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The Cranes

Status Survey and Conservation Action Plan

Whooping Crane

(Grus americana)


JPG-Whooping Crane

Subjects:
Summary
Subspecies/populations
Population Numbers and Trends
Conservation Status
Historic and Present Distribution
Distribution by Country
Habitat and Ecology
Principal Threats
Current Conservation Measures
Priority Conservation Measures

Summary

The Whooping Crane is the rarest of the world’s 15 crane species. The species’ historic decline, near extinction, and gradual recovery is among the best known and documented cases in the annals of conservation. Over the last fifty years, a combination of strict legal protection, habitat preservation, and continuous international cooperation between Canada and the United States has allowed the only remaining wild population to increase steadily from a historic low of just 15 known individuals in 1940-41 to more than 150 at present. Since the mid-1960s, captive propagation has provided security against extinction of the species while affording opportunities to initiate new populations. The species provides an important case study in the conservation of rare and endangered species, and serves as a symbol for international cooperation in conserving not only threatened cranes, but biodiversity in general. The species is classified as Endangered under the revised IUCN Red List Categories.

The Whooping Crane occurs exclusively in North America. The historic mid-continental breeding range stretched from Alberta across the northeastern portions of the mid-continental prairies to near the southern end of Lake Michigan. The historic wintering grounds included the highlands of northern Mexico, the Texas Gulf coast, and portions of the Atlantic coast. Non-migratory populations occurred in Louisiana and possibly other areas in the southeastern United States. The species declined rapidly in the late 1800s and early 1900s as a result of hunting, collecting, and the conversion of its habitats to agriculture. By 1940, only the one self-sustaining flock remained.

As of August 1996 the adult Whooping Crane population numbered 205 in the wild and another 91 birds in captivity. In the wild, the species exists in three separate populations1: the historic Aransas-Wood Buffalo population; an experimental cross-fostered population, containing 3 birds, in the Rocky Mountains of the U. S.; and an experimental non-migratory population of released birds in central Florida. Whooping Cranes are maintained in captivity at five locations.

Historically, the species bred primarily in wetlands of the northern tall- and mixed-grass prairies and aspen parklands. The remnant wild population breeds at the northernmost extreme of the historic range in intermixed muskeg and boreal forest in Canada’s Wood Buffalo National Park. During migration, this population uses a variety of feeding and roosting habitats, including croplands, marshes, and submerged sandbars in rivers along the migration route. They winter in bays and coastal marshes in and near the Aransas National Wildlife Refuge on the Texas Gulf Coast. The cross-fostered population in the Rocky Mountains utilizes high elevation marshes and riparian wetlands from Idaho to New Mexico. The experimental non-migratory population inhabits palmetto grasslands, savannahs, and shallow marshes in the Florida’s Kissimmee Prairie region.

Whooping Cranes continue to face multiple threats, including habitat loss and pollution in their traditional wintering grounds, collision with utility lines, human disturbance, disease, predation, loss of genetic diversity within the population, and vulnerability to natural and human-caused catastrophes. Concern over the near extinction of the Whooping Crane has prompted a broad range of conservation actions, including national and international legal protections; comprehensive scientific research and monitoring programs; protection of key habitats; development of Whooping Crane recovery teams and comprehensive recovery plans; and extensive public education campaigns.

Priority conservation measures for the future include: integration and implementation of the U.S. and Canadian Whooping Crane Recovery Plans; special attention to key problems within existing habitats, potential breeding areas, and potential reintroduction sites; continued efforts to establish two additional self-sustaining wild populations and a viable self-sustaining captive population; and research on a variety of specific topics important for the recovery and establishment of the species.

1The Whooping Crane in the experimental Rocky Mountain population did not successfully reproduce, while those in the Florida population have not yet reached sexual maturity. Thus, these are not self-sustaining biological populations in the strict sense. The term "population" is used in this account to differentiate the three wild flocks.

