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< > Grus americana - Whooping crane (Click photographs/illustrations: full picture & further details)

Young whooping crane chick hock-sitting. Click here for full-page view with caption. Whooping crane. Click here for full-page view with caption. Whooping crane in large pen. Click here for full-page view with caption. Whooping crane - head. Click here for full-page view with caption. Whooping crane chick hock-sitting. Click here for full-page view with caption. Whooping crane pair in large pen. Click here for full-page view with caption. Pair of whooping cranes. Click here for full-page view with caption. Whooping crane chick legs. Click here for full-page view with caption. Whooping crane doing a bow threat. Click here for full-page view with caption. Large whooping crane chick with crane head puppet. Click here for full-page view with caption. Whooping crane chick with toe splints. Click here for full-page view with caption.  Whooping crane chick scratching. Click here for full-page view with caption. Well-grown whooping crane chick - legs. Click here for full-page view with caption. Whooping crane chicks foraging in marsh. Click here for full-page view with caption. whooping crane chick. Click here for full-page view with caption. Whooping crane chicks in adjacent pens. Click here for full-page view with caption Whooping crane chick probing soft ground. Click here for full-page view with caption Whooping crane jumping. Click here for full-page view with caption Grus americana - Whooping cranes, unison call. Click here for full-page view with caption. Grus americana - Whooping crane, strut walk. Click here for full-page view with caption. Chicks on icy pool. Click here for full-page view with caption. Pair of whopping cranes with large chick. Click here for full-page view with caption. Whooping cranes on nest with egg. Click here for full-page view with caption. Grus americana - Whooping crane. Click here for full-page view with caption. Whooping crane. Click here for full-page view with caption. Whooping crane pair with chick. Click here for full-page view with caption. Whooping crane distribution map. Click here for full-page view with caption.

INFORMATION AVAILABLE

GENERAL & REFERENCES

APPEARANCE & ANATOMY

REPRODUCTION

BEHAVIOUR

NATURAL DIET & PHYSIOLOGY

RANGE & HABITAT

CONSERVATION

 

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General and References

Alternative Names (Synonyms)

  • The hooping crane (B474)
  • La Grue d'Amérique (B474)
  • Ardea americana (B474)
  • La Grue Blanche (B474)
  • Grus clamator (B474)
  • de Amerikaansche (Dutch)
  • The American crane
  • der weisse Amerikanische Kranich (German) (B474)
  • Big white crane (B107.w8)
  • Whooper (B107.w8)
  • Grue blanche (French) (B107.w8, W2.Dec06.w2)
  • Schreikranich (German) (B107.w8)
  • Gruella Trompetera (Spanish) (B107.w8, W2.Dec06.w2)
  • Grue blanche d'amérique (French) (W2.Dec06.w2)
  • Grulla americana (Spanish) (W2.Dec06.w2)
  • Grulla gritona (Spanish) (W2.Dec06.w2)

Names for newly-hatched

Chick

Names for non-breeding males or other colour-phases

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References

Species Author

Debra Bourne MA VetMB PhD MRCVS (V.w5)

Major References

B97, B107.w8, B475, B477, B480.6.w6, B481.II.10.w18, W2.Dec06.w2, W2.Nov2013.w6

Aviculture references:
B115.2.w7, D437, J23.17.w5, J54.2.w1, N31.33.w2, P1.1986.w4, P96.1.w1,P92.1.w6, P87.11.w12

ORGANISATIONS

ELECTRONIC LIBRARY
(Further Reading)
Click image for full contents list of ELECTRONIC LIBRARY

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TAXA Group (where information has been collated for an entire group on a modular basis)

Parent Group

Specific Needs Group referenced in Management Techniques

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Aviculture Information

Notes

General Information:
  • Cranes are tall birds with a long beak and sharp claws, and can be aggressive. Their ability to injure humans must be considered in enclosure design and handling. (B115.2.w7, B197.9.w9)
  • Most cranes are wetland species, a few being primarily grassland species. They should be given the opportunity to wade and bathe, and to forage and/or dig for food in natural vegetation and soft soil substrates.
  • Good nutrition, with adequate protein and micronutrient levels, is essential for the general health of the cranes and for breeding.
  • Cranes form monogamous pairs and can be extremely territorial, particularly in the breeding season. Therefore it is important to house each pair of adult cranes in a separate enclosure from other cranes, and preferably not directly adjacent to another pair of cranes, particularly of the same species. Visual barriers should be put in place between crane enclosures before the breeding season
  • Care is required when introducing intended mates to each other, to avoid injury to one or both birds; formation of a good pair bond can take time.
  • Cranes are unlikely to breed if they feel insecure, such as in mixed species enclosures with hoofstock, or if there is no part of their enclosure which is free from daily human disturbance.
  • If possible, rotational pens should be provided, such that a pen can be left empty in alternate years, to reduce soil burdens of parasites and pathogenic microorganisms which may otherwise build up to problematic levels; this is particularly important if chicks are to be parent-reared, to avoid overwhelming exposure to e.g. gapeworm very early.

