Birds

Birds

13

7 Animal Facts You Didn’t Learn In School

You don’t have to be an animal expert to appreciate the natural world. In fact, simple short cuts like the fun facts listed below, can be very conducive to gaining a better understanding of the Animal Kingdom. Enjoy!

Monkeys have tails and apes don't.

1. Monkeys have tails and apes don’t.
Since we have more in common with our great ape cousins than we do with monkeys, a good way to remember this fact is to simply look at your rear end.

There’s no such thing as a poisonous snake.

2. There’s no such thing as a poisonous snake.
Contrary to pop culture and older versions of Encyclopedia Britannica, snakes are venomous, not poisonous. If they were poisonous, touching or licking a serpent would be the more appropriate fear than death by snakebite. And that’s even debatable, since statistics show that out of 7,000 to 8,000 snakebites per year in the U.S., only 5 or 6 are fatal. Call it semantics, but the truth is only 10 percent of the 3,000 species of snake are venomous, meaning they inject toxins into their prey (biting or stinging). The difference is skin deep.

3

To Fledge or not to Fledge…

Su'nan is back in her nest...for now!

Su’nan is back in her nest…for now!

That is the question.

Fledging is the process in which a young bird leaves the nest. We consider a California condor chick to be fledged when it can fly to the higher perches in the flight pen, approximately 10 feet off the ground. When condor chicks fledge, they tend to be 140 to 150 days old. The youngest bird to fledge here at the San Diego Zoo Safari Park was 123 days old. Su’nan in now 162 days old, but she has yet to fledge.

Many viewers have been worried about this Condor Cam chick’s health and/or development. First of all, let me assure you that Su’nan is very healthy and safe. We are not concerned that she is a “late bloomer.” Although she may be a little behind compared to some of our condor chicks, we have had birds fledge even later than this.

Our condor nest boxes are on the second floor of the condor breeding facility. The nests have one entrance that leads to the roost area. The entrance has an 18-inch barrier at the base to prevent young hatchlings from wandering out of our camera’s view. This barrier also provides exercise for the chick when it is big enough to start jumping up onto the barrier. The roost area is open to the flight pen and has a ledge that is about 8 feet above the ground. There is a 5-inch-diameter pole leaning from the ground to the ledge; we call this the “pole ladder.” The condors can walk up or down this pole ladder to get to or from the nest; they can, of course, fly to the nest as well.

Early in the day on September 24, at 149 days of age, Su’nan walked down the pole ladder into the flight pen for the first time. Her parents, Towich and Sulu, kept a close eye on her as she investigated her new surroundings. She drank from the pool, even dunking her head in the water. She picked at old food from the ground. She had a fun time hopping around and flapping her wings. Towich and Sulu watched nervously, making sure their chick was safe and didn’t stray too far from the nest. At one point, when she did move to where her parents were uncomfortable, they corralled her back toward the nest. Frustration ensued and some firm discipline followed. Please note that Towich and Sulu were merely trying to protect their chick, their “investment,” you might say! Su’nan did not take kindly to this, and she stayed on the ground, hiding behind a sumac bush for the remainder of the day. Towich and Sulu made attempts to try to get her back up the pole ladder and back into the nest, but Su’nan did not comply. Su’nan spent that night out of the nest, on the ground in the pen. Her parents perched nearby to watch over her.

The next morning, after Towich and Sulu again tried to move her toward the nest, she finally climbed back up the pole ladder and quickly hopped back into the nest box. She stayed in there for several days, eventually warming back up to her parents’ company. Regular feeding bouts were reestablished. She has been a little standoffish with Towich, but he is the one to do most of the disciplining and preening—two necessary activities that the chicks don’t seem to appreciate. Sulu usually just comes into the nest to feed; naturally, Su’nan is more excited to see her! It’s important to note that BOTH parents are still heavily invested in this chick and are trying their best to ensure her success.

When condor chicks fledge in the wild, it can be a long process as well. They often walk around the mouth of their nest cave, hopping about, testing their wings. They may hop or climb into nearby shrubs or trees to get a better vantage point. Very seldom do chicks just spring forth from their nest into the wild, blue yonder. They usually need to exercise and build their abilities before embarking on such a dangerous venture. Mom and Dad are always present to escort or protect the chicks, too. Parent condors can be very vigilant and defensive of their chicks. After all, much energy and many resources went into producing just this one chick, so they try very hard to ensure success for their only nestling. One pair of condors in California actually chased a black bear away from the nest!

