In a letter to relevant agencies in mid-July, Mr. Rick Passaro, director of the white-headed langur preservation project, said that guards had not seen a langur since April.
The last time guards saw the three female langurs together on April 14, 2012. Since April 30, cameras laid by the project only filmed two of the three female langurs. The guards had only seen two langurs since then.
Previously, there were four white-headed langurs, including a male and three females on Dong Cong Islet, to the northwest of Cat Ba Island. In 2001, a hunter shot to death the male langur. Meanwhile, locals have destroyed forest to build shrimp breeding lagoons, which have prevented the three remaining female langurs from joining other langur troops.
Eight years ago, experts suggested moving the three langurs from Dong Cong Island to Cat Ba Island, to enable them to join other troops of langurs. This project was approved and experts planed to move the langurs in October 2012.
However, several months before this project is implemented, one langur has disappeared.
According to guards, this langur was seen the first time in 1990. The animal was around 5 years old at that time.
“That langur is around 27 years old at present. The average lifespan of langurs is 25 years. It is highly possible that the langur is dead,” Passaro said.
Guards said in early 2011, they saw the three langurs in 2-3m and the disappeared langur lost many teeth and it moved very slowly.
Mr. Hoang Van Thap, director of the Cat Ba National Park said it is difficult to investigate the missing of the langur because langurs live in the 30,000ha forest.
“After several months of investigation, we believe that the langur died of old age,” he said.
The Cat Ba langur (Trachypithecus poliocephalus) is a critically endangered langur from Cat Ba Island.
The dominate subspecies, often known as the golden-headed or Cat Ba langur, is the rarest primate in the world.
The golden-headed langur is considered to be one of "The World's 25 Most Endangered Primates," and is assumed to have declined by 80 percent over the last three generations.
According to the Cat Ba Langur Conservation Project, the The Cat Ba langur's skin is black and the pelage color is dark brown; head and shoulder are bright golden to yellowish-white. The tail is very long (ca. 85 cm) compared to the body size (ca. 50 cm). Babies are colored golden-orange; the pelage starts to change its color from about the fourth month on. Males and females look alike.
The Cat Ba langurs live in groups, usually one male with several females and their offspring. They are diurnal animals, adapted to living in limestone habitat. Each group has its own territory, defended by the adult male who also initiates the location of the group. The females usually give birth to a single baby every 2-3 years, which becomes mature at 4-6 years old. Langurs have an average life expectancy of 25 years. Food mainly consists of leaves, but also fresh shoots, flowers, bark, and some fruits.
There are around 50-60 langurs on Cat Ba Island and two langurs at the primate rescue center in Cuc Phuong National Park in Ninh Binh province.
The fate of langurs is now the public concern after several photos featuring several langurs, including a pregnant one which was killed, and were posted on Facebook.
After this incident, experts had been worried that this rare animal would go extinction like one-horn rhino in Vietnam. Compiled by Thu Ha