At first glance, an adult metallic starling looks completely black with bright red eyes. Upon closer inspection, a visitor is rewarded with an iridescent collage of blues, purples, and greens. If one lone metallic starling is something to give you pause, the polychromatic flock of over 60 starlings in the Owens Aviary at the San Diego Zoo is always a complete showstopper!
The metallic starlings start their breeding season in early spring. For these months the starlings are only interested in nesting material (see October’s digital ZOONOOZ article on Owen’s Aviary for their nest-building shenanigans). Once the nests are fairly well built, we know we have only a few weeks—the incubation time for a metallic starling egg—before the flock switches from being crazy for nesting material to being batty for bugs! Adult metallic starlings are omnivores and eat everything from fruit and nectar to crickets, mealworms, ants, and wasps! Baby starlings, however, need a lot more protein than their parents, hence their dependence on bugs for the first few weeks.
After being fed a diet of mealworms and crickets to help feather and muscle development, a growing chick is eventually brought fruit and pellets to pack on the ounces. About three weeks after hatching, the chick is ready to make its first flight. The chick has to scoot to the small hole of its enclosed nest, jump out, spread its wings, and try to land on a nearby perch. With a healthy set of lungs and a loud chirp, the chick is able to advertise its new location to Mom and Dad. The parents are still responsible for feeding the chick for a few more weeks as it learns how to eat a bug without one being placed directly into its gaping mouth!
We start to see young starlings leaving their nests from the beginning of June through late August. When they first leave the nest, they have dark eyes, black-and-white streaked chests, and yellow markings on their bill. As they develop, they quickly lose their yellow markings and slowly get some red coloring in their eyes. It takes a full year before they trade in their streaked chests for smooth, glossy black ones and their dull, red eyes for brilliant ruby-colored ones.
In September and October we see the starling colony settle down into its new routines. The newest members of the flock stick closely together and explore their huge exhibit free from their parents’ watchful eyes. The chicks from the previous summer have just attained their adult plumage; since they will be old enough to breed next spring, they do a lot of “showing off” for possible future mates. The adults that have just survived yet another crazy breeding season are able to take a breather and relax before the madness of nest-building season starts once again.
No matter what time of year it is, be sure to check out the metallic starlings and their many avian neighbors in the Owen’s Aviary at the San Diego Zoo.
Mike Grue is a senior keeper at the San Diego Zoo. Read his previous post, A Big Story for a Little Goose.