SARUS CRANE (Grus antigone antigone)

NOTES ON SARUS CRANE ( Grus antigone antigone) 

The Sarus Crane ( Grus antigone antigone) is basically a wetland bird and widely distributed in India. The Sarus Crane has 3 disjunct populations in the Indian subcontinent, South-East Asia and northern Australia. The nominate race (c. 8,000 to 10,000 birds)  inhabits Pakistan, northern and central India, and Nepal, with occasional  vagrants in Bangladesh. Subspecies sharpii occurs in South-East Asia where its  range has declined dramatically and it is now confined to Cambodia, extreme  southern Laos, south Vietnam (c.800-1,000 birds between these three countries),  and Myanmar (c.500-800 birds). The Australian population gilliae is estimated  at less than 10,000 individuals. It is extinct in Thailand, Malaysia, the Philippines  and probably China. 

Description: The adult Sarus Crane is very large with grey wings and body; a bare red head and part of the upper neck; a greyish crown; and a long greenish-grey pointed Bill. In flight, the long neck is held straight, unlike that of an heron, which folds it back, and the black wing tips can be seen; the crane's long pink legs trail behind them. This bird has a grey ear covert patch, an orange-red iris and a greenish-grey bill. Juveniles have a yellowish base to the bill and the brown-grey head is fully feathered.

Measurements
G. a. antigone
Culmen 172–182 mm (6.8–7.2 in) ? Wing 670–685 mm (26.4–27.0 in) 625–645 mm (24.6–25.4 in) Tail 255–263 mm (10.0–10.4 in) ? Tarsus 310–355 mm (12.2–14.0 in) ?
Combined
Culmen 156–187 mm (6.1–7.4 in) 155–169 mm (6.1–6.7 in) Wing 514–675 mm (20.2–26.6 in) 557–671 mm (21.9–26.4 in) Tail 150–200 mm (5.9–7.9 in) 100–200 mm (3.9–7.9 in) Tarsus 269–352 mm (10.6–13.9 in) 272–350 mm (10.7–13.8 in) Weight 8.4 kg (19 lb)

The bare red skin of the adult's head and neck is brighter during the breeding season. This skin is rough and covered by papillae, and a narrow area around and behind the head is covered by black bristly feathers. 

The sexes do not differ in plumage although males are on average larger than females; male Sarus of the Indian population can attain a maximum height of about 180 cm (5.9 ft) making them the world's tallest extant flying bird. 

Habitat: It inhabits wet and dry grasslands, agricultural fields, marshes and pools, either  open or enclosed by forest. It prefers a mixture of flooded, partially flooded and dry ground for foraging, roosting and nesting. In the Indian subcontinent, populations make seasonal movements in response to monsoons and droughts

Food: Sarus Cranes forage in shallow water,  fields, frequently probing in mud with their long bills. They are omnivorous, eating insects (especially grasshoppers), aquatic plants,frogs, crustaceans and seeds. Sarus Cranes may in rare cases feed on the eggs of birds and turtles. Plant matter eaten includes tubers, corms of aquatic plants, grass shoots as well as seeds and grains from cultivated crops such as groundnuts and cereal crops such as rice.

Breeding Behavior:

NESTING DETAILS:

Nest Site Selection:  The Sarus Crane generally nested in Marshy areas land but due to depletion of such areas Sarus also nested in  agricultural marshlands such as paddy fields. Sarus pair select a elevated area in marshy area which is surrounded by water completely. On such area they build nest platform using surrounding vegetation. 

Sarus Crane generally show strong attachment to previous year nest site even when previous clutch size get destroyed. So less nest site fidelity.

Nest:  The Nest building activity generally started  just 2-3 days prior to egg laying. Both partners actively engaged in nest building. Nest is platform which is generally oval in shape and partially submerged in water. In the central part, little depression is made and it filed with soft green material. this addition of green material continuously going on through out incubation period. This addition is also known  as 'Amendment activity'.

    If there any changes happens in water level then pair immediately adds vegetation to nest platform and increased the level. Even when chick is present in nest, amendment activity was observed. when eggs are present in nest the incubating bird periodically stood up on the nest for egg rolling and also performed amendment activities.

Eggs:  Generally white colour with shades of creamy yellow and Pinkish or light blue pigmentation. They are long oval shape with mean length 10 cm and mean width 6.5 cm, weighted  200 gm  approx. The clutch size is generally 2 in some case 3 is also recorded. 

Incubation & Parental care : The incubation period is of 30-40 days and when chicks come out the egg, the eggshells are removed by the parents after the hatch either by carrying away the fragments or by swallowing them. The chicks are fed by the parents for the first few days, but are able to feed independently after that and follow their parents for food. When alarmed, the parent cranes use a low korr-rr call that signals chicks to freeze and lie still.  Young birds stay with their parents for more than three months.

Approximately 30% of all breeding pairs succeed in raising chicks in any year, and most of the successful pairs raise one or two chicks each, with brood sizes of three being relatively rare.

CURRENT STATUS &  POSSIBLE THREATS:

There were about an estimated 15–20,000 mature Sarus Cranes left in the wild in 2009.The Indian population is less than 10,000, but of the three subspecies, is the healthiest in terms of numbers. They are considered sacred and the birds are traditionally left unharmed, and in many areas they are unafraid of humans. Many farmers in India believe that these cranes damage standing crops, particularly rice, although studies show that direct feeding on rice grains resulted in losses amounting to less than one percent and trampling could account for grain loss of about 0.4–15 kilograms (0.88–33 lb).

The Sarus Crane is classified as Vulnerable on the IUCN Red List. Threats include habitat destruction and/or degradation, hunting and collecting, as well as environmental pollution and possibly diseases or competing species.