(B115.2.w7, D437, J23.17.w5, P1.1986.w4, P96.1.w1)

Species-specific information:

  • Captive whooping cranes have generally started breeding later than their wild conspecifics. Possible factors in this include: "improper photoperiod, rainfall, rearing conditions, dominance relationships, age of separation of potential pairs from a bachelor flock, sexual incompatibility, inadequate pen size, lack of access to ponds, and stress associated with handling and disturbance." (P87.11.w12)
    • Pairs should be separated from a bachelor flock as soon as they have formed. (P92.1.w6)
  • These cranes definitely appreciate having a pond, and this may stimulate strong pair formation and breeding.
  • Isolated enclosures in which the cranes feel they have a secure territory may be important for breeding. (N31.33.w2)
  • At Patuxent Wildlife Research Center, additional lighting is provided for Grus americana - Whooping crane starting in February, six to eight weeks before the expected onset of laying, and increased gradually so that by the day length will equal that which would be occurring at Wood Buffalo National Park (the natural breeding grounds) at the same time that the Patuxent temperatures are similar to those of Wood Buffalo at the start of the breeding season. (J54.2.w1)
  • Having a consistent person in the role of "stroker" appeared to be important in encouraging production of good semen samples by AI. (N31.33.w2)
  • AI performed three times per week appears to give the best fertility. (N31.33.w2)
  • In general, locking the male inside the shed and leaving the female outside appeared to be least stressful for the birds (as well as protecting the AI team from aggressive males); this should be determined by the behaviour of the individual birds, as one male became very disturbed if shut away, and stood aff a distance, not interfering, if left in the pen. (N31.33.w2)
Management Techniques

 

Bird Husbandry and Management

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External Appearance (Morphology)

Measurement & Weight

Height
  • 130-160 cm. (B107.w8) 132 cm. (B475); 124-142 cm (B477)
  • Wingspan 200-230 cm. (B107.w8); 210-230 cm. (B477)
  • Males are generally slightly larger than females. (B107.w8)
Adult weight General 4,500-8,500 g. (B107.w8)
Male Average 7,300 g. (B481.II.10.w18)
Female Average 6,400 g. (B481.II.10.w18)
Newly-hatched weight --
Growth rate Cranes general: Crane chicks grow rapidly. Growth of the legs is particularly rapid in the first six weeks, with the wings then developing rapidly after this. (B107.w8)

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Head

Adult Bill Male Horn-colour. (B475) Yellowish. (B97) Variously described as olive grey with a darker tip, but pinker at the base and "wax yellow" with a dull greenish or yellowish tip. (B480.6.w6, B481.II.10.w18)
Variations (If present) Female: As male. (B477)
Eyes (Iris) Male Yellow. (B107.w8, B477, B481.II.10.w18)
Variations (If present) --
Juvenile Bill Downy chick's bill pale buffy-brown, with the base flesh-coloured. (B480.6.w6)
Eyes (Iris) --

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Legs

Adult Male Black. (B97, B477)
Variations (If present) --
Juvenile Downy chick, legs light brownish. (B480.6.w6)

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Plumage

Adult Male
  • Primarily white. Head has a dark red crown and dark red or black elongated malar stripe. Primaries and alulae are black. (B107.w8)
  • Mainly white; wing tips black, cap, face and throat red skin with sparse black feathering. (B477)
Variations (If present)
--
Juvenile
  • Head: fully feathered, pale brown. (B107.w8)
  • Body: mottled white and cinnamon. (B107.w8)
  • Whitish, but with scattered brown feathers over the wings and head and neck pale reddish-brown. (B475)

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Identification Notes

Cranes general: 
  • "Cranes are large to very large birds with long necks and legs, streamlined bodies and long, rounded wings." (B107.w8)
  • Compared to the day-herons, cranes have longer legs and hold their necks straighter. (B107.w8)
  • Compared to egrets, the body is proportionately larger. (B107.w8)
  • In flight, cranes have their necks straight forwards and their long legs trailing behind, forming a straight line from the bill; in very cold weather the legs may be pulled in against the body. (B107.w8)
  • Compared to storks, the legs are longer, bodies lighter and bills smaller. (B107.w8)

Whooping crane:

  • The tallest North American bird. (B107.w8)
  • White except for the black primaries and alulae, and the head markings: a dark red crown and dark red or black elongated malar stripe. (B107.w8)
  • Large white crane with a red crown, black forehead, lores and moustache (tipped red) and red facial skin. In flight, the black primaries are visible. (B475)
  • Two other cranes are primarily white:
  • White with black wing tips and deep red cap, face and throat. (B477)

Voice:

  • Loud, trumpet-like calls. (B107.w8)
  • Trumpeting "Ker-loo ker-lee-loo" calls. (B475)

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Newly-hatched Characteristics

  • Initial down is brown. (B107.w8)
  • Precocious, leaving the nest very soon after drying. (B480.6.w6, B481.II.10.w18)
  • Cranes general: The initial down is replaced by a second coat of down; this is replaced by feathers. (B107.w8)

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Detailed Anatomy

  • The trachea is coiled and fills the sternum. (B107.w8)
  • Cranes have ten functional primary flight feathers (with a vestigial 11th in most species), and 18-25 secondary flight feathers. (B107.w8)

