Oil and wildlife
Penguins use natural oils, secreted from a gland near the tail, to keep their feathers waterproof. This helps trap a layer of air near the skin which provides insulation to penguin warm in the water. When feathers come into contact with mineral oils they absorb it like a sponge, displacing the insulating air layer. Not only are the penguins then at risk of dying of hypothermia, their attempts to preen the oil off can poison them.
Spills at sea
Stricken oil tankers spilling huge quantities of oil is a scenario not yet seen in New Zealand, but many smaller spills occur on a regular basis. Spills of light fuel oil from sinking fishing boats and the emptying of engine-room bilges have both oiled penguins around New Zealand but, fortunately, they are rare occurences
Spills on land
Most penguins are not at risk of land-based oil spills, however the sometimes urban-dwelling blue penguin is. Blue penguins sometimes nest in and around harbours and their associated industrial areas. Fledgling chicks and nest prospecting adults are those greatest at risk as they explore their neighbourhood. Poorly stored waste engine oil is the most common thing that penguins have walked or fallen into, but both tar and grease-covered penguins have been found.
Penguins must be carefully cleaned of oil and allowed to regain their natural oils before they can be released to the wild. This is a slow process requiring several washes with detergent. If oil has been swallowed, charcoal is given to help pass it through the digestive tract. Once the feathers have been properly cleaned and the bird has been given a few days to waterproof its feathers using its natural oils it can be released to the wild.