Animals site sub feature

Animals site sub feature

1

Gorilla Snacks

By
Peggy Sexton
– May 23, 2013Posted in: Animals and Plants, Animals site sub feature, Apes and Monkeys, Uncategorized
Kale is one of the many leafy green items fed to the Zoo and Safari Park gorillas.

Kale is one of the many leafy green items fed to the Zoo and Safari Park gorillas.

Primarily herbivorous, gorillas eat the leaves and stems of herbs, shrubs, and vines. In agricultural areas, they may raid farms, eating and trampling crops. They will also eat rotten wood. The fleshy fruits of close to a hundred seasonally fruiting tree species make up a large part of their diet. Gorillas get some protein from invertebrates found on leaves and fruits. In the wild, gorillas spend much of the morning and evening feeding in a small area. However, since lowland gorillas rely heavily on fruit, they sometimes travel up to about a half mile or more in search of fruiting trees.

Although they don’t have to travel far at the San Diego Zoo Safari Park to find a meal, the gorillas do get a wide variety of fruits, vegetables, low-carb biscuits, and browse (plant material). Browse varieties include acacia, ginger, bamboo, grewia, tipuana, eugenia, and ficus, all grown at the Safari Park. The items are all offered on a rotating basis so they don’t get the same food every day. The gorillas are fed five to six times a day, and food is distributed throughout their bedrooms and exhibit to encourage foraging.

Two of their meals are fed inside the night bedroom. Although the keepers do not go in the bedrooms with the gorillas, we do have limited contact through the bars. This allows us the opportunity to develop relationships with each of the gorillas. Hand feeding creates a bond with each gorilla and facilitates health assessments and distribution of medications. Operant conditioning, a training technique using positive reinforcement and rewards, is also used to further enhance the rapport between the gorillas and the keepers. The gorillas enjoy the individual attention!

Each day the gorilla troop at the Safari Park consumes approximately 5 pounds of fruit (such as apples, oranges, pears), 43 pounds of greens (such as kale, romaine lettuce, spinach), 16.5 pounds of veggies (such as jicama, onions, broccoli), and 7 to 10 branches of browse. Snack food is offered in limited quantities on a rotating basis and may include air-popped popcorn, sunflower seeds, tamarind pods, raisins, prunes, applesauce, peanuts, and popsicles made with fruit juice/nectar.

Peggy Sexton is a lead keeper at the San Diego Zoo Safari Park. Read her previous post, Introducing Gorillas to a New Troop.

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3

A Closer Look at Burrowing Owls

By
Colleen Wisinski
– May 21, 2013Posted in: Animal Stories, Animals and Plants, Animals site sub feature, Birds, Conservation, Projects in the Field, Uncategorized
Note the difference in coloration (female on left, male on right) with this burrowing owl pair.

Note the difference in coloration (female on left, male on right) with this burrowing owl pair.

For the past two years, our burrowing owl project has been focused on how to effectively relocate California ground squirrels to help re-engineer nonnative grasslands and make them more amenable to burrowing owls (see Burrowing Owls: Closer than You Think and Digging into Burrowing Owl Recovery). But this year, we get to take a closer look at the owls themselves. Don’t get me wrong, I love the squirrels (more than I ever thought I would), but I’m a bird biologist, so I’m really excited to start working directly with the burrowing owls!

Burrowing owls range widely across the western US and make use of a variety of “grassland” habitats, from open prairie to empty suburban lots to airports. But their populations are declining, mostly due to loss of habitat and eradication of the fossorial (digging) mammals that they depend on to build burrows. One solution is the installation of artificial burrows. However, artificial burrows are not self-sustaining like natural squirrel burrows and, although we know the owls use them, we don’t know how they compare to natural burrows.

A male burrowing owl guards his burrow entrance.

A male burrowing owl guards his burrow entrance.

This year, one of our main objectives is to compare reproductive output, food provisioning, and predation at natural versus artificial burrows, using camera traps and banding the birds to accomplish this. The camera traps allow us to see what is going on at the burrow while we aren’t there, and the banding allows us to identify each individual (see Bling with a Purpose).

