Overview
Brief Summary
Biology
Trusted
Description
Trusted
Distribution
Range
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, B.L. Sullivan, C. L. Wood, and D. Roberson. 2012. The eBird/Clements checklist of birds of the world: Version 6.7. Downloaded from http://www.birds.cornell.edu/clementschecklist/downloadable-clements-checklist
Trusted
Range Description
Trusted
Geographic Range
Wattled cranes are found in the Ethiopian region of the world. They are comprised of three main populations. The smallest population is found in the highlands of Ethiopia, where they are isolated from the largest population residing in south-central Africa. Even further south in Africa, between Swaziland and Lesotho, populations of cold upland and semi-nomadic lowland wattled cranes are found. Southern Zambia, Mozambique, and Botswana are areas where wattled cranes are most populous.
The Kafue Flats sustain the largest population of wattled cranes, ranging from around 300 breeding pairs and around 3,000 individuals during peak season. Information about this population, however, is somewhat skewed because part of the population moves outside of the flats during seasonal changes and uses the flats as a staging area.
Wattled cranes once covered a greater geographic range in southern Africa, ranging from southern Tanzania to the southwestern Cape Province. This decline in geographic range can be attributed to cattle herding and food gathering before European settlement. Habitat destruction and disturbance by humans further limited the distribution of the cranes in Western, Eastern and Northern Cape Province after European settlement. Very few breeding pairs have been recently observed in Cape Province and Trasnkei. Present decline in geographic range is due to agricultural practices, afforestation, and the draining or damming of wetlands. Wattled cranes have been extirpated from Swaziland.
Biogeographic Regions: ethiopian (Native )
- Johnsgard, P. 1983. Cranes of the World: Wattled Crane (Bugeranus carunculatus). Pp. 121-128 in Cranes of the World. Lincoln, NE: University of Nebraska-Lincoln. Accessed February 18, 2011 at http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1029&context=bioscicranes.
- Konrad, P. 1981. "Status and Ecology of Wattled Crane in Africa" (On-line pdf). International Crane Foundation. Accessed February 16, 2011 at http://www.savingcranes.org/images/stories/pdf/conservation/CRAW_Pages_219-237_Wattled.pdf.
- McCann, K., A. Burke, L. Rodwell, M. Steinacker, U.S. Seal. 2001. Population and Habitat Viability Assessment for the wattled crane (Bugeranus carunculatus) in South Africa. South African Wattled Crane PHVA Invitation: 1-169. Accessed February 18, 2011 at http://www.cbsg.org/cbsg/workshopreports/23/wattledcranephva_final_report.pdf.
- Meine, C., G. Archibald. 1996. The Cranes: Status Survey and Conservation Action Plan. Cambridge, U.K.: IUCN, Gland, Switzerland.
Trusted
Eastern and Southern Central Africa: Ethiopia; S Tanzania, S DR Congo, E Angola - Botswana, Mozambique; outlying populations in Angola, Namibia, E South Africa.
Trusted
Range
Trusted
Physical Description
Morphology
Physical Description
Wattled cranes are the largest cranes in Africa. The wingspan of male wattled cranes ranges from 613 to 717 mm, compared with females ranging from 619 to 687 mm. The culmen, or upper part of the bill, ranges from 150 to 185 mm in males and from 124 to 183 mm in females. The tarsus, or cluster of bones in the feet, ranges from 298 to 342 mm in males and from 232 to 330 mm in females. Eggs are on average 101.9 mm by 65.3 mm in size and are estimated to weigh around 240 g. An adult male has been weighed to be 8,996 g and a female to be 8,285 g.
Adult males and females look the same, except that males have darker red bare skin than females. The head of wattled cranes is mostly white, with the exception of the dark gray feathered section above the eyes and on the crown. The common name "wattled cranes" is derived from the two almost completely feathered white wattles that hang from the upper throat. Wattled cranes have a very noticeable long white neck. Most parts of the midsection are shades of black, including the mantle, primaries, secondaries, tail coverts, and tail. The back and wings are a dusty gray color, while the breast is white. Legs and toes can be black or dark gray. While the bill is a light red to brown color, the iris is dark orange. The inner secondaries extend past the tail and come close to the ground.
