Crane and keeper have been in love for nearly 20 years and gave birth to 7 babies? Crane: It's true!

The Smithsonian Conservation Biology Institute (SCBI) is not well known to the public. It is located deep in the remote Blue Ridge of Virginia, has only 21 species of animals, and is open to the public only on October 2 every year. But in recent years, it has become famous because of a "gossip": it is said that a female white-naped crane living in the institute's campus and its male keeper have been "in love" for many years.

Mehgan Murphy

Faced with this controversial "love" across species, the party involved, SCBI, was very frank - yes, it did happen, but it was not what you think.

The story begins with the meeting of this pair of "partners".

First encounter

In December 2004, Chris Crowe joined SCBI as a bird keeper, responsible for taking care of 17 cranes and 36 ducks. Crowe believed that he could handle the situation with ease with his many years of experience in animal breeding and conservation, but he soon found that he was overly optimistic - among the animals assigned to him, there was a crane that had caused headaches for his colleagues.

Chris Swall with a Guam rail on his shoulder | Lexey Swall

The female white-naped crane Walnut is actually a newcomer to SCBI. She was transferred from the Cincinnati Zoo to SCBI in October of this year, but her story has been circulating for many years.

Most female white-naped cranes reach sexual maturity at the age of three, but Walnut, who is already 23 years old, showed no signs of reproduction. The Denver Zoo and Cincinnati Zoo, where she had lived before, had conducted multiple rounds of breeding attempts for her, but Walnut was hostile to the male white-naped cranes that shared the same room with her . An unconfirmed rumor even mentioned that Walnut had kicked and killed two adult males who expressed their love to her.

White-naped Crane (Antigone vipio) Walnut｜SCBI

However, people really needed this strong-willed girl to participate in reproduction.

The white-naped crane relies on the wetland environment of East Asia and Northeast Asia, but in the past few decades, due to habitat destruction and poaching , the number of wild adult white-naped cranes has rapidly declined to 3,700 to 4,500. A considerable number of these white-naped cranes often move around the unstable military demarcation line on the Korean Peninsula. The prospects for this species remain worrying.

In response to this situation, the International Crane Foundation (ICF) has led an artificial breeding program to breed white-naped cranes in zoos in North America and bring them to protected areas in Russia for release. However, the number of captive white-naped cranes is limited, and the decline in genetic diversity of crane populations is becoming increasingly serious.

An adult white-naped crane with eggs | Shell Kinney / Wikimedia Commons

Walnut is the key to alleviating this problem. Both of its parents were poached from the wild and were sent to the International Crane Foundation after being rescued. Walnut and six other chicks were born, providing valuable genetic diversity for the captive white-naped crane population.

Conservation work is in a race against time, but Walnut, who carries precious genes, shows no signs of reproduction, which undoubtedly makes conservation workers particularly anxious. Therefore, after repeated failures, they still send Walnut to SCBI for further breeding attempts. However, considering Walnut's past performance and increasing age, most people pessimistically believe that this last effort to "get rid of singleness" is also hopeless .

This is the difficult problem that the newly hired Claude faces.

Love grows over time

It can be said that from the first day of taking care of walnuts, Claude has been working driven by a strong sense of mission.

Walnut didn't like Crowe and repeatedly attacked him. His colleagues also reminded Crowe to protect himself. But this didn't affect Crowe's attention to Walnut. After taking care of other animals, Crowe spent almost all of his time with Walnut . He stayed by Walnut's cage, observing its behavior, using small snacks to please it, or just standing there to let it get familiar with his shape and smell.

Crowe tidies up the enclosure, and you can see SCBI’s amazing environmental enrichment｜SCBI

All of Crow's efforts were to ease Walnut's vigilance against him. Previously, SCBI had found an ideal male partner for Walnut, Ray, by comparing pedigrees; but Walnut's performance was as cold as ever, and Ray quickly changed his target and paired with another female, no longer showing any interest in Walnut. Therefore, collecting Ray's semen for artificial insemination became the only way - but this work required Walnut's cooperation. Now no one can easily get close to Walnut, let alone control it and complete the insemination.

The turning point came in late spring of 2005. At that time, Walnut had already adapted to Crow's daily presence and no longer ran away nervously when Crow approached. Realizing this change, Crow and his colleagues practiced repeatedly, and finally cornered Walnut in the corner of the cage and semi-forced Walnut's first insemination. A few weeks later, Walnut laid two eggs.

This was an exciting development, but new problems followed. Walnut left after laying the eggs, and Crow had to send the eggs to other adult birds for incubation. The hatched chicks did not attract Walnut's interest, as if the two eggs had never been related to her. A few months later, an even more bizarre situation occurred - Walnut took the initiative to courtship actions such as spreading its wings and lowering its head, but the target of the courtship was Crow, who was standing nearby and observing it.

Kurumi showing courtship gesture to Claude｜SCBI

Until this moment, researchers finally figured out the reason why Walnut refused to mate for a long time. It was not because of its introverted personality, but because of the misplacement of sexual imprinting , which made it unable to recognize its true peers - in other words, Walnut might think it was human.