At this point, the breeding season is in full swing. We are monitoring almost 30 nest burrows (both natural and artificial); this includes placing camera traps at about 20 of the burrows. We check on each burrow about once a week (we don’t want to visit too often and risk disturbing the birds) and do any camera trap maintenance needed, such as changing batteries and switching out the memory cards that contain our priceless data in the form of photographs. We also watch the birds from a distance to figure out what stage of the breeding season they are in—for me, this is the best part!

A camera trap photo shows a burrowing owl pair allopreening at their burrow entrance.

A camera trap photo shows a burrowing owl pair allopreening at their burrow entrance.

Over the last two months, we have been inventorying burrows and following their progression through the breeding season. On any given day, we head out to the field in the morning and work our way through our route for the day checking on each burrow as we go. When we arrive at a burrow, we observe from the truck (which acts as our blind) from a safe distance to see what is going on at the burrow. Early in the breeding season, we might see both parent birds or just the male standing guard at a burrow. In general, the males are lighter in color than the females, because they spend more time outside so the sun bleaches their feathers. As the breeding season progresses, the difference in plumage becomes more marked, as the males get more and more bleached. By the end of the summer, though, it can be hard to tell the males and females apart as both get bleached by the sun.

Two burrowing owl chicks rest at the burrow entrance while Mom stands guard. Camera trap photo.

Two burrowing owl chicks rest at the burrow entrance while Mom stands guard. Camera trap photo.

Once the pair has chosen their nest burrow, we usually only see the male of the pair; he is often standing watch over the burrow from nearby (often at the entrance of a satellite burrow where he spends much of his time—we call it the “man cave”). At this point, the female is spending most of her time in the burrow incubating the eggs. After about a month, the eggs hatch, and two weeks after that, the young start to come out to the burrow entrance. We usually do a quick examination of the photos in the field to help us determine if there are chicks present, but we also get good clues from the female’s behavior. If she is very protective of the burrow or stays very close to the burrow when we approach, it’s a safe bet that there are babies in the burrow.

Currently, we have nests in all different stages of breeding—some have pretty large chicks, some still have eggs, and some still seem to be deciding if they are even going to breed. In the coming weeks, we will band all of the owls from burrows that have camera traps, and over the next several months, we will pour over the hundreds of thousands of camera trap photos to catalogue how often prey was delivered to the burrow, what type of prey was brought, what types of predators come to the burrow, and other pertinent information. This is a huge undertaking, since we have almost 40 camera traps set up that can take over 30,000 pictures in one week alone! Any volunteers? Seriously, if you’re interested in helping, visit our volunteer page and sign up! Who wouldn’t want to spend their time looking at pictures of these adorable and comical little birds?!

Colleen Wisinski is a senior research technician for the San Diego Zoo Institute for Conservation Research.

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1

A Dusty Day Off

By
Lauren Marks
– May 20, 2013Posted in: Animals and Plants, Animals site sub feature, Birds, Conservation, Hawaiian Birds, Uncategorized
Lauren is ready to plant mamane saplings.

Lauren is ready to plant mamane saplings.

My day off began before the sun had even given thought to rising. I suppose this is more normal to me, a young ornithologist, than to most others. I packed my bag, laced up my boots, and slipped out the door just as the first streaks of light graced the horizon; this day was to be dedicated to planting native trees on the high slopes of Hawaii’s Mauna Kea.

Historically, the yellow-flowered mamane tree used to be so abundant that an aerial view of Mauna Kea looked like a big yellow lei encircling the highest elevation of the peak. Unfortunately, this habitat has degraded to sparse grasslands in recent years. Mamane seeds are extremely toxic to most animals if ingested. Ironically enough, the seeds make up most of the critically endangered palila’s natural diet. Yellow headed and charismatic with a finch-like bill, the palila is one of the honeycreepers involved in the Keauhou Bird Conservation Center’s captive-breeding program. I have the privilege of seeing and working with these birds every day, and it was an honor to physically make a difference in the restoration of their natural habitat. In 2002, the Mauna Kea Forest Restoration Project began the task of reestablishing the mamane forests that once dominated the arid terrain of the mountainside, starting with the west and north slopes.