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Subspecies/populations

No subspecies. In the wild, the species exists in three populations: the historic Aransas-Wood Buffalo population (AWP); an experimental cross-fostered Rocky Mountains population (RMP); and an experimental population of recently released non-migratory birds in central Florida (FP).

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Population Numbers and Trends

Population Number2     Trend
Aransas-Wood Buffalo     150 Increasing slowly
Rocky Mountain 3 Declining
Florida 52 Increasing through

2Population numbers current as of August 1996. These numbers include only adult birds. At this time, another 91 adult birds were being maintained in captivity at five sites (see table 1.2). All numbers and information on trends in the Whooping Crane population provided by Dr. James Lewis of the U.S. Fish and Wildlife Service and the members of the Canadian and U.S. Whooping Crane Recovery Teams.

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Conservation Status

IUCN category     Endangered, under criterion D
(also meets sub-criterion B1, but does not meet either B2 or B3;
in order to fully qualify for Endangered under Criterion B, two
out of three sub-criteria must be met).
CITES Appendix I

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Historic and Present Distribution

GIF-Distribution Map

The Whooping Crane was likely never very common in historic times. The total population prior to 1870, when European settlement began to have a significant impact on the species and its habitats, has been variously estimated at between 500 and 1400 (Allen 1952, Banks 1978, Lewis 1995b). The principal historic breeding range stretched across central North America from central Alberta through southern Saskatchewan and Manitoba, northeastern North Dakota, western Minnesota, southern Wisconsin, northern Iowa, and northern Illinois (Allen 1952). Wintering grounds included southwestern Louisiana, the Gulf Coast of Texas, interior west Texas, the highlands of northern Mexico, and Atlantic coastal areas of New Jersey, Delaware, South Carolina, and Georgia (Allen 1952, Howell and Webb 1995). Non-migratory populations were found in coastal Louisiana, and possibly in other portions of the southeastern United States (Nesbitt 1982, Gomez 1992, USFWS 1994).

The species' range shrank rapidly in the second half of the 19th century, and by the 1890s it was extirpated from the U.S. portion of the historic breeding range (Allen 1952, McNulty 1966). Nesting in the aspen parklands of Canada was last observed in 1929, with unconfirmed reports continuing into the early 1930s (Hjertaas 1994). By the late 1930s, only two breeding populations remained: a remnant non-migratory population around White Lake in southwestern Louisiana, and a migratory population that wintered in coastal Texas but whose breeding grounds were unknown. Birds in the Louisiana population last nested in 1939. A hurricane in August 1940 reduced this population from 13 to 6 individuals. The last member of this flock was taken into captivity in 1950.

The only remaining flock of wild Whooping Cranes, the wintering population in coastal Texas, reached a low of 15 birds in the winter of 1941-42, and hovered between the low 20s and mid 30s over the next two decades (Boyce 1987, USFWS 1994) (see Figure 2.1). Efforts to locate the flock's breeding grounds intensified following World War II. Evidence of breeding was first reported in 1954, when several adults and pre-fledged juveniles were observed in Wood Buffalo National Park (WBNP) in Northwest Territories, Canada. Researchers were able to locate the first nests the following year (Allen 1956). The inaccessibility of the breeding grounds, protection of the wintering grounds, and extensive public education campaigns have contributed to the population's increase to its current (August 1995) level of 150 birds (Lewis 1995a). Since 1967, biologists have removed single eggs from two-egg clutch nests of the population, using these eggs in establishing captive and experimental wild populations (Erickson 1976, Kuyt 1993, Edwards et al. 1994).

GIF-Whooping Crane winter population

The Aransas-Wood Buffalo flock remains the only self-sustaining wild population. The 47 known breeding pairs within the population (as of 1995) nest almost exclusively within the borders of WBNP. The population follows a relatively narrow (80-300 km wide) migration route across nine provinces and states: Alberta, Saskatchewan, Montana, North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, and Texas (Kuyt 1992). The wintering grounds are found within and near the Aransas National Wildlife Refuge (ANWR) in Texas.