Su’nan is starting to come back out into the roost and onto the ledge. She has been seen testing her wings on the ledge in the morning sun. Her wings are looking nice and full. Hopefully soon, she will take that next step and fledge into the flight pen. When she does, we will be sure to switch the Condor Cam view to the pen view so you can watch her.

So what’s next for Su’nan once she fledges? She’ll stay in the pen with her parents for a little while longer. She is still learning from them. In the wild, condor chicks stay with or around their parents for up to 18 months. We don’t let them stay that long here at the Park. If we did, the next breeding season would probably be compromised; the presence of the fledgling may prevent the parents from breeding the next year, or the parents may turn aggressive to the chick if they try to nest again. Soon, Su’nan will be removed from her parents so they can prepare for the next breeding season, and she will be introduced to other birds her age and an adult bird to act as a behavioral mentor.

And on that note, we have some exciting news! This year, we were able to install some cameras at our remote socialization pen at the Safari Park. Once Su’nan is moved up there with the other young condors, we will be able to provide a view from those cameras, so you will be able to watch Su’nan for much longer than you were able to watch the previous Condor Cam chicks, Saticoy and Cuyamaca.

The interest and enthusiasm over the hatch and growth of Su’nan have been wonderful. We really appreciate all of the comments and questions we have received throughout her development. Thanks again for all of your patience and support. We couldn’t do it without you!

Ron Webb is a senior keeper at the San Diego Zoo Safari Park. Read his previous post, Condor Chick Fostering: Close to Fledging.

3

Mangrove Finch: Chick Transfers

Anita Carrion (Charles Darwin Foundation) and Paula Castaño (Island Conservation) load mangrove finches into transport crates for their voyage to Isla Isabela.

Anita Carrion (Charles Darwin Foundation) and Paula Castaño (Island Conservation) load mangrove finches into transport crates for their voyage to Isla Isabela.

Be sure to read the previous post, Mangrove Finches: Hand-rearing Chicks.

Nearly 40 days after the first mangrove finch eggs and chicks were harvested from their nests at Playa Tortuga Negra, it was time to send them home. Ever since they had arrived at the Charles Darwin Research Station in the Galápagos as young chicks or embryos yet to hatch, we had spent all of our time hovering over them and attending to their every need with one goal in mind: to send healthy mangrove finches back to Isabela Island for release. It was an exciting and hectic time as we prepared to transfer the oldest chicks while the younger chicks were still being fed every hour!

Pre-release aviaries had been constructed in the mangrove at Playa Tortuga Negra by local builders and awaited the arrival of the seven oldest chicks that would make up the first release cohort. After the remaining eight were grown and feeding themselves, they would join the first cohort in the aviaries.

Members of the first cohort were fitted with a unique combination of color bands on their right leg for identification from a distance as well as a silver, numbered band on their left leg. A drop of blood was drawn from under the wing of each bird (just like pricking a finger) for DNA sexing. Transport crates were inspected by the Galápagos Biosecurity Agency to ensure that quarantine conditions would be maintained during the chicks’ transfer. The gear the field team would take with them was sprayed with insecticide and put into quarantine before it was allowed to leave for Isabela.

Mangrove finches relax in their transport crates aboard the Galápagos National Park boat "Guadalupe River."

Mangrove finches relax in their transport crates aboard the Galápagos National Park boat “Guadalupe River.”

The evening of our departure, we transferred the chicks from their fledging cages to mosquito-proof travel crates that we then covered with black sheets. Keeping the birds in the dark while traveling helps keep them calm as it simulates nighttime, when they are typically inactive. A small crowd of staff members from the research station and their children gathered outside of the lab to catch a glimpse of the chicks as we carried them to the truck that would take us to the dock. This group had supported us throughout the project, but due to the quarantine conditions in the lab, this was their only opportunity to see the chicks. The public turnout for the chick transfer was a touching reminder of the support we had received from so many to make the project a success. We loaded the chicks in their crates into a truck for the short ride from the lab to the dock where we took a small boat, or panga, to the Galápagos National Park boat Guadalupe River. The finches got their own bunk on the boat, and we were underway for Isabela.