A "wrong love"

As early as the mid-16th century, Thomas More, the founder of utopianism, described in his book Utopia that chicks would closely follow the first moving individual they saw after hatching. In the early 20th century, animal behaviorist Konrad Lorenz conducted in-depth research on this type of imprinting behavior and found that precocial bird chicks would produce parental imprinting through visual recognition and develop an attachment to objects that they recognized as their parents .

In this process, the chicks will further learn and memorize the appearance, voice and other characteristics of the "parent", which will affect their reproductive behavior in adulthood, that is, they tend to mate with targets similar to their "parents" . Lorenz believes that this sexual imprinting behavior can ensure that animals find mates of the same species.

Greylag goose chicks that left a parental imprint on Lorenz｜presidentsmedals.com

It is not uncommon for precocial birds that are completely artificially incubated and raised to mistake humans for their parents . Some of them have further evolved into sexual imprinting, viewing humans as targets of courtship and mating. This is especially common in parrots that are incubated and raised individually.

Sexual imprinting also occurs in mammals. The prototype of the World Wildlife Fund (WWF) LOGO, the giant panda Chi Ji at the London Zoo, showed similar courtship behavior to Hu Tao in response to her keepers because she was young when she was captured and had been interacting with humans for a long time.

Giant panda Chi Chi also showed courtship behavior to her keeper｜Christine Matthews / Wikimedia Commons

In today's animal conservation work, it has become a consensus to prevent animals from leaving too deep an impression on humans. But in 1981, when Hu Tao was born, the standardized work process had not yet been fully established.

Although the International Crane Foundation, which took in Walnut's parents, was the most advanced organization in the field at the time, the lack of funds and limited staff made them unable to take care of the imprinting issue . In fact, the place where Walnut was born was the stable of the founder of the International Crane Foundation. There was a serious shortage of staff to take care of the chicks, and even the children in the family had to participate in the care.

Due to the long time, people can no longer trace who was responsible for taking care of Walnut. We can only speculate that this kind volunteer may have treated the young Walnut closely like a pet at home. The meticulous care may have left a deep impression of humans in Walnut's mind.

Having the mother bird raise her chicks can greatly reduce the problem of misplaced imprinting｜SCBI

Walnut may be the last batch of young cranes affected by the dislocation imprint.

In the second year after it was born, the International Crane Foundation had begun to realize the problem of imprinting, and global animal conservation work has gradually reached a consensus on preventing imprinting. In particular, a mature method was quickly found for the conservation of precocial birds that are prone to imprinting. Before Claue switched to SCBI, he had participated in the conservation of whooping cranes. When interacting with young cranes, they had to wear clothes that imitated the feather colors of adult cranes and learn bird calls to reduce imprinting. Claue did the same when taking care of other newborn cranes at SCBI.

A conservationist cares for a whooping crane (Grus americana), wearing clothing that mimics the plumage of an adult crane and holding a prop that mimics the crane's head and neck. Joseph Duff / PBS WNET

This is an unfortunate story for Walnut, who has already grown up. Although some studies have shown that many birds can re-establish sexual imprints through frequent contact with their own kind and gradually get rid of their attachment to humans, this change has not occurred in Walnut - its misplaced sexual imprint is too solid, and Walnut may not be able to truly integrate into its own group throughout its life.

But Walnut was lucky, as he met a persistent and determined breeder. After finding out the truth about Walnut's refusal to reproduce, Clau took on the responsibility of being Walnut's partner. In the following years, Clau patiently guided Walnut to complete artificial insemination through dancing and participating in nest building. After Walnut finally showed signs of hatching, Clau would take care of the eggs for him in a timely manner - just like in nature, the male crane would help the female to hatch when she was resting.

To date, Hu Walnut has given birth to seven offspring, at least two of whom are already participating in the next generation of artificial breeding projects.

Rather than a piece of gossip, it is a touching conservation story｜SCBI

Telling this story on Valentine's Day inevitably touches on a sensitive topic: Can the relationship between Walnut and Crow be considered love?

From Walnut's perspective, the answer is yes. White-naped cranes are strictly monogamous birds, and the adult birds will maintain a lifelong bond after pairing. This bond is not only related to reproductive behavior - according to Crowe, in the first few years, whenever he returned to work after vacation, Walnut would always express his dissatisfaction with the inexplicable disappearance of his "partner"; when he accidentally saw Crowe taking care of other female cranes, Walnut's anger was even more obvious. Obviously, Walnut has invested all his emotions in this relationship.

Walnut｜Chris Crowe / SCBI

What about Crowe?

After nearly 20 years of companionship, there is no need to say much about Claure's affection for Walnut. He even plans to live nearby after retirement to continue fulfilling his lifelong "bond" with Walnut.

This is obviously not the kind of love that everyone talks about on Valentine's Day, which is limited to two individuals. It doesn't even belong to Walnut alone. But it is certainly love - this is a love letter that Crow dedicated to the beauty of nature . This love shines in the efforts of crane conservation around the world, and is also practiced by more animal conservation and environmental workers; even in the hearts of you and me who pay attention to these stories, the same love is surging for a long time.

The life span of a captive white-naped crane can reach 60 years. Crowe said: If she is still here when I retire, I will not leave | SCBI

Author: A man is wandering

Editor: Mai Mai

This article comes from the Species Calendar, welcome to forward

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