Chicks have completely white heads and display lighter plumage color than the adults. Juveniles do not possess bare skin on the face like the adults do. Their wattles are also less conspicuous. Plumage on the juvenile body is a dull yellow color. Immature wattled cranes look similar to the adults, but their backs and under parts are a lighter shade of black and they do not have a black crown.
Range mass: 8,285 to 8,996 g.
Range wingspan: 613 to 717 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike; male larger; ornamentation
Trusted
Diagnostic Description
Distinct red facial patch which extends along the front of two large wattles covered in white feathers; white neck and breast
Trusted
Ecology
Habitat
Habitat and Ecology
Systems
- Terrestrial
- Freshwater
Trusted
Two extremely important habitats for wattled cranes are wetlands and grasslands. Wetlands make up around 76 % of the habitats occupied by these cranes, while grasslands make up around 10 %.
Wattled cranes occur in aquatic areas, preferably in sedge and grass wetlands along river bank floodplains. These areas are prime feeding and nesting sites for these cranes. Some notable wetlands sustaining populations of wattled cranes include the Kafue Flats, the Lukanga Swamp, the Sioma-ngwezi Plain in Zambia, the upper Chambeshi basin, the Luangwa Valley, and the Okavango Delta. Populations of 250 to 3,000 cranes can be sustained by one wetland during peak seasons.
Wattled cranes inhabit highland marshes in South Africa, Malawi, and Zimbabwe year round. The cranes utilize ephemeral and seasonal wetlands as areas for breeding or dispersal after breeding. Within Ethiopia they can live at elevations from 2,134 to 3,900 m. These populations in Ethiopia rely less on wetlands, with the exception of the breeding season. They typically inhabit montane grasslands, wet meadows, savannas, streams or marshes, and river bank areas. Outside of the breeding season, they can also migrate to plowed fields or areas of lower elevation and drier climates.
Range elevation: 3,900 (high) m.
Habitat Regions: tropical ; terrestrial ; freshwater
Terrestrial Biomes: savanna or grassland
Aquatic Biomes: lakes and ponds; rivers and streams
Wetlands: marsh
Other Habitat Features: riparian
Trusted
Trusted
Dispersal
Movements and dispersal
Resident (Lack 2010)
Generally not migratory but those that inhabit seasonal wetlands are irregularly nomadic in response to water availability (BirdLife International 2011)
Trusted
Trophic Strategy
Food Habits
Wattled cranes feed mainly on vegetation and insects; however, they have been known to eat frogs and snakes occasionally. Their main food source consists of water lilies and sedge vegetation. A large portion of their day is spent foraging through wet substrate. Upon locating a food source, such as insects or tubers, the crane intently probes its bill into the soil and digs. The crane will flail about using its large body as a digging force behind the bill. These cranes usually only dig as deep as their bill can reach, but they have been observed to immerse their entire head and neck under deeper water.
Soft soil covered by shallow water is a prime location to dig for food. This digging action comprises most of their foraging activity, but they have been observed pecking, picking up snails, and stripping grass for other food sources. To strip grass, cranes will clench the grass stem with their bills and strip the seeds by quickly moving the bill upwards. Wattled cranes can often be observed feeding along side of lechwes, a species of antelope that utilizes similar plant resources.
Animal Foods: amphibians; reptiles; insects; mollusks
Plant Foods: leaves; roots and tubers; flowers
Primary Diet: omnivore
Trusted
Associations
Ecosystem Roles
Very scant information is available about the roles that wattled cranes play in the ecosystem. However, it is hypothesized that they may be seed dispersers. They may also expose nutrients from the bottom of the wetlands by agitating soil with their bills while foraging.
Ecosystem Impact: disperses seeds
Trusted
Predation
There is very little information available regarding predators of wattled cranes. It is thought that they have few predators due to their large body size as adults. Jackals are potential predators of crane chicks, while humans cause mortalities to young birds during land developments. Adult wattled cranes have been observed to hide their young chicks from predators in tall grass while they go off to forage elsewhere. This behavior is usually practiced until the chicks reach fledging age. Most often the chicks are quiet while hiding, but they will make a “chirruping” call to allow the adults to find them.
