“Some birds let you do anything to them, but with others you have to be heavily protected with gloves and padding,” Burns says. Gently and cautiously, she reaches under the bird, extracting its egg and substituting a pre-warmed dummy. The egg weighs 420 g and is 124 mm long by 75.5 mm wide. Pretty standard measurements. At 10 days the egg will be candled to determine whether it is fertile. If it is not, it will be removed and replaced by an imitation egg, thereby keeping the parents in the colony. “You never know when you might need a spare ‘incubator’ for a fertile egg, or a set of foster parents for a young chick,” Burns remarks.