In 1975, experimental efforts to establish a second migratory wild flock through cross-fostering began at Grays Lake National Wildlife Refuge in southeastern Idaho (see Drewien and Bizeau 1978 for a summary of the methods used in this program). Eggs were transferred from the nests of AWP Whooping Cranes to nests of Greater Sandhill Cranes. Sandhill Crane "foster parents" raised the Whooping Cranes and taught them their traditional migration route to wintering grounds along the middle Rio Grande Valley in New Mexico. Continued artificial supplementation increased the number of Whooping Cranes in this population to a peak of 33 in the winter of 1984-85. However, the cross-fostered birds failed to form pair-bonds with others of their species. High mortality rates within the population, the failure of the birds to pair and breed (due likely to improper sexual imprinting), and prolonged drought in the summer range led to the decision in 1989 to curtail the egg-transfer program (Lewis 1995b, J. Lewis pers. comm.). Three captive-reared, Whooping Crane-imprinted juveniles have subsequently been released to test the viability of using adults as "guide birds" to teach cranes raised in captivity to migrate. Three birds remain in the population (J. Lewis pers. comm.).

In the 1980s, other options for release programs were explored. Potential sites for establishing a third wild population were selected for evaluation in 1983 and research at these sites began the following year. In 1988, the U.S. Whooping Crane Recovery Team selected the Kissimmee Prairie area in Florida for establishment of an experimental non-migratory population. This decision was made based on the failure of the cross-fostered migratory Whooping Cranes to pair and reproduce, and the lack of a proven technique for teaching migration to captive-raised birds. The project was endorsed by the Canadian recovery team in 1988 and approved by the respective government wildlife agencies in 1989. The first releases, involving 33 captive-reared juvenile cranes, occurred from January 1993 to March 1994 (Nesbitt 1994b). As of August 1996, 52 of the released birds had survived. Additional releases of 20 to 40 birds annually are planned until the population is self-sustaining.

In addition to the wild populations, approximately 91 (as of August 1996) captive Whooping Cranes are maintained at five locations (see "Captive Propagation and Reintroduction" below) (Lewis 1995a).

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Distribution by Country

Canada B (AWP)
Mexico X
United States     NB (RMP), R (FP), W (AWP)
    
B = Present during breeding season
NB = Present during breeding season but not currently breeding
R = Permanent resident; not currently breeding
W = Present during winter
X = Extirpated
    
AWB = Aransas-Wood Buffalo population
FP = Florida population
RMP = Rocky Mountain population

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Habitat and Ecology

JPG-Unison calling, Aransas NWR, Texas, USA

Historical records indicate that during the breeding season the migratory populations used the aspen parklands and wetlands along the northern and eastern borders of the tall- and mixed-grass prairie regions of central North America. In the winter, these populations foraged in grasslands, coastal marshes, and other wetlands on wintering grounds in Texas and Louisiana and along the Atlantic coast. The extirpated non-migratory population in Louisiana used tallgrass (Panicum) prairie.

The nesting grounds of the AWP within Wood Buffalo National Park are in poorly drained areas where muskeg and boreal forest intermix (Allen 1956, Novakowski 1966, Kuyt 1981a). Nesting territories range widely in size, from 1.3 to 47.1 km2 (Kuyt 1981a, 1993). The cranes nest in emergent vegetation (primarily bulrush and sedges) in the shallow portions of ponds, small lakes, and wet meadows (Kuyt 1995). Nests are usually constructed of bulrush and other surrounding wetland vegetation in shallow (14-28 cm) water (Allen 1956; Kuyt 1981a, 1981b, 1995). Kuyt (1995) provides a comprehensive summary of data on Whooping Crane nests and eggs collected over 25 years at WBNP. More than 90% of clutches contain two eggs. The incubation period is 29-30 days (Kuyt 1982). Chicks fledge at 80-90 days. Whooping Cranes are omnivorous. On breeding grounds, they feed primarily on mollusks and crustaceans, insects, minnows, frogs, and snakes (Allen 1956, Novakowski 1966).

