Ravens Can Figure Out When Someone Is Spying on Them

Jana Mueller
Jana Mueller

Corvids, the family of birds that includes crows and ravens, are canny beasts. They've been known to exercise self-control, count, hold grudges, and more. Now, new research suggests they possess at least a rudimentary Theory of Mind—the ability to attribute mental states to others.

A study in Nature finds that ravens can tell when someone else can see them, guarding their food when a peephole to their cache is open. While previous research suggested that birds might have an awareness of other animals' mental states, the results have been inconclusive. The Nature study is evidence that corvids can do more than just track other birds' gaze; they may understand the concept of "seeing."

Vienna-based researchers set up two rooms separated by windows that could be closed with covers. These covers had peepholes in them that could also be opened or closed. First, the 10 ravens were each allowed to cache food, while other birds were in the next room and the windows were open or closed. Then, they were trained to look through the peepholes to find food in the other room, so that they knew that the holes could be used to see through the window covers. Afterwards, each of the ravens was again presented with food with one of the two peepholes open. The adjacent observation room didn't have any birds in it, but the researchers played the sounds of another raven recorded during one of the previous trials.

When the birds heard the sounds of another raven in the next room, and the peephole was open, the birds behaved as if they knew they were being watched—they hid their cache of food quickly and didn't add more food to it as often, as if they knew that it might be compromised. However, they behaved normally when the peephole was closed.

This suggests that ravens don't just track their competitors' gaze to know when they’re being watched, but can infer from past experience when they can be seen.

Hundreds of Kangaroos Roam the Green at This Australian Golf Course

burroblando/iStock via Getty Images
burroblando/iStock via Getty Images

Anglesea Golf Club has all the makings of a regular golf club: an 18-hole golf course, a mini golf course, a driving range, a clubhouse, and a bistro. But the kangaroo mobs that hop around the holes add an element of surprise to your otherwise leisurely round of one of the slowest games in sports.

Person takes photo of a kangaroo
Anglesea Golf Club

According to Thrillist, the kangaroos have been a mainstay for years, and the club started giving tours a few years ago to ensure visitors could observe them in the safest way possible. For about 25 minutes, a volunteer tour guide will drive a golf cart with up to 14 passengers around the course, sharing fun facts about kangaroos and stopping at opportune locations for people to snap a few photos of the marsupials, which are most active in late afternoon and early morning. Kangaroos are friendly creatures, but Anglesea’s website reminds visitors that “they can also be quite aggressive if they feel threatened.”

Post-graduate students and academic staff from Melbourne University’s zoology department have been researching Anglesea’s kangaroo population since 2004, and some of the animals are marked with collar and ear tags so the researchers can track movement, growth, survival, and reproduction patterns throughout their life cycle.

One of the reasons kangaroos have continued to dwell on land so highly trafficked by people is because of the quality of the land itself, National Geographic reports. The golf course staff regularly sprinkles nitrogen fertilizer all over the green, which makes the grass especially healthy.

Kangaroos graze on Anglesea Golf Course
Anglesea Golf Club

If you decide to plan a trip to Anglesea Golf Club, you can book a kangaroo tour here—adult tickets are $8.50, and children under 12 can come along for just $3.50 each.

[h/t Thrillist]

10 Surprising Facts About Shoebill Storks

MikeLane45/iStock via Getty Images
MikeLane45/iStock via Getty Images

Shoebill storks have been called the world’s most terrifying bird (though the cassowary might disagree). These stately wading birds stalk the marshes of South Sudan, Uganda, and elsewhere in tropical East Africa, snatching up prey with their unique, immediately recognizable bills. But there are a lot of misconceptions about shoebill storks—the first being that they're not actually storks. Here are some more surprising facts.

1. Shoebill storks could win staring contests.

Shoebills live in the vast wetlands of the Nile watershed in eastern Africa. You really can’t mistake them for any other bird: They grow 4 to 5 feet tall, have bluish-gray plumage and an 8-plus-foot wingspan, and their bill, which takes up a majority of their face, looks like a huge Dutch wooden clog. Shoebills can stand virtually motionless for hours with their bills held down against their necks. Complemented by their golden eyes, the posture affects a very convincing death stare.

2. Shoebills may be more closely related to pelicans than storks.

Shoebill stork looking at the camera
ApuuliWorld/iStock via Getty Images

Over the past couple of centuries, naturalists have debated where shoebills should appear on the Tree of Life. Some taxonomists said that the shoebill's syrinx, or vocal organ, resembled those of herons belonging to the family Pelecaniformes, which also includes ibises, pelicans, and boobies. Others countered that herons have specialized feathers than release a powdery down to help with preening, but shoebills didn’t have these feathers, so they must be storks belonging to the family Ciconiiformes. “There is, in fact, not the shadow of a doubt that it is either a heron or a stork; but the question is, which?” zoologist Frank Evers Beddard wrote in 1905. More recent studies on the shoebill's eggshell structure and DNA have supported its place among the Pelecaniformes.

