Ants Build Raft to Escape Flood, Protect Queen
Serguei S. Dukachev, Wikimedia Commons
Tragedies like the Boston Marathon bombings remind us how important first responders are. Animals come to the rescue of members of their own species too.
Dolphins, for example, form "living rafts" to keep ill or injured dolphins buoyant, according to a paper published in Marine Mammal Science. Up to 12 dolphins, working together in a pod, may swim together to try and keep one of their own afloat.
Meerkats have one of the animal kingdom's most efficient security operations. A sentinel stands guard, watching for any potential threats. Should an intruder approach, an entire clan -- from elderly grandmas to younger dads -- mob the unwelcome visitor.
"Non-dangerous terrestrial animals most often ran away when they were approached and mobbed by the meerkats," explained Beke Graw and Marta Manser of the University of Zurich. More threatening animals, such as poisonous snakes, were also mobbed, but the meerkats often had to back down and leave, knowing they might be safer doing so.
Charles J. Sharp, Wikimedia Commons
Risking their own lives, vervet monkeys make loud alarm calls when they spot a predator, saving others from harm. According to Robert Seyfarth of the University of Pennsylvania and colleagues, the monkeys even identify, the specific type of predator in the loud calls.
"Animals on the ground respond to leopard alarms by running into trees, to eagle alarms by looking up, and to snake alarms by looking down," the researchers explained.
U.S. Department of the Interior
American bison are formidable animals, both in terms of size and weight, so they are usually only taken down by large predators, such as mountain lions, wolves and humans. According to Animal Diversity Web, bison travel in lines led by dominant adults. If they detect a predator, a meaningful bison-emitted grunt or snort tells the herd to be wary. Mother bison, as for many animal moms, will also fight to the death to save their young.
John Verive, Flickr
Male wild chimpanzees living in Bossou, Guinea, have figured out how to deactivate, and sometimes even destroy, snares set out by human hunters, according to Gaku Ohashi of the Japan Monkey Center and colleagues. The researchers documented instances where the chimps set free trapped individuals and took steps to deactivate snares, such as by shaking or hitting the devices.
Vampire bats starve to death if they do not feast on a blood meal after two nights. Roost-mates come to the rescue during famines, according to biology Gerald Wilkinson of the University of Maryland. "A buddy system ensures that food distribution among the bats is equitable," he explained. Bats seem to have BFFs with whom they regularly share blood meals via regurgitating. Barfing up blood may be a stomach churner for humans, but for these bats, it's a lifesaver.
Dave Otee, Flickr
Ants, well known for their complex societies, put the preservation of the overall colony above their individual needs. They identify colony members by scent, according to Gregg Henderson and colleagues from the USDA. Intruders who literally stink -- not matching the colony's signature scent -- will be attacked with as much force as an ant can muster.
Captain Budd Christman, NOAA
Walruses breed during harsh Arctic winters, with mothers giving birth to just one offspring per season. If disaster strikes and the infant becomes an orphan, another walrus female may adopt it, according to The Encyclopedia of Earth. Communal care of young by multiple female walruses has also been documented.
Alvesgaspar, Wikimedia Commons
There are many accounts of cats saving members of their own species and humans. One example of the former was Scarlett, a calico owned by Karen Weller of New York. When Scarlett and her litter of five kittens became trapped in a Brooklyn garage fire, the mother feline carried out each of her kittens to safety. During the five separate trips, Scarlett sustained severe burns to her eyes, ears and face, but she forged ahead until all kittens were out of danger.
In fiction, Lassie came to the rescue of seemingly everyone and everything. Fiction in this case mirrors fact, as there are countless reports of heroic dogs saving the day. A video on Animal Planet, for example, (http://animal.discovery.com/tv-shows/weird-true-and-freaky/videos/dog-rescues-dog-on-highway.htm) captured footage of a dog in Santiago, Chile, pulling another injured dog to safety. This first responder canine had to navigate through heavy traffic, but the brave dog managed to pull off a happy ending
Ants may be small, but they’re certainly not stupid, as evidenced by the discovery that they build rafts to save themselves and their queen during floods.
What’s more, they construct the rafts using themselves — living ants — linked together to form a nearly waterproof buoyant vessel, according to a study published in the latest issue of PLOS ONE.
“Social organisms have an advantage when responding to ecological adversity: They can react in a collective and organized way, working together to perform tasks that a solitary individual could not achieve,” Jessica Purcell from the University of Lausanne and her colleagues wrote.
Surprisingly, baby ants were used to form the base of the raft. Worker adult ants then joined together to form the rest of the structure. The queen was always placed in the safest spot — right at the center of the raft.
“We expected that individuals submerged on the base of the raft would face the highest cost, so we were astonished to see the ants systematically place the youngest colony members in that position,” Purcell said in a press release.
She continued, “Further experiments revealed that the brood are the most buoyant members of the society and that rafting does not decrease their survival … this configuration benefits the group at minimal cost.”
Who knew that baby ants float? Well, we do now. It’s no wonder that ants so often outsmart humans, foiling extermination attempts.
Ants are up there with cockroaches and other tough creatures that are true survivors. They aren’t the only non-human organisms, though, to join forces for self-preservation.
Purcell and her colleagues share that Japanese honeybees “will surround large predatory hornets and form an ‘oven,’ raising the interior temperature to kill the intruder.”
Another example is demonstrated by leafcutter ants, which form defensive lines around vulnerable ants to block invaders.
As for the fate of the rafting ants, nearly all survived.
Photo: Ants build a raft. Credit: Jessica Purcell