Honey is not only a good source of natural sugar; it is also delicious. Most people and many animals like eating it. Unless people build beehives, however, the only way for them to get honey is to find a wild bees’ nest and take the honey from it. Often, these nests are high up in trees, and it is difficult to find them. In parts of Africa, though, people and animals looking for honey have a strange and unexpected helper - a little bird called a honey guide.

The honey guide does not actually like honey, but it does like the wax in the bees’ honeycomb. The little bird cannot reach this wax, which is deep inside the bees’ nest. So when it finds a suitable nest, it looks for someone to help it. The honey guide gives a loud cry that attracts the attention of both passing animals and people. Once it has their attention, it flies through the forest, constantly waiting for the curious animal or person as it leads them to the nest. When they finally arrive at the nest, the follower reaches in to get at the delicious honey as the bird patiently waits and watches. Some of the honey and the wax always falls to the ground, and this is when the honey guide takes its share.

Scientists do not know how the honey guide digests the wax, but it is very determined in its efforts to get it. The birds seem to be able to smell wax from a long distance away. They will quickly arrive whenever a local beekeeper is taking honey from his beehives.

If a person follows a honey guide to a nest, the bird is especially sure of getting a good share. Tribesmen in Africa are very grateful to the honey guide for leading them to good sources of honey, but they are also afraid of the little bird. They believe that if they do not open a bees’ nest and leave some honeycomb for the honey guide, the next time the bird cries to them through the forest, it will lead them to a snake in revenge. So they should consider the share of the honey guide seriously.

Scientists estimate that over 500 million species have died out throughout evolution. Here is a list of 4 incredible extinct animals.

Researchers have discovered a unique group of polar bears who’ve survived in the absence of sea ice: by hunting from the ice that breaks off glaciers (冰川). The bears live in southeast Greenland and are a genetically(基因地) distinct subpopulation, which suggests they’ve been separated from other polar bears for around 200 years, according to a paper published this week in Science.

“The findings show us how some polar bears might survive under climate change. but I don’t think glacier habitat is going to support huge numbers of polar bears,” said Kristin Laidre, a polar research scientist at the University of Washington. “There’s just not enough of it. We still expect to see large declines in polar bears across the Arctic under climate change.”

When temporary ice sheets form on the ocean during each fall’s freeze, the bears walk across it in search of food, often by sitting next to gaps in the ice and waiting for seals to come up for air. When the ice melts (融化) in spring, polar bears typically survive between 100 and 180 days without food until the ice forms again. As temperatures rise, however, that period is becoming longer, which is harming the bears and pushing them toward starvation. The bears living in southeast Greenland go even longer without sea ice—around 250 days. But they’ve been able to continue bunting during that period by using large pieces of ice that break off from glaciers into the water.

There are roughly 26, 000 polar bears remaining across the globe. Though the southeast Greenland bears have adapted to surviving in their surroundings, rising temperatures may ultimately cause their glacial ice to shrink, too. As Steve Armstrup, a scientist with Polar Bears International says, the study “is not some kind of effective rescue for polar bears”. While the southeast Greenland bears are able to hunt through glacial ice today, he says, “In the future, that will change unless we arrest the rise of global greenhouse gases.”