During migration, they feed and roost in a wide variety of habitats, including croplands, large and small freshwater marshes, the margins of lakes and reservoirs, and submerged sandbars in rivers (including the South Saskatchewan, Platte, Niobrara, Cimarron, and Red) along the migration route (Howe 1989, Armbruster 1990, Kuyt 1992). Especially in the Canadian portion of the migration route, waste grain (barley and wheat) are an important part of the diet.

Most of the winter is spent in the brackish bays, estuarine marshes, and tidal flats of the Gulf of Mexico in and near Aransas NWR in Texas (Allen 1952, Stehn and Johnson 1987). These areas are dominated by salt grass, cordgrass, and other aquatic vegetation (Allen 1952, Labuda and Butts 1979). There the cranes feed primarily on blue crabs, clams, fiddler crabs, shrimp, and other aquatic invertebrates, small vertebrates, and plants (Allen 1952, 1956; Blankinship 1976). Upland areas are also used, especially when flooded or prescribe-burned. Cranes forage there for acorns, snails, insects, rodents, and other food items (Hunt 1987).

The cross-fostered population at Grays Lake shares the habitat of the Rocky Mountain population of Greater Sandhill Cranes: high elevation marshes and riparian wetlands in the Idaho-Wyoming-Montana border region, along the migration route through Utah and Colorado, and on wintering grounds in the middle Rio Grande valley. The cross-fostering site was an 8900 ha marsh at 1946 m elevation. The birds also use grain fields and pastures on private lands surrounding the refuge (Lewis 1995b).

The birds of the experimental Florida population are being released in the Kissimmee Prairie region -- a flat, open area of palmetto (Serenoa repens) grassland and savannah interspersed with shallow freshwater marshes and lake-edge wetlands (Lewis 1995b). The release area also contains open, low-growth grasslands, including nearby private ranches where native grassland has been converted to pasture.

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Principal Threats

JPG-Gulf Intracoastal Waterway runs through wintering grounds at Aransas NWR

Several factors contributed to the historic decline of the species. Much of the former range became unsuitable as a result of conversion to agriculture (Allen 1952). The migratory populations of the mid-continent lost large portions of their breeding and wintering habitat in the late 1800s and early 1900s. Conversion to rice culture deprived the non-migratory population of much of its habitat in the coastal marshes and prairies of Louisiana and Texas. In addition to outright habitat loss, these activities increased the level of human disturbance, which may have had adverse effects on crane behavior. At the same time, hunting, egg collecting, and specimen collecting were a substantial drain on the population, particularly from 1870 to 1920 (Allen 1952, Doughty 1989).

Whooping Cranes continue to face a wide variety of threats.

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Current Conservation Measures

JPG-Nesting grounds, Wood Buffalo National Park, Canada

Legal and Cultural Protection

The Whooping Crane is legally protected at the international level under the Migratory Bird Treaty (1916) and the Convention on International Trade in Endangered Species (1975). At the national level, legal protection is provided by the U. S. Migratory Bird Treaty Act (1918), the Canadian National Parks Act (1930), the Canada Wildlife Act (1972), the U. S. Endangered Species Act (1973), and the Canadian Migratory Birds Convention Act (1994). Although the species no longer occurs in Mexico, it is legally protected there.

International Agreements and Cooperation

The Whooping Crane provides an important example of international cooperation on behalf of wildlife, and a model for collaborative efforts to protect other migratory cranes. Lewis (1991) notes that, "cooperation between Canada, which protects the nesting ground and important fall staging areas, and the United States, which manages the wintering grounds and migration stopovers, has been essential [in bringing] the species back from the brink of extinction."

The Canada-U.S. Migratory Bird Treaty of 1916 provided the first international-level protection for the Whooping Crane. The conservation agencies of the two countries had already worked together successfully for several decades when their respective roles and responsibilities were formally outlined in 1985 in a Memorandum of Understanding (MOU) on the Conservation of the Whooping Crane Relating to Coordinated Management Activities. The MOU has been renewed twice, in 1990 and 1995. The parties to the MOU are the USFWS, the CWS, the U.S. National Biological Service, and the Canadian Parks Service. The MOU provides mechanisms for shared decision-making and implementation of recovery activities, and for appointment of coordinators to facilitate such cooperation.