This particular morning, I met with the rest of the volunteers and headed up to the north slope site, Ka’ohe Restoration Area. The outreach coordinator, Jackson Bauer, gave us a detailed history of the mountain and forests, showing us native plants as we hiked around the area. We searched for what seemed in vain for wild palila. Suddenly, I heard it: churr-eep! My heart beating madly in my chest, I raced down the hill and around a cluster of mature mamane just as Jackson spotted it hopping from branch to branch. It watched us warily as it inspected each dangling flower and seedpod within reach. I was beyond thrilled to see one of our birds thriving in the wild, and it further instilled a sense of responsibility as to why I was there that day.

A'ali'i (pictured) and mamane saplings are carefully planted on Mauna Kea's slope.

A’ali’i (pictured) and mamane saplings are carefully planted on Mauna Kea’s slope.

After everyone settled down, we got down to business with the planting. We unloaded the eight-month old mamane and a’ali’i saplings, dibbles, and watering backpacks from the trucks and carried them to the plot. After a quick planting lesson, the group split easily into groups with distinct roles and set to work. Saplings were laid out in rows, and everyone worked in a leapfrog-like assembly line to dig holes, nestle the plants in the ground, and water each one carefully and efficiently. This was especially important to give them the best start in life on their own without the luxuries they had in the nursery.

With such a large group, we finished planting what we had brought much quicker than I expected. I wiped the sweat off my dirty face and admired the healthy 550 trees we had just planted. With a little time, they will become the native forest that once covered these mountainsides. With a little hope, they will become a sanctuary for the palila and other native animals dependent on this unique ecosystem.

For more information on restoration efforts, visit: facebook.com/MKFRP

Lauren Marks is an intern at the San Diego Zoo’s Keauhou Bird Conservation Center in Hawaii.

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2

Tortoise in the Glass: Evaluating Health Problems

By
Kali Holder
– April 15, 2013Posted in: Animals and Plants, Animals site sub feature, Conservation, Conservation at the Zoo, Desert Tortoises, Reptiles and Amphibians, Uncategorized

To you, a typical tortoise might look like this:

desert tortoise adult

But to me, a tortoise may also look like this:

desert tortoise tissue samples

I’m a veterinary pathologist, which means I spend a lot of quality time looking through a microscope at slides with tissues to try to evaluate health problems that show up as changes in those tissues. I can find dying cells, inflammation, various pathogens, scarring, thinning, thickening, bleeding, tumors, strange crystals, and unusual pigments. All of the changes help us understand the health problems affecting an animal.

At the San Diego Zoo Institute for Conservation Research, I work exclusively on tortoises that have died at the Desert Tortoise Conservation Center. Why bother? Well, it turns out that one of the best ways to figure out what health indicators most accurately indicate disease is to compare the information from the live tortoise to the changes we see in the tissues if the animal dies. The more we know about which tools work to predict severity and type of disease, the faster and more precise we are at identifying and helping animals at risk.

To get information from enough tortoises to allow good conclusions to be drawn, I need to look at a lot of slides. Since 2009, over 4,500 slides have been made of desert tortoise tissues, providing an invaluable resource for the understanding of disease in desert tortoises. Since November 2012, I’ve been describing the changes I see so that they can be correlated to what was found in the live animal. Thankfully, I haven’t been working all alone; Dr. Lily Cheng, another veterinary pathologist, volunteered to spend two whole months staring at a mountain of desert tortoise slides. Between the two of us, we’ve done more than 3,000 slides belonging to over 250 tortoises!

Are you curious about what sorts of things we see? Good! We are always on the lookout for bacteria or viruses that cause that most feared of tortoise infections: upper respiratory disease. This is more than just a head cold like people get and is a big factor in tortoise population decline. Some savvy souls may note that no light microscope can show an individual virus particle (you really need an electron microscope for that, since viruses are smaller than the wavelength of visible light). Conveniently, however, some viruses clump together to form rafts of virus particles. These are big enough to see with a microscope, just as you can see a patch of lawn even if you are too far away to pick out a single blade of grass. The virus most common and dangerous in tortoise respiratory disease (herpesvirus) forms these aggregations in the nuclei of cells, and they are called intranuclear inclusions.