We sailed overnight and awoke in the morning in the shadow of Volcan Darwin off the west coast of Isabela. After a rushed breakfast, we loaded the finches back into the panga and headed for the beach. The mangrove forest here is protected by a wide, black sand beach, but the porous lava bedrock lets the forest flood at high tide. Navigating the thick tangle of roots and branches is downright treacherous when the forest is flooded, so we were fortunate to land at low tide when the walk from the beach to the pre-release aviaries was relatively easy.

A wild mangrove finch visits the chicks in the pre-release aviary in the mangrove forest at Playa Tortuga Negra, Isla Isabela.

A wild mangrove finch visits the chicks in the pre-release aviary in the mangrove forest at Playa Tortuga Negra, Isla Isabela.

The first step toward getting the chicks used to their new surroundings was transferring them from their travel boxes into fledging cages identical to those they had lived in at the lab. These cages were hung inside one of the three large aviary chambers and allowed the chicks to have a look at their new home while still keeping them confined to a smaller space in case the novelty was too scary or overwhelming. They settled in quickly, and we spent the afternoon watching them while finishing up the fine details of the aviaries and filling in gaps.

Both of the local snake species had been spotted at the aviary site, and we hadn’t gone to all of the work raising these finches for them to be snake food! Rather than snakes, though, the chicks attracted the attention of two wild mangrove finches that came down to the aviary to check out the new arrivals! The wild visitors were the cherry on top of an exciting day that had gone almost precisely as planned. We bid the babies goodnight and went to set up our camp. I was only going to be at the field site for about a week, but the rest of the team would be there for two months, and there was a lot of food, water, and gear to be hauled and organized.

Chick #1 forages in the pre-release aviary on Isla Isabela.

Chick #1 forages in the pre-release aviary on Isla Isabela.

The next morning we let the chicks out of the fledging cages to explore the full aviary. We had furnished their new home with rotten logs, strips of bark, and trays of leaf litter—all places that they would find food in the mangrove forest after their release. They set about busily exploring these new things. It was entertaining for the field crew to watch them interact and learn to navigate in the larger space and to see their foraging instincts kick in.

The next several days were mostly spent observing the chicks in the aviary, finishing the aviaries in preparation for the arrival of the second cohort of chicks, and watching wild mangrove finches at their nests. We even managed to trap and band one of the wild finches that kept coming around the aviaries to check out the chicks! The days were hot, and one afternoon as I was having a combination bath/swim in the ocean, a Park boat showed up out of the blue with instructions to take me to a cruise ship that would take me back to Puerto Ayora. I had to bid goodbye to the field crew, pack up my gear, and go with them right away because the ship was already underway, and we would have to catch it sailing down the coast of Isabela. It was an abrupt ending to a really special part of my Galápagos experience. I got to bring the first of our hand-raised mangrove finches back to their home forest and spend a week camping on a beautiful, remote beach flanked by volcanoes and surrounded by the spectacular wildlife of the Galápagos.

The first release cohort of hand-reared mangrove finch chicks gather together in the pre-release aviary.

The first release cohort of hand-reared mangrove finch chicks gather together in the pre-release aviary.

I arrived back in Puerto Ayora the following morning and was immediately back in preparation mode. It was nearly time for the second cohort of chicks to be transferred to the release site. We went through the entire process once more, and a week later, Michelle Smith with the Hawaii Endangered Bird Conservation Program and Anita Carrion of the Charles Darwin Foundation sailed for Playa Tortuga Negra with the second cohort of chicks.

With all of the chicks grown and moved back to Isabela, there was nothing left for me to do but clean and pack up the lab and wait to hear from the field team. I could do that from San Diego, so I headed home, excited by what we’d accomplished but still nervous about how the chicks would fare after their release.

Beau Parks is a senior keeper at the San Diego Zoo. Read his previous post, Mangrove Finch Eggs Hatch: A World First!

5

Condor Chick Ready to Fledge

The Condor Cam caught Su'nan perched on the ledge.

Su’nan is perched on the barrier between the nest box and the roost area.