Cooperative conservation activities have also been stressed at the state and province level. To reduce the risk of loss during migration and to improve treatment of sick or injured birds when necessary, a Contingency Plan for Federal-State Cooperative Protection of Whooping Cranes was developed and adopted in 1985. The plan, approved by thirteen states and the USFWS, coordinates monitoring and response activities along the Whooping Crane's migration route. In Canada, a parallel contingency plan has been in place since 1987. The plan was outlined in the initial Canadian Whooping Crane Recovery Plan (Cooch et al. 1988). These contingency plans have also been incorporated into the Canada-U.S. MOU (Lewis 1992).

Whooping Crane Recovery Plans

The U.S. Endangered Species Act (1973) provides for the development and implementation of recovery plans for endangered species. These plans are prepared and periodically updated by recovery teams appointed by the U.S. Secretary of the Interior. The U.S. Whooping Crane Recovery Team was appointed in 1976 and the USFWS published its first Whooping Crane Recovery Plan in 1980. Since then, the plan has been revised twice, in 1986 and 1994. The Canadian Whooping Crane Recovery Team was established in 1987 to define and coordinate recovery activities within Canada. Its first plan was published in 1988 (Cooch et al. 1988) and revised in 1994 (Edwards et al. 1994)3.

Recovery activities have been closely coordinated between the two nations, and the 1995 MOU on Conservation of the Whooping Crane calls for the preparation of a combined plan and the formation of a single recovery team comprising five U.S. and five Canadian members. At the time of publication these steps had not yet been taken, but were expected to be achieved directly (J. Lewis pers. comm.). The goals and strategies of the two national recovery plans are outlined below in the "Priority Conservation Measures" section.

Protected Areas

Much of the critical nesting, migration, and wintering habitat of the AWP is contained within protected areas. The main nesting grounds are located within Wood Buffalo National Park (established in 1922). Many of the population's migration stopovers and staging areas are protected within federal, state, and provincial wildlife refuges, waterfowl management districts, and other designated conservation areas. Several Whooping Crane staging areas are protected under Saskatchewan's Wildlife Habitat Protection Act of 1992 (B. Johns pers. comm.). Saskatchewan's Last Mountain Lake National Wildlife Area (established in 1887) also protects a significant stopover site. In the U. S., migrating Whooping Cranes utilize approximately twenty national wildlife refuges in eleven states (Lewis 1991). The Cheyenne Bottoms State Wildlife Area in Kansas is an important stopover point. The Aransas NWR, established in 1937, protects the main wintering grounds. Additional habitat surrounding Aransas NWR has been purchased by the U.S. government and the state of Texas with the assistance of The Nature Conservancy (Doughty 1989). The National Audubon Society has also entered into leasing arrangements on lands outside Aransas.

The Rocky Mountains population is concentrated at Grays Lake NWR in the breeding season and Bosque del Apache NWR in the winter, and utilizes several other state and federal wildlife refuges (especially Ouray NWR in Utah and Monte Vista and Alamosa NWRs in Colorado) during migration.

The core of the area where the experimental Florida population has been established consists of state wildlife management areas and parklands, as well as several large and small private holdings (including lands owned by the National Audubon Society) (Lewis 1995b).

Habitat Protection and Management

In addition to the establishment of the protected areas noted above, extensive habitat protection and management activities have been undertaken. These include the following.

Surveys/Censuses/Monitoring

All three populations of the species are closely monitored. The AWP has been counted annually on its wintering grounds since 1938. The AWP has been monitored on the breeding grounds by CWS since 1966 (Novakowski 1966, Kuyt 1993). The USFWS initiated a migration monitoring program in 1975 to compile information on sightings and stopover points. The program has been expanded and coordinated with information gathering activities of the CWS and states and provinces along the migration corridor. Aerial surveys of the breeding grounds are undertaken each spring to determine the number of breeding pairs and their nesting success. Annual productivity in the population is determined through surveys conducted annually at the Aransas NWR by the USFWS (see Binkley and Miller 1983, Boyce and Miller 1985, Boyce 1987, and Nedelman et al. 1987).