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Reproduction

Reproductive Season

Time of year Spring; eggs are laid late April to mid-May. (B107.w8, B475, W2.Dec06.w2)
No. of Clutches --

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Nest placement and structure

  • In a nesting territory of 1.3 - 47 km², average 7.2 km²; the nest 60-150 cm diameter and up to 45 cm above water level, is constructed from wetland plants. (B107.w8)
  • Nests may be as large as 120 x 150 cm or larger across at the base, within a large patch of rushes, with a bare areas surrounding the nest - from which the nest material had been taken. (B480.6.w6)

Cranes general:

  • Crane pairs each occupy a territory during the breeding season. This is an area of suitable habitat, the size of the territory being based on food resources, so that territories are larger in years and areas where food resources are poor, and also based on visual barriers: territories often are side by side, separated by a visual barrier such as a low hill or a row of trees. (J23.17.w5)
  • Cranes nest on the ground. (J23.17.w5)
  • The nests of cranes usually are made from aquatic vegetation and their size varies depending on the depth of water where the nest is built; species nesting in dry locations (Grus canadensis - Sandhill crane (Species) nesiotes, Grus virgo - Demoiselle crane (Species) and Grus paradisea - Blue crane (Species) build little or no nest. (J23.17.w5)

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Egg clutches

No. of Eggs Average Usually two. (B107.w8)

Cranes general: Cranes are indeterminate layers; if the nest or eggs are destroyed, they will lay again. (J23.17.w5)

Range
  • Almost always two, rarely only one (B480.6.w6); usually two, occasionally one and very rarely three. (B481.II.10.w18)
  • Renesting may occur occasionally. (B481.II.10.w18)
Egg Description Ovate or elliptical ovate, variously described as cream-buff to olive-buff, and as greenish-brown, spotted over the whole surface with brown, buff and purplish markings, with more spots at the larger end of the egg; 38 eggs averaged 98.4 x 62.4 mm. (B480.6.w6)

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Incubation

  • 28-31 days. (B107.w8)
  • Incubation begins after the first egg has been laid. (B107.w8)
  • The two eggs are laid two days apart. (B481.II.10.w18)

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Hatching

Asynchronous. (B107.w8, B481.II.10.w18)

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Fledging

80-90 days. (B107.w8)

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Sexual Maturity

Males
  • There are records of pairs being formed at two years and pairs nesting at three years old. (B107.w8)
  • Cranes general: Data from artificial collection of semen indicates that sperm are occasionally found in males of just on year old, but sperm production usually starts at 2-3 years of age and regular production of good-quality sperm generally begins at 3-4 years of age. Natural fertility generally is observed when the birds are 3-4 years old. (P76.1990.w2)
Females
  • There are records of pairs being formed at two years and pairs nesting at three years old, but the average age for first eggs laid is just over four years of age. (B107.w8)
  • Egg laying has been observed by three-year-old birds in Wood Buffalo National Park. (P76.1990.w2)
  • Cranes general: egg laying by female cranes generally starts one to two years after the pair bond has been established. (P76.1990.w2)

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Behaviour

Feeding Behaviour

Adults
  • Probe soil with bill for food items, also take foods from the surface. (B107.w8)
  • In winter, wade in water about 5 - 10 inches deep, at intervals lowering the head to forage e.g. probing in holes/burrows of invertebrate prey, and digging when necessary. (B481.II.10.w18)
Newly-hatched
  • Take food offered directly by the parents, or pick up food which the parents repeatedly drop and pick up in front of them. (B480.6.w6)

Cranes general: 

  • Crane chicks are precocial. In the wild, they can feed themselves from about 2-3 days old, but they appear to be dependent on their parents for some of their food and will continue begging until they leave/are driven away at the start of the next breeding season. (J23.17.w5)
  • Chicks, from a very early age, follow their parents to preferred feeding areas. (J23.17.w5)

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Parental Behaviour

Nest-building
  • Both birds build the nest. (B480.6.w6)
  • Cranes general: Both male and female build the nest. (B107.w8)
  • Cranes general: A secluded spot in the pair's territory is chosen, and the cranes unison-call there, then walk away from the selected place and toss nesting materials over their shoulders towards it. Returning to the nest site, they pull into the nest material which is within reach, then slowly walk away and toss more material towards the nest, repeating this sequence until sufficient nesting material has been gathered. (B107.w8)
Incubation
  • Both birds incubate the eggs, with the female more commonly incubating over night than the male, but more of the daytime incubation carried out by the male. (B480.6.w6, B481.II.10.w18)
    • For a pair at Audubon Park Zoo (previously observed in the wild), the female incubated more in the day and the male at night. (B481.II.10.w18)
    • The crane which is not incubating stands guard and chases away other birds and even mammals such as deer. (B481.II.10.w18)
  • Cranes general: 
    • Both male and female incubate, changing over several times during the day, but with the female usually incubating during the night. (B107.w8)
    • About every 30-80 minutes, the bird which is incubating will rise and roll the eggs or adjust the nest. (B107.w8)
Newly-hatched
  • The parents offer food to the chick in its bill; if the chick does not take the food, the adult drops it and picks it up again, several times, until the chick starts to pick up the food. The chick does not always accept all food offered. (B480.6.w6)
  • Mostly the female feeds the chick and shows it where to find food, and the male stands guard. (B480.6.w6)
  • Cranes general: Adult cranes feed their chicks from soon after hatching. Both male and female bring small items to the chicks, presenting them by holding the food item at the tip of the bill or dropping the food in front of the chicks. (B107.w8)
Juveniles
  • Parents, particularly the female, still feed the juveniles on the wintering grounds. Juveniles gradually becme more independent towards spring. (B481.II.10.w18)