As many Condor Cam viewers have experienced, the rearing process for a California condor can be long and slow. It makes sense, though, for a condor to develop so slowly. She has lots of growing to do! When our chick, Su’nan, hatched on April 29, she weighed approximately 6.3 ounces (180 grams). When she reaches her fledge weight of 17 pounds (8 kilograms) or more, she will have increased her hatch weight by 44 times! In contrast, I have only increased my birth weight by 19 times.

On August 27, at 121 days of age, Su’nan took her most recent step toward leaving the nest: she jumped up onto the barrier between her nest box and the adjoining roost area. She quickly hopped back into her nest, but that’s okay. There’s no hurry to fledge, or leave the nest, just yet. Her feathers still need time to fill in. Hopping up and down from the barrier will exercise her muscles, as well as improve her balance. She has since started hopping into the roost area on the other side of the barrier. Here, she can warm herself in the sun, if she chooses.

Su'nan stretches out one of her fast-growing wings.

Su’nan stretches out one of her fast-growing wings.

While out in the roost, she can also rest or sleep in the shade, perch with her parents (if they are not perched out in the flight pen), or step out to the roost ledge to soak up the sun’s rays for the first time. The ledge is about 8 feet (2.4 meters) from the ground—high enough to make the parents feel comfortable and secure in their nest but not as high as a condor nest in the wild. Su’nan may get near the edge, but she will be cautious in doing so, so she doesn’t teeter off. It is natural for condor chicks to explore and exercise on the edge of their nest cavities. Rarely do they fall out; in 32 years of raising California condors here at the San Diego Zoo Safari Park, we have never seen a chick fall from its nest area.

The next step of Su’nan’s development will be to fledge. When she is ready, she will jump off of the nest ledge. She will either slow her fall to the ground below the ledge or fly to a nearby perch. We consider her fledged when she can get up on a perch by herself. The youngest we have seen a condor chick fledge here at the San Diego Zoo Safari Park is 123 days old. Sometimes chicks have waited until over 165 days. It all depends on the chick.

She's made it to the other side!

She’s made it to the other side!

The parents tend to be very vigilant during this phase of their chick’s development. It could appear overprotective to us, but keep in mind that they have invested an entire breeding season and lots of energy into this one chick. It benefits them greatly to make sure that their sole offspring is safe, healthy, and strong. They usually don’t coax or pressure their chick to leave the nest; on the contrary, we have seen parents make sure a chick doesn’t stray too far from the nest if it’s not ready yet. The parents will usually perch and/or roost near the fledgling.

They also will join her when she finally starts going to the feeding area of the flight pen. Most of the time, though, they will push her aside and eat first, feeding her when they are done. In condor culture, the bigger, more dominant birds usually eat first, while the subordinate birds wait their turn. The earlier Su’nan learns this from her parents, the better she will assimilate into a wild population after she is released. Don’t worry: Towich and Sulu won’t let Su’nan starve. They will continue to feed her even when she is out in the flight pen. Eventually, she will eat more and more on her own.

Her foster parents keep her company in the roost area.

Her foster parents keep her company in the roost area.

Depending on Su’nan’s development and activity levels, we will try to switch the Condor Cam view from the nest box/roost area to the flight pen. You’ll be able to see the roost area, most of the perches in the pen, the feeding area, shade areas created by plants, and the pool, where she can either drink on her own or bathe (one of my favorite condor activities to observe!). The view will be wide, so detail will be harder to discern. Also, we do minimal maintenance in the pen once the chick is large enough to look over the nest box barrier. So the pen has lots of plant growth and dried food (animal carcasses) in it. We limit our activities in/near chick pens so as not to expose the chick to humans, thus desensitizing her to our presence. We have found that chicks raised in isolation from humans tend to be more successful once they are released to the wild. The flight pen won’t look as nice as an exhibit you might see at the Zoo or the Safari Park, but Towich and Sulu prefer it that way, if it means we stay away from their precious chick!

Thanks so much to all of our faithful and dedicated Condor Cam viewers. Soon, your support and devotion will be rewarded when our “little big girl” spreads her wings and takes that next step. Rest assured, though, that Su’nan’s story will be far from over!

Ron Webb is a senior keeper at the San Diego Zoo Safari Park. Read his previous post, Condor Chick Foster: Name is Chosen!

