Van Long nature reserve in northern Ninh Binh Province, well known for hosting the world’s largest population of Delacour's langurs, is also home to rare bird species. 

Around 80 kilometers to the south of Hanoi, Van Long Lagoon in Ninh Binh Province, famous for appearing in Hollywood blockbuster "Kong: Skull Island", is surrounded by karst limestone mountains and spectacular caves.

Covering more than 3,000 hectares, it is considered the Red River Delta's wetland nature reserve and home to thousands of terrestrial and aquatic fauna and flora. Among them are rare and endangered species listed in Vietnam’s Red Book such as Delacour's langur. 

A flock of Asian openbill storks (Anastomus oscitans) is seen perching on trees by Van Long Lagoon. It is a large wading bird in the stork family Ciconiidae. 

This distinctive stork is found mainly in the Indian subcontinent and Southeast Asia. It is greyish or white with glossy black wings and tail. The adults have a gap between their arched upper and recurved lower mandibles.

Northern pintail (Anas acuta) is migratory and usually winters in flooded habitats in northern and central plains, including Van Long lagoon. Both sexes have blue-grey bills and grey legs and feet.

The species feeds by dabbling for plants and adds small invertebrates to its diet during the nesting season. 

The Eurasian coot (Fulica atra) is a member of the rail and crake bird family. It has a slaty-black body, glossy black head and white bill with a white frontal shield. 

White-browed crake (Poliolimnas cinereus) feeds on a water lily pond. The species has small, slim-bodied crake with relatively long legs and toes and always scrambles over floating plants and densely vegetated wetlands. 

Pheasant-tailed jacana (Hydrophasianus chirurgus) is one of the most impressive birds seen in Van Long lagoon. 

During the breeding season, this bird is easily recognized by its long tail feathers. The pheasant-tailed jacana forages by swimming or by walking on aquatic vegetation.

The black bittern (Ixobrychus flavicollis) flies with a fish in its beak. Compared to related species, it has a longish neck and long yellow bill. The adult is uniformly black above, with yellow neck sides.

Their breeding habitat is reed beds. They nest on platforms of reeds in shrubs, or sometimes in trees and feed on insects, fish, and amphibians. 

A flock of Northern shoveler (Anas clypeata) flies into the sky above Van Long lagoon.

The male has a green head, a white breast, a chestnut belly and chestnut sides, and a blue patch on the forewing. They inhabit shallow marshes and lagoons where they use their large bills lined with comb like teeth to sift small organisms and seeds from the mud.

Falcated ducks (Anas falcata) are normally found in freshwater lakes, ponds, rivers and marshes surrounded by forest and feeds by dabbling for plant food or grazing. It is gregarious outside the breeding season and will then form large flocks.

Both sexes have black bills, a brown iris, gray to yellowish colored legs, and an iridescent green speculum on each wing. 

"Accessing birds in general in Vietnam is not an easy task. Because birds are often caught by traps, they are shy. Therefore, in order to get beautiful pictures of birds, in addition to shooting equipment, it is necessary to understand their behavior," said Nguyen Manh Hiep, who captured these photos during a trip to Van Long Lagoon. 

Van Long Lagoon is also home to more than 200 Delacour's langurs (Trachypithecus delacouri). 

It has the world’s largest population of Delacour's langurs, according to non-profit Fauna & Flora International (FFI) Vietnam. The Delacour’s langur is a primate indigenous to Vietnam, first discovered by and named after Jean Théodore Delacour in 1930.

Their fur is predominantly black, with white markings on the face and distinctive creamy-white fur over the rump and the outer thighs, while females also have a patch of pale fur in the pubic area. The Delacour's langur lives in limestone karst forest, either broadleaf evergreen or evergreen shrubs.

Photos by Nguyen Manh Hiep