At 4 a.m., the sound of the frogs seemed much hoarse after a night of busy calling for their mates, but the Cat stream still kept its constant murmuring rhythm through the rocks. At this time, Mr. Tran Van Hung gently woke everyone up to leave.
After preparing their belongings, the survey team divided into 3 directions, looking for high points where the recorder had previously been placed. Our group, in addition to Mr. Hung, also includes Tran Dang – an officer of Bac Huong Hoa Nature Reserve.
Mr. Tran Van Hung recorded the habitat characteristics and weather factors of the investigation area
It was still dark. Each person had to carry a flashlight on their head, clinging to each other’s feet and climbing up steep rock formations with countless dangers waiting.
From the stream bank to the listening point is only about 400 m but it took us more than half an hour to get there. The GPS locator shows that this mountain peak is more than 500 m above sea level. After checking, turning on the recorder, everyone turned off all flashlights, sat leaning against the forest tree, waiting for the gibbons to sing. Wild mosquitoes came buzzing and rushed to suck blood.
While waiting, Tran Dang said just enough to hear that Siki gibbons often howl at 5-9 am. Their howls are believed to protect territory, food, and may also be used to attract mates. As for males, their howls are loud, strong, resonant and clear. Females often howl after males in the herd, lasting longer and more persistently.
Siki gibbon has the scientific name Nomascus siki, belongs to the extremely endangered group in the world Red Book. In Vietnam, this primate species has only been recorded in the mountainous areas of three provinces, Quang Tri, Quang Binh and Ha Tinh, with quite modest numbers.
“Observing them is very difficult, because this species is very clever. They only live in forests around 1,000 m high, where there is no human impact. Therefore, the method of investigating listening points is based on Howling is used to evaluate the growth density of Siki gibbons” – Dang said.
The story only interrupted when the opposite high mountain peak began to hear the howl of the Siki gibbon after the song of the “lonely, lonely” bird. The howl came from one mountain peak to the other. This herd stops howling and another herd follows. Which are “hiu…u….u ha…ah…ah”, “whistle…u…u whistle”, “whistle, whistle”, “whistle…whistle…whistle…whistle…”. The whole forest was immersed in the chords of the ape Siki like that, it sounded strangely pleasing to the ears.
Both Hung and Dang strained their ears to listen to determine the azimuth and distance from the listening point to the location of the howling gibbons. They meticulously recorded the coordinates of the listening point, time, frequency, volume and number of individuals howling. Even habitat characteristics and weather factors are meticulously recorded. These are the basis for investigating and determining the living area, number of individuals, and number of Siki gibbon herds in the forest stand managed by this unit.
According to Mr. Hung, there were times when the investigation team encountered the rain and could not capture the howl of the Siki gibbon, so they had to stay in the forest for many days to continue investigating. During this process, the members of the group faced many dangers such as being bitten by poisonous snakes, suffering from wild malaria or falling…
Recorded hundreds of herds
In 2022, through investigation, the Management Board of Bac Huong Hoa Nature Reserve determined that in the forest management unit there are about 112 herds with 336 Siki gibbon individuals living. That is the result after a year of staff of this unit coordinating with the consulting unit to develop an outline, plan and investigate in the forest.
Mr. Ha Van Hoan, Director of the Bac Huong Hoa Nature Reserve Management Board, said that the Siki gibbon area is mainly distributed in rich and medium tropical evergreen broadleaf closed forests. Specifically, in 21 forest sub-areas in Huong Lap, Huong Viet, Huong Son and Huong Linh communes (Huong Hoa district) all recorded Siki gibbons living.
The survey team patiently waited for Siki the ape to howl
According to Mr. Hoan, Siki gibbon is one of the primate species of concern in Vietnam and around the world. However, funding for conservation of this species is still very limited, especially domestic funding sources.
“Because their reproductive rate is very slow and their development takes a long time, they can easily become extinct if they are not cared for and protected” – Mr. Ha Van Hoan worried.
Two threats
According to Mr. Ha Van Hoan, in many places, due to its loud and long song and the brightly colored females, Siki gibbons are often the subject of wildlife hunting activities. Besides, habitat destruction is an indirect threat to the living environment of Siki gibbons.
“Understanding these two threats to this primate species, we have been constantly propagandizing and mobilizing people to join hands to protect the forest and conserve the species. Along with that, we have increased patrol activities, monitoring to determine the development trend of the population, from which effective conservation plans are created” – Mr. Hoan affirmed.
