As the baby eagle has grown, its appetite has kept pace! The Avian Propagation Center’s (APC) animal food preparers are now providing skinned mice and rats that are minced into bite-sized pieces before being fed to the hungry chick. Yum! We supplement the chick’s meals with vitamin B and calcium and set them outside each day (weather permitting) to soak up vitamin D from the sunlight. The temperature in the eagle’s brooder is reduced little by little as the chick is able to better regulate its own body temperature. Soon the medium-white fluff ball will be moved out of the brooder’s confines and into a larger nest tub. There, as it gains strength, the eaglet will be able to stand up, stretch its wings and eventually “branch.” (To branch means to leave the nest and begin to climb out onto the surrounding branches.) Nobody knows yet if the eaglet is a boy or a girl. Adult female harpy eagles are significantly larger than their male counterparts, but the only way to definitively sex a baby is with a DNA test. Fortunately, such a test can be performed without laying a finger on the eaglet. As the chick developed inside the egg, blood vessels also formed on the inner surface of the shell. That vascular tissue was left over after hatching and the broken eggshell has been sent off to a lab where technicians will be able to recover enough DNA from the tissue to determine the chick’s sex.
Beau Parks is a keeper at the San Diego Zoo.