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4 Reasons Why You Shouldn’t Feed the Birds (Or Any Animals)

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People love to feed birds. And squirrels, chipmunks, deer—even bears and sharks. We do it for our own pleasure and, sometimes, under the misguided impression we are helping hungry animals. But step away from the stale bread—here are four reasons why feeding wildlife is almost always a bad idea, both for the animals and for us.

1. FEEDING CAN LEAD TO INJURED ANIMALS AND PEOPLE.

Researchers at Murdoch University in Western Australia and University of Aberdeen in Scotland analyzed nearly two decades worth of data from Chicago’s Brookfield Zoo Sarasota Dolphin Research Program and Mote Marine Laboratory’s Stranding Investigations Program and found an increase in the number of dolphins being fed by humans—along with an increase in dolphins injured or killed by boat strikes, entanglement in fishing gear, and ingestion of hooks and lines.

At Stingray City, a shallow lagoon off Grand Cayman where large numbers of stingrays gather around boats of tourists that feed them, handling by those tourists had caused skin abrasions on the rays.

Fed animals begin to equate humans with food, and can exhibit increased aggressiveness toward people, which has resulted in human injuries and even death. People have been bitten while feeding wild animals, some of which carry infectious diseases such as rabies, bubonic plague, or Hantavirus.

2. FEEDING ALTERS THE NATURAL BEHAVIOR OF ANIMALS.

Feeding wildlife can change the animals’ activity levels and metabolic rates, reduce the size of their home range, and increase both intra- and inter-species aggression.

Sharks, for example, don’t naturally share territory, and when they group around boats to feed, it can cause stress and shark-on-shark conflict. “Sharks are solitary predators not normally found in groups,” George Burgess, director of the Florida Program for Shark Research, told mental_floss. “With feeding, they associate humans in the water—and even the sound of a motor boat—with food, and come from long distances away. Most don’t go far away once the boat leaves, but hang out in the area knowing the boat comes every day, so the reality then is sharks in unusually high densities.” Unnaturally high numbers of predators in one place equals equally unnaturally high levels of predation, which affects the ecology of the entire area.

Whitetip reef sharks that are fed in order to attract them for tourists showed elevated activity levels and increased metabolic rates during times they normally would rest. Metabolism influences most of an animal’s biological and ecological processes, so this represents clear evidence of feeding affecting the sharks’ critical biological functions.

Researchers found that the rays at Stingray City have distinctly different patterns of activity than their wild counterparts. Wild stingrays forage at night across large distances and rarely encounter each other. The fed rays form schools, feed together, and mate year-round rather than during a specific season. They also show signs of unusual aggression, such as biting each other. Scientists don’t yet know whether these behavior changes could be harmful in the long run.

In Slovenia, where bears are fed corn year-round, scientists found that the animals shortened the number of days of hibernation by as much as 56 percent. Bears regularly visited feeding sites throughout the winter, increasing their likelihood of interactions with other species as well as humans.

3. FEEDING CAN MAKE ANIMALS SICK.

On some islands in the Bahamas and throughout the Caribbean, tourist operators take people to feed grapes, ground beef, and other foods to one of the world's most endangered lizards, northern Bahamian rock iguanas. Researchers reported different levels of calcium, cholesterol, and various minerals in fed versus unfed populations of the iguanas, as well as diarrhea, higher levels of glucose, and a staggering 100 percent endoparasitic infection rate in the tourist-fed animals. One of the study’s authors, Charles Knapp of the Chicago John G. Shedd Aquarium, recommends an education campaign to discourage iguana feeding and, at a minimum, using food specially formulated for the iguanas.

In another devastating example, people frequently feed bread, popcorn, and fast food to white ibis in parks in Georgia. As a result, the birds are more sedentary than normal, and they come into contact with ducks, gulls, and city birds they normally wouldn’t encounter. Increased inter-species contact, combined with higher levels of stress hormones and weaker immune systems, could increase the spread of pathogens such as salmonella among them. A previous study found ibises infected with strains of salmonella that also make people sick—because of their range, the birds could move these pathogens over large distances.

4. FEEDING CAN EVEN LEAD TO ANIMALS BEING KILLED.

All U.S. national parks prohibit the feeding of wildlife. But in some parks, bears have learned to forage for unattended human food. Rangers relocate these bears away from human food sources, but many eventually return and continue seeking human food—eventually, such problem bears must be euthanized. Being fed from cars can cause bears and other animals to congregate near roads where they may be killed by vehicles. Hanging around roads and parking lots can also make animals such as squirrels, birds, and deer easier for predators to catch.

Tourists on Fraser Island, Australia have come to expect interaction with dingoes, including feeding the wild dogs. As numbers of tourists increased, so have reports of dingo attacks, and after a human fatality in April 2001, the government ordered a cull of the dingoes.