Below are some cells from a tortoise that had severe upper respiratory disease. On the left side of the picture, you can see normal nuclei: round or oval purple shapes that look very speckled, like chocolate chip cookies. On the right side of the picture, the nuclei are bigger and have clumps of magenta in the center surrounded by a clear rim. They no longer resemble chocolate chip cookies at all. Those magenta blobs are viral inclusions from herpesvirus!

Herpes inclusions

The work continues at a good pace, and there are only about 1,300 slides left to look at. They weigh almost 7 kilograms (15 pounds) altogether. Wish me luck!

Kali Holder, D.V.M., is a postdoctoral associate in the Wildlife Disease Laboratories for San Diego Zoo Global.

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1009

Yun Zi Masters New Tree

By
Anastasia Horning
– April 12, 2013Posted in: Animal Stories, Animals and Plants, Animals site sub feature, Bears, Pandas
Yun Zi's new "tree"

Yun Zi’s new “tree”

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This new artificial tree for Yun Zi has been a lot of fun! Zoo guests can watch our three-and-a-half-year-old panda climb all over it, and keepers can provide enrichment items in and on it in new ways. I love to watch our keepers hide food for  Yun Zi in the tree’s little nooks and crannies and throw the bamboo up high where he has to work to get it. Although he did recently pay a little too much attention to the small elm tree in his enclosure, he has been a bit better about not destroying the poor “real” tree.

As we panda narrators watch him figure out how to maneuver his way to the top of the tree, keepers have the fun job of trying to make it more difficult for him. I always tell people that bears are really never given enough credit for being problem solvers (or starters, in Yun Zi’s case!). Yun Zi, like his siblings before him, is very good at figuring out different ways of remodeling the enclosures.

A Zoo guest recently asked me why the bears don’t have more grass and plants in the exhibits. Laughingly, I replied that we try all the time to add vegetation to the exhibits, but if the bears don’t like it or want to change it, there really isn’t a whole lot we can do. I still remember the morning we put grass in with Bai Yun and Yun Zi when he was a small cub. The Horticulture Department and many other bear keepers came down to help us get everything ready for the pandas. Every single time we came in to service the enclosure, Yun Zi had moved pieces of sod around, and Bai Yun had begun to flip sod pieces over as well. At every cleaning we had to put the puzzle back together for them and hope that it would take.

Our keepers are always finding new ways to enrich our animals’ exhibits and try to out-smart our animals. We are grateful for the planning and dedication they give to each and every one of our animals!

Anastasia Horning is a panda narrator at the San Diego Zoo. Read her previous post, Living Life in Front.

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217

Early Mornings at Elephants

By
Mindy Albright
– February 18, 2013Posted in: Animal Stories, Animals and Plants, Animals site sub feature, Elephants, Uncategorized
Vusmusi

Vusmusi

After doing 24-hour watches for each calf born to our African elephant herd at the Safari Park, we keepers have had the opportunity to watch a lot of early morning behavior from all the elephants. We have noticed that during this time the elephants tend to be very playful. You may see things such as walking forward or backward, head bobbing, sitting, lying down, tusking the ground, kicking logs or other toys in the yard, chasing each other, trunk wrestling with each other, making a dog pile (mostly with the youngsters), swimming, trumpeting, ear flaring, mock charging items in their environment… the list is endless. One thing is for sure, they are fun to watch any time of day!

Mindy Albright is a senior keeper at the San Diego Zoo Safari Park. Read her previous post, Elephant Treat Time.

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12

Is Our Cheetah Pregnant?

By
Corinne Pisacane
– January 29, 2013Posted in: Animal Stories, Animals and Plants, Animals site sub feature, Birds, Conservation, Conservation at the Zoo

CheetahThat’s the big question: did female cheetah Lindiwe successfully breed, and is she currently pregnant? Just last month we saw strong interest between Lindiwe and one of our proven breeder males, Noka. Lindiwe is a young cheetah, and this would make her a first-time mom, which is very exciting! From our point of view, the most important thing about getting a naïve female cheetah to breed is that once she breeds, she tends to continue having litters throughout her reproductive years. So the question remains: was Lindiwe actually in estrus and did not allow breeding, or did she simply not come into estrus during our breeding attempts? To answer the question, follow me into the Behavioral Biology Endocrinology Lab.

