Justification This species is listed as Endangered because it has an extremely small population. However, the conservation status of the species is improving, with not only increases in the natural wild population but also establishment of two reintroduced flocks that may become self-sustaining. If the number of mature individuals continues to increase, this species may merit downlisting to Vulnerable.

Family/Sub-family Gruidae

Species name author (Linnaeus, 1758)

Taxonomic source(s) AOU checklist (1998 + supplements), Sibley and Monroe (1990, 1993), Stotz et al. (1996)

Identification 132 cm. Large white crane. Adults white with red crown and black forehead, lores and moustache (tipped red), and red facial skin around large, horn-coloured bill. Shows black primaries in flight. Immature whitish with scattered brown feathers over wings and paler, reddish-brown head and neck. Similar spp Immature Sandhill Crane G. canadensis is smaller with grey basal colour. Voice Trumpeting ker-loo ker-lee-loo.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

50-249

increasing

4,180 km²

No

Range & population Grus americana declined from historic estimates of 10,000+ prior to European settlement of North America to 1,300-1,400 birds by 1870 to 15 adults in 1938². The three wild populations totalled 382³ in December 2007, including two reintroduced populations in the eastern U.S. that are not yet self-sustaining. The only natural wild population breeds in Wood Buffalo National Park, on the border of Northwest Territories and Alberta, Canada, and winters at and near Aransas National Wildlife Refuge, Texas, USA⁵. It totalled a record 266 birds in 2007³, with 65 active nests¹⁴. A reintroduced, non-migratory flock in Florida numbered c.41 individuals in 2007, with additional releases put on hold³. A reintroduced flock migrates between Wisconsin and Florida, numbering 75 birds in 2007³. The first wild born chick fledged in Wisconsin and migrated successfully in 2006³. Captive flocks totalled 148 birds in 2007 at 5 breeding centers and 6 display facilities in the USA and Canada³. The global wild population has increased in numbers for the past 68 years.

Ecology: It breeds in prairie wetlands, preferring small, shallow lakes and ponds, willow communities, marshes, mudflats and perhaps sedge meadows, but this may be atypical considering its historical range^1,11. Eggs are laid from late April to mid-May¹. It winters in coastal brackish wetlands.

Threats Over-hunting, habitat conversion and human disturbance were the main causes of the decline. Currently, the most significant known cause of death or injury to fledglings is collision with powerlines⁷, and in 2007 a lightning strike during severe weather killed 17 young birds being housed in a top-netted release pen in Flordia³. Pre-fledged eggs and chicks are subject to predation (raven, bald eagle, wolf, black bear, lynx)². Powerline markers can reduce collisions by 50-80%¹⁶, but most power lines remain unmarked and collision is a major and growing problem⁷. The anticipated placement of thousands of wind turbines in the migration corridor will decrease availability of crane stopover habitat and may also dramatically increase the number of power lines³. Drought is detrimental to all habitats utilized year around, but is especially harmful by dramatically lowering production on the nesting grounds⁹. Coastal development, sea level rise, climate change, chemical spills, reduced fresh water inflows, and human disturbance threaten the Texan wintering grounds^2,9. Aransas NWR can only support a maximum of 500 birds through the winter³ and falls short of the initial downlisting target of 1,000 birds. Continued population growth may force some cranes in future to use disturbed and suboptimal habitat¹³. Much of the currently unoccupied crane habitat at Aransas where the cranes would be expected to expand into is being threatened with construction of homes³. There are currently concerns about oil spills and about river inflows to Aransas National Wildlife Refuge², and the spread of West Nile virus and avian influenza in the future may pose a threat to the species¹⁵. The long-term effects of genetic drift after a severe population bottleneck are unknown⁴.

Conservation measures underway CITES Appendix I and II. CMS Appendix II. There is an international recovery plan² focusing on increasing the size of the natural flock, establishing additional wild populations through experimental releases, teaching captive-bred birds to migrate^6,8,9, and increasing the captive population for experimental releases and ecological research. Considerable progress has been made in improving the genetic health of captive stock and breeding under-represented genetic strains, but delayed reproduction in captivity and the failure of some pairs to breed at all has slowed down progress¹⁷. In the past, recruitment was increased in certain years in Canada by removal of a single egg from two-egg broods¹²; the removed eggs are used to supplement captive flocks, but the overall impact of the egg pickup program is largely undetermined². An eastern migratory population which mostly winters in Florida and summers in Wisconsin has now been established but only one instance of successful breeding has been recorded so far¹⁸. If passed, the Crane Conservation Act (H.R. 1771 and S. 1048) would allocate $5 million per year over five years to be spent on crane conservation efforts world-wide, with strict limitations on the amount going to help Whooping Cranes.

Conservation measures proposed Survey and monitor breeding grounds to determine nesting effort⁹, and the wintering grounds to determine flock size. Research food resources and high mortality⁹. Alleviate threats in Texas. Reduce powerline collisions. Continue establishment of two further self-sustaining populations^5,9. Continue raising cranes for reintroduction⁹.

References 1. Archibald and Meine (1996). 2. CWS and USFWS (2007). 3. T. Stehn, in litt. (2007). 4. Glenn et al. (1999). 5. Meine and Archibald (1996). 6. Lewis (1995). 7. Lewis (1997). 8. Line (1995). 9. RENEW report (1999) 9: 27. 10. T. Stehn and J. Cannon, in litt. (2007). 11. Timoney (1999). 12. Boyce et al. (2005). 13. M. Reid. in litt. 2003. 14. B. Johns, in litt. (2007). 15. Chu et al. (2003). 16. T Stehn and T. Wassenich (in press). 17. Putman (2007). 18. J.Hook in litt. (2007).

Further web sources of information

Alliance for Zero Extinction (AZE) species/site profile. This species has been identified as an AZE trigger due to its IUCN Red List status and limited range.

Alliance for Zero Extinction (AZE) species/site profile. This species has been identified as an AZE trigger due to its IUCN Red List status and limited range.

Audubon WatchList

International Crane Foundation Species Field Guide

Status, Survey and Conservation Action Plan

U.S. Fish and Wildlife Service - Draft Recovery Plan (2005)

Text account compilers Phil Benstead (BirdLife International), Jeremy Bird (BirdLife International), Matt Harding (BirdLife International), Isabel Isherwood (BirdLife International), John Pilgrim (BirdLife International), David Wege (BirdLife International)

Contributors George Archibald (International Crane Foundation), Bruce Reid (Mississippi Audubon Society), H Reid, H Stehn, Tom Stehn (US Fish & Wildlife Service)

IUCN Red List evaluators Jeremy Bird (BirdLife International), Stuart Butchart (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Grus americana. Downloaded from http://www.birdlife.org on 10/2/2010

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

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