Across the globe, butterflies are under threat. According to the German Wild Animal Foundation, the number of butterfly and moth species present in Germany has halved over the last 30 years. For diurnal butterflies, that decline is nearer 70 percent. This photo shows Colias hyale, which was selected as Germany's "butterfly of the year" in 2017.

Butterflies adore the sweet sap from flowers and blossoms, and enjoy a broad palate. But plant diversity is dwindling, particularly in regions where intensive monoculture agriculture dominates, which leaves little choice for our beloved butterflies.

Crop protection products like herbicides and pesticides destroy biodiversity. Wild herbs, plants or flowers can't survive in areas with monoculture farming. In many parts of Germany, the scarce Swallowtail butterfly pictured here was once a common sight, but has now vanished from the landscape.

The big problem is that pesticides aren't only harming butterflies. Studies show that some regions have seen 80 percent decline in insect numbers compared to 30 years before. Bees, bumblebees, dragonflies, wasps, flies, bugs and butterflies - they all struggle to survive in our intensive-agricultural world of pesticides and fertilizers.

A recent study shows that bird numbers are also in a decline. One reason: They can't find enough insects for food. The population of northern lapwings in Germany, for example, is estimated to have shrunk by 80 percent between 1990 and 2013. The number of whinchats has dwindled by 63 percent and black-tailed godwits by 61 Prozent.

Astonishingly, the butterfly decline is particularly obvious in the countryside. In towns and cities butterflies are more numerous. They thrive in parks, on cemeteries, on uncultivated land but even in city centers. Here, they obviously find the plant diversity which they miss in the countryside.

Among giraffes, there's more same-sex than opposite-sex activity. In fact, studies say gay sex accounts for more than 90 percent of all observed sexual activity in giraffes. And they don't just get straight to business. Male giraffes know how to flirt, first necking with each other - that is, gently rubbing their necks along the other's body. This foreplay can last for up to an hour.

Both female and male bottlenose dolphins display homosexual behavior, including oral action where one dolphin stimulates the other with its snout. In the bottlenose world, homosexual activity occurs with about the same frequency as heterosexual play. Male bottlenose dolphins are generally bisexual - but they do go through periods of being exclusively homosexual.

Homosexuality is common among lions as well. Two to four males often form what is known as a coalition, where they work together to court female lions. They depend on each other to fend off other coalitions. To ensure loyalty, male lions strengthen their bonds by having sex with each other. Many researchers refer to this behavior as your classical "bromance" rather than homosexual pairing.

Homosexual activity between male bisons is more common than heterosexual copulation. That's because female bisons only mate with bulls about once a year. During mating season, males that get the urge engage in same-sex activities several times a day. And so, more than 50 percent of mounting in young bison males happens among the same gender.

Both female and male macaques engage in same-sex activity. But while males usually only do so for a night, females form intense bonds with each other and are usually monogamous. In some macaque populations, homosexual behavior among females is not only common, but the norm. When not mating, these females stay close together to sleep and groom, and defend each other from outside enemies.

The Layson albatross, which nests in Hawaii, is known for its large number of homosexual partnerships. Around 30 percent of pairings on the island of Oahu are made up of two females. They are monogamous, and usually stay together for life - as it takes two parents to successfully rear a chick together. The chicks are often fathered by males that are already in another committed relationship.

Bonobos are considered the closest living relative to us humans, and are known for seeking sexual pleasure. They copulate frequently, including with the same sex. They do so for pleasure - but also to bond with each other, climb the social ladder and reduce tension. About two-thirds of homosexual activities happen among females, but also males enjoy a roll in the grass with each other.

Like many birds, swans are monogamous and stick with one partner for years. Many of them choose a same-sex partner. In fact, around 20 percent of swan couples are homosexuals - and they often start families together. Sometimes, one swan in a male couple will mate with a female, and then drive her away once she's laid a clutch of eggs. In other cases, they adopt abandoned eggs.

Male walruses only reach sexual maturity at the age of 4. Until then, they are almost exclusively gay. Once they've reached maturity, most males are bisexual and mate with females during breeding season - while having sex with other males the rest of the year. It's not just gay sex though - the males also embrace each other and sleep close to one another in water.

Studies suggest that up to 8 percent of males in flocks of sheep prefer other males, even when fertile females are around. However, this only occurs among domestic sheep. Studies have found that these homosexual sheep have a different brain structure than their heterosexual counterparts, and release less sex hormones.

January 20 is Penguin Awareness Day - which is not the same as World Penguin Day on April 25. Adelie penguins and all their relatives are so great that someone decided to give them not one but two annual holidays. So in honor of this special day, DW is raising awareness of the adorable, flightless birds.

They can't fly and they're not great at walking either. Despite their fancy tuxedoes, penguins often look slighty clutzy on land. That all changes as soon as they hit the seas. Their streamlined bodies allow them to shoot through water like a torpedo. Even the tallest and heaviest species, the emperor penguins, can swim as quickly as 2.7 (8.9 feet) meters per second.

It seems like an odd combination at first: sand, sun - and penguins? But the birds don't just live in Antarctica. These guys are African penguins. A whole colony of them can be found at Simon's Town in South Africa. Sunny Australia is home to the little penguins. The smallest penguin species grows to be only 30 centimeters (12 inches) tall. Emperor penguins get to be 1.3 meters (4.3 feet).

Here you see an honorary Colonel-in-Chief inspecting his troops. King penguin Brigadier Sir Nils Olav III. lives at Edinburgh Zoo in Scotland. He was knighted in 2008. In 1913, Norway presented the zoo with its first king penguin and in 1972, the King's Guard adopted one: Nils Olav I. He and his two successors at the Edinburgh Zoo have since risen through the ranks from mascot to Colonel-in-Chief.

After oil spills penguins are often cleaned by volunteers. But the gentle hands can't scrub all the oil from the birds' sticky feathers. That's why they put little wool sweaters on the penguins so they don't swallow oil trying to clean their feathers themselves. The oil also destroys the birds' isolating fat layer and the sweaters protect them from the cold.

The cute birds are also successful movie stars. Movies like "The Penguins of Madagascar" and "Happy Feet" were successful animated flicks that featured penguins as protagonists. "March of the Penguins" was a documentary about emperor penguins and the struggles they go through for their chicks. It won the Oscar for Best Documentary Feature.

The film shows emperor penguins during breeding season. The birds walk for weeks from the sea to their breeding spots in the middle of Antarctica's ice dessert. There the male keeps the egg on his feet. The female goes back to sea to eat. The males huddle together to keep warm in the freezing winds. When the chick hatches after 60 days of growing, the father has lost one third of his body weight.

The Bremerhaven Zoo in northern Germany wanted to breed the endangered Humboldt penguins in captivity. But because it's hard to determine the birds' gender, no one at the zoo realized for a long time that most of the animals they had were males. The penguins didn't mind and formed "gay" couples. In the absence of egg-laying females, the homosexual couples tried to hatch stones.