Known Predators:
- jackals (Canis species)
Trusted
Life History and Behavior
Behavior
Communication and Perception
Wattled cranes utilize both visual displays and vocal calls to communicated with each other. Siberian cranes are the only other cranes that have a higher pitched call than wattled cranes. To make this high pitched sound, wattled cranes contort and move their necks. The female starts the call by lowering her head via coiling it near her shoulders then quickly extending her neck vertically with her head slightly angled in front of the neck. Her posture is maintained throughout the remainder of the call display, which is around three to seven seconds long. After she is done calling and starts movement, the male joins in by vocalizing in a similar manner. The female produces a short call in series, while the male produces a long and broken call with a series of short calls following. Like most birds, wattled cranes perceive their environments through visual, auditory, tactile and chemical stimuli.
Communication Channels: visual ; acoustic
Trusted
Life Expectancy
Lifespan/Longevity
Currently, little is known regarding the lifespan of wattled cranes.
Trusted
Reproduction
Wattled cranes are monogamous birds that form pair-bonds that often last for life. Nest building is a part of a breeding pair’s courtship ritual, along with displays of jumping and dancing.
Mating System: monogamous
With an average clutch size of only one egg per breeding pair, the reproductive rate of wattled cranes is lower than any other crane. They can produce a clutch of two eggs, but usually only rear one of the eggs. Wattled crane eggs are incubated longer than any other crane, for 33 to 36 days. The pre-fledging stage, lasting 90 to 130 days, is also longer than any other crane. At around five months, the chicks will be able to fly. Although recorded during all months of the year at some point, peak breeding activity occurs from May to August.
Weather and landscape are important factors for breeding wattled cranes. The floodplains of Zambia, Botswana, and Mozambique provide a nesting area utilized by most wattled cranes at peak flood time. Peak flood time varies with each wetland due to environmental factors affecting water levels. Average flooding months are August and September. With receding water, chicks are reared in shallow areas.
The drier and cooler months of July and August are prime breeding times for wattled cranes that nest in smaller and more broadly distributed wetlands. During the rainy season from November to February, chicks will fledge. Populations of Ethiopian wattled cranes breed in May or June at the start of the high altitude wet season. Photoperiod changes can also affect breeding patterns for wattled cranes. Some sources indicate that wattled cranes reach sexual maturity at three to five years of age, while others indicate seven to eight years. When maturity is reached, the cranes will find a mate and create a pair bond that generally lasts for life.
Nest building is an important behavior of wattled cranes. They build nests out of large mounds of vegetation and surround it with a moat. This allows protection against predators.
Breeding interval: Wattled cranes breed once annually.
Breeding season: The breeding season for wattled cranes occurs from May to August.
Range eggs per season: 1 to 2.
Average eggs per season: 1.
Range time to hatching: 33 to 36 days.
Range fledging age: 90 to 130 days.
Average time to independence: 5 months.
Range age at sexual or reproductive maturity (female): 3 to 8 years.
Range age at sexual or reproductive maturity (male): 3 to 8 years.
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization
Both parents care for the young constantly during the fledgling period, which may last 90 to 130 days. Chicks will remain with their parents until around one year old when the adult pair will be preparing to nest again. Nesting parents are very territorial, defending areas over a kilometer in size, and because of this they do not do well in areas with human disturbance. The adults build nests in open grass and sedge marshes with medium vegetation. They prefer the water level to be a maximum of one meter. The reproduction of wattled cranes is limited due to the declining number of acceptable nest sites and their territorial behaviors.
Parental Investment: altricial ; male parental care ; female parental care ; pre-fertilization (Provisioning, Protecting: Male, Female); pre-hatching/birth (Provisioning: Male, Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)
- Johnsgard, P. 1983. Cranes of the World: Wattled Crane (Bugeranus carunculatus). Pp. 121-128 in Cranes of the World. Lincoln, NE: University of Nebraska-Lincoln. Accessed February 18, 2011 at http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1029&context=bioscicranes.
- Konrad, P. 1981. "Status and Ecology of Wattled Crane in Africa" (On-line pdf). International Crane Foundation. Accessed February 16, 2011 at http://www.savingcranes.org/images/stories/pdf/conservation/CRAW_Pages_219-237_Wattled.pdf.