0

Alala Breeding Season a Success

alala puppet fedPartially feathered and squawking for meals, `alalā chicks at San Diego Zoo Global’s Keauhou Bird Conservation Center keep animal care staff busy. With nine new chicks this year, the rare bird’s population now numbers 114. `Alalā (also known as Hawaiian crows) are extinct in the wild, and the entire remaining population is managed in captivity through a collaborative effort by the Hawai`i Endangered Bird Conservation Program (HEBCP). Some of the chicks are fed and cared for by animal care staff, which the chicks never see to ensure they do not imprint on humans.

“`Alalā are very intelligent birds and are susceptible to imprinting”, said Bryce Masuda, program manager for San Diego Zoo Global. “We use puppets to hand-rear and feed the birds when they are young to keep them from imprinting onto us, so they will behave naturally as adults.”

The last `alalā were recorded in their Hawaiian forest natural habitat in 2002, where they were threatened by habitat destruction, introduced predators and avian disease. The HEBCP has been working with the species in managed care since 1993, bringing the population from a low of only 20 individuals to 114 today.

The Hawai`i Endangered Bird Conservation Program is a field program of the San Diego Zoo Institute for Conservation Research, in partnership with the State of Hawai’i Division of Forestry and Wildlife and the U.S. Fish and Wildlife Service. Planning and preparation efforts are currently underway to restore `alalā back into its vital niche within the forest ecosystem on the Big Island of Hawai`i. It is hoped that the first reintroduction activities will begin in the near future.

CONTACT: SAN DIEGO ZOO GLOBAL PUBLIC RELATIONS, 619-685-3291

6

Condor Chick: Name is Chosen!

Su'nan peeks over the ledge at Dad, left, and Mom.

Su’nan peeks over the ledge at Dad, left, and Mom.

The naming poll results are in: the name of the California condor chick featured on San Diego Zoo Global’s Condor Cam is Su’nan, Chumash for “to continue to, to keep on”! She is now over 90 days old and is starting to get her big-bird feathers. Some of the first feathers that start to grow are the wing feathers.

It is easy to see the feathers growing through Su’nan’s down: the down feathers are gray, but the new flight feathers are black. The long feathers that grow from the tip of the wing are called primary feathers, and the feathers from the wrist to the armpit are secondary feathers. Primary and secondary feathers are the giant feathers that make the California condor’s wing so large and impressive. An adult can have a wingspan of up to 9.5 feet (2.9 meters)! We are estimating Su’nan’s wingspan to be around 5 feet (1.5 meters) right now, between the size of a red-tailed hawk and a bald eagle. Her tail feathers are also starting to grow. They’re a little harder to see on camera, but you should be able to spot them soon.

After the wing and tail feathers fill in, the feathers on Su’nan’s back will start to grow, as well as the small feathers on the top of the wing, called coverts. Even though many new, black feathers will be covering parts of her body, she will still have lots of gray down showing, making it easy to differentiate her from her parents. Eventually, her light-colored skin will turn dark gray or black and be covered with fine, fuzzy feathers, but this won’t happen until well after she leaves the nest. Her skin will stay dark until she reaches maturity at 6 years, and it turns pink-orange, just like her foster parents’, Towich and Sulu.

Su’nan had her second health exam on July 14, during which our veterinary staff administered her second, and final, West Nile virus inoculation. A blood sample was obtained, and she weighed 11 pounds (5 kilograms), over half of her projected adult weight. Even though our little girl is getting big, she still has room to grow!

The adult condors are fed four days a week. The other three days they are fasted. They often don’t eat every day in the wild, sometimes fasting for up to two weeks, so our nutritionists recommend not feeding them every day to prevent obesity and food waste. Their diet, depending on the day, can consist of rats, rabbits, trout, beef spleen, or ground meat. We offer 2 to 3 pounds (1 to 1.3 kilograms) of food per bird per feeding day. When the condors are raising a chick, we offer extra food every day: 1 rat, 1.5 pounds (0.7 kilograms) of beef spleen, 1 trout, and 0.5 pounds (0.2 kilograms) of ground meat. They don’t end up feeding all of this food to Su’nan, but we want to be sure they have enough for the growing baby. It’s difficult to calculate exactly how much food Su’nan is eating each day, but we estimate that she could be eating 1.5 to 2.5 pounds (0.7 to 1.1 kilograms) of food per day.

