Crows Form, Nurse, and Share Grudges Against People

Walter Siegmund via Wikimedia Commons // CC BY 2.5
Walter Siegmund via Wikimedia Commons // CC BY 2.5

Consider this a friendly reminder not to antagonize crows: According to a 2011 study in Proceedings of the Royal Society B, American crows remember the faces of people who wrong them, and enlist other birds to attack the offenders.

When it comes to intelligence, birds get no respect. For a long time, scientists assumed birds were stupid because their brains had significant differences from ours. But recent studies on bird brains and abilities are putting those fallacies in their place. Researchers have found sophisticated behavior in birds from finches and pigeons to Antarctic gulls. But there’s one group of birds that consistently amazes: crows and ravens.

Within the last 10 years we’ve learned that crows can make, store, and care for tools. They can count and exercise self-restraint. They can use bait to catch fish. They can certainly play. And, the authors of the Royal Proceedings study say, they can nurse some serious grudges.

Researchers at the University of Washington’s School of Forest Resources bought two masks that looked like human faces. A caveman-looking mask was designated the “dangerous” mask, while a Dick Cheney mask was “neutral.” They then visited wild crows at five sites around Seattle. At each site, the person wearing the caveman mask would approach the crows, trapped a few, banded their legs, and set them free—an experience the birds did not enjoy. As soon as the researcher let them go, the birds began yelling at their captor with a harsh, aggressive cry called “scolding.”

The sounds of conflict attracted more birds, which joined in scolding and attacking the researcher, even though they’d never met. “The mob of two to 15 birds hounds us, sometimes diving from the sky to within a few meters or less. This pursuit lasts about 100 meters (328 feet) as we walk away,” crow expert John Marzluff told Discovery News.

The Dick Cheney mask did not elicit a response.

Marzluff and his colleagues then traveled to other crow territories. The sight of the caveman mask caused an immediate ruckus among these crows—even though none of them had ever been caught or banded. Crows up to a mile away from the original site had heard about this no-good caveman guy, and they knew he was trouble when he walked in.

The grudge didn’t wear off, either. Marzluff said return trips in the caveman mask provoked the same hostile response, even five years later. He told Discovery News, "Individual crows that are adults can live 15-40 years in the wild (most die when young, but those that make it to adulthood can live a long time) and they probably remember important associations they have formed for much of their lives."

These associations aren't all negative. An 8-year-old girl, also in Seattle, made news last year when her family revealed that local crows had pretty much made her their queen.

Want to Give a Retired Police or Military Dog a Forever Home? Mission K9 Rescue Can Help

Mission K9 Rescue
Mission K9 Rescue

Over the course of their careers, working dogs perform lifesaving duties while assisting members of the police force and military. These dogs receive a lot of appreciation while they're on the job, but as they enter retirement, they're often forgotten in animal shelters. An organization called Mission K9 Rescue is dedicated to placing these dogs in loving forever homes after they've served the United States.

"Our mission is to give K9 veterans—and other working dogs who have served our country—safe, peaceful, and loving homes upon retirement from service," K9 co-founder and president Kristen Maurer tells Mental Floss. "There are so many animal-loving patriots in America, and most don't realize that many of these brave, selfless dogs often remain overseas much longer than needed when they are no longer able to work. Some do not receive adequate care. We bring awareness of their plight to the public, and we work tirelessly to rescue, reunite, re-home, rehabilitate, and repair these dogs so they can live out the rest of their days in a safe and comfortable environment."

Many retired dogs are abandoned in kennels—both in the U.S. and abroad—but for some, the situation is even more severe. According to Mission K9 Rescue, working dogs are sometimes euthanized en masse when they can no longer do their jobs. The organization aims not only to remove these dogs from harm's way, but to find them forever families that are a perfect fit for them.

After rescuing dogs from both the U.S. and overseas, Mission K9 Rescue matches them with new owners. If the dog has a past handler who is interested in adopting them permanently, reuniting the pair is a priority. For all other cases, the organization goes through a rigorous process to find dogs a brand-new home.

Mission K9 also specializes in rehabilitating dogs who have suffered either mental trauma or physical injuries in their work. Just like humans, canines can develop PTSD from working in stressful, high-pressure situations. After they're rescued, animals are given as much time as they need to decompress and reintegrate into society before they're adopted. On top of the mental demands, being a working dog causes physical strain, and Mission K9 provides medical care to dogs with injuries and other issues.

Anyone can apply to adopt a retired working dog from Mission K9 Rescue. If you're interested in bringing one into your home, you can fill out the application on the group's website.

German shepherd in a bed at home.
Mission K9 Rescue

Two dogs in the backseat of a car.
Mission K9 Rescue

Dog and owner in front of home.
Mission K9 Rescue

Some Fish Eggs Can Hatch After Being Pooped Out by Swans

iStock/olaser
iStock/olaser

A question that’s often baffled scientists is how certain species of fish can sometimes appear—and even proliferate—in isolated bodies of water not previously known to harbor them. A new study has demonstrated that the most unlikely explanation might actually be correct: It’s possible they fell from the sky.

Specifically, from the rear end of a swan.

A study in the journal Ecology by researchers at the Unisinos University in Brazil found that killifish eggs can, in rare cases, survive being swallowed by swans, enduring a journey through their digestive tracts before being excreted out. This kind of fecal public transportation system explains how killifish can pop up in ponds, flood waters, and other water bodies that would seem an unlikely place for species to suddenly appear.

After discovering that some plants could survive being ingested and then flourish in swan poop, researchers took notice of a killifish egg present in a frozen fecal sample. They set about mixing two species of killifish eggs into the food supply of coscoroba swans living in a zoo. After waiting a day, they collected the poop and dug in looking for the eggs.

Of the 650 eggs they estimated to have been ingested by the swans, about five were left intact. Of those, three continued to develop. Two died of a fungal infection, but one survived, enduring 30 hours in the gut and hatching 49 days after being excreted.

Because killifish eggs have a thick outer membrane, or chorion, they stand a chance of coming through the digestive tract of an animal intact. Not all of what a swan ingests will be absorbed; their stomachs are built to extract nutrients quickly and get rid of the whatever's left so the birds can eat again. In rare cases, that can mean an egg that can go on to prosper.

Not all fish eggs are so durable, and not all fish are quite like the killifish. Dubbed the "most extreme" fish on Earth by the BBC, killifish have adapted to popping up in strange environments where water may eventually dry up. They typically live for a year and deposit eggs that can survive in soil, delaying their development until conditions—say, not being inside a swan—are optimal. One species, the mangrove killifish, can even breathe through its skin. When water recedes, they can survive on land for over two months, waddling on their bellies or using their tails to "jump" and eat insects. A fish that can survive on dry land probably doesn't sweat having to live in poop.

The researchers plan to study carp eggs next to see if they, too, can go through a lot of crap to get to where they’re going.

[h/t The New York Times]

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