Bio Facts: Heron, Javan Pond
Javan Pond Heron
Southeast Asia – Cambodia, Indonesia, Malaysia, Myanmar, Philippines, Thailand, and Viet Nam; vagrant in Singapore
Shallow fresh and salt-water wetlands
Adult length: approximately 17 in (45 cm); coloration: white wings, a yellow bill with a black tip, yellow eyes and legs. Its overall color is orange, slatey and white during breeding season, and brown flecked with white the rest of the year.
In the wild: up to 20 years; in captivity: up to 30 years
In the wild, they eat insects, crabs and fish; in the Zoo, they are fed a scientifically developed, commercially available bird of prey diet, capelin and insects.
IUCN – Least Concern
The neck is able to retract and extend, and is retracted during flight. In flight the legs and feet are held backward.
Herons are carnivores. The most common hunting technique is for the bird to sit motionless on the edge of or standing in shallow water, waiting until prey comes within range. Birds may either do this from an upright posture, giving them a wider field of view, or from a crouched position, which is more cryptic and means the bill is closer to the prey when it is located. Having seen prey, the head is moved from side to side, so that the heron can calculate the position of the prey in the water and compensate for refraction, and then the bill is used to spear the prey.
Herons are monogamous and mostly colonial. The Javan pond heron breeds from June to September. Courtship usually takes place on the nest. Males arrive first and begin the building of the nest, where they display to attract females. Nests are usually found near or above water in vegetation. It is migratory.
The necks are able to kink in an s-shape, due to the modified shape of the sixth vertebrae. The legs are long and strong and unfeathered from the lower part of the tibia. The feet of herons have long thin toes, with three forward pointing ones and one going backward. The bill is long and harpoon like.
The non-breeding plumage of the Javan pond heron is similar to that of the Chinese (Ardeola bacchus) and Indian pond herons (Ardeola grayii) and is virtually indistinguishable in the field.
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion. The population trend is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion. The population size may be moderately small to large, but it is not believed to approach the thresholds for Vulnerable under the population size criterion. For these reasons the species is evaluated as Least Concern.
Jacksonville Zoo History:
Javan Pond Herons first arrived at the Jacksonville Zoo in 2009.