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1

Orangutans: Why the Burlap?

A young Cinta enjoyed burlap, too!

A young Cinta enjoyed burlap, too!

Satu sits slightly down with a piece of burlap over his head; Indah lies in a hammock completely covered by burlap, and Karen has a burlap bag clutched in her foot as she does somersaults in front of the glass. What’s up with the burlap? Burlap is one of the enrichment items we give the orangutans on exhibit. If you have spent anytime at the San Diego Zoo, you probably have heard of enrichment. Enrichment basically refers to anything given to the animals that will increase their activity both physically and mentally.

When animals are on exhibit, we are limited to items that are natural in appearance, and with orangutans, we are limited further to items that are “orangutan proof.” Orangutans are intelligent, strong, and creative animals. Great care has to be given so that individuals cannot hurt themselves, destroy the items, or, more likely, use the item as a tool for mischief.

In addition to the burlap, pinecones, gourds, bamboo, browse, and palm fronds are enrichment items we commonly use on exhibit. We try to give them items that will encourage natural behaviors. Orangutans are arboreal mammals from the rain forest. They use branches and large fronds to protect themselves from the rain and sun. We give them burlap, browse, and palm fronds to mimic this behavior. We put treats and smears in and on the pinecones, gourds, and bamboo to encourage foraging behaviors and tool use. We have a simulated termite mound in the exhibit, which, of course, does not contain ants or termites but different sauces. It is not so important what is in the termite mound but that they use tools to extract what they want out of it.

Tool use is a learned behavior passed from mother to offspring. We saw Indah actively teaching Cinta to use the termite mound, and it will be great to see her do the same with her newest baby, Aisha. Different groups have different tool use methods, and even individuals have a preference when it comes to extracting the enrichment. When we give bamboo cups with gelatin inside, Satu likes to use his strong jaws and teeth to just break it open, Cinta would pound it on rocks and knock out the gelatin, while Karen uses a small stick to get the good stuff.

You will also notice when you look at the exhibit that there are large, plastic items hung on ropes. While they are not natural looking, they fulfill the other requirement: they are orangutan proof. We use these as permanent enrichment items in the exhibit. In addition to the animals using them to swing and play with, we also put food items inside periodically. As a result, the orangutans check them every day. This increases their activity level, but it also mimics a natural behavior. Orangutans have a mental map of the rain forest: where the fruiting trees are located, and what is edible. They remember where they found food in the past and return to it later.

Tanya Howard is a senior keeper at the San Diego Zoo. Read her previous post, Orangutan Aisha at 5 Months.

53

Entertaining Panda Cub Xiao Liwu

Xiao Liwu relaxes in his off-exhibit bedroom next to his rocking "horse." See, he likes apples!

Xiao Liwu relaxes in his off-exhibit bedroom next to his rocking “horse.” See, he likes apples!

What has our panda cub been up to, now that he’s been on his own for a few weeks? Keeper Jennifer Becerra filled me in on all things “Wu,” and I’m eager to share what I learned with Xiao Liwu’s many fans!

Jennifer says Xiao Liwu, now 20 months old, is doing quite well. He is not as playful as his older siblings have been and instead has become a bamboo-eating machine. Now weighing 70.5 pounds (32 kilograms), “Mr. Wu” eats about 22 pounds (10 kilograms) of bamboo each day—a lot for a little bear! Shunning most non-bamboo food items, he is developing a taste for Fuji apple slices and applesauce. Lately, keepers have been blending steamed carrots, yams, applesauce, and banana-flavored biscuits into a mush for him. They serve the concoction in a metal pan, which you may have seen in his enclosure.

Lest you think Wu is all about food, don’t worry. He does enjoy playing in a long, plastic tray filled with ice cubes. He climbs all over a recycled plastic “rocking horse,” which is really in the shape of a whale, that is in his off-exhibit bedroom area. And you’ll be proud to know he is doing well with his training. He already urinates on command when he hears the words “go potty”! Being able to collect this vital fluid for periodic testing is part of our animal care protocol. Mr. Wu knows how to “target” or touch his nose to a target stick, and he knows to put his paws up, paws down, and to sit when asked to do so. He also enjoys his new bedding material, called excelsior hay, that is on top of the cave structure. This hay product was on his Wish List—thank you, donors!

Ice cubes feel good on a warm day!

This ice feels good on a warm day!

And then there are scents! Our pandas love to roll and anoint themselves with different odors. Their keepers found a fragrance company that provides a huge variety of choices. They all like the smell of cinnamon, but I found it interesting that each panda also has his or her favorites. For Mr. Wu, it’s wintergreen. Bai Yun enjoys those in the mint family: wintergreen, peppermint, and spearmint. Yun Zi, who is now living in China, loved honeysuckle and earthworm! And Gao Gao? He tends to lean toward more musky scents, but his all-time favorite is rubbing alcohol!

Debbie Andreen is an associate editor for San Diego Zoo Global. Read her previous post, Delightful Tasmanian Devils.

14

Orangutan Aisha at 5 Months

What fun to watch Aisha grow!

What fun to watch Aisha grow!

The past five months have gone by so fast! Little orangutan Aisha is growing by leaps and bounds. I forget how small she actually was until I see a picture of her first day outside. Indah continues to be a great mother. She seems even more relaxed with Aisha than she did with Cinta, her first offspring.

The last few weeks have seen an increase in Aisha’s activity level on exhibit. Typically, Indah is active and moving around the exhibit first thing in the morning, and by 11a.m., she finds a comfortable perch in the climbing structure and relaxes for the rest of her time on exhibit, with Aisha hanging on her. Lately, we have seen Aisha off of Mom on the climbing structure and hammocks—it’s so exciting! At first, Indah’s hand was right there, and she was very vigilant. Now, Indah will be a few feet away, sometimes with her back to Aisha, and one time Indah even left the tree and went to the ground for a few minutes! It is amazing to see Aisha on her own, so interested in her surroundings.

