Behaviour
Blue duck © zabdiel
Blue ducks are highly territorial and will vigorously defend their river territories (typically a 1–2km stretch of river) all the year round.
Territorial pairs have a regular daily routine:
- feed for 1–1.5 hours, beginning just before dawn
- rest for a similar period before feeding again until mid-morning
- mid-morning to late afternoon, inactive in secluded location by river
- further feeding from late afternoon
- roost at dusk
Feeding and diet
Feeding occupies about a quarter of the bird’s active day. They sometimes also feed at night.
The birds feed mostly in shallow water at river edges by:
- scraping bill tip over rocks to remove invertebrates
- probing amongst rocks on river bed
- pecking on water surface
Their diet consists predominantly of invertebrates that include:
- stonefly and mayfly nymphs
- chironomid (midge) larvae
- caddisfly larvae
The ducks will also consume silt and periphyton (algal and microbial growth on submerged surfaces), and where present, will take berries from riverside plants.
Migration
Blue ducks do not migrate - they are highly sedentary.
Adult pairs establish a territory that they occupy throughout the year and throughout life.