  • Cranes general: Adult cranes continue to care for their chicks throughout the pre-fledging period and may bring food to the chick for several months (although chicks also follow their parents to food sources from an early age). Juveniles remain with their parents through the non-breeding periods but leave at the start of the next breeding season or are driven away after the return to the breeding territory. (B107.w8)

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Social Behaviour

Intra-specific
  • Whooping crane pairs establish a breeding territory and return to it each year. On autumn migration, they stay in family groups, although they also form larger groups formed from several families. In winter they also maintain territories, with pairs with young defending their territories strongly. (B480.6.w6)
  • Resident pairs will attack both single birds and other pairs entering their territory. (B481.II.10.w18)
  • Cranes general: 
    • Cranes are gregarious outside the breeding season, but separate for the breeding season. (B107.w8)
    • Juveniles which are not yet paired gather in non-breeding flocks and may be nomadic through the breeding period. (B107.w8)
    • By the end of their second year the young birds may have started to initiate pair bonds. (B107.w8)
    • Soon after the chicks fledge, families of migratory cranes gather in flocks at pre-migratory staging areas with dependable food and safe roosting sites. As the weather deteriorates, they move further south to join larger congregations of cranes, before setting out on the main migration. (B107.w8)
    • Cranes are highly territorial. They use stereotyped calls and threat displays to avoid contact with conspecifics. (J23.17.w5)
  • Aggressive displays of cranes (B115.6.w8)
    • A basic, low-intensity display involves a change in the appearance of the head. In cranes with bare skin on the cap of the head, Crown-expansion is seen, and in those with wattles, these are extended (Bare-skin-expansion); the bare areas also become brighter in colour. In the species with fully feathered heads, the head plumage is elevated, increasing the apparent size of the head. These head-based displays can also be used as part of other aggressive displays. (B115.6.w8)
    • Alert-posture: the crane raises its head to full height, extending its neck upwards and slightly forwards. Crown expansion or Bare skin expansion may be seen with this.
    • There are two ritualised display walks, the Horizontal-strut and the Vertical-strut, with exaggerated, rhythmic steps and the bill bobbing slowly up and down in time with the steps. During the vertical-strut the crane's toes are rigidly fanned and extended. During these display walks, the crane may turn its bill away from the intruder, so its crown is towards the intruder in a Crown-present, or may direct its bill dowwards towards the intruder. During strutting of higher intensity, the walk is faster, or the crane lowers its head, sometimes to close to the ground. Some species raise their tertial feathers during the display walk, forming a bustle; this is seen in the common (greatest), hooded, whooping, black-necked, sandhill and Siberian cranes.
      • In more intense versions of the Vertical-strut, the red-crowned crane and closely related species (Eurasian, hooded, black-necked, whooping?) sometimes slightly raise their wings.
    • In the Ruffle-bow, seen in all crane species, the crane elevates its feathers then ruffles its plumage, initially slowly, but increasing until the whole body is shaking rapidly. In the blue, demoiselle and wattled cranes, this is the principle aggressive display behaviour. In sandhills, the Ruffle-bow is finished by the crane throwing its head downwards and preening its breast or tibiotarsus, while in the whooping crane at the end of the Ruffle-bow the crane tucks its bill in high up. Brolgas, sarus and white-naped cranes all perform an exaggerated downwards bow as part of their Ruffle-bow; after the ruffle usually they bow deeply forwards then either perform a Ritualized Thigh Preen or they elevate their head far over the back.
    • In the Ritualized-preen display, seen in all crane species, the bill is placed between the back and one wing. the details of this display vary between species: Siberian cranes keep their bill still and lower the primary feathers of one wing; most species make rudimentary preening movements, periodically raising their heads to look around; several species Stomp (stamp their feet) a few times; the red-crowned crane often Stomps, then it performs an Arch, arching the head back and raising its wings above its back, so the head is nearly between the wings, over its back; the whooping crane performs a display known as the Butterfly, with its body and neck nearly vertical and its wings held backwards.
    • The Crouch is believed to be the most aggressive display; the crane lowers its body to a lying posture, wings slightly to mostly spread, its bill in front of its body and usually touching the ground or probing the ground. From this posture the crane may spring up suddenly and charp , flapping its wings and rapidly gliding over the ground in a Rush. The Rush ends either with a Stomp and a Ruffle-bow or by Attacking the intruder. Alternative ends to the Crouch are a Ritualized-preen (e.g. Siberian, sandhill) or an Arch (red-crowned).
      • It a territory owner is driving an intruder away, the Rush may lead to an aerial pursuit, during which the attacker may slash at the other crane with its feet, while flying. 
    • Attacking may involve "spearing the opponent with the bill (Bill-stab), Leaping in the air and slashing the intruder with the inner toenails (Jump-rake), and thrashing with the wings (Wing-thrash).
    • Sometimes a crane will circuitously walk closer and closer to an intruder while feeding, then will abruptly Rush it. 
    • Cranes may bill-spar with one another aggressively, standing erect, spreading their wings, and Bill-stabbing; they hiss loudly while bill-sparring.
    • Pecking or grasping at the wings or tail of a subordinate crane, to displace the other bird, are considered minor forms of Attack. 
  • Dancing includes behaviours described as Rushing, Flapping, Leaping, Tuck-bobbing, gaping and tossing feathers or sticks. It can last only several seconds or for up to a few minutes. While dancing is mostly pair-related, it is also seen in young cranes, apparently in appeasement of dominant cranes. Elements of aggressive displays, such as Crown-expansion, are seen during Dancing; sham Bill-stabs and Jump-rakes can be seen, but in stable pairs do not usually involve physical contact with the other bird. (B115.6.w8)
  • Submissive behaviours include fleeing and submissive displays. They indicate the crane is stressed. (B115.6.w8)
    • A crane may run away at the approach of a dominant crane or a person, push at the fence of its enclosure as if trying to walk through it, or nervously pace along the fence, raking its feet on the fence as if climbing it, and dragging its neck and bill along the fence. 
      • These behaviours can result in physical trauma such as abraded wrists and even a broken bill.
    • A submissive crane may Cower, with a hunched posture, fluffed neck and head feathers and contracted crown/wattles/bare skin patches. Often the head is lowered by a subordinate crane, the wings slightly spread with the elbows lifted away from the flanks, and the crane gives purring calls. This display is often seen in chicks; in adults the Cower is probably a reversion to chick behaviour to placate the dominant crane/person.
    • Another submissive display, used by both females and males, and in chicks and subadults as well as adults, is for the crane to spread its wings out, trailing edges drooping, and turn its back on the dominant crane/human, as if in the female crane's Pre-copulatory Display
Inter-specific A breeding pair of whooping cranes were noted to chase away great blue herons, American Egrets, Snowy Egrets, Louisiana herons, Reddish Egrets, white pelicans, mottled ducks and even deer. (B480.6.w6, B481.II.10.w18)

