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10 Gigantic Facts About Moose

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For most people, moose are a pretty foreign concept, but for some, they're part of everyday life. Michelle Carstensen, Wildlife Health Program Supervisor at Minnesota Department of Natural Resources, gave mental_floss the scoop on these furry giants.

1. Moose are huge.

Moose are the largest members of the deer family, weighing as much as 1200 pounds; they can grow to be 5 to 6.5 feet from hooves to shoulders. This does not include a raised head or antlers, so it's safe to say that the majority of moose tower over all non-basketball players. 

2. They eat a lot.

With huge size comes a huge appetite. Moose are browsers and will casually devour 73 pounds a day in the summer and 34 pounds in the winter. They eat an assortment of shrubs, woody plants, and aquatic vegetation; in the winter, their diet is more restricted, so they eat the buds of plants.

3. Organisms of all sizes pose a threat to moose.

Moose are formidable opponents with sharp hooves that can kick with tremendous force, but even they have predators. A pack of wolves or a black bear is no match for a healthy adult moose, so bears and wolves typically pick off the young, sick, and old. And even though moose are powerful and quite large, a single bite can do one in: There's a good chance the bite will cause an infection that eventually kills the animal up to two weeks later. 

Moose also have a much smaller menace to worry about: parasites. Brain worm (Parelaphostrongylus tenuis) is a parasite contracted from eating snails. The infectious larvae migrate to the moose's brain and cause neurological damage. "It’s interesting thinking of something as big as a human hair killing a 1200 pound moose, but they do," Carstensen says. 

Another tiny nuisance is the winter tick. Tick infestations depend on the weather and habitat: Harsh winters mean less ticks the following year; when ticks fall off animals to complete their cycle and there's still snow on the ground, they die. So hard, long winters are great news for moose. 

4. Their antlers are used for fighting...

When fighting off predators, the antlers, or paddles, don't come into play as much as you would think; a moose's first line of defense is its sharp hooves, which are capable of mortally wounding a wolf or bear.

Paddles are only found on males, and used mainly for fighting and displaying. During mating season in autumn, bulls will cover a lot of ground looking for females to mate with. They establish breeding territory by fighting off other males in the area. The fights are not always fight-to-the-death scenarios, and often a competing moose will back away from a fight if the challenger has a more impressive rack of antlers. Great paddles are not the only way to find mates; some males with better navigational skills—or just sheer luck—may come across a female by chance and completely skip antler combat. 

5. ...and they shed every year.

Moose lose their paddles every winter and grow new ones the following spring. "Antler growth is based on testosterone levels and day length," Carstensen says. "So they start to grow those antlers in the late spring and summer, and they’re covered in velvet. The velvet is vascularized so there is a blood-flow supplying these antlers as they’re growing." By early fall—a.k.a. mating season—bulls start to shed and shine their paddles by rubbing them against trees. Their fuzzy velvet-covered antlers go through a gory transformation, and by October they will have shiny new paddles for competition and display. 

Antlers are also a great indicator of age. With each winter, young moose paddles grow in size: nubs become spikes and spikes become full racks. Bulls in their prime, between ages 5 and 8, have the largest racks. With old age, the antlers become more deformed and less impressive. 

6. Antlers are heavy. 

Just like the moose themselves, antlers can come in different sizes. The paddles are essentially a big bone, so they generally weigh quite a bit; bulls develop muscular necks to help hold up the enormous paddles. A full grown moose's antlers can weigh about 40 pounds. 

7. The babies need help from their mom.

Female moose, or cows, generally have 1 to 2 calves in May. On average, the calves weigh about 30 pounds at birth and grow very quickly. Still, baby moose don't have the ability to run or protect themselves very well, so the mother stays with her offspring for a year and a half, fighting off wolves and bears that try to pick off the young calves.

8. They're great swimmers.

Moose are naturally gifted swimmers. It's common to see one hop right into a lake and swim across at up to 6 mph. The animals have an innate ability to know how to swim, so even calves can swim. 