Fed sharks lose their natural fear of humans and become bolder, coming closer than they normally would once they associate humans with food. When bites result, it contributes to the negative image sharks can have, Burgess says. “The sharks get the blame, not the humans in the water with bait and fish. We have a designation in the shark attack file, 'Provoked Attack,' meaning ones in which humans initiated the attack by doing something to provoke the animal. What is more provocative than dangling fish in front of a shark’s nose? Of course, the word provoked doesn’t appear in the headline. Whatever advantage is gained in conservation by letting people see what beautiful animals sharks are gets cancelled out by the headlines of someone getting bit.” In response to shark bites, officials sometimes kill sharks in the area where the encounter occurred even though, Burgess says, the chances of killing the specific shark involved are slim to none.

He notes that feeding can result in shark deaths another way: “There have been examples where fishermen came to areas where sharks were attracted by a feeding operation and fished them out."

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Big Questions
What Makes a Cat's Tail Puff Up When It's Scared?
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Cats wear their emotions on their tails, not their sleeves. They tap their fluffy rear appendages during relaxing naps, thrash them while tense, and hold them stiff and aloft when they’re feeling aggressive, among other behaviors. And in some scary situations (like, say, being surprised by a cucumber), a cat’s tail will actually expand, puffing up to nearly twice its volume as its owner hisses, arches its back, and flattens its ears. What does a super-sized tail signify, and how does it occur naturally without help from hairspray?

Cats with puffed tails are “basically trying to make themselves look as big as possible, and that’s because they detect a threat in the environment," Dr. Mikel Delgado, a certified cat behavior consultant who studied animal behavior and human-pet relationships as a PhD student at the University of California, Berkeley, tells Mental Floss. The “threat” in question can be as major as an approaching dog or as minor as an unexpected noise. Even if a cat isn't technically in any real danger, it's still biologically wired to spring to the offensive at a moment’s notice, as it's "not quite at the top of the food chain,” Delgado says. And a big tail is reflexive feline body language for “I’m big and scary, and you wouldn't want to mess with me,” she adds.

A cat’s tail puffs when muscles in its skin (where the hair base is) contract in response to hormone signals from the stress/fight or flight system, or sympathetic nervous system. Occasionally, the hairs on a cat’s back will also puff up along with the tail. That said, not all cats swell up when a startling situation strikes. “I’ve seen some cats that seem unflappable, and they never get poofed up,” Delgado says. “My cats get puffed up pretty easily.”

In addition to cats, other animals also experience piloerection, as this phenomenon is technically called. For example, “some birds puff up when they're encountering an enemy or a threat,” Delgado says. “I think it is a universal response among animals to try to get themselves out of a [potentially dangerous] situation. Really, the idea is that you don't have to fight because if you fight, you might lose an ear or you might get an injury that could be fatal. For most animals, they’re trying to figure out how to scare another animal off without actually going fisticuffs.” In other words, hiss softly, but carry a big tail.

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Animals
10 Notable Gestation Periods in the Animal Kingdom
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The gestation periods of the animal kingdom are varied and fascinating. Some clock in at just a few weeks, making any human green with envy, while others can last more than a year. Here are 10 notable gestation times for animals around the globe. The lesson? Be thankful that you’re not a pregnant elephant.

1. ELEPHANTS: 640-660 DAYS

Elephants are pregnant for a long time. Like really, really long. At an average of 95 weeks, the gestation period is more than double the length of a human pregnancy, so it shouldn't come as a shock that female elephants don't often have more than four offspring during their lifetimes. Who has the time?

2. HIPPOS: 8 MONTHS

A photo of a mother hippo and her baby in Uganda

Yes, it takes less time to make a hippopotamus than it takes to make a human.

3. GIRAFFE: 14-15 MONTHS

Baby giraffes can weigh more than 150 pounds and can be around 6 feet tall. Another fascinating tidbit: giraffes give birth standing up, so it's pretty normal for a baby to fall 6 feet to the ground.

4. KILLER WHALE: 17 MONTHS

There’s a reason for the long wait: after that 17 months, Baby Shamu emerges weighing anywhere from 265 to 353 pounds and measuring about 8.5 feet long. Yikes.

5. OPOSSUM: 12-13 DAYS

A baby opossum wrapped up in a blanket

Blink and you'll miss it: This is the shortest gestation period of any mammal in North America. But since the lifespan of an opossum is only two to four years, it makes sense.

6. GERBILS: 25 DAYS

Hey, they get off pretty easy.

7. GORILLAS: 8.5 MONTHS

It's not a huge surprise that their gestational periods are pretty similar to ours, right?

8. BLACK BEAR: 220 DAYS

A pair of black bear cubs

Also less than a human. Interestingly, cubs might only be 6 to 8 inches in length at birth and are completely hairless. 

9. PORCUPINE: 112 DAYS

This is the longest gestation period of any rodent. Thankfully for the mother, porcupine babies (a.k.a. porcupettes) are actually born with soft quills, and it's not until after birth that they harden up.

10. WALRUS: 15 MONTHS

Baby walruses? Kind of adorable. They certainly take their sweet time coming out, though.

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