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Sexual Behaviour

  • Monogamous; form a new pair if one partner dies. (B481.II.10.w18)
  • During the unison call the male strongly lowers his carpi, so that the black primary feathers are exposed; the tertials are held upwards by both male and female. (B481.II.10.w18)
  • Cranes general: Monogamous. Crane pairs stay together all year, and usually remain together until one partner dies. (B107.w8)
  • Cranes general: (B107.w8)
    • Cranes copulate repeatedly, starting several weeks before egg laying.
    • Mating usually occurs before sunrise, but can also occur at other times during daylight hours. 
    • In newly-established pairs, copulation is preceded by long bouts of dancing. Well-established pairs mate without any tension. 
    • The copulatory sequence is initiated by the male or the female. The initiating bird elevates its bill, arches slightly forwards and gives a low, purring call. The mate then shows similar behaviour. 
    • The male bird (usually) circles its mate with exaggerated steps.
    • The female spreads her wings. The male approaches, jumps onto her back with his wings flapping, and crouches.
    • The female elevates her tail, the male lowers his tail, and the cloacae of the two birds meet.
    • The male jumps forward off the female over her head and for a few seconds performs threat displays.
    • Both birds perform a long preening sequence.

    (B107.w8)

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Predation in Wild

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Activity Patterns

  • Bathe thoroughly, almost completely submerging in the water. (B480.6.w6)
  • Diurnal. (B481.II.10.w18)
  • On migration, roost in shallow water at night, and forage during the day. (B481.II.10.w18)
  • Both on migration and in the wintering areas, in addition to foraging and roosting, some time is spent dancing, particularly just after arrival at the wintering grounds and just before leaving in the spring. Fighting also occurs. (B481.II.10.w18)

Cranes general:

  • Roosting:
    • Cranes (except the Balearica spp.) generally roost in shallow water, occasionally on mudflats, sandbars or dry ground.
    • In flocks, cranes stand about a "peck distance" apart while roosting.
    • Most of the time they stand on one leg, switching legs several times during the night.
    • The head and neck are tucked onto or under one shoulder.
    • Cranes defecate at regular intervals while roosting.
    • On the roosting site they are still and silent unless disturbed.
    • If there is an unfamiliar sound, or one member of the flock gives an alarm call, all the birds become alert and are ready to fly.

    (B107.w8)

  • At dawn, they wake, stretch, preen and drink.
  • In small groups, they fly to a post-roosting staging area, and preen more; cranes may gather at such a site from several roost sites.
  • Small and then larger groups move from the staging area to a feeding area for the day.
  • Generally, cranes feed for a long time in the early morning, then move to loafing areas.
    • At loafing areas, cranes preen and drink, and also engage in social displays, establishing a pecking order for families, and facilitating pairing of unattached birds.
  • In the middle of very hot days, they may fly, spirally high up on thermals.
  • Later they return to feeding and watering areas and forage.
  • They then move to pre-roosting staging areas before flying to a roost site.
    • On the pre-roost staging areas they may engage in social displays.

