Fast Fact Attack: Endangered Species No. 56 – The Cat Ba Langur

New image for FFA 56 Cat Langur

Image courtesy of the Cat Ba Langur Conservation Project. This image is taken from their poster currently being displayed throughout Vietnam – Photographer Jörg Adler

Animals lose their habitat for a variety of reasons.  Slash and burn agriculture is one of the biggest culprits, followed closely by illegal logging and illegal plantation building. But Bonsai trees!  Who would have thought a species would succumb to someone stealing the trees from their protected park to make little potted things.  But, it is big business at the moment.  With hunting  (the main reason for the decline of the Cat Ba langur) no longer a worthwhile pastime, the locals are finding other ways to plunder the forests for profit.  And yet again, it is at the expense of the wildlife.

The common Ficus benjamica  ( fig – Cat Ba langur love figs)  can sell for more than one thousand US dollars as a Bonsai item.  But, that is absolute peanuts compared to some rewards.  One particular ‘harvester’ was reported to have said ‘some of his trees, which were about one hundred and fifty years old, sold for as much as three hundred and fifty thousand US dollars each’.  Wow!  Quite an incentive there for the unscrupulous!

Unfortunately, they are pillaging more than anyone’s fair share and the forest park is suffering.  Some of the trees are decades old, and are gone in hours.  Furthermore, it has become increasingly difficult to catch the perpetrators.

And, to make things a little worse;  in 2012, two lonely female Cat Ba were transferred from the limestone cliffs of Dong Cong  (where they had been stranded since the year 2000)  to the safety of Cat Ba Island.  Whilst high on the cliffs, locals cleared part of the mangrove forests below to create shrimp farms.  The trees had been used as a bridge by the langur.  The two females were unable to leave the cliffs for the next twelve years.  At times, the odds seem to be quite stacked against this species.

The Cat Ba langur is now one of the rarest primates on the planet.   And, it is one of the most endearing.  Its coat is dark brown, with bright to pale yellow on the head, shoulders and rump.  The long hair at the back falls across the shoulders like a cape.  Babies are born with bright orange hair, which will start to change at about four months of age.  Males and females are similar in appearance.  They have very long tails which well exceed the length of  body.  Their bodies grow to twenty four inches in length  (tails thirty-three inches)  and they can weigh up to twenty kilos.  They have long thin hands and feet, and reduced thumbs.  They have large salivary glands and complex sacculated stomachs, helping to break down plant material.

Known to be sociable, they live in groups of up to five to nine animals.  They are diurnal and sleep together in caves, tending to have many different caves at a time.  Every few nights, they leave one and move to another.  Groups establish their own territory and are defended by the dominant male.  Groups usually consist of one dominant male, some females and their offspring.  They are known to live up to twenty-five years.
Births normally occur in April.  Females birth every two to three years.  One single baby will be born.  Sadly, little else is known of the reproductive biology of the Cat Ba langur.

Karst limestone forest.
Cat Ba Island, Vietnam.
What they eat
Mainly folivorous, but they also eat flowers, fresh shoots, bark, and sometimes fruit.
Habitat loss is currently the greatest contributor to their declining numbers.  Hunting for sport and poaching for traditional medicine (monkey-balm) has been very popular in the past, but has now all but ceased.  They have not been hunted often for food either,  as their meat is said to smell very bad.
Status: Critically Endangered
The Cat Ba langur is listed on the  IUCN Red List of Threatened Species  as Critically Endangered.   A dramatic decline in numbers occurred, taking the population from two thousand eight hundred individuals in the 1960s to an alarming fifty-three individuals in the year 2000.  At this point, and at the behest of the Vietnamese authorities, an exceptional programme  (the Cat Ba Langur Conservation Project)  was put together by the Münster Zoo and the Zoological Society for the Conservation of Species and Populations to protect these langur and their habitat.   [1]   And the good news is,  it is now finally working.   The Cat Ba Langur population is stabilised at around the sixty mark, and educational programmes, amongst other provisions, have led to local villages and schools helping to protect and save a species they once were responsible for pushing towards the brink of extinction. A further program, the Forest Protection Clubs, was established in 2007.  The species still remains critical, but there is now hope for its survival.

“When the Earth is sick, the animals will begin to disappear, when that happens, The Warriors of the Rainbow will come to save them.”
Chief Seattle

19 thoughts on “Fast Fact Attack: Endangered Species No. 56 – The Cat Ba Langur

  1. Hi – I am the new Cat Ba Langur project manager. Nice post, and I appreciate you helping to raise awareness of the Cat Ba Langur. The photo you have posted is of the White Headed Langur (found in southern China, but not in Cat Ba). The photo was taken by Jed Weingarten (

    The Cat Ba Langur is fond only on Cat Ba Island and next year will no longer be considered to be a sub species of the White Headed Langur, but its own independent species.

    • Hi Earth Knight – How very nice to meet you. Thank you for reading my post, and thank you so much for your valuable information.

      Sometimes it is hard to get the right images on the internet and clearly I have made a mistake with this one! I do have another image, which I was originally unable to trace to source as well, but after a bit of research, I see it is one of yours and being used on your poster with the text: “Cat Ba Langur – Vietnam’s Rarest Primate – Symbol of Cat Ba Island”

      I would like to change the current image with this, using the following caption:

      “This image is taken from the poster currently being displayed throughout Vietnam by the Cat Ba Langur Conservation Project” – Photographer ………………….

      I have unable to read the name of the photographer!

      Please let me know if this is acceptable to you.

      I have also linked to the Cat Ba Langur Conservation Project.

      Best wishes, Amelia

      • Hello Amelia,

        It is indeed difficult to find the right images and information on the internet. And that photo of the white-headed langur is a lovely photo, just begging to be shared. I wish we had ones as nice as that one.

        The name of the photographer on the poster image is Joerg Adler, but the proper spelling is Jörg Adler.

        Thank you for adding a link to our project website (which very much needs to be updated to reflect a number of personnel changes).

        We are happy for all the support we can get and very much appreciate the efforts of folks such as yourself.

        Best, Neahga

  2. And yet another instance of incomprehensible stupidity! I’m really worried here because the numbers of monarchs migrating over our area have dramatically descreased since I retired. Sadly, again it’s because of the destruction of habitats in Mexico and elsewhere. Natalie

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