From 1977-1988, a color banding program undertaken at WBNP allowed U.S. and Canadian biologists to identify and study individual birds, yielding valuable information on many aspects of the population's demographics, migration behavior, and habitat use (Kuyt 1992). Radiotelemetry studies of the local movements and migration patterns of the cross-fostered RMP were carried out from 1979 to 1982. Similar studies of the AWP were undertaken from 1981-83. These studies were especially useful in providing information on migration dynamics and causes of mortality (Drewien and Bizeau 1981, Drewien et al. 1989, Kuyt 1992).

Research

Since the 1940s, the Whooping Crane has benefited from intensive research on virtually all aspects of its biology, life history, and ecology. These efforts were first carried out under the Cooperative Whooping Crane Project (Allen 1952, 1956). Since then scientists have built upon this foundation with wide-ranging studies of demographics, genetics, reproductive biology, migration, food habits, environmental threats, behavior, habitat ecology and restoration, captive propagation, health management, and reintroduction. This information has been summarized in several publications, including Walkinshaw (1973), Johnsgard (1983), Doughty (1989), Mirande et al. (1993), USFWS (1994), and Lewis (1995b). Recent research topics include studies of historical summer and breeding records, winter habitat and ecology, breeding range expansion, new reintroduction and release techniques, potential release sites, the availability of migration habitat, and conservation genetics (e.g., Armbruster 1990, Ellis et al. 1992, May 1992, Kuyt 1993, Hjertaas 1994, Snowbank 1995).

Non-governmental Organizations

Non-governmental organizations have played a key role in drawing attention to the Whooping Crane's precarious status and in supporting and coordinating conservation programs. These groups include:

Population Viability Assessment

A population viability assessment workshop for the Whooping Crane was conducted in August 1991. The workshop included representatives of the U.S. and Canadian Whooping Crane Recovery Teams, the USFWS and CWS, ICF, other captive breeding programs, and the IUCN/SSC Conservation Breeding Specialist Group. The final report (Mirande et al. 1993) analyzed genetic and demographic characteristics of both the wild and captive populations. Its findings included the following:

The final report also identified specific priorities for research and management to retain maximum genetic heterozygosity and to minimize the risk of extinction.

Education and Training

Educational programs have been key to the survival of the Whooping Crane. Over the decades, the story of the species has been widely disseminated through books, newspaper and journal articles, radio, television, and documentary films. These efforts date to the late 1940s, when the Royal Saskatchewan Museum in Regina undertook an extensive education program focused on the species (B. Johns pers. comm.).

After the discovery of the AWP breeding grounds in 1954, educational efforts were initiated along the population's migration route. Hunter education was and continues to be important in reducing the risk of hunter-caused mortality in both the Aransas-Wood Buffalo and Rocky Mountain populations. The U.S. and Canadian Contingency Plans for protection of the species include educational components designed to enhance the public's ability to identify cranes and to encourage reporting of observations during migration (Lewis 1992, Edwards et al. 1994).

The Whooping Crane is also used in educational programs to convey broader lessons involving the conservation of endangered species and biodiversity in general. Recent education projects focused on Whooping Cranes include: a live interactive video conference for students coordinated by the Patuxent Environmental Science Center and the Alliance for Environmental Education; exhibits at the new National Wildlife Visitor Center at Patuxent; and a new Whooping Crane educational exhibit at the International Crane Foundation.