- McCann, K., A. Burke, L. Rodwell, M. Steinacker, U.S. Seal. 2001. Population and Habitat Viability Assessment for the wattled crane (Bugeranus carunculatus) in South Africa. South African Wattled Crane PHVA Invitation: 1-169. Accessed February 18, 2011 at http://www.cbsg.org/cbsg/workshopreports/23/wattledcranephva_final_report.pdf.
- Meine, C., G. Archibald. 1996. The Cranes: Status Survey and Conservation Action Plan. Cambridge, U.K.: IUCN, Gland, Switzerland.
Trusted
Molecular Biology and Genetics
Molecular Biology
Barcode data: Grus carunculatus
There is 1 barcode sequence available from BOLD and GenBank. Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species. See the BOLD taxonomy browser for more complete information about this specimen. Other sequences that do not yet meet barcode criteria may also be available.
-- end --
Download FASTA File
Trusted
Statistics of barcoding coverage: Grus carunculatus
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1
Trusted
Conservation
Conservation Status
IUCN Red List Assessment
Red List Category
Red List Criteria
Version
Year Assessed
Assessor/s
Reviewer/s
Contributor/s
Justification
History
- 2006Vulnerable
- 2004Vulnerable
- 2000Vulnerable
- 1996Vulnerable
- 1994Vulnerable
Trusted
Out of the six African crane species, wattled cranes are the rarest. The recruitment rate of wattled cranes was estimated to be 4.2 percent among a population of 784 adults. This estimate indicates that the cranes had a 13% pairing success, which is much lower than other crane species. The estimated age that wattled cranes first breed is around seven or eight years of age. This can have significant impacts on population success.
Wattled cranes were declared threatened by the International Union for Conservation of Nature and Natural Resources (IUCN) in 1988. From 1994 to the present year they have been listed as vulnerable. Data was last assessed in 2008. Their population has been estimated to be fewer than 8,000 individuals. With an insufficient understanding of population trends for these cranes, they are labeled as vulnerable on the premises that their small population has experienced rapid decline. Threats to their population are ongoing and possibly increasing.
Wattled cranes are highly dependent on wetland habitats for reproduction and survival. Wetlands are usually exploited for agricultural development, irrigation projects, hydroelectricity sources, mining areas, and more. With the degradation of these wetland habitats, populations of wattled cranes became seriously threatened. Small wetlands in particular are vital habitats for wattled cranes and are much more susceptible to damage via draining, damming, afforestation, and human habitation. As breeding sites of these cranes are sparsely scattered over a large range, fragmentation can significantly affect population numbers.
Reproduction and nesting is directly correlated with the flooding seasons of the wetlands for these cranes. With the advent of hydroelectric power interests comes the alteration of flood cycles, which in turn affect reproduction rates of the cranes. Hydroelectric operations have put limits on total wetland habitat, feeding areas, and nesting territories.
Grassland habitats are also critical to populations of wattled cranes. These areas have been altered via exotic timber plantations and agriculture. As humans take over territories for agricultural interests, wildlife populations, including wattled cranes, can be replaced by domestic livestock herds. A significant loss in the eggs and unfledged chicks can be attributed to management of wetland habitats through fire regimes. These fire breaks for farmlands are often carried out during vital winter breeding months for the cranes. Other forms of threats to wattled crane populations include inexperienced birds flying into power lines and removal of eggs for the international bird trade.
Genetic analysis has revealed differences between the South African and south-central African populations of wattled cranes. Due to this genetic distinctiveness between the two populations, the South African Crane Working Group has developed a Population and Habitat Viability Assessment (PHVA) in 2000 to evaluate the population dynamics of wattled cranes. This analysis evaluated various management approaches in hopes of enhancing the long term survival of the species. Population statistics are difficult to obtain and give a skewed view on the rate of decline of the species. With the population information available, the PHVA concluded that roughly two breeding sites per year are lost or abandoned due to habitat alteration.