9. There are four subspecies in North America.

Moose can be categorized into four different species in North America: the eastern moose (A. alces americana), the Shiras moose (A. alces shirasi), the Alaskan moose (A. alces gigas), and the northwestern moose (A. alces andersoni), which Carstensen works with in Minnesota. Moose can be distinguished by different sizes and antler shapes. The largest moose is the Alaskan moose (pictured above) that can stand at 7 feet tall with an antler span of 6 feet. 

10. They're dying at an alarming pace.

Something is happening to all the moose in Minnesota. The state once had a flourishing moose population in the north that was hunted and doing quite well: In the mid-1980s, there were 2000 of the animals in the northwest, but that number dropped to less than 200 in just two decades. This prompted the state to do some research to prevent further drops in population. Unfortunately, the northeast is now facing similiar a problem; the moose population has dropped 50 percent since the mid-2000s. 

Carstensen is leading a $1.2 million moose mortality study to figure out what's killing Minnesota's moose. Her team has collared 150 animals with GPS trackers to keep tabs on them; when a moose dies, an e-mail and text are sent out so the team knows when and where. "The goal is to get there within 24 hours to determine the cause of death," Carstensen says. "[That's important] because moose are a very large animal and they have very thick skin, a very insulating coat, and when they do die, they decompose very rapidly. Being able to get to an animal in 24 hours gives us the best diagnostic level samples that we can collect and help us determine cause of death."

In order to collect that data, they need to bring the moose to their diagnostic lab. Transporting a thousand-pound moose out of the woods is no easy task, so Carstensen's team has modified trucks, ATVs, and snowmobiles to help move these gigantic animals. One moose was even pulled out with a helicopter. 

The study is now two years old, but unfortunately, there are no clear answers yet. "In the health category, we’ve confirmed causes such as brainworm, severe winter tick infestations, bacterial infections from injuries and liver flukes, as well as undetermined health issues," Carstensen says. "What we might end up determining overall is that there is no smoking gun that points to just one factor that’s driving this system; it may very well end up as a mix of causes related to health, predation, habitat, weather, and even climate change."

All images courtesy of iStock. 

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14 Bold Facts About Bald Eagles
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Bald eagles are powerful symbols of America—but there’s a whole lot more to these quirky birds.

1. YOUNG BALD EAGLES AREN'T BALD.

A young bald eagle with a brown head on a beach.
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So obviously adult bald eagles aren't really bald, either—their heads have bright white plumage that contrasts with their dark body feathers, giving them a "bald" look. But young bald eagles have mostly brown heads. In fact, for the first four or five years of their lives, they move through a complicated series of different plumage patterns; in their second year, for instance, they have white bellies.

2. BALD EAGLES SOUND SO SILLY THAT HOLLYWOOD DUBS OVER THEIR VOICES.

A red-tailed hawk.
A red-tailed hawk's screech is usually dubbed over the bald eagle's weaker scream.
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It's a scene you’ve probably seen countless times in movies and on TV: An eagle flies overhead and emits a rough, piercing scream. It's a classic symbol of wilderness and adventure. The only problem? Bald eagles don't make that sound.

Instead, they emit a sort of high-pitched giggle or a weak scream. These noises are so unimpressive that Hollywood sound editors often dub over bald eagle calls with far more impressive sounds: the piercing, earthy screams of a smaller bird, the red-tailed hawk. If you were a fan of The Colbert Report, you might remember the show's iconic CGI eagle from the opener—it, too, is making that red-tailed hawk cry. Listen for yourself and decide who sounds more impressive.

3. THEY EAT TRASH AND STOLEN FOOD.

Two bald eagles guard their prey against two magpies on a snowy field.
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Picture a majestic bald eagle swooping low over a lake and catching a fish in its powerful claws. Yes, bald eagles eat a lot of fish—but they don't always catch them themselves. They've perfected the art of stealing fish from other birds such as ospreys, chasing them down until they drop their prey.

