| Black-necked Swan: |
Scientific name: Cygnus melancoryphus
Registered by Molina in 1792.
No subspecies recognized. |
| Distribution: |
South America: from Brazil to Tierra del Fuego. |
| Movements: |
Some populations are migratory, others are sedentary. |
| Flight: |
Strong, capable of long journeys. |
| Status: |
Common. |
| Habitat: |
Freshwater lakes and large ponds, brackish water, and sea coast. |
| Behavior: |
Sociable when not nesting. Territorial during nesting. |
| Nesting: |
Small colonies well spread out, or solitary.
Usually once a year. |
| Season: |
Southern spring. |
| Nest: |
Among the grass next to lakes. |
| Clutch: |
From three to seven eggs. |
| Eggs: |
Cream color.
Length: from 93 to 109 by from 63 to 69.3 mm - average 101 X 66 mm.
Weight: from 173 to 274 grams - average 247 grams. |
| Incubation: |
34 to 36 days. Done by the female. |
| Cygnets: |
Born with white feathers.
Next day after birth weight from 129 to 184 grams. |
| Adulthood: |
From three to four years of age. |
| Food: |
Aquatic plants. Possibly complemented with small invertebrates and other small animals. |
| Description: |
Sexes are alike except for males are bigger. Usually red thickening on beak grows larger on males. |
| Dimensions: |
Length from 102 to 124 cm. (40 to 49 inches). |
| Weight: |
Male: 4.5 to 6.7 Kg.
Female: 3.5 to 4.4 Kg. |
| Tarsus: |
Male: 85 to 88 mm.
Female: 78 to 80 mm. |
| Wing: |
Male: 435 to 450 mm.
Female: 400 to 415 mm. |
| Head: |
Small in proportion to the body. Covered with feathers. |
| Bill: |
Very dark gray.
Medium size in proportion to the head.
Males: 82 to 86 mm. Females: 71 to 73 mm.
Wide and flattened. Nostrils at the middle.
A red thickening (or knob) grows on top of base. |
| Neck: |
Long. Covered with feathers. |
| Legs: |
Short. Pink on adults. Gray on juveniles. |
| Feet: |
Pink on adults. Gray on juveniles. |
| Molt: |
Once a year. |
| Life Span: |
In captivity estimated seven years, some have exceeded twenty years. |
| Other names: |
| Spanish: | “Cisne de Cuello Negro” |
| Portuguese: | “cisne-de-pescoço-preto” |
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