It’s a weIrd world
jackdaws leave after vote
NOISy jackdaws known for suddenly taking flight in their thousands only do so after calling out to each other louder and louder in a type of bird democracy, according to a study.
The racket made by the black birds is believed to be a form of "consensus decision-making" - something that may draw comparisons with the uproarious House of Commons.
While the huge noise may sound chaotic, experts believe the cacophony is actually the creatures each casting a 'vote'.
Researchers from the University of Exeter recorded the rising noise of jackdaw calls that happens before mass departures at various roosts in Cornwall.
By combining this with tests in which pre-recorded jackdaw calls were played at a colony, the team found evidence that the birds' calls are used to form a group decision.
"After roosting in a large group at night, each jackdaw will have a slightly different preference about when they want to leave, based on factors like their size and hunger," said Alex Dibnah, who led the study as part of a Masters by Research at Exeter's Penryn Campus in Cornwall.
"However, it's useful to reach a consensus. Leaving the roost together has various benefits, including safety from predators and access to information such as where to find food.
"Our study shows that by calling out jackdaws effectively 'cast a vote' and, when calling reaches a sufficient level, a mass departure takes place."
Jackdaws roost in groups of hundreds or even thousands and it is common for most or all of the birds to take flight suddenly around sunrise. — Sky News. venomous crabs on beaches Thousands of venomous crabs have swarmed the beaches of Cornwall, shedding their shells before returning to the depths of the sea.
The carpet of crabs that gathered in the shallow waters of St Ives is a sight that is becoming increasingly common in the summer due to rising sea temperatures.
Spider crabs are instantly recognisable for their long legs and pincer claws and have a venomous bite that is poisonous to their prey but harmless to humans.
While their presence at Porthgwidden
Beach was enough to put many bathers off entering the sea, some did take the chance to snorkel above the mass of crustaceans to view the hair-raising spectacle.
Once the crabs shed their shells, they return to depths of 300ft, leaving the water clear for those hoping to paddle in the waters.
Kate Lowe, a marine photographer, captured the event in the same week a woman snorkeller was bitten by a blue shark further around the Cornish coast, off Penzance.
Kate said: "I go snorkelling most of the time throughout the year, but I have never seen spider crabs in such numbers.
"When we turned up at the beach, it looked as though there were lots of dark rocks under the surface.
"But it turned out that there were thousands of crabs just two or three steps into the water.
"It was just really incredible, they were only knee-deep. I was able to float on the water above them and tried not to step on them.
"A lot of the tourists were squealing at the sight of them." — Sky News.