Where do they go to fish?
We found that our penguins like to forage close to the coastline. The generally forage within 30km of the coast in water that is less than 50m deep.
When they are away from the colony for a single day, they stay within 25km of home.
When they leave for a longer period of time, they travel north.
The picture here shows some example penguin foraging tracks.
Blue penguins at Oamaru eat mainly slender sprat; a small, schooling fish similar to a sardine. When foraging at sea the penguins dive on average 800 times a day and mostly feed in the top 10m of the water column, staying under the water on average, only 20-30 seconds at a time. They can swim up to 8km per hour.
We found the penguins are capable of holding their breath for over 2 minutes. The longest duration of a dive from one of our penguins was 2 minutes and 17 seconds.
See the graph for what this dive looks like.
Predators of blue penguins at sea are sharks, sea-lions and leopard seals. The dark blue feathers on the penguins backs help to hide them when predators look down into the dark water. The white feathers on their underside merge them with the lighter water as the predator looks up.