    (B107.w8)

Circadian
  • Cranes general: Diurnal. Outside the breeding season, cranes roost at night and feed during the day. (B107.w8)

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Natural Diet

Adult Diet

Omnivorous. (B107.w8)
  • Summer: insects, small vertebrates (small fish, frogs, small birds, rodents), berries. (B107.w8)
  • Migration: tubers and waste grain. (B107.w8)
  • Winter: mainly animal food, particularly blue crabs, clams. Occasionally acorns and invertebrates. (B107.w8)
  • Foods include shrimp, crabs, Pelecypoda, Gastropoda, grasshoppers and other insects, snakes etc. The blue crab appears to be the preferred winter food, with shrimp also important. Grains and other vegetable matter may be taken when other foods are less available. (B480.6.w6)
  • Polychaete worm (Laeonereis), pistol shrimp (Cragnon sp.), mud shrimp (Callianassa sp.), blue crabs (Callinectes sapidus), crayfish (Cambarus hedgpethi), short razor clams (Tagellus gibbus), green razor clams (Solen sp.), also fish, insects, reptiles, frogs, and insects, and plant foods such as marsh onions (Crinum sp.), prarie lily (Mothoscordum sp.), roots of Scirpus olneyi - Three-square and Spartina, as well as crops such as sprouting corn and sweet potatoes. (B481.II.10.w18)

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Newly-hatched Diet

  • Presumed to be insects and aquatic invertebrates, later also berries. (B481.II.10.w18)
  • A pair, Crips and Josephine, offered their chicks earthowrms, also dragonflies and grasshoppers. (B480.6.w6)

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Detailed Physiology Notes

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Range and Habitat

Distribution and Movement (Migration etc.)

Normal

Whooping crane distribution map. Click here for full-page view with caption.

  • Canada, USA; previously also Mexico. (W2.Nov2013.w6)

Breeding: 

  • West central Canada (Wood Buffalo National Park). (B107.w8)

  • Wood Buffalo National Park, on the border of Northwest Territories and Alberta, Canada. (W2.Dec06.w2)

  • Historically, northern prairies and plains of North America, Alberta to Lake Michigan; there was a non-migratory flock in Louisiana. (B107.w8)

  • Previously also Mexico. (W2.Nov2013.w6)

Movements:

  • Migrate down a migratory corridor, 100-300 kg wide, across nine Canadian provinces and US states; several important resting and staging areas in large marshes and riparian wetlands, particularly along the River Platte. (B107.w8)

  • Historically, wintered in the highlands of New Mexico, the Gulf Coast in Texas and Louisiana, and the south Atlantic coast of the USA. (B107.w8)

  • Winters at and near the Aransas National Wildlife Refuge, Texas, USA. (B477, W2.Dec06.w2)

  • Cranes general: 
    • Migratory cranes spend days to weeks at pre-migratory staging areas, integrating into the flock as well as building up fat reserves. (B107.w8)
    • To migrate, they feed for several hours early in the morning, then on a clear day with breezes, fly up, climbing in large circles by flap-flying and lifting on thermals, to as high as 2,00m, then assume a V-formation, wings extended, and glide south; after a certain amount of altitude has been lost, they spiral again to regain height, before gliding. Over water, without thermals, they flap-fly in V-formation. (B107.w8)
    • Young cranes stay close to their parents during migration and learn the route. (B107.w8)
    • Cranes call constantly during migration. (B107.w8)
Occasional and Accidental

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Introduced
  • Small experimental flock in the Rocky Mountains, western USA. (B107.w8)

    • Migrate between eastern Idaho and central New Mexico. (B107.w8)

  • Experimental non-migratory flock in Florida, south-east USA. (B107.w8)

    • Dispersed up to 120 km from the release site, but non-migratory. (B107.w8)

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Habitat

Lowland wetlands.(B475)

Breeding: 

  • Historically potholes and other wetlands of the North American prairies and northern plains. (B107.w8)
  • Remaining population, in a poorly drained area consisting of ponds, marshes, muskeg and boreal forest; nesting grounds have mainly bulrush, cat-tail and sedge as emergent vegetation. (B107.w8)
  • Prairie wetlands; prefers shallow, shallow lakes and ponds, willow communities, marshes, mudflats and possibly sedge meadows (considering the historic range, this habitat may by atypical). (B475, W2.Dec06.w2)
  • Prairie, muskeg, marshes and grasslands. (B477)

Migration:

  • Variety of habitats for feeding and roosting, such as riparian marshes, margins of reservoirs, submerged sandbars, cropland. (B107.w8)

Winter:

  • Brackish bays, saltflats, coastal marshes. (B107.w8)
  • Brackish coastal wetlands. (B475, W2.Dec06.w2)
  • Saline coastal lagoons. (B477)

Introduced flocks:

