Grus antigone

Geographic Range

Sarus cranes ( Grus antigone ) are located in northern India, southeast Asia, and in the northern parts of Australia. Most sarus cranes are widely distributed along the Gangetic plain and in eastern Rajasthan in the northern states of India. Population densities decrease going to the south. This species is not known to be migratory.

• Biogeographic Regions
• oriental oriental
  • native native
• australian australian
  • native native

Habitat

Sarus cranes have grown accustomed to living in large agricultural areas, specifically along low wetlands and flooded rice paddies. They tend to prefer natural wetlands over agricultural paddies however, there is still debate on which habitat these birds prefer. Extensive research has been performed to understand the interaction of the sarus crane with paddy ecosystems. Paddies have become more desirable habitats for these cranes because nesting sites are situated in proximity to areas with an abundance of food. Sarus cranes, though likely to use wetlands adjoining flooded rice paddies, also have the ability to make use of drier habitats relative to other crane species. They have also adapted well to the increased presence of human activity.

• Habitat Regions
• terrestrial terrestrial

• Terrestrial Biomes
• savanna or grassland savanna or grassland

• Wetlands
• marsh marsh

• Other Habitat Features
• agricultural agricultural

Physical Description

Sarus cranes are considered the tallest of flying birds with a standing height of 1.8 m (5.9 feet). They can have a wingspan of 2.5 m and can weigh anywhere from 5 to 12 kg. These cranes have a very light gray coloration throughout their trunk with darker gray patches near the tips of their wings. The most prominent feature, however, is the bright red coloration on the head and top of the neck. The very top of the head has a white patch as well as a small white spot behind the eye. The beak tends to be white to light grey in color, and the long legs have a pale red coloration. Males and females do not differ in their coloration, but males are typically larger than females. Adults and juveniles can be distinguished by their crown color, that is, the coloration of the head. Juveniles (less than four months of age) have a solid “dull brick red” color while adults have a “dark red color with a bald patch on top.”

• Other Physical Features
• endothermic endothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger

Reproduction

The main breeding season for sarus cranes typically lies within the rainy season, between the months of June and September. It has been suggested that sarus cranes will mate for life, though there has been little research to substantiate this claim.

Not much research has been carried out on the mating behavior of the species. However, as a member of the crane family, it is likely that they perform courtship dances in order to attract attention and to impress the other mate. Dancing behavior typically occurs across the age groups, from young fledglings developing motor skills to mated pairs displaying courtship.

• Mating System
• monogamous monogamous

Breeding and egg laying usually peaks July through September, though if conditions are favorable, breeding can occur year-round. Pairs of birds build enormous nests within the wetlands. Often, these nests look like islands because they are built with reeds and grasses which can reach roughly two meters high above the water surface. Crane nests can also be found in local areas of dry grasses. Clutches generally consist of two or three eggs though some nests will have only one egg. Most members of the crane family lay eggs which incubate in about 28 to 31 days.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• year-round breeding year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous

After hatching, both parents are thought to contribute to the development of fledglings. Each parent feeds the offspring and cares for them until well past the juvenile stage of development. Parents coerce their offspring away from the nests to find mates of their own and start the cycle over again. After mating during the rainy season, parents will remain with their fledglings until about mid-November, when the juveniles become independent and free-flying.

• Parental Investment
• altricial altricial
• male parental care male parental care
• female parental care female parental care
• extended period of juvenile learning

Lifespan/Longevity

Little is known about the lifespan of sarus cranes. It has been estimated that cranes in general can live 30 to 40 years, though some species of cranes have been recorded to live up to 80 years.

Behavior

Sarus cranes are considered to be the least social of the crane family. Especially while nesting, these birds can become very protective and act with aggression to any intruders. Therefore, they can be seen as a territorial species. Breeding pairs stay close to areas with an ample water supply. Non-breeding pairs flock together in larger wetland areas. This increases the interaction between the cranes and the likelihood of an individual finding a suitable mate. Despite the territorial behavior of breeding pairs, sarus cranes form larger flocks during the non-breeding season. Flock sizes usually depend on the area of the wetland. Within these flocks, the birds feed and roost.

• Key Behaviors
• terricolous
• flies
• diurnal diurnal
• motile motile
• migratory migratory
• territorial territorial

Home Range

During the breeding season, sarus cranes establish territories, but little is known about the size of the territories.

Communication and Perception

As noted above, cranes in general are known for their dances, often displaying their feathers. Sarus cranes use these dances to attract possible mates, though it has been suggested that the dances can be used to establish territory. There is not much research present to support these claims, however. These dances can be accompanied by the characteristic loud trumpeting sounds of the crane call.

• Communication Channels
• visual visual
• acoustic acoustic

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Breeding pairs prefer to forage on the vegetation of natural wetlands but will also forage on the wet crops of rice and wheat. Sarus cranes also consume soybean and cucumber crops, and show preference to these crops. They have also been known to feed on aquatic vertebrates and invertebrates.