Many Condor Cam viewers have seen some rough-looking interactions between Su’nan and her parents. What may have been happening was a form of discipline. As Su’nan has gotten bigger, her begging displays and efforts have gotten more vigorous, which can be bothersome or problematic for parents wanting some peace and quiet. They have two ways to make sure Su’nan does not cause too much trouble while begging: leave immediately after providing food, which is what we’ve seen a lot of on Condor Cam, or discipline the unruly chick. This discipline can come in the form of the parent sitting or standing on Su’nan, or the parent may nip or tug at her. Either of these behaviors results in Su’nan being put in her place by the dominant bird in the nest, thus ending the undesired behavior. Sometimes, this discipline may occur before the chick acts up. Be mindful that this is perfectly normal for condors to do, even though it would be cruel for us to treat our own babies like that! When condors fledge, or leave the nest, they need to know how to interact with dominant birds at a feeding or roost site. This seemingly rough behavior from the parents will benefit Su’nan later when she encounters a big, unrelated bird that might not be as gentle.

Su’nan hasn’t jumped up on the nest box ledge yet, but she may soon. Stay tuned for our next blog that will discuss this big milestone! Also, we would like to thank all of the Condor Cam viewers for their patience while we had camera difficulties for a week or so in July. Our technician replaced the power supply and the camera with very minimal disturbance to the condor family.

Ron Webb is a senior keeper at the San Diego Zoo Safari Park. Read his previous post, Condor Chick Fostering: First Exam.

8

Condor Cam Chick Needs Name

Name the Condor ChickHatched on April 29, a small condor chick emerged into the world observed closely by animal care staff at the San Diego Zoo Safari Park. Adding to the more than 180 condors hatched at the Safari Park since the breeding program began in 1982, the little chick was placed with adult condors Sulu and Towich so they could raise it to adulthood. Its growth has been watched by thousands of people through a live Condor Cam placed in the nest box. Now animal care staff are asking these interested watchers to help choose a name for the young female bird.

Viewers can go online at http://bit.ly/condorname to vote for one of five suggested names. In keeping with the tradition of the condor program, the names have been selected from the Kumeyaay language. The name receiving the most votes will be used for the chick for the rest of its life. Voting closes at end of day on July 20.

“California condors are an important native species in the western United States and hold a special place not only in the ecosystem but in the culture of the people native to this area,” said Michael Mace, curator of birds at the San Diego Zoo Safari Park. “By giving condors names from the Kumeyaay language, we hope to honor the role of condors in human culture throughout history.”

At more than 2 months of age, the condor chick is covered with fluffy, gray feathers and is still closely cared for by its foster parents. The young bird will continue to grow and mature over the next couple of months until its flight feathers grow in and it is ready to leave the nest. Animal care staff at the Safari Park hope that the chick will be able to take its place among the wild populations that have been released in California, Arizona and Mexico.

CONTACT: SAN DIEGO ZOO GLOBAL PUBLIC RELATIONS, 619-685-3291

5

Bird Keeper: A Busy Calendar

Blue-winged pittas love their megaworms.

Blue-winged pittas love their megaworms.

The Tiger River “string” is composed of six bird exhibits that line the Tiger Trail above and below the Malayan tiger exhibit at the San Diego Zoo. In these 6 exhibits there are around 120 birds. Normally, the birds are fairly predictable and easy to keep track of. The blue-winged pittas Pitta moluccensis come out of hiding for their tossed megaworms. The Malay great argus male Argusianus argus greets me at the door but expects his peanuts to be tossed deeper into the exhibit. His friendlier mate comes directly up to my shoe for the same thing.

Our nice-and-quiet routine is dramatically altered once their hormones kick into high gear. Starting around March and typically lasting through August or September, the breeding birds behave differently. They find new hiding places to make nests, they need more fruit or bugs added to their daily diet, and they become more territorial. The easy-to-predict birds suddenly become much more unpredictable!

I have my own calendar at my workstation that helps me visualize what is going on in these six exhibits. When I find eggs that I expect to hatch (fertile eggs that are being incubated), I look up the incubation duration for that species and figure out when those eggs should hatch. The earliest date when an egg should hatch is labeled and highlighted in pink. Any approaching pink-highlighted date lets me know I have to get ready for a potential new chick! The actual hatch is highlighted in yellow. Having hatches easily visible and clearly marked comes in handy many times. Expected fledges are noted in blue. These dates are important, because keepers need to know when a chick is expected to leave the nest, as we frequently add low perching or empty a deep pool for the young and inexperienced fliers.

