Metallic Starlings: Showstoppers

An adult metallic starling watches the action in the Owens Aviary.

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!

A metallic starling puts the finishing touches on its nest.

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!

A juvenile metallic starling still sports its “baby” colors.

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.


Zoo Hospital: Eat Your Food

Who knew babirusas could be such picky eaters?

Hey, Hospital Keepers! Can you get that animal to eat this food, please?

When animals arrive here from other facilities, they often are not used to eating what’s on our menu. During their quarantine period at the San Diego Zoo’s Jennings Center for Zoological Medicine, hospital keepers team with Nutritional Services staff to help animals transition to their new diets.

Upon arrival, each new animal is accompanied by a lot of paperwork from the shipping institution. The information is distributed to the appropriate staff here at San Diego Zoo Global. Such things as diet summary, enclosure description, husbandry management, enrichment ideas, likes and dislikes, photos and videos, medical records, and reproductive history are sent by the shipping institution. You can never have too much information when it comes to caring for animals!

Our nutritionists will have the animal’s most recent diet information, as well as the target diet we will be feeding printed up for the hospital keepers. Our goal is to get our newest resident heartily eating our diet by the end of the 30-day quarantine period. “They are currently eating this; we would like them to eat this. You have a month. Do your best. Go!”
The first week we usually feed our newest arrivals 100 percent of the familiar diet from the prior institution. Depending on the species, we try to offer a bit of our diet, too—a side order to their usual entrée, just to “test the waters.” Sometimes the animal chooses the novel item over their old standby, and within a week or two we have them completely transitioned. For other animals we need to go much slower, starting with 90 percent old diet and 10 percent new diet, then 75/25, 50/50, 25/ 75, and so on.

In many cases we are asked to transition new hoofed animals to our pellets prior to their release from quarantine. There are many ways we can go about completing this important task. We’ll offer one dish of the old diet and one dish of the new diet, or we’ll put the old pellets on one side of the dish and new pellets on the other side of the same dish. Sometimes we’ll mix the pellets together. If there are multiple items being offered, the food dish begins to look like a beautiful pie with wedges of different shades and textures.

One fun example was a pair of young babirusa boys that were in quarantine earlier this year. They were surprisingly stubborn about eating the new Zoo pellets. Pigs are usually easier to transition than most species because they like to eat. A picky pig is rare. So we were surprised when we would mix together the old and new pellets into one bowl, and these boys literally ate around the new Zoo pellets to get to their old stuff! After some brainstorming between keepers and nutritionists, we experimented and made an amazing discovery: if we lightly misted the new Zoo pellets with water and then “dusted” them with Crystal Light powder, the babirusa boys suddenly LOVED our Zoo fare! It then turned into the transition game of getting them off the “powdered pellets” and eating the plain pellets.

We monitor what amounts of food go in with an animal and then weigh and record everything that is left over the next day. These sheets are called “Ins and Outs” and give the animal care staff information to better understand what the animal is choosing to eat. We’ll also weigh the animal, at least weekly, to get a more accurate measure of how they are eating.

And then there is the poop. Yes, that funny topic from my previous post! We note the amount, the color, and the consistency. If a bird doesn’t look like they’ve eaten much out of their food pan, but there is a decent amount of poop on the ground, we know they’re eating enough. If a carnivore is transitioning between meat products, it might get the runs for a day. One indicator we use for a current group of deer is how many “shovelfuls” of poop we haul out every morning!

Gold-breasted starling

A gold-breasted starling just cleared quarantine this week. The bird came in eating “red pellets,” but we had to transition him to “yellow pellets.” This bird was healthy, and so was his poop, which—don’t be shocked—was red. Having the choice to eat red or yellow pellets, he would consistently choose the red. The next morning there would be nothing left but yellow pellets, not a single red one left in his food pan. So we started grinding the red pellets and dusting the yellow pellets. It took a bit, but the bird started picking up more of the yellow pellets, and we slowly phased out the red pellets. Soon his poop changed to a beautiful yellow, and we knew that he was successfully transitioned to his new diet—just another story about the fun we have here at the hospital and just a few more examples of how teamwork, communication, and patience help get the animals on the road from the hospital to Zoo grounds.

Kirstin Clapham is a senior hospital keeper at the San Diego Zoo. Read her previous post, Zoo Hospital: The Importance of Poop.