The PHVA set goals for analyzing population dynamics of wattled cranes. These goals included closely monitoring population numbers, population locations, and all aspects of habitat degradation effects and proposing ideas for dealing with these issues. A central database was established to enter all of this data into. Specific models were constructed to analyze the data. Each event contributing to population structure change was evaluated from habitat loss due to industrialization and agriculture to mortality by means of power lines and fences, and accidental and/or purposeful poisoning, etc. This analysis also evaluated the effectiveness of captive breeding programs. This PHVA was carried out in collaboration with the Conservation Breeding Specialist Group. Conservation efforts of wattled cranes are still underway and require long term data sets to construct further results.
The Provincial Nature Conservation Ordinances also currently protect wattled cranes in all four provinces of South Africa. Tampering with the nests, eggs, or chicks of the cranes is punishable by law. These ordinances have also made it illegal to house captive cranes and to shoot, trap, poison, or injure cranes without conservation authority. The National Parks and Wildlife Act in Zambia and Malawi restricts hunting of the cranes and removal of crane nests. Varying amounts of protection are incurred by Designated Game Management Areas; however, human settlement is still authorized in some areas.
CITES: appendix ii
IUCN Red List of Threatened Species: vulnerable
- Coverdale, B. 2003. Breeding age and pair formation of Wattled Cranes, Bugeranus carunculatus, in the wild.. Ostrich: Journal of African Ornithology, 74 (3/4): 226.
- International Union for Conservation of Nature and Natural Resources (IUCN), 2010. "Grus carunculatus" (On-line). IUCN Red List. Accessed March 26, 2011 at http://www.iucnredlist.org/apps/redlist/details/143779/0.
Trusted
Status
Trusted
Trends
Population
Population Trend
Trusted
Threats
Trusted
Trusted
Management
Conservation Actions
CITES Appendix II. CMS Appendix II. Protected areas (including Ramsar Sites) have been established in several key wetlands, notably in Zambia, Namibia and Botswana4,6. In South Africa, and some other countries, action has included legal protection, marking and relocation of powerlines, awareness programmes, and encouragement of habitat protection and management by private landowners1,3,4. A conservation group is conducting aerial surveys, field research and a community awareness programme in the Kafue Flats20. Aerial surveys, nest monitoring24,28,30 and monitoring of adult:juvenile ratios24,29 take place annually on the Okavango Delta. In 1993, an action plan was developed for the species at the African Crane and Wetland Training workshop25. A continent-wide programme for the species was launched in 2001 to monitor the species's status and threats, and help develop effective conservation programmes for the management of wetland systems34. National conservation plans have been developed for Botswana, Namibia, South Africa and Zimbabwe, and research projects are being conducted in Malawi, Mozambique and Zambia34. In South Africa, abandoned eggs from clutches of two are harvested, and a total of 60 chicks have been fledged from these eggs since 198635. Between 1995 and 2000, feasibility trials involved the release of 13 captive-reared birds in South Africa35. In 1995, a captive breeding programme was started in South Africa27. Following a workshop in July 2000, the Wattled Crane Recovery Programme was initiated in South Africa34,35. In 2006 management for the programme was shifted to the Johannesburg Zoo and a dedicated chick-rearing facility was built. Ten captive management facilities throughout South Africa now participate in the breeding programme, which is designed to produce South African origin birds for release once a stock of 40 adults has been achieved (the captive population in South Africa stood at 29 birds in late 2007)35. It had been proposed that the severely declining South African population be supplemented with eggs from captive birds of the south-central population, however analyses have discovered a high degree of genetic isolation between these populations, which indicates that they should be treated separately, and no significant loss of genetic diversity was detected in the South African population31. The taxonomy of the species is being investigated across its range31. Fund raising is ongoing for the construction of a dedicated breeding facility. Poor fertility remains a major obstacle to captive-breeding. However, on 1 September 2006, a captive-bred chick hatched at Johannesburg Zoo, after a period of nearly 10 years of unsuccessful breeing35. In November 2003, three birds were successfully captured and ringed on the Boro floodplain (Botswana), and following this it was suggested that a project memorandum and funding proposal be put forward for a satellite tracking project, perhaps concentrating on young 'floaters' rather than established pairs26. In 2005, it was announced that a veterinary fence would be constructed to the east of the Makgadikgadi Pans National Park in Botswana, effectively extending the park boundary and protecting grasslands used by the species from the high density of livestock in the area32. Conservation Actions Proposed
Develop a coordinated range-wide action plan15. Coordinate range-wide surveys and long-term monitoring4, partly in order to understand population movements between sites and countries6. Continue and expand ecological research4,18,25. Strengthen key protected areas, especially in the Kafue Flats and Bangweulu Swamps (Zambia)4. Improve protection of birds outside of protected areas such as the Jao/Boro rivers of Botswana22. Increase educational campaigns16, targeting landowners with breeding cranes4. Assess viability of artificial nest-platforms8,14. Transfer species to CITES Appendix I3. Employ satellite tracking to study the species's movements across its range26,34. In South Africa, work with farming communities to conserve natural grasslands that surround wetlands33. Investigate whether the South African34 and Ethiopian31 populations represent separate subspecies. Assess the levels of legal and illegal trade in the species34. Study the extent and control of Mimosa, which is invading a number of large wetland systems34. Assess the impacts of fire and management on the species34. Study the impact of indigenous game compared with domestic cattle34. Plan and conduct research into semen cryopreservation, genetic fingerprinting, eggshell membrane sexing and nutrition34. In South Africa, supplement existing wild populations with captive-bred fledglings of South African origin37.