  • In the Rocky Mountains, intermountain lacustrine and riparian wetlands. (B107.w8)
  • In Florida (Kissimmee Prairie region), savannas, wet meadows, shallow marshes and lake margins. (B107.w8)

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Conservation

Intraspecific variation

Monotypic. (B107.w8)

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Conservation Status

Wild Population -
(Importance)
  • Endangered. (B107.w8, W2.Nov2013.w6)

  • Historically, this species was probably never very numerous. (B107.w8)

    • Population was severely reduced due to hunting, collecting and habitat loss (main breeding areas were lost to agriculture). (B107.w8)

    • Hunting, habitat loss and human disturbance were major reasons for the decline of whooping crane populations. (B475, W2.Dec06.w2)

    • The Louisiana non-migratory population died out in the 1940s; the migratory population reached a low of 14-15 individuals in 1941 and remained at 20-40 birds until the 1960s, then began to increase to reach about 150 birds [1996 data]. (B107.w8)

  • Endangered; population 183 but increasing at about 5% per year since 1966, with 50 active nests in 2000. (B475)

  • The remaining wild population increased at about 5% per year from 1966 to 1998, but has since stabilised; it totalled 216 birds in 2004; there were 50 active nests in 2000. (W2.Dec06.w2)

  • Historically, probably more than 10,000 prior to European settlement of North America, declining to 1,300 - 1,400 by 1870 and only 15 adults in 1938. In December 2008 there were 385 birds in three free-living populations, but the two reintroduced populations are not yet self-sustaining. (W2.Nov2013.w6)

    • The remaining natural population reached 266 birds and 65 active nests in 2007, and 270 individuals in spring 2008, but 247 by spring 2009 after a drought in Texas in the wintering habitat. (W2.Nov2013.w6)

  • Reintroduced populations:

    • The experimental migratory flock in Idaho, wintering south to New Mexico, dwindled to 1-2 birds in 1999 and has been discontinued. (W2.Dec06.w2)

    • A non-migratory flock in Florida numbered about 74 in 2004, with more released annually. (W2.Dec06.w2)

      • By 2007 this population numbered 41. (W2.Nov2013.w6)

    • A reintroduced flock migrating between Wisconsin and Florida included 42 birds in 2004. (W2.Dec06.w2)

      • This population reached 75  birds in 2007 and about 90 in 2008, with the first wild-born chick successfully migrating in 2006 and another hatched in June 2009.. (W2.Nov2013.w6)

    • Anther reintroduced flock was started in south-western Louisiana in early 2011. (W2.Nov2013.w6)

Threats

  • Loss and degradation of habitat (migratory and winter); (B107.w8)

  • Pollution; (B107.w8)

  • Human disturbance; (B107.w8)

  • Vulnerability of the small flock to catastrophic accidents or storms;(B107.w8)

  • Collision with utility lines; (B107.w8)

    • This currently is the most significant known cause of fledgling deaths/injuries. (B475, W2.Dec06.w2)

  • Shooting (accidental or illegal); (B107.w8)

  • Loss of genetic diversity; (B107.w8)

    • Unknown effects of genetic drift after the population bottleneck. (B475, W2.Dec06.w2)

  • Predation by Aquila chrysaetos - Golden eagle, particularly on migration. (B475, W2.Dec06.w2)

  • Wintering grounds in Texas are threatened by pollution, boat traffic, wave erosion and dredging. (B475, W2.Dec06.w2)

  • "Aransas NWR can only support a maximum of 150 birds through the winter, forcing remaining birds to use disturbed and suboptimal habitat - this is considered to have stabilised the growth of the wild population in recent years." (W2.Dec06.w2)

  • Possible threats from oil spills, changes in river flows in the Aransas National Wildlife Reserve, and West Nile Virus. (W2.Dec06.w2)

  • Drought: this can dramatically reduce production on the nesting grounds. Additionally a drought in 2009 reduced availability of key winter foods, Callinectes sapidus - Blue crabs and Lycum spp. wolfberries, which doubled whooping crane mortality rates in Texas. (W2.Nov2013.w6)

  • Other threats to the Texas wintering grounds include coastal development (much of the local habitat which is not currently being used by cranes in Texas is being targeted for housing construction), rising sea levels, climate change, chemical spills, human disturbance and reduced inflows of fresh water. (W2.Nov2013.w6)

  • It has been calculated that the Aransas National Wildlife Refuge in Texas can only support up to 500 cranes through the winter, which is only half of the population needed before whooping cranes can be downlisted from Endangered. (W2.Nov2013.w6)

    • Population growth could force cranes into disturbed, suboptimal habitat. (W2.Nov2013.w6)

  • There are concerns regarding reduced water flows in the central Platte River Valley (key migration stopover site) in Nebraska, as well as river flows into Aransas NWR; there are also concerns regarding oil spills in Texas. (W2.Nov2013.w6)

  • West Nile virus and avian influenza could be threats. (W2.Nov2013.w6)

  • The effects long-term of the severe population bottleneck are not yet known. (W2.Nov2013.w6)

  • In Alabama and Indiana, illegal shooting of whooping cranes has occurred. (W2.Nov2013.w6)

Conservation:

  • Intense monitoring, protection and study since the species nearly reached extinction in the 1930s and 1940s. (B107.w8)

  • Transnational recovery plan:

    • Increasing captive population for release;

    • Ecological research and monitoring;

    • Experimental releases and establishment of additional wild populations, including teaching migration to captive-bred birds. 

