Who speaks to the cranes

When Bernhard Weßling first saw a pair of cranes 40 years ago, he had no idea that these birds would change his life

A short, blustering call penetrates the silence. Bernhard Weßling lets the telescope sink and peers over the meadow in Hansdorfer Brook. There, about 80 meters away, a pair of cranes strutted through the tall grass, in gray-black plumage, their necks stretched, their beaks up. “That was a warning call. It means I should withdraw, ”says Weßling. “I respect that”. He turns around, gets on his bike and drives back down the meadow path to the gravel road.

The migration season of the cranes begins in September and October. They fly from the breeding areas in the north to their winter quarters in the south. One of the routes runs over the Hansdorfer Brook, a nature reserve near Hamburg. They return to their territories in February and March and can often be seen doing so.

Bernhard Weßling is a man in his late sixties with friendly eyes, his skin tanned from the sun in the Brook. He has learned to understand the language of the cranes. Since he moved into the area with his young family almost forty years ago and heard the duet call of a couple of cranes for the first time, he has been investigating their behavior and communication. The hobby ornithologist became an internationally sought-after crane expert. He developed a technique that enables him to decipher their calls. This technology was the key to success in a globally unique reintroduction project for endangered whooping cranes.

Bernhard Weßling grew up in Herne in the Ruhr area. The nearby coking plant left soot stains on the white laundry in the garden, and the family of eight lived in poor conditions. Bernhard was a loner, spending months making a shoe shine machine out of scrap or repairing the phone line in the house. When Weßling talks about it, he sounds like someone who has discovered everything for the second time. The childlike enthusiasm that still drives him flashes in his eyes.

Every day after school he passed a shop window with a telescope on display. The planetary system fascinated him, so he saved up on the device in order to be able to look into space from now on. Once, when he was 14 years old, he was overcome by a deep fear. He realized that space is hostile to human life. Only on earth will he survive. He thought of how badly people treated the earth and deep depression befell the boys. He felt lonely and had little support from his family.

He found refuge in nature. In a forest in Herne he discovered the blue shimmering feather of a jay. He put them in a box. More and more feathers were added. And he got better with every feather. “I treated myself,” says Weßling and it sounds like an explanation for his life path.

After graduating from high school, he moved to Bochum and studied chemistry. During the semester break he earned a little extra money and analyzed illegally stored barrels on a cyanide dump. An apocalyptic image that shapes his attitude towards nature conservation to this day.

He did his doctorate in chemistry, then he moved with his wife and sons Bengt and Børge to Bargteheide, a small town northeast of Hamburg. There he founded his own company as a chemical entrepreneur. During a trip to Duvenstedter Brook, which adjoins Hansdorfer Brook, he heard the trumpet-like call of a pair of gray cranes for the first time.

At that time the animals were almost extinct in West Germany and the couple the family saw from the edge of the forest was the first to breed here in a long time. To this day there is probably no other place in the world where the cranes live and breed so close to a big city, he says.

In the Brook he met some nature and crane conservationists. He begins to deal with the animals. He learns amazing things in the process. Cranes live to be around 25 years old, and some species are said to be 80 years old. Your windpipe can be up to 1.30 meters long, the wingspan up to 2.40 meters. On the way to their winter quarters, they can fly for up to 24 hours at a time. To do this, they need surprisingly little food: around 100 grams are found in a crane’s stomach, 30 grams of which are pebbles.

Weßling tells all of this on the side as he steers his bicycle through the brook, past moor meadows and heather areas, which he scans with his eyes, looking for more crane pairs. Some things he tells just like from an encyclopedia, others sound more like a thriller: In 1997, a bird breeder was charged at the Kiel District Court for breeding illegally procured eggs. During the investigation, a smuggler’s ring was exposed. In 1999 several collectors were arrested who exchanged bird eggs like postage stamps.

That’s why, he says, the crane guards at Brook began to guard the nests of the breeding animals. He got involved himself in the early 1980s and later headed the crane protection program. He is fascinated by the elegance with which the cranes swing their wings and dance around each other. He begins to research and notes: There are many myths about these birds that have lived on earth for 60 million years, longer than the earliest mammals, and how ultimately all birds descended from dinosaurs. They are considered to be lucky charms and heralds of spring. Many believe that cranes are lifelong loyal to one another. In China and Japan they are said to be immortal.

But hardly anything was known about the social behavior, learning ability and intelligence of animals. In addition, the cranes that Weßling observes day after day behave differently than described in the scarce scientific literature. He is certain that he can observe different forms of behavior and communication. Confrontations, strategic action, but also grief and joie de vivre. Weßling, who has always had a strong musical ear, recognizes that the sound and melody of the calls differ depending on the situation. “A warning call sounds different than a duet call or a lure call,” he says.

He also believes that he can distinguish between individual animals based on the sound and pitch of their calls. Weßling is clear that his observations do not represent a verifiable, scientific test arrangement. There remain residual doubts. Is the crane that flies through the brook so often and disturbs other animals one and the same animal? Do crane pairs really stay together forever or is this just another myth?

In order to be able to answer these questions, he has to identify the animals unequivocally. Capturing and ringing them goes against his understanding of nature conservation. And so in 1996 he began to assign the animals based on their voice. There is no suitable method for analyzing bird calls at this point in time. So he bought a recording device and a powerful directional microphone with a gray, hairy windscreen. With it he wanders through the brook, waits by the roadside, in the bushes and behind trees to pick up their calls. Within four weeks he collects the first 140 recordings.