Bald eagles will also snack on gulls, ducks, rabbits, crabs, amphibians, and more. They'll scavenge in dumpsters, feed on waste from fish processing plants, and even gorge on carrion (dead, decaying animals).

4. BALD EAGLES USUALLY MATE FOR LIFE ...

Two bald eagles perched on a tree.
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Trash and carrion aside, they're pretty romantic animals. Bald eagles tend to pair up for life, and they share parenting duties: The male and the female take turns incubating the eggs, and they both feed their young.

5. … AND THEY LIVE PRETTY LONG LIVES.

Two bald eagles sitting on a rock.
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Those romantic partnerships are even more impressive because bald eagles can survive for decades. In 2015, a wild eagle in Henrietta, New York, died at the record age of 38. Considering that these birds pair up at 4 or 5 years of age, that's a lot of Valentine's Days.

6. THEY HOLD THE RECORD FOR THE LARGEST BIRD'S NEST.

Two bald eagles in their large nest.
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Bald eagles build enormous nests high in the treetops. The male and female work on the nest together, and this quality time helps them cement their lifelong bond. Their cozy nurseries consist of a framework of sticks lined with softer stuff such as grass and feathers. If the nest serves them well during the breeding season, they'll keep using it year after year. And, like all homeowners, they can't resist the thought of renovating and adding to their abode. Every year, they'll spruce it up with a whopping foot or two of new material.

On average, bald eagle nests are 2-4 feet deep and 4-5 feet wide. But one pair of eagles near St. Petersburg, Florida, earned the Guinness World Record for largest bird’s nest: 20 feet deep and 9.5 feet wide. The nest weighed over two tons.

7. FEMALES ARE LARGER THAN MALES.

Two bald eagles in their large nest.
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In many animal species, males are (on average) larger than females. Male gorillas, for example, dwarf their female counterparts. But for most birds of prey, it's the opposite. Male bald eagles weigh about 25 percent less than females.

Scientists aren't sure why there's such a size difference. One reason might be the way they divide up their nesting duties. Females take the lead in arranging the nesting material, so being bigger might help them take charge. Also, they spend longer incubating the eggs than males, so their size could intimidate would-be egg thieves.

If you're trying to tell male and female eagles apart, this size difference may help you—especially since both sexes have the same plumage patterns.

8. TO IDENTIFY THEM, LOOK AT THE WINGS.

A bald eagle flies across the water.
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People often get excited about a big soaring bird and yell "It's an eagle!” just before it swoops closer and … oops, it's a vulture. Here's a handy identification tip. Bald eagles usually soar with their wings almost flat. On the other hand, the turkey vulture—another dark, soaring bird—holds its wings up in a shallow V shape called a dihedral. A lot of large hawks also soar with slightly raised wings.

9. THEY'RE COMEBACK KIDS.

Baby eagle chicks in a nest.
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Before European settlers arrived, bald eagles were abundant across the U.S. But with settlement came habitat destruction, and the settlers viewed the eagles as competition for game and as a threat to livestock. So many eagles were killed that in 1940 Congress passed an act to protect the birds.

Unfortunately, another threat rose up at about that time. Starting after World War II, farmers and public health officials used an insecticide called DDT. The chemical worked well to eradicate mosquitos and agricultural pests—but as it traveled up the food chain, it began to heavily affect birds of prey. DDT made eagle eggshells too thin and caused the eggs to break. A 1963 survey found just 471 bald eagle pairs in the lower 48 states.

DDT was banned in the early 1970s, and conservationists began to breed bald eagles in captivity and reintroduce them in places across America. Luckily, this species made a spectacular recovery. Now the lower 48 states boast over 9700 nesting pairs.

10. THEY'RE UNIQUELY NORTH AMERICAN.

An African fish eagle flies over the water.
The African fish eagle is a relative of the North American bald eagle.
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You've probably heard of America's other eagle: the golden eagle. This bird lives throughout much of the northern hemisphere. But the bald eagle is only found in North America. It lives across much of Canada and the U.S., as well as northern parts of Mexico.

