Pilchards make penguins puke, or at least give them a serious tummy ache. This was one of the many things I learned at the yellow-eyed penguin symposium last weekend at the University of Otago.
Bridey White, a wildlife technician from Massey University and the penguin keeper there, told us how high levels of histamines in this fish can cause stomach ulcers in birds, so it is not a recommended penguin food. The same goes for fish bait, because the added preservatives will kill a penguin. Oddly enough, even though penguins eat fresh fish in the ocean, frozen fish is better for them because freezing kills parasites. When a penguin is fighting for his life it’s better not to give them anything that might add to the burden of recovery.
A penguin is taken into the hospital when things are so bad the bird cannot feed itself any more. What we feed them in hospital is important because good nutrition promotes faster healing. A high calorie fish is required because penguins must have a good layer of fat to stay warm in the ocean.
Young salmon “fit the bill” perfectly. For many reasons they are the food of choice at the penguin hospital and luckily, penguins enjoy eating them. From the caretaker’s point of view, salmon have very accommodating gills that make it easy to insert medicine so the penguin will swallow pills without a fuss.
The way the salmon is prepared is key. Defrosting the fish in water is not recommended because as the fish warms up, the water will leach out most of the vitamins and minerals. Air defrosting is best, and when they are defrosted the fish should be firm to the touch, have clear eyes and a pleasant smell. After all, would you like to eat stinky old fish when you are used to ocean sushi? I think not!