A black-throated laughingthrush parent is kept busy feeding its chicks.

A black-throated laughingthrush parent is kept busy feeding its chicks.

For example, I noticed a pair of black-throated laughingthrushes Garrulax chinensis sitting on a nest earlier in the month and had figured out that April 12 was the earliest hatch date for the egg. Just before expected hatch, I ordered more bugs to go into their exhibit, as laughingthrush chicks eat a lot of insects. But there was a gap of two days before the chick did hatch. I did not go up to the nest and disturb the parents but knew there was a hatch based on the parents’ behavior—they were stacking bugs in their beaks and bringing a mouthful of mealworms, crickets, and waxworms up to their nest!

Usually 12 days after a black-throated laughingthrush hatches, the chick leaves the nest or fledges. A few days before the chick fledged, I put out some shallow water pans and emptied the pool in their exhibit. If the chick left the nest early, I wanted to make sure that it didn’t get trapped in the cold water. But that is not all! In May, I wrote down the date when the chick would be big enough to have an ID band put on its leg.

One last thought. As crowded and as colorful as this calendar can get, the six exhibits on the Tiger River string are not even the busiest breeding exhibits in the Bird Department. There are eleven other strings in the department, and many of them have more going on during this dynamic time of the year! I am humbled by the amount of knowledge my coworkers have and the amount of work they and our supervisors—who have to organize and manage all 12 strings!—put into their jobs. My hat’s off to all of them!

Mike Grue is a senior keeper at the San Diego Zoo. Read his previous post, Food Time!

5

Condor Chick Fostering: First Exam

Boy or girl? We'll find out soon!

Boy or girl? We’ll find out soon!

On Thursday, June 12, 2014, the California condor chick you’ve been watching on Condor Cam received its first health exam. The goal was to obtain a blood sample for our labs, administer a vaccine for West Nile virus, inject a microchip for identification, and weigh the chick.

The first step in this process is to separate the parents from the chick. Of course, the foster parents (father Towich and mother Sulu) don’t want any invaders in the nest and do their best to defend the chick and keep it safe, as all good parents do. Adjacent to the flight pen, we have a shift pen, used to safely and calmly move large or dangerous animals from one area to another. We offer all of the condors’ diet in the shift pen, so Towich and Sulu are very comfortable entering the shift pen for every meal. We shifted Towich into the pen and kept him there until after the exam. From his shift pen, he cannot see the nest area, so he was unaware that we were even in his nest, thus keeping him very calm. He ate and waited patiently until he had access back into his flight pen.

Sulu was not shifted but instead was able to see us go into her nest. We posted one keeper in the nest entryway to keep Sulu out, while another keeper entered the nest and covered the little chick with a towel. This is the first time that the 45-day-old chick had ever seen a person and was understandably nervous and defensive, hissing and lunging at the intruder. Once under the cover of the towel, the chick could not see and calmed down. It was then brought into the adjoining vestibule where our veterinarian staff was waiting.

First, the veterinarian obtained a blood sample from the chick’s leg. This sample was sent to the lab to make sure that the chick is healthy. Also, our geneticists can determine if it is male or female from this sample. Next, a vaccine for West Nile virus was administered and a microchip was injected under the chick’s skin. The veterinarian did a quick health assessment, checking the chick’s eyes, nares (nostrils), beak, feet, legs, wings, and abdomen. Lastly, we weighed the chick to make sure it was growing on schedule.

While the exam took place, a third keeper was able to enter the nest to clean the camera domes and make sure there were no hazards in the nest cavity. The whole exam, from capture to release, took about 10 minutes.

Once the exam was over, the chick was returned to the nest and Sulu was allowed to approach and check on her baby. The chick was rightfully disturbed by this process, despite our best intentions to minimize stress. Although we feel bad that the chick was so nervous, it is actually good that it was not comfortable in our presence. We have to keep in mind that we don’t want the young condor to become accustomed to or feel reassured by humans; we want it to be a wild condor, uninterested and wary of humans, so that it may someday fly free in California, Arizona, or Mexico. Condors that show an affinity for humans seldom survive in the wild.