Trusted
Conservation
Trusted
Relevance to Humans and Ecosystems
Benefits
Economic Importance for Humans: Negative
There are no known adverse effects of wattled cranes on humans.
Trusted
Economic Importance for Humans: Positive
Various conservation programs for wattled cranes and other species provide funds from eco-tourism that strengthens the livelihood of local communities.
Positive Impacts: ecotourism
- Boere, G., C. Galbraith, D. Stroud. 2006. Waterbirds around the world. Edinburgh: The Stationery Office Limited.
Trusted
Wikipedia
Wattled Crane
The Wattled Crane (Bugeranus carunculatus) is a large bird found in Africa, south of the Sahara Desert. It is monotypical for its genus, though some authorities place it with other crane species in the genus Grus, as Grus carunculata.[2]
Contents |
Description [edit]
At a height of up to 175 cm (5.74 ft), it is the largest crane in Africa and is the second tallest species of crane, after the Sarus Crane. The wingspan is 230–260 cm (7.5–8.5 ft), the length is typically 120 cm (3.9 ft) and weight is 6.4–7.9 kg (14–17 lb) in females, 7.5–9 kg (17–20 lb) in males.[3] Among standard measurements, the wing chord length is 61.3–71.7 cm (24.1–28.2 in), the exposed culmen is 12.4–18.5 cm (4.9–7.3 in) and the tarsus is 23.2–34.2 cm (9.1–13.5 in). The back and wings are ashy gray. The feathered portion of the head is dark slate gray above the eyes and on the crown, but is otherwise white, including the wattles, which are almost fully feathered and hang down from under the upper throat. The breast, primaries, secondaries, and tail coverts are black. The secondaries are long and nearly reach the ground. The upper breast and neck are white all the way to the face. The skin in front of the eye extending to the base of the beak and tip of the wattles is red and bare of feathers and covered by small round wart-like bumps. Wattled Cranes have long bills and black legs and toes. Males and females are virtually indistinguishable, although males tend to be slightly larger.
Juveniles have tawny body plumage, lack the bare skin on the face, and have less prominent wattles.
Range [edit]
The Wattled Crane occurs in eleven sub-Saharan countries in Africa, including an isolated population in the highlands of Ethiopia. More than half of the world’s Wattled Cranes occur in Zambia, but the single largest concentration occurs in the Okavango Delta of Botswana. Wattled Cranes are thought to have historically ranged over a much larger area including coastal West Africa.[4] The range has certainly retracted considerably in historical times.
