| Kingdoms / Animalia / Craniata / Aves / Anseriformes / Anatidae / Cygnus / Species |
| < > Cygnus atratus - Black swan (Click photographs/illustrations: full picture & further details) |
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Alternative Names (Synonyms) |
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| Cisne negro (Spanish) Cygne noir (French) Schwarzschwan (German) Trauerschwan (German) Chenopis atratus |
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Names for newly-hatched |
Cygnet, downy. |
Names for non-breeding males or other colour-phases |
Leucistic (pale). Male swan often called "Cob". |
Species Author |
Debra Bourne |
Major References |
B1, B2, B3, B4, B8, B9, B19, B25, B26 Aviculture references: |
Other References |
B38 |
TAXA Group (where information has been collated for an entire group on a modular basis) |
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Parent Group |
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Specific Needs Group referenced in Management Techniques |
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Aviculture Information |
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Notes |
General information:
(B7, B10.26.w2, B29, B30, B40, B94, B95, B97, B108, B128.w4, D1). Species-specific information:
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Management Techniques |
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External Appearance (Morphology)
Measurement & Weight |
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| Length | 45-55", 115-140cm (B3); 110-140cm (B1) | |
| Adult weight | General | 3.7-8.75kg (B1) |
| Male | 4.6-8.75kg average 6.27kg (B3); mean 13.8 lbs. (B8) | |
| Female | 3.7-7.2kg average 5.1kg (B3); mean 11.3 lbs. (B8) | |
| Newly-hatched weight | 170g (B9.5) | |
| Growth rate | 26.5 times hatching weight at 180 days (B9.5) | |
| Adult | Bill | Male | Red with white stripe across bill near nail. |
| Variations (If present) | -- | ||
| Eyes (Iris) | Male | Red. Sometimes pink or white. | |
| Variations(If present) | -- | ||
| Juvenile | Bill | Dark grey with pale nail. | |
| Eyes (Iris) | Brown. | ||
| Adult | Male | Black |
| Variations (If present) | -- | |
| Juvenile | Dark grey | |
| Adult | Male | Head, neack, body
and tail: Black. Wing: mainly black. Primaries and outer secondaries (flight feathers) white, inner secondaries white tipped. Inner wing feathers (tertials), which are black, have a pronounced undulating structure. |
| Variations (If present) | Light brown and fawn in leucistic colour phase, paler in adults than in juveniles. Silver, white, pied and reverse pied mutations have also been described (B139). | |
| Juvenile | Grey-brownish. Leucistic colour phase light brown and fawn. | |
Newly-hatched Characteristics |
| General: Upperparts
light grey (white in leucistic); underparts white. Bill: Nearly black with pale tip; (pink in leucistic). Feet: Dark grey with brown tinge; (pink in leucistic). |
Reproductive Season |
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| Time of year | Varies depending on
geographic location, usually timed to coincide with highest water levels. January to April and August to October reported most common in Britain (B9.5). |
| No. of Clutches | May re-clutch if eggs or young cygnets lost. |
Nest placement and structure |
| Large mound of vegetation, floating or on the ground. A little down lining. |
Egg clutches |
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| No. of Eggs | Average | 5-6 (B1); |
| Range | 4-8 (B8); 1-14 (B1). More than eight usually indicates two swans laying. | |
| Egg Description | Pale green or whitish-green (B3, B8). Size: 115 x 65mm, weight: 300g (B3). | |
| 35-48 (usually 36-40) days (B1); average 36-40.5 days (B8). |
| Synchronous. |
| 150-170 days, less if very good food supply (B1); 90-165 days (B8). |
Sexual Maturity |
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| Males | 18-36 months. |
| Females | 18-36 months. |
Feeding Behaviour |
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| Adults | Dabbles on surface, upends. Grazes pasture or flooded fields. |
| Newly-hatched | Make use of food brought to surface by parents while feeding. |
Parental Behaviour |
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| Nest-building | Both build the nest. |
| Incubation | Both sexes incubate, usually the female at night. |
| Newly-hatched | Both parents tend the cygnets. Carry cygnets on back, but less often than the Mute swan (Cygnus olor - Mute swan); female carries more frequently than male. |
| Juveniles | -- |
Social Behaviour |
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| Intra-specific | Highly gregarious. Nest in colonies, often seen in thousands on favoured waters. |
| Inter-specific | In captivity noted to be most aggressive to dark coloured geese when breeding. |
Sexual Behaviour |
| Generally permanent pair bonds but sometimes form trios (male and two females) and cobs are more promiscuous than in the other swans. |
Predation in Wild |
| -- |
| -- | |
| Circadian | Very active at dusk and also on moonlit nights. |
| Basically vegetarian, mainly eating submerged aquatic plants, algae and pondweeds. |
| Vegetarian, eating same plants as adults, and frequently seeds. |
Distribution and Movement (Migration etc.) |
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| Normal | Australia, Tasmania. Sedentary if suitable habitat, but move to make use of temporary waters and also from usual waters if they dry up in droughts. Concentrate on coast, on sheltered lagoons and bays, in dry spells. Non-breeding birds move to suitable safe areas ready for moulting. |
| Occasional and Accidental | Vagrant to New Guinea. |
| Introduced | Introduced into New Zealand, now well established. Small feral population from escaped birds in Britain. Have also nested in wild in USA, Canada, Hawaii, Japan (in parks) and in several countries in Europe, but without becoming established (B38). |
| Large lakes and lagoons, preferring shallow, permanent, fresh or brackish water. Other waters including rivers in non-breeding season. |
Intraspecific variation |
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Conservation Status |
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| Wild Population - (Importance) |
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| CITES listing | -- |
| Red-data book listing | -- |
| Threats | -- |
Captive Populations |
| Common in collections, easy to keep and breed (B8). |
| -- |