Though it may be North American, the bald eagle has seven close relatives that are found throughout the world. They all belong to the genus Haliaeetus, which comes—pretty unimaginatively—from the Latin words for "sea" and "eagle." One relative, the African fish eagle, is a powerful symbol in its own right. It represents several countries; for example, it's the national symbol of Zambia, and graces the South Sudanese, Malawian, and Namibian coats of arms.

11. THEY'RE AERIAL DAREDEVILS.

A bald eagle carries a fish off in its talons.
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It seems too weird to be true: While flying, bald eagles sometimes grab each other's feet and spin while plummeting to the earth. Scientists aren't sure why they do this—perhaps it's a courtship ritual or a territorial battle. Usually, the pair will separate before hitting the ground (as seen in this remarkable set of photographs). But sometimes they hold tight and don't let go. These two male bald eagles locked talons and hit the ground with their feet still connected. One subsequently escaped and the other was treated for talon wounds.

12. THEIR EYES ARE AMAZING.

Close-up of a bald eagle's face.
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What if you could close your eyes and still see? Besides the usual pair of eyelids, bald eagles have a see-through eyelid called a nictitating membrane. They can close this membrane to protect their eyes while their main eyelids remain open. The membrane also helps moisten and clean their eyes.

Eagles also have sharper vision than people, and their field of vision is wider. Plus, they can see ultraviolet light. Both of those things mean the expression "eagle eye" is spot-on.

13. THEY MIGRATE … SORT OF.

A bald eagle sits in a snowy tree.
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If you're a bald eagle that nests in northern Canada, you'll probably head south for the winter to avoid the punishing cold. Many eagles fly south for the winter and return north for the summer—as do plenty of other bird species (and retired Canadians). But not all bald eagles migrate. Some of them, including individuals in New England and Canada's Maritime provinces, stick around all year. Whether or not a bird migrates depends on how old it is and how much food is available.

14. THEY CAN SWIM … SORT OF.

A bald eagle
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There are several videos online—like the one above—that show a bald eagle swimming in the sea, rowing itself to shore with its huge wings. Eagles have hollow bones and fluffy down, so they can float pretty well. But why swim instead of soar? Sometimes, an eagle will swoop down and grab an especially weighty fish, then paddle it to shore to eat.

Note that the announcer in the video above says that the eagle's talons are "locked" on a fish that's too heavy to carry. In fact, those lockable talons are an urban legend.

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New Health-Monitoring Litter Box Could Save You a Trip to the Vet
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Unsure if your cat is sick or just acting aloof per usual? A “smart toilet” for your fur baby could help you decide whether a trip to the vet is really necessary.

Enter the Pet Care Monitor: More than a litter box, the receptacle is designed to analyze cat urine for health issues, The Asahi Shimbun in Tokyo reports. Created by the Japan-based Sharp Corporation—better known for consumer electronics such as TVs, mobile phones, and the world's first LCD calculator—the product will be available for purchase on the company’s website starting July 30 (although shipping limitations may apply).

Sensors embedded in the monitor can measure your cat’s weight and urine volume, as well as the frequency and duration of toilet trips. That information is then analyzed by an AI program that compares it to data gleaned from a joint study between Sharp Corp and Tottori University in Japan. If there are any red flags, a report will be sent directly to your smartphone via an application called Cocoro Pet. The monitor could be especially useful for keeping an eye on cats with a history of kidney and urinary tract problems.

If you have several cats, the company offers sensors to identify each pet, allowing separate data sets to be collected and analyzed. (Each smart litter box can record the data of up to three cats.)

The Pet Care Monitor costs about $225, and there’s an additional monthly fee of roughly $3 for the service. Sharp Corporation says it will continue developing health products for pets, and it has already created a leg sensor that can tell if a dog is nervous by measuring its heart and respiratory rates.

[h/t The Asahi Shimbun]

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