Captive Propagation and Reintroduction

Captive propagation of Whooping Cranes for conservation purposes was first proposed in the mid-1950s (see Doughty 1989 for a review of the history of the captive propagation program). The initial step in establishing the program was taken in 1966, when a single male bird was transferred to the USFWS Patuxent Wildlife Research Center (now the Patuxent Environmental Science Center). In 1967, the CWS and USFWS began to remove single eggs from the nests of the AWP for hatching and raising at Patuxent. Birds from these eggs produced their first eggs in 1975. To minimize the risk of disease outbreaks and other potential threats, the captive propagation program was eventually expanded to the International Crane Foundation in 1989 and the Calgary Zoo in 1992. The Patuxent program provided eggs for the experimental cross-fostering efforts at Grays Lake. The programs at Patuxent and ICF are currently providing juvenile birds for the establishment of the non-migratory flock in Florida (USFWS 1994).

As of August 1996, 91 adult birds were maintained at the three principal propagation centers: 39 at Patuxent, 29 at ICF, and 18 at the Calgary Zoo. In addition, 4 adult Whooping Cranes are maintained at the San Antonio Zoo and one bird at the White Oak Conservation Center. Studbooks for both the captive and wild populations of Whooping Cranes are maintained by Claire Mirande of the International Crane Foundation and are available through ICF. Mirande et al. (in press a) and Mirande (pers. comm.) summarize current trends in the captive populations as follows:

The GCAR for cranes has recommended that Whooping Cranes be given the highest priority for intensive management, and endorses current efforts to develop a viable, self-sustaining captive population and to establish two separate additional self-sustaining wild populations (as per the recommendations of the U.S. and Canadian recovery plans) (Mirande et al. in press a). At present, reintroduction and release efforts are focusing on: continued supplementation, monitoring, and evaluation of the experimental Florida population; evaluation and selection of future release sites in Canada; further development of release techniques for establishing a migratory population; and development and testing of techniques for teaching captive-raised birds to migrate and survive in the wild. In the summers of 1995 and 1996, preliminary efforts were undertaken to identify an appropriate release site in Canada for establishment of the third wild population (A. Burke pers. comm.).

Teaching migration to young Whooping Cranes continues to be the most significant barrier to reestablishing wild populations through captive propagation. At present, two methods are being tested on an experimental basis using Sandhill Cranes. The first involves using ultralight planes to guide imprinted juvenile cranes on migration. This method has been successfully used to guide Canada geese and is now being tested on cranes at two sites. The second method involves transporting captive-raised juvenile cranes along migration routes and releasing them at intervals (+/- 35 km) to allow them to orient themselves. If these methods prove successful with Sandhill Cranes, they may be used to teach migration to Whooping Cranes within several years (D. Ellis pers. comm.).

3The Canadian National Recovery Plan for the Whooping Crane has been published under the auspices of the Recovery of Nationally Endangered Wildlife (RENEW) Committee. It is now required that recovery plans be prepared for all endangered and threatened species on the Canadian Endangered Species List, which is prepared annually by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). These plans are prepared following a standard format and are approved by the RENEW Committee. See Edwards et al. (1994) for further information.

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Priority Conservation Measures

JPG--Captive-reared Whooping Cranes at release site in Kissimmee Prairie area, Florida, USA

Implementing the Whooping Crane Recovery Plans

Unlike other crane species, the Whooping Crane has long been the focus of intensive conservation programs. The conservation needs of the species are defined in detail in existing recovery plans of the Canadian Wildlife Service and the U.S. Fish and Wildlife Service (Edwards et al. 1994, USFWS 1994). Priority should be therefore be given to the full implementation of the actions recommended and described in these plans. The goals and recommendations of the plans are summarized here.

  1. The U.S. Whooping Crane Recovery Plan

    The long-term objective of the U.S. Whooping Crane Recovery Plan is to downlist the status of the species from Endangered to Threatened. The plan states that, "based on existing knowledge, the minimum requirements for downlisting are maintenance of the AWP above the current 40 nesting pairs and the establishment of at least two additional, separate, and self-sustaining population, each consisting of 25 nesting pairs" (USFWS 1994). The plan seeks to expand the AWP to 1000 individuals. These goals are to be met for ten consecutive years before the species is reclassified. In order to attain these goals, the plan prescribes specific actions under four categories:

    The Whooping Crane Recovery Plan includes an implementation schedule that provides priority rankings for these tasks, assigns responsibility, and estimates costs.