This lab offers us an opportunity to test hormone levels in a variety of exotic species. Hormone research adds an additional dimension to our research projects by providing another tool for unraveling the mysteries of animal behavior. When we are trying to test reproductive hormone levels in cheetahs, our preferred method involves non-invasive hormone sampling, a technique where the animals are unaware that we are testing their hormones. Blood collection can be a stressful procedure, which often results in adverse affects on reproductive hormones and/or behavior, so we usually sample urine, feces, and sometimes saliva and hair instead. The cheetahs go about their normal daily routine having no idea that we are testing their hormones levels!

Fecal (or poop) samples are collected by our cheetah care staff, promptly frozen, and brought to the lab for hormone testing. The first thing I do is dry the samples on a lyophilizer, a really big, fancy freeze drier that removes all the water from the fecal samples. I then crush and sift the dried fecal samples before weighing out a specific amount. I now have dried, weighed fecal material in a test tube and am ready to extract the hormones held within. There are many ways to do this, and they usually involve using a solvent in combination with some type of force. In our cheetah samples, I add solvent to the fecal material and mix (vortex) or heat the samples. At the end of this extraction process I am left with a test tube full of solvent that contains not only extracted hormones but also other extracted compounds. The trick is for me to find an appropriate laboratory procedure (or assay) that I can use to examine the concentrations of the specific hormones in question (in this case, female reproductive hormones). In humans, hormone assays are generally routine, but in exotic animals, extractions and assays can vary both between species and within species, depending on the hormones of interest and what biological sample they are from (fecal, urine, or saliva).

So back to the original question: was Lindiwe physiologically in estrus during the time she was showing the appropriate female sex behaviors? To answer this question, I needed to test her fecal samples for the hormone estradiol (a specific form of estrogen). In most species I could usually determine if the animal in question is cycling by looking at progesterone levels. But cheetahs are more complex as they are induced ovulators (see Cheetah Breeding Excitement). As such, their progesterone levels remain low unless a follicle, or egg, has actually been released from the ovary. To complicate matters further, when we study hormone levels in urine or feces, we usually only see metabolized hormones because we are looking at a waste product of the body. These are different from the hormones moving around in the bloodstream (known as parent or non-metabolized hormones) that are much easier to measure. Examining the concentrations of estradiol metabolites can be complicated and tricky because different animal species often metabolize hormones uniquely. These are the types of challenges we face in our endocrinology lab when studying hormones in exotic species.

After testing Lindiwe’s samples for hormones to see if she was truly in estrus during our breeding attempts, it appears that her rolling and tail flicking behaviors were somewhat misleading. Her hormone levels were quite low on the days she showed such estrus behavior. Interestingly, her hormone levels did go up, indicating a mild, short estrus, after we had stopped our breeding attempts. Welcome to the frustrating world of cheetah breeding!
We see a wide range of estrus behaviors varying from “silent” to “clear,” and some of our continual challenges include trying to decode the differences in behaviors between the females in our collection. We had very high hopes that Lindiwe was truly in estrus and would allow breeding by Noka, but alas, they did not end up breeding. We will continue our breeding attempts between the two, so please cross your fingers and hope for the best.

Corinne Pisacane is a senior research technician in the Behavioral Biology Division of the San Diego Zoo Institute for Conservation Research.

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62

Orangutans: Planned Parenthood

By
Tanya Howard
– January 25, 2013Posted in: Animal Stories, Animals and Plants, Animals site sub feature, Apes and Monkeys, Uncategorized
Is Indah ready to become a mother again?

Is Indah ready to become a mother again?