Mom and baby are still going inside at 1p.m. so the siamangs can go on exhibit. It will be a while before we are comfortable introducing the baby to the siamangs. Because of male siamang Unkie’s previous behavior with Cinta, we do not want to try this too early, as it could result in unnecessary stress to Indah and Aisha or possibly injury.

When inside, Indah is even more relaxed. At a very young age Indah would put Aisha down in the bedroom and let her explore. It varies greatly between individual mothers when they break that mother-child contact for the first time. Literature has the range as early as 2 months and as late as 18 months. Indah was definitely on the low end of the range! She feels very safe in her bedroom and knows that there is no threat to Aisha inside. In her bedroom, Aisha climbs up the bars and across the ropes and back again. She is very active, but sometimes she just wants to be on Mom. We have a camera system set up in the bedroom, and this has really allowed us to see behaviors between Mom and baby and to see early development that we would not have seen if we were standing there watching. Indah typically is more protective if there are people present and usually will grab Aisha and hold her until people leave the area.

Aisha still does not have any teeth, but she is tasting everything, and everything goes into her mouth. She eats lettuce and would probably eat or try to eat other foods, but Indah is not good with sharing. The majority of Aisha’s nutrition is from nursing.

I get asked a lot how much Aisha weighs. Even though Indah lets Aisha climb and move around, she would never leave Aisha and move to another area without her. We can get weights anytime on Mom and baby together.

It will be great to see Aisha grow and change in the coming months. Every day I am excited to get to work and see all the cute stuff she does. Everything she does is cute!

Tanya Howard is a senior keeper at the San Diego Zoo. Read her previous post, Orangutan Personalities.

30

Yun Zi Travels to China, Part 2

Dr. Beth (at right) and Jennifer pose with their flight captain.

Dr. Beth (at right) and Jennifer pose with their flight captain.

Be sure to read Yun Zi Travels to China, Part 1!

Panda Yun Zi was a natural traveler in the van all the way to the Los Angeles Airport. He sat quietly in his crate and ate bamboo all the way. When we got to the airport, he decided to take a nap while we waited to get checked by security. We had to wait a short time before Yun Zi and all of his luggage was strapped down safely onto a pallet and ready to load onto the plane. The pilots were very kind to ask what temperature and light settings would make Yun Zi most comfortable in cargo during our long flight.

The time flew by, and before I knew it, Yun Zi, Dr. Beth Bicknese, and I were boarded onto the plane. Yun Zi was nice and calm all the way onto the plane. Not me! I was super-nervous, as this was my first flight overseas and flying on a large cargo plane. We met with all five pilots and introduced them to Yun Zi. He did extremely well meeting the pilots, and they even spoke a little Chinese (Mandarin) so he could practice.

Jennifer and Dr. Beth meet Yun Zi's new keepers upon arrival.

Jennifer and Dr. Beth meet Yun Zi’s new keepers upon arrival.

Our flight departed around 9 p.m., and we were off for our 22-hour journey. The airlines and the pilots were wonderful, as we all felt like we were in first class. They understood our needs and the care we needed to provide Yun Zi on his flight. Dr. Beth and I did not get much sleep on the plane, as we were making sure Yun Zi was as comfortable as possible. It was extremely easy to access Yun Zi, as he was only behind one door, and we checked on him every three to four hours.

I will tell you he was a much better flyer than I! Every time I checked on him, he was resting and calm. He enjoyed his biscuits, bread, and honey water in first-class style. I didn’t sleep much at all, wanting to make sure he was comfortable, and I was reassured every time I checked on him that he was calm. The flight was entirely at night as we flew up the coastline to Alaska and over the Pacific Ocean and landed in Shanghai two hours early, around 6 a.m.

When we landed, we were greeted by airline security, and the pilots quickly took us through customs so we could get back to Yun Zi. It was wintertime in Shanghai, and lucky Yun Zi had his fur coat on, as it was 40 degrees Fahrenheit outside. We waited for Yun Zi to be unloaded and noticed his small welcoming party (small because we landed two hours early!). Dr. Beth and I were immediately introduced to one of his new keepers (Mr. Strong) and veterinarians (Mr. Deng). They checked on Yun Zi and offered him a fresh apple. Yun Zi was polite but decided he would rather sleep.

And off he goes to his new home!

And off he goes to his new home!

Dr. Beth and I passed along Yun Zi’s training video (we had made a video for his new keepers to show them what he knows so far) and all his information to his new keepers. Mr. Deng asked several typical questions about Yun Zi: how much he eats, how much he poops in a day, his favorite scents, and favorite toys. We talked about his training and how he likes to see people.

I know Yun Zi is in good hands with his new staff and was ready for his journey to Wolong with them. I did leave a little piece of my heart in Shanghai that day, but I know Yun Zi will do well in China.

Jennifer Becerra is a senior keeper at the San Diego Zoo.

3

A New “Tree” for Woodpeckers

A yellow-naped woodpecker is hard at work.

A yellow-naped woodpecker is hard at work.

Nothing beats natural behavior. Allowing birds to use their evolved traits, behaviors, and abilities usually results in a healthier bird in both mind and body. We encourage natural foraging behaviors by hiding earthworms in loose soil for the kiwis to hunt. We do bug scatters in the diving duck aviary for the ducks to dive for (it is so cool to watch!). And we try to make available various nesting material the birds would look for and use in the wild. Hummingbirds get spider webs, weavers get thorny twigs, and woodpeckers get…hmm…how do you replicate the tall, thick, dead trees most woodpeckers prefer to use in the wild? The San Diego Zoo’s Horticulture department does such a good job at keeping