  2. The Canadian National Recovery Plan for the Whooping Crane

    The Canadian National Recovery Plan for the Whooping Crane lays out a series of actions "to be carried out in Canada, which will protect and increase Whooping Crane populations in Canada and elsewhere, and which will result in an eventual downlisting of the species from its present endangered status" (Edwards et al. 1994). The primary objectives of the plan are (1) to establish a stable or increasing AWB population with a minimum of 40 breeding pairs by the year 2000, and (2) to establish and support two other wild Whooping Crane populations, each with a minimum of 25 breeding pairs, by the year 2020. These objectives are substantially the same as those defined in the U.S. Whooping Crane Recovery Plan and must also be met for ten consecutive years before the species is reclassified. The plan identifies five strategies to meet these objectives:

    The plan describes specific activities to support these strategies and includes a detailed implementation schedule. The implementation schedule ranks these activities, assigns responsibility and target dates for carrying them out, and provides cost estimates.

Integrating the U.S. and Canadian Recovery Plans
  1. Combine and coordinate the national recovery plans for the species. The Canada-U.S. MOU on the Conservation of the Whooping Crane directs the CWS and USFWS to work toward this goal, and efforts to do so should proceed.
Protected Areas

Priorities in this area are outlined within the recovery plans. Special attention, however, should be given to the following measures:

  1. Prevent future habitat loss and mitigate current habitat degradation at the Aransas NWR.

  2. Initiate long-term measures to maintain freshwater inflow from the rivers into the bay systems at and near Aransas NWR.

  3. Monitor disturbance levels and minimize detrimental activities at Aransas NWR and adjacent wintering grounds.
Habitat Protection and Management

Priorities in this area are outlined within the recovery plans, while many others are discussed within the Sandhill Crane species account in this volume. Special attention should be given to the following needs:

  1. Maintain instream flow of the Platte River.

  2. Prevent habitat loss and mitigate habitat degradation on the Platte River and at other key stopover and staging areas.

  3. Implement existing habitat management plans for the Kissimmee prairie release site in Florida.

  4. Reduce the risk of utility line collisions.

  5. Evaluate and develop preliminary habitat management guidelines for potential release sites in Canada.
Research

Priority topics for research on Whooping Cranes are:

  1. The capacity of the Aransas NWR winter habitat to absorb more cranes if the population continues to increase.

  2. Expansion of the AWP breeding range at WBNP.

  3. Continuation of breeding and wintering ground surveys.

  4. Continued development of techniques for reintroducing and establishing new breeding populations and for establishing migratory routes among released birds.

  5. Continuation of current efforts to evaluate potential Canadian reintroduction sites.

  6. Evaluation of disease risks and management of diseases in the wild, especially in relation to the existing and potential release programs (see research recommendations in Brand et al. 1991).

  7. Genetic studies (see research recommendations in Mirande et al. 1993)
Captive Propagation and Reintroduction

Detailed recommendations can be found in the Canadian (Edwards et al. 1994) and U. S. (USFWS 1994) recovery plans. Following these recommendations, as well as those outlines in the GCAR and CAMP for cranes (Mirande et al. in press a), the following general priorities are endorsed.

  1. Continue efforts to establish a viable captive population aimed at producing young birds to support release efforts. The goal, as described in the U.S. Whooping Crane Recovery Plan (1994), is to have 40 actively breeding pairs in captivity by the year 2000: 15 at Patuxent, 15 at ICF, and 10 at the Calgary Zoo.

  2. Continue efforts to establish two additional, separate, self-sustaining, wild populations. Efforts to establish the Florida population should proceed as determined by the combined Whooping Crane Recovery Team. Immediate attention should be given to identification and selection of potential sites for establishment of a migratory breeding population of Whooping Cranes in Canada in the late 1990s (Edwards et al. 1994, USFWS 1994).

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