated notes, which is consistent with a trade-off between showing off accuracy and packing in variety.

Dalziell described it this way: “This mimicry is the accomplishment of years of practice and is probably used to show female lyrebirds the quality of the singer.” Note the “probably.” It is offered as a hypothesis, not a verdict.

A 2021 study added a stranger wrinkle. Dalziell and colleagues found that males create an acoustic illusion of a whole mixed-species mobbing flock at very particular moments. As Dalziell put it, “The male lyrebird recreates that sound when a potential mate tries to leave a displaying male without copulating, or during copulation itself.” The illusion may work as a sensory trap rather than a simple display of extravagance, though the Cornell write-up is careful that it is not clear exactly how males benefit.

The tidy phrase “all in service of winning over a mate” runs into a basic problem: females mimic too. The first systematic study of female superb lyrebird song found they are skilled mimics in their own right, copying at least 19 species. Co-author Justin Welbergen noted that “The females imitated fewer bird calls than males but performed more imitations of hawks.” A trait that existed only to attract a mate would have no obvious reason to appear, in a different form, in the sex that does not display.

The function is plainly more than one thing. Courtship is the best-documented driver, and mimicry does peak in the breeding season. But the same skill turns up in what looks like deception during copulation, and in displays whose structure shifts depending on the moment. Each of these is a working hypothesis backed by an observational or playback study, not a closed case.

What the lyrebird exposes is perhaps a habit of ours, not of the bird’s. The temptation is to attach one clean purpose to a behaviour because one purpose is easy to tell as a story. The animal keeps refusing to cooperate. The most interesting thing about a bird that can imitate almost anything is that we still cannot say, with confidence, exactly why it bothers.

The post The Australian superb lyrebird can imitate almost any sound it has ever heard — chainsaws, camera shutters, car alarms, the calls of more than 20 other species — with enough accuracy that the birds being imitated often can’t tell the difference appeared first on Space Daily.