• Primary Diet
• carnivore carnivore
  • eats terrestrial vertebrates
  • insectivore insectivore
• herbivore herbivore
  • granivore granivore
• omnivore omnivore

• Animal Foods
• amphibians
• fish
• insects

• Plant Foods
• seeds, grains, and nuts

Predation

Jackals ( Canus aurius ) and house crows ( Corvus splendens ) have been recorded to prey on crane eggs and adults. Both of these predators are opportunistic. Wild dogs also prey on eggs and fledglings. It appears that these birds are common targets in human hunting and egg collecting.

Ecosystem Roles

As a predator on small vertebrates and invertebrates, sarus cranes play an important role in maintaining these populations. Abundance of their eggs can also influence food sources for jackals and house crows. They also help maintain vegetation. Sarus cranes can be primary, secondary, and tertiary consumers.

Economic Importance for Humans: Positive

Little is known about the positive benefits of sarus cranes for humans, but it has been suggested that the chicks and eggs as well as adults are harvested for food and trade and supposed medicinal purposes.

• Positive Impacts
• pet trade pet trade
• food food
• source of medicine or drug source of medicine or drug

Economic Importance for Humans: Negative

The tension between sarus cranes and local farmers has increased dramatically over the last few decades. Researchers have suggested that it is due to the increased area of wetland farming, leaving less area for natural wetlands. As a result, sarus cranes have adapted to living in close proximity to humans. There is debate about whether agroecosystems are more ideal for cranes than natural wetland areas because of the readily available supply of food. Since these cranes like to feed on wheat, rice, soybeans, and cucumbers, farmers have become less tolerant of the birds because of crop destruction. Farmers have taken to relocating nests to uncultivated areas, but this has been linked to the decline of clutch success.

• Negative Impacts
• crop pest

Conservation Status

Extensive research has been conducted on the conservation status of sarus cranes. According to the IUCN, they have been categorized as “vulnerable”. Cranes have been adversely affected by poaching and agriculture. Fertilizers for crops have been consumed by cranes which often result in death. Conserving as much natural wetlands as possible has been suggested as the best way to protect the crane by allowing them to live apart from harmful effects of agriculture. Awareness efforts have also been implemented to spread the knowledge of the sarus crane and describe how local villages can put forth effort to protect these birds. There has been some success in these efforts and community action seems to be the key to their protection through the establishment of disturbance-free nesting sites.

Additional Links

Encyclopedia of Life

Contributors

Isaac Jinks (author), Indiana University - Purdue University Fort Wayne, Mark Jordan (editor), Indiana University-Purdue University Fort Wayne, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

BirdLife International, 2015. "Sarus Crane Antigone antigone " (On-line). BirdLife International. Accessed April 02, 2015 at http://www.birdlife.org/datazone/speciesfactsheet.php?id=2787 .

Blashfield, J. 2004. Cranes. Pp. 1093-1095 in The Gale Encyclopedia of Science , Vol. 2, 3 Edition. Detroit: Gale.

Borad, C., A. Mukherjee, S. Patel, B. Parasharya. 2002. Breeding performance of Indian Sarus Crane Grus antigone antigone in the paddy crop agroecosystem. Biodiversity and Conservation , 11/5: 795-805.

International Crane Foundation, 2015. "Sarus Crane Grus antigone " (On-line). Internation Crane Foundation. Accessed May 29, 2015 at https://www.savingcranes.org/sarus-crane.html .

Kaur, J., A. Nair, B. Choudhury. 2008. Conservation of the Vulnerable sarus crane Grus antigone antigone in Kota, Rajasthan, India: a case study of community involvement. Oryx , 42/3: 452-455.

Sarkar, A., B. Upadhyay, A. Chauhan, A. Sharma, P. Mishra. 2013. Habit and Habitat of Sarus Crane Grus antigone antigone , and Egyptian Vulture Neophron percnopterus in Mainpuri (Uttar Pradesh), India. Journal of Chemical, Biological and Physical Sciences , 3/3: 1808-1816.

Sundar, K. 2009. Are Rice Paddies Suboptimal Breeding Habitat for Sarus Cranes in Uttar Pradesh, India?. The Condor , 111/4: 611-623.

Wood, T., C. Krajewski. 1996. Mitochondrial DNA Sequence Variation among the Subspecies of Sarus Crane ( Grus antigone ). The Auk , 113/3: 655-663.

World Association of Zoos and Aquariums, 2015. "Sarus Crane Grus antigone " (On-line). World Association of Zoos and Aquariums WAZA. Accessed April 01, 2015 at http://www.waza.org/en/zoo/visit-the-zoo/storks-herons-flamingos-cranes-and-relatives/grus-antigone .

Yaseen, M., R. Saxena, S. Dubey. 2013. Population Composition, Distribution and Habitat Preference of Indian Sarus Crane ( Grus antigone antigone ) in Chittaurgarh District, Southern Rajasthan. Journal of Chemical, Biological and Physical Sciences , 3/4: 2784-2792.