We have just been given the go-ahead by the Species Survival Plan for orangutans (a part of the Association of Zoos and Aquariums) to have a baby with San Diego Zoo orangutans Indah and Satu! Indah has been taken off birth control. She was on birth control because we did not want her to become pregnant while raising her son, Cinta. Typically, sons stay with their mother for eight to nine years. Indah had been implanted with a device similar to Norplant in humans, so she needed a trip to the vets to get it removed. Just like with humans, it may take a while for her hormones to balance out. We are hoping that this time next year we will have a pregnancy or may be even a baby!

The siamangs and the orangutans get along for the most part. The assertiveness of the siamangs directed toward the orangutans at feeding times is behavior seen by researchers in the wild. We do see positive interactions with Indah and the siamangs. She shares food with them (and Satu, too!). Also, she has been playing a lot with Unkie, our male siamang, wrestling and wearing him on her head! It is really amazing to watch.

Even though our female orangutans have been hand raised, they are still wild animals. Their behavior is unpredictable, and, as such, we do not go in with any of them. There is plenty of keeper interaction with each individual with a protective barrier between ape and keeper.

Tanya Howard is a keeper at the San Diego Zoo. Read her previous post, Orangutans: Change is Good.

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16

Clouded Leopards: Beautiful Boys Arrive

By
Janet Hawes
– December 12, 2012Posted in: Animal Stories, Animals and Plants, Animals site sub feature, Cats, Uncategorized

Clouded leopard cub Riki-san

I sat waiting in the dark, searching the various doors on the gigantic FedEx plane for signs that Nicki Boyd, behavior husbandry manager, was about to emerge. Nicki had safely landed in San Diego on this cargo-only flight from Tennessee, bringing very precious cargo from the Nashville Zoo’s clouded leopard breeding program. Suddenly, one of the security guards approached my vehicle, knocked on the window, and said, “Here they come.” Nicki and a FedEx employee carried a large airline crate across the tarmac. Inside were two beautiful clouded leopard brothers, only 14 weeks old. They were hand raised at the Nashville Zoo at Grassmere and were coming to the San Diego Zoo as ambassadors for our Backstage Pass program.

All new animals to our collection must undergo a period of quarantine, necessary to ensure that they not have any infectious disease. So, before the boys could join the gang at Backstage Pass, we had to keep them segregated while our veterinarians cleared them for a variety of infectious agents. Since the boys were young and needed TLC, we decided to quarantine them inside our Neonatal Assisted Care Unit (NACU), known as the nursery by many, facility rather than at our Jennings Center for Zoological Medicine as we usually do.

For the NACU keepers, this was something new and exciting! We hadn’t had a chance to work with clouded leopard cubs since 1990, and these cats had always been a favorite species of ours. We prepared everything in advance: our unit was clean and ready for the boys’ arrival.

The two cubs were surprisingly calm in the transfer crate, curious about their surroundings and greeting me with a shrill chirp. They cried just a few times on the drive to the Zoo but were calm and patient. We carried the crate to the nursery area and opened the crate door. As each cub was released, we weighed him and held him awhile for reassurance, then released him into his new, temporary home. We had constructed a climbing structure for the cubs to play on and placed soft towels, rugs, cat trees, toys, and other enrichment items around the nursery. The cubs sniffed around tentatively at first but were playing with each other and exploring their new climbing structure and toys almost immediately.

NACU keeper Mary Dural prepared their evening diet as directed; she weighed out a portion of raw meat-based zoo carnivore food. Nicki brought some of the meat with her from Nashville, since our zoo does not use the same product. Our Nutritional Services department will change the diet for the cubs, transitioning them from the product they are currently on to our zoo carnivore diet. Since all diet changes are made gradually, we will make the transition slowly, increasing the new diet a little bit on each successive day.

That night each cub ate heartily and drank fresh water. We watched as they played, explored, and attacked each other until they began to tire and flopped themselves down on the floor. It was time to turn out the light and put the cubs to bed. They had arrived safe and sound, but it had been a long day for them.


Janet Hawes is a lead keeper at the San Diego Zoo. Read her previous post, No Babies? What Do Nursery Keepers Do?

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3

Metallic Starlings: Showstoppers

By
Mike Grue
– October 2, 2012Posted in: Animal Stories, Animals and Plants, Animals site sub feature, Birds, Uncategorized

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.

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