With the help of software that he developed with an engineer, he creates so-called sonagrams on the computer. They show the frequencies of the crane calls, i.e. the pitch, as a graphic along a time axis. The sonagram reveals the characteristic melody, the ups and downs of a call. In this way he learns to understand the language of the cranes, even if Weßling himself would never put it that way. “I was able to assign some call meanings, but that is only a fraction of their communication,” he says.

He also uses a second analytical method. It shows the volume per frequency, added up over the entire call time. Weßling calls it “power spectrum”. He can prove that each power spectrum is unique and thus a kind of “acoustic fingerprint”. This enables him to identify individual individuals. That hadn’t happened before.

The world of crane experts is small. Word quickly gets around that a hobby ornithologist from Germany has developed a method to identify cranes based on their voice. George Archibald, nature conservationist and founder of the International Crane Organization ICF, soon got in touch with him and involved him in various projects.

Archibald’s favorite cranes are the Japanese red-crowned cranes. And so it happens that Weßling, who is a chemical entrepreneur on a business trip to Korea and Japan in 1999, is sent on a detour to Hokkaido, the northernmost island of Japan. In the snow when it is freezing cold, he picks up the calls of the red-crowned cranes that live there. The individual recognition is used to monitor the animals and thus protect them. And it helps research to learn more about these beings who like to keep themselves hidden.

Archibald is delighted with the results. Therefore, a few months later, Weßling is at one of the most fragile borders in the world: In the demilitarized zone between North and South Korea. Here he wants to investigate the question of whether the cranes on the North Korean border “speak” differently than their Japanese relatives. He was a bit queasy when he and an attendant approached the entrance to the civil control zone, which he is only allowed to enter with a special permit. An armed soldier accompanies him to the demilitarized zone. Weßling works there under difficult conditions: he has to wait until the propaganda loudspeakers on both sides fall silent for a moment in order to be able to pick up the calls of the cranes.

Then he sets off on his largest and most important expedition to date. To Arkansas, Texas, to a huge nature reserve where the last few individuals of wild whooping cranes hibernated. Their existence was particularly threatened. The plane from Germany lands at a small airport called “Corpus Christi”. From there he drives out into the wilderness. The night is black and his car has no interior light, so he has to stop to read the map in the headlights. When he arrives at the entrance to the nature reserve, he sees an abandoned campsite. There are old caravans in which the volunteers who are involved in the nature reserve live, and now also the hobby researcher from Germany.

The area covers around 500 square kilometers. It’s 50 times bigger than the brook. Much of the area is not open to the public. When Weßling set off into the wilderness for the first time, he saw signs warning of killer bees. The other volunteers talk about alligators and poisonous snakes. He realizes why no one has taken up the call of a wild whooping crane so far. He pushes his doubts aside and from now on gets up before daybreak, drives his car into the night. Then he marches through the wilderness in sub-zero temperatures, shivering waiting for the cranes. At dawn and dusk he is the first person to be able to pick up their calls.

In addition to his thirst for knowledge, one thing above all drives him: to be so close to the animals filled him with gratitude. Sometimes he was moved to tears. “I was incredibly lucky,” he will later write about the expedition in his book. Ever since he found the blue jay’s feather in the forest as a teenager, studying nature has been a source of strength and relaxation for him. When he observes the birds, picks up their calls and analyzes them, he feels at one with his surroundings. Then the fear of the infinity of the universe and the loneliness out there disappears.

The Arkansas recordings are key to his greatest success. Weßling wants to use the calls to reintroduce young whooping cranes that were born in a breeding station in Texas to the wild. Together with an employee, he is developing a “Robo-Crane”, a kind of mechanical crane dummy, from whose beak mealworms are placed in front of the chicks after the call for “Come here, here is food” was sounded from a mini loudspeaker. This is how the young birds learn to look for food – and their own language. The keepers also dress up as birds. Later, during flight lessons, an ultralight aircraft with a disguised pilot and megaphone takes on the role of the guide bird.

In mid-October 2001, the first autumn train began, which was led by an ultralight aircraft. From Wisconsin to Florida, to the Chassahowitzka National Wildlife Refuge. A flight distance of 1218 miles. Eight young cranes follow the aircraft, accept it as a lead bird and thus learn the way to their winter quarters. In the following spring, the cranes that had survived the winter period fly back on their own. In the years that followed, one to two dozen young cranes are directed to Florida every year. For Weßling it is the confirmation and reward for his many years of work.

In Germany, the cranes have now been removed from the red list of endangered species – also because of people like him. He gives lectures and continues to campaign for the protection of animals. The crane population has recovered. There are around 7500 breeding pairs in Germany today, many of them live in Brandenburg and Mecklenburg-Western Pomerania. Wessling waves it away. That is no reason for euphoria: Cranes used to breed all over Central Europe, today they are still rare.

Cranes, he says, are threatened wherever people drain wetlands. “The Brook is also affected”. He pulls the brake on his bicycle, then he points to drainage ditches at his feet. The fact that something like this is allowed in a nature reserve is a point of contention between conservationists, foresters and the Senate. The drainage causes the birds’ feeding areas and resting places to disappear, and the breeding pairs leave their territory.

For Weßling, protecting cranes therefore first and foremost means protecting their habitat. A task that goes far beyond his research. He sighs, takes a picture of the ditch, gets back on his bike. Behind the next bend, the gable of a house appears on the horizon. It stands on the edge of a meadow, a stream flows next to it. Bernhard Weßling lives there. It is the last house before the nature reserve. It is also his habitat.

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