    (B475, W2.Dec06.w2)

  • Extensive public awareness campaigns. (B107.w8)

  • Cooperative international research and management. (B107.w8)

  • Monitoring and surveying programmes. (B107.w8)

  • coordinated Whooping Crane Recovery Plans. (B107.w8)

  • Protection of breeding, migratory and wintering habitats. (B107.w8)

  • Marking of powerlines: this has reduced collisions by 40-60%. (B475, W2.Dec06.w2)

  • Reintroduction programmes:

    • Attempt to produce a second migratory flock by placing eggs into the nests of in the western USA were unsuccessful since cranes surviving to adulthood failed to form pair-bonds with conspecifics and breed. This programme started 1975 and was discontinued in 1989. (B107.w8)

      • By 1999 this population had decreased to one or two birds. (B475)

    • First birds released to form a new non-migratory population in Florida in 1993. (B107.w8)

      • By 1999 there were about 60 birds in the flock, with more being released annually. (B475) This flock numbered about 41 birds in 2007 and additional releases were put on hold. (W2.Nov2013.w6)

    • A reintroduced flock winters in Wisconsin and migrates to Florida; there were 75 birds in this flock in 2007 increasing to about 90 in 2008, with the first successful wild-raised chick migrating in 2006 and another chick born 2009. (W2.Nov2013.w6)

      • The juveniles led by ultralight are now split into two, with half led to Chassahowitzka NWR and half to St. Marks NWR along the Gulf Coast of Florida; this reduces the risks of too many birds being wiped out in a single incident as happened in a severe storm in 2007. (W2.Nov2013.w6)

    • Another flock was started in south-western Louisiana in early 2011 with 10 juveniles. (W2.Nov2013.w6)

Further conservation targets:

  • Surveying and monitoring of the breeding grounds to determine nesting effort. (B475, W2.Dec06.w2,W2.Nov2013.w6)

  • Research on food resources and high mortality. (B475, W2.Dec06.w2)

  • Reduce the threats to the wintering population in Texas. (B475, W2.Dec06.w2, W2.Nov2013.w6)

  • Reduce collisions with utility lines. (B475, W2.Dec06.w2, W2.Nov2013.w6)

  • Investigate suitable locations for reintroductions. (B475, W2.Dec06.w2)

  • Continue the establishment of two additional self-sustaining populations. (W2.Nov2013.w6))

  • Continue raising birds for reintroduction. (B475, W2.Dec06.w2, W2.Nov2013.w6)

General Legislation
  • Strict legal protection. (B107.w8)

CITES listing
  • CITES I. (B107.w8)
  • CITES Appendix I and II. (B475, W2.Dec06.w2, W2.Nov2013.w6)
  • CMS Appendix II. (B475, W2.Dec06.w2)
Red-data book listing
  • EN D ver 3.1 (2001). Assessed 2006. "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. " (W2.Dec06.w2)
  • Endangered ver. 3.1 (2012 assessment) due to very small population size, although there have been increases in the remaining natural population, as well as the establishment of two reintroduced flocks. (W2.Nov2013.w6)

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Captive Populations

  • A number of whooping cranes were held in collections in Europe  during the mid- to late-1800s. (P87.11.w12)
  • Three main captive propagation centres: at Patuxent, Maryland, USA, International CCrane Foundation, Baraboo, Wisconsin USA and Calgary Zoo, Alberta, Calgary, Canada. (B107.w8)
  • Active captive propagation, with birds coming from eggs taken from wild nests starting in the 1960s; in 1975 the first eggs were produced in captivity. By 1994, about 120 individuals at these three sites plus other locations. (B107.w8, P87.11.w12)
  • In 1998, 124 captive individuals at four main locations in the USA and Canada. (B475)
  • In 2001, captive birds totalled 151 at four main locations in the USA and Canada. (W2.Dec06.w2)
  • The captive population in 2007 was 140 individuals at five locations, plus four display birds. (P87.11.w12)
  • The captive population in 2008 was 151 individuals at five breeding centres plus six display facilities, all in the USA and Canada. (W2.Nov2013.w6)
  • Note: The current whooping crane population is derived from 6-8 founders (estimated), with 66% of historic genetic material having been lost. About 87% of the genetic diversity which survived the bottleneck was maintained in the wild flock from 1938-1990, while in captivity it is estimated that 98% of genetic diversity has been retained for the period 1980-2006. (P87.11.w12)
  • It is estimated that a population of 153 individuals with 21 productive pairs passing on their genetic material is needed to maintain good genetic health with 90% retention of genetic diversity for 100 years. Recommendation was for 50 captive breeding pairs by 2010; a new facility was constructed at the Audubon Species Survival Center, Louisiana, USA, to enable that number to be kept in total. (P87.11.w12)

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Trade

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