For several minutes, the chick showed a defensive posture, hissing at everything it saw, even its mother. Sulu slowly approached her chick and calmly preened it, eventually soothing it. That is the reason we shifted only one parent; we wanted the other parent present to calm the chick after the exam. After only about two minutes, the chick was showing proper begging behavior, resulting in a feeding session from Sulu. With everyone appearing calmer, Towich was let out of his shift pen. About five minutes after that, he approached the nest to peek in on the chick and to perch in the adjoining roost area.

So far, the health exam looks to have been successful. Hopefully, the blood work will show that the chick is healthy. The veterinarian’s initial inspection revealed that the chick’s eyes and nares were clear, the feet, legs, and wings were solid, and its vitality was very strong. The chick weighed 6.8 pounds (3.10 kilograms) and was about the size of a bowling ball. We hope to receive the sex results from the Genetics Lab soon. When we do, we’ll let you know if the chick is a male or a female.

Ron Webb is a senior keeper at the San Diego Zoo Safari Park. Read his previous post, Condor Chick Fostering: 30 to 45 Days.

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Condor Chick Fostering: 30 to 45 Days

The growing chick has lots of feathers to play with.

The growing chick has lots of feathers to play with.

At a little over 1 month of age, our California condor chick should weigh around 4.5 pounds (2 kilograms) (see previous post, Condor Chick Fostering: 1 Week to 1 Month). The foster parents, Towich and Sulu, have started leaving the chick alone overnight, sleeping near the nest. If the weather is still cool or it’s raining, the parents may brood overnight until the weather improves. Even though the parents are increasing their time away from the chick, they remain VERY vigilant and protective of their nest and, especially, their chick. Some field biologists have even seen wild condor parents chasing black bears away from the nest area!

Up until now, the chick has been scooting around the nest on its tarsal joints—we call it the tarsal crawl. It’s not uncommon, at this age, to see the chick standing all the way up on its feet, teetering around the nest, holding its wings out for balance. As its legs get sturdier, the chick may even approach the parent, begging for food. The wing-begging behavior we’ve been seeing gets more pronounced: lots of wing-flapping, head-bobbing, and trying to position itself in front of the parent.

It is possible that the parents, who are offering larger quantities of food per feeding session, might be providing a small amount of fur/hair in the chick’s diet. (Part of the adults’ diet includes mammals, like rats and rabbits.) Condors can digest just about every part of the animals they eat, except for fur. This fur accumulates in the digestive tract and is eventually regurgitated as waste. We refer to this as casting. A condor’s cast is composed of predominantly fur, whereas a cast from an owl has fur and bones; owls can’t digest bones, but condors can. We have seen condor chicks cast hair pellets as young as three weeks of age. When the chick casts, it throws its head forward several times, mouth open, until the pellet is ejected from its mouth. It can look like the chick is in trouble, but it is perfectly normal, and good for the chick.

At 45 days of age, or around June 12, the chick will get its first health exam. We will obtain a blood sample for the lab to make sure it is healthy and to determine if the chick is male or female. Also, during the exam, we will weigh the chick—it should weigh between 7.7 and 8.8 pounds (3.5 and 4 kilograms)—and inject a transponder chip as a form of identification. It’s the same kind of chip you can get for your dog or cat. Most importantly, this exam allows us to administer a vaccine for West Nile virus, a disease that originated in Africa and was accidently introduced to North America by humans. North American wildlife, including condors, usually doesn’t have a natural immune response to West Nile virus, so we are trying to give the chicks as much of a head start as we can.

This exam will be the first time that the chick will see humans, so it will naturally be disturbing for it. We try to be quick (9 to 10 minutes) to minimize the disturbance. Additionally, we will keep the chick covered with a towel to reduce its exposure to humans and to provide it a bit of security. Towich and Sulu are usually away from the nest when we perform the procedure, to keep them as calm as possible as well. We don’t want the chick to become accustomed to or feel reassured by our presence; we want it to be a wild condor, uninterested and wary of humans, so that it may someday fly free in California, Arizona, or Mexico.

The chick will look very large at this age compared to how big it was at hatch, but remember that it is still less than half of its adult weight. There is much more growth and fun to come on Condor Cam!

Ron Webb is a senior keeper at the San Diego Zoo Safari Park.