Biology
Blue duck © zabdiel
Size
Male:
- wing: 231–251mm
- tail: 99–117mm
- bill: 42.7–47.3mm
- weight: 820–1050g
Female:
- wing: 204–240mm
- tail: 90–112mm
- bill: 41.0–45.3mm
- weight: 680–870g
Breeding
There are no obvious social courtship rituals.
Nests are made in sheltered locations such as:
- caves
- hollow logs
- holes in bank up to 30m from river edge
Eggs are laid late August to October (or December if the first brood fails). Broods of 3–7 (usually 6) white eggs are laid and incubated by the female for 33–35 days.
About half (54%) of nesting attempts lead to successful hatching of ducklings. Flooding or mammalian predation can lead to nest failure.
60% of ducklings survive to fledging.
Both parents care for the young throughout a 70–82 day fledging period.
Life expectancy
Mean lifespan: 6–7 years.
