Recognized as a world biosphere reserve by UNESCO, Cat Tien National Park in southern Vietnam is home to about 1,500 species of animals, including endangered species.

A boatman carries his customers on a tour around Bau Sau biosphere reserve inside Cat Tien Park. Bau Sau was recognized by Ramsar Convention as a wetland of international importance.

Spanning three provinces of Dong Nai, Lam Dong and Binh Phuoc at more than 80,000 hectares, Cat Tien National Park boasts abundant natural resources and biodiversity.

Bau Sau, which spans nearly 1,600 hectares during the rainy season, is home to 286 Siamese crocodiles. A Siamese crocodile weighs 100-150 kilograms and lives in shallow water to avoid cold temperatures and high water pressure.

Tourists can hire a boat accompanied by a tour guide and a local ranger to view Siamese crocodiles, though it is advised to keep a safe distance of four to five meters.

After summer rains, butterflies appear across Cat Tien Park.

Andy Nguyen, who shot these photos and works as a guide in Cat Tien National Park, said tours are ideal for nature enthusiasts and scientific research purposes. Each tour includes a maximum six guests to limit the impact on animal behavior.

The best way to approach wildlife inside Cat Tien Park is via binoculars. Entry tickets to the park cost VND60,000 ($2.63) per person.

The Indochinese spitting cobra (Naja siamensis) varies from grey to brown to black, with white spots or stripes. Like a water pistol, a spitting cobra defends itself by shooting venom at an enemy’s eyes through a small hole in its bottom fangs.

“Those wishing to work as wildlife tour guides need to have a strong passion and understanding of biodiversity as well as animal behavior," said Andy.

The lesser yellownape (Picus chlorolophus) is seen perching on a branch inside Cat Tien Park. It has a typical woodpecker shape. The upperparts are green apart from the bright yellow tufted nape. Its neck and breast are green and belly whitish, finely barred with green.

With 351 species, accounting for about 42 percent of the total number of birds in Vietnam, including many rare species, Cat Tien is like a "miniature kingdom".

The banded kingfisher (Lacedo pulchella) is found in lowland tropical forests of Southeast Asia, including Vietnam.

The male has a bright blue crown with black and blue banding on the back while the female has rufous and black banding on the head and upperparts.

The orange-breasted trogon (Harpactes oreskios) is insectivorous and hunts from a perch. The species measures between 25-31 centimeters in length and weighs about 49-57 grams.

Both sexes possess orange-yellow underparts. The male has a cinnamon-brown back and yellow-green head while the female has a duller brown back and less extensive yellow on the underparts.

Germain's peacock-pheasant (Polyplectron germaini) is endemic to mainland Southeast Asia. The name commemorates the French veterinary army surgeon Louis Rodolphe Germain.

The bird, approximately 60 centimeters long, has a finely spotted buff, short crest, bare red facial skin, brown iris and purplish-blue ocelli on its upper-body plumage.

Bar-bellied Pitta (Hydrornis elliotii) is one of the most favored birds in Cat Tien National Park. Its natural habitat is seasonal tropical forests. Males have an aquamarine-blue patch on the back of the crown and dark purplish-blue one on the belly while females have a pale orangish head.

Cat Tien is home to endangered primates, including red-faced monkeys, pig-tailed monkeys, black-shanked douc langur, yellow-cheeked gibbons and lorises, all listed in the World Red Book.

This photo shows the yellow-cheeked gibbon, originally discovered and named after British naturalist Gabrielle Maud Vassal. The species is born blond and later turns black. Males carry this coloring throughout their lifespan and have distinguishing golden cheeks while females are born blond to blend into their mother's fur, but later turn black.

The pygmy slow loris (Nycticebus pygmaeus) is found east of the Mekong River in Vietnam, Laos, eastern Cambodia, and China.

The pygmy loris measures from 20-23 centimeters in length and weighs 300-600 grams. The species has a black nose, black skin on the hands and feet and little hair on the ears. The habitat of the pygmy loris in Vietnam was greatly reduced due to extensive burning, clearing, and defoliating of forests during the Vietnam War.

The package tour to Cat Tien Park organized by Andy Nguyen costs VND2-3 million a day, including accommodation, tickets and transportation. If you only hire a guide, the price is VND800,000 to 1.2 million a day.

Photos by Andy Nguyen