The Wattled Crane has been spotted in Uganda for the first time in 2011, seen in the Kibimba Rice region in the eastern side of the country. This sighting brings the total number of bird species in Uganda to 1040.[5]
Habitat and diet [edit]
Wattle Cranes inhabit fairly inaccessible wetlands under most conditions. It requires shallow marsh-like habitats with a good deal of sedge-based vegetation. All cranes are omnivorous. The principal food of the Wattled Crane is mainly aquatic eating the tubers and rhizomes of submerged sedges and water lilies. It is one of the more herbivorous of extant cranes. The other primary portion of the diet is comprised by aquatic insects. They will supplement the diet with snails, amphibians and snakes when the opportunity arises. Roughly 90% of foraging done by this species occurs in shallow waters. They typically forage by digging vigorously with their bill into the muddy soil. On occasion, it will eat grain and grass seed as well, but does so much less often than the other three African crane species.[6]
Behavior [edit]
There does seem to be some seasonal movements in this crane species, but they are not well-known. Movements seem to be dictacted by local water conditions rather than by seasonal temperature variations. During local floods, the number of Wattled Cranes can increase from almost none to as much as 3,000 individuals. These movements, in pursuit of ideal feeding conditions, seem more opportunistic movement rather than a fixed migration pattern. On the other hand, there has been observed a migration movement from the high to the low plateaus in Mozambique for the species.[6]
Somewhat gregarious outsize of the breeding season, flocks of Wattled Cranes can often include 10 or more birds, occasionally as many as 89 individuals. The crowned cranes occasionally interact with this species but, given those species largely terrestrial foraging patterns, this is uncommon. Two species are known to associate closely with Wattled Cranes due to shared habitat and dietary preferences: the antelope known as the lechwe and the spur-winged goose, the latter nonetheless usually being found in slightly deeper waters. There is no data on significant predation on the Wattled Crane, as its size often insures it from being killed. Jackals may be occasional predators of chicks.[6]
Wattled Cranes commence their breeding season around April. Most nest are sloppily crushed impressions of grass along the border of a marsh. They may use an old spur-winged goose nest or make their own. Eggs are laid approximately 3 weeks after the nests are built. The average clutch size of the species is reportedly the smallest of any of the world's cranes, with an average of 1.6 eggs. Even if there are two eggs, usually only one chick successfully survives to hatch or fledge. The incubation period, roughly 33 to 36 days, is on average the longest of any crane and both parents participate. The chicks are immediately feed by both parents, which take shifts. After around 80 days, the chick(s) start to forage with their parents. At the first sign of any danger, the parents force their young into tall grasses to hide. The fledging period occurs at 100–150 days, the longest it takes any crane to fledge. The young remain with their parents for up to a year (when the next breeding period starts) and may gather in flocks with unrelated juveniles.[6]
Threats [edit]
Destruction, alteration, and degradation of wetland habitats constitute the most significant threats to the Wattled Crane, perhaps one of the most habitat sensitive of all cranes. Hydroelectric power projects and other water development have caused fundamental changes in the species expansive floodplain habitats, and their most important food source Eleocharis spp. Human and livestock disturbance, powerline collisions, mass aerial spraying of tsetse flies, and illegal collection of eggs, chicks and adults for food are also significant threats to Wattled Cranes throughout their range.
The Wattled Crane is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.[7] It is listed as Vulnerable in the IUCN Red List.[1]
Notes [edit]
- ^ a b Butchart, S. & Taylor, J. (2008). "Grus carunculatus". IUCN Red List of Threatened Species. Version 2010.1. International Union for Conservation of Nature. Retrieved 31 July 2010.
- ^ "IOC Lists (v3.2)". 16 October 2012. Retrieved 27 November 2012.
- ^ "Wattled Crane". savingcranes.org. International Crane Foundation. Retrieved 31 July 2010.
- ^ "Wattled Crane". birdlife.org. Birdlife International. Retrieved 31 July 2010.
- ^ Wattled crane brings the total bird species to the 1040 mark in Uganda. Safari.co.uk (2011-06-24). Retrieved on 2012-08-23.
- ^ a b c d Johnsgard PA (1983). Cranes of the world. Bloomington: Indiana University Press. ISBN 0253112559.
- ^ "Agreement on the Conservation of African-Eurasian Migratory Waterbirds: Annexe 2". unep-aewa.org. AEWA. Retrieved 31 July 2010.
References [edit]
- The Cranes: status survey and conservation action plan. Gland, Switzerland: IUCN.
- Wattled Crane (Bugeranus carunculatus) from Cranes of the World, by Paul Johnsgard
Unreviewed
Disclaimer
EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.
To request an improvement, please leave a comment on the page. Thank you!