3. Shoebills poop on themselves.

Shoebills practice urohydrosis, the effective—if revolting—habit of defecating on their legs to lower their body temperature. In fact, this characteristic confused taxonomists: In the past, some felt that the shoebill’s habit placed it within the family of true storks, since all true storks also use their own droppings to cool off.

4. European naturalists were introduced to shoebills in the 1840s.

Shoebill stork
neil bowman/iStock via Getty Images

A German diplomat and explorer named Ferdinand Werne was the first European to hear about the shoebill. On his expedition in Africa to find the source of the White Nile in 1840, Werne camped at Lake No, part of a 12,000-square-mile wetland called the Sudd in what is now South Sudan. Werne’s indigenous guides told him “that they had seen an extraordinary bird, as big as a big camel, with a bill like a pelican’s, though wanting a pouch,” according to a 1908 edition of The Avicultural Magazine.

About 10 years later, a collector named Mansfield Parkyns brought two shoebill skins to England, giving British zoologists their first look at the weird bird. At an 1851 meeting of the British Zoological Society, naturalist John Gould presented a description of the shoebill based on Parkyns’s specimens and gave it the scientific name Balaeniceps rex.

5. Shoebills are also called whale-headed storks.

Balaeniceps rex means “whale-head king,” evidently a reference to its bill shape resembling the head of a baleen whale (as well as a shoe). Other names for the shoebill include the boat-bill, bog-bird, lesser lechwe-eater (referring to the shoebill’s alleged taste for lechwe, or aquatic antelope), and abu markub, or “father of a slipper” in Arabic.

6. Shoebills love lungfish.

Yum, lungfish! These air-breathing, eel-like fish grow to more than 6 feet long and comprise the shoebill’s favorite food. Shoebills also chow down on actual eels, catfish, lizards, snakes, and baby crocodiles. To catch their prey, shoebills stand still in the water and wait for an unsuspecting fish to appear. Then, the bird swiftly “collapses” on its target, spreading its wings and diving down bill-first to ambush the fish. Then, with the fish in its mouth, it decapitates it by grinding the sharp edges of its bill together.

7. Shoebills really earned their fierce reputation.

Victorian photographers learned the hard way that shoebills could be as mean as they looked. “The shoebill is capable of inflicting a very powerful bite,” 19th-century zoologist Stanley S. Flower wrote, “and is by no means a safe bird for a stranger ignorant of its ways to approach, a fact which we often have to impress on amateur photographers anxious to obtain ‘snap-shots’ of Balaeniceps at close quarters. It has been amusing to see how rapidly in some cases their enthusiasm has waned, when (as requested) confronted with the great bird screaming shrill defiance and crouching as if were about to spring, with gaping bill and half-spread wings.”

8. Shoebills have always been a rare curiosity at zoos.

Shoebill stork with its mouth open
neil bowman/iStock via Getty Images

In the 19th century, the Sudanese government made the shoebill a protected species, but that did not stop collectors from attempting to transport shoebills to zoos. Flower, then director of the Zoological Gardens in Giza, Egypt, brought three shoebills (along with four giraffes, nine antelopes, a lion, a leopard, three servals, two ostriches, two porcupines, an aardvark, five tortoises, a crocodile, and several other animals) on a train north from Khartoum to the gardens. The temperature rose to 118°F and the irritated shoebills barfed up their dinners. Their diet of fresh fish that Flower had ordered never materialized, so he resorted to feeding the birds canned shrimp. Miraculously, the birds arrived at the Zoological Gardens in one piece and survived in captivity for at least five years. Today, only a handful of zoos open to the public have shoebills, including the Prague Zoo in the Czech Republic, Pairi Daiza in Belgium, the San Diego Zoo Safari Park, and the Dallas World Aquarium.

9. Shoebills are worth thousands of dollars on the black market.

Shoebills rarely breed in captivity: In the last hundred years at least, only two chicks have hatched. In today’s zoos, all shoebills were either born there or were legally collected from the wild. Unfortunately, their scarcity and mystique have also made shoebills a sought-after bird for poachers in the illegal wildlife trade. According to Audubon magazine, private collectors in Dubai and Saudi Arabia will pay $10,000 or more for a live shoebill.

10. Shoebills are at risk of extinction.

The IUCN Redlist estimates between 3300 and 5300 mature shoebills live in the world today, and that number is decreasing. The iconic birds are threatened by a number of anthropogenic forces, including loss of their marshland habitat from farming, livestock ranching, oil and gas exploration, fires, pollution, and more. International wildlife groups and local conservationists are monitoring shoebill habitats in South Sudan, Uganda, Tanzania, and Zambia and patrolling the sites for poaching, but much more attention is needed to protect shoebills.

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