CHENGDU, China — Japan and China share an age-old love for cranes. In recent years there have been many exchanges and co-operative projects between these countries, working toward the protection of cranes.

Black-necked cranes begin their mating dance in Nongbaotan.

One of the major focuses of crane conservation in China is the black-necked crane, which, since its migration route lies entirely within China’s borders, is little known to the rest of the world. In May this year, I joined a group to study black-necked cranes in the Nongbaotan wetlands of the Tibetan Plateau.

The black-necked crane (Grus nigricollis) is a large waterfowl, standing about 150 cm tall. Its crown is bare and bright red; the rest of its head and neck are black. It breeds in marshlands on the Tibetan Plateau between April and October, and then migrates to the Yunnan-Gueizhou Plateau to winter.

As recently as 1983, fewer than 200 of the birds were reported to remain, and little was known about them. On the brink of extinction, the black-necked crane was listed as a Class-1 protected bird in China.

In the 18 years since then, vigorous conservation measures with the support of many international organization have met with significant success. Areas of crane habitat have been designated as nature reserves. The count of birds has now recovered to a figure between 4,700 and 5,000 cranes.

A newly hatched black-necked crane chick considers its surroundings in Qinghai’s Nongbaotan wetlands. Below, an adult crane in captivity.

It was early summer on the Tibetan Plateau when we arrived at Nongbaotan Nature Reserve in Yushu Tibetan Autonomous Prefecture in Qinghai Province, a major breeding area for the cranes. The reserve is about 4,200 meters above sea level, 30 km long and 4 km wide. The views are spectacular: lakes and marshlands dot the area, white clouds float like fine gauze in the sky, with black-necked cranes flying against the background of the magnificent Bayankela Mountains.

We camped in an area where some nine pairs of cranes were reported to nest during the cool Tibetan summer. Near the shore was a high cairn of stones, called a doubeng in Tibetan. Each pilgrim who passes must add a stone to the cairn and walk round it once, an act considered to accrue merit equivalent to a recitation of the scriptures.

We did not have long to wait. Early one morning a pair of black-necked cranes flew down from the clouds and alighted on the grassland scarcely 200 meters from where we watched. Almost at once they began their mating dance. One bird spread its wings, jumped up and down, picked up a stick in its bill and threw it up into the air. Then it flapped its wings and ran in a large circle, leaping and dancing as if full of joy. At the same time its partner bowed and stretched out its neck, beat its wings and rose and fell, cutting an elegant figure.

When we tried to approach them, however, hoping to get closer photos of the dance, they spotted us at once and retreated into the marsh, crying rhythmically. The male’s cry sounded like “Ga — ga, ga,” while the female’s shrill cry went “Gage — gage — gagege.” They sang on together, their bills pointing up to the sky, and were still easily audible 1.5 km away.

Back by the cairn I asked our guide, a Tibetan herdsman called Doujiminchou, how to tell the male from the female.

“Observe the body and the behavior,” Doujiminchou advised. “The male’s neck is thick and strong, usually wider at the front and upper part, whereas the female’s neck is thinner, and often bends.”

At that moment we heard the cry of a black-necked crane calling to its partner: “Ge — ge — ge.” A pair of them were walking quite near our campsite. They bobbed their heads up and down as they walked, crying loudly. The male stepped behind the female, and his cry became more loud and sonorous. Leaping onto the female’s back, he mated with her for 5-6 seconds; then both danced and sang for about two minutes.

The nest is built on a small grassy island, surrounded by water to guard against enemies. The male and female take turns incubating the clutch of (usually) two eggs for about 30 days until they hatch. The parent birds tend their babies lovingly, keeping a sharp eye out for predatory gulls and feral dogs.

Sitting in Doujiminchou’s tent at dusk, I listened as he chanted Buddhist scriptures.

“The black-necked crane is an auspicious bird of the holy mountains,” he said. “They must not be harmed.”

I sat cross-legged on a blanket and drank pure qingke (highland barley) wine, but I was intoxicated already by the fairyland of the Bayankela Mountains, inhabited by the fortunate black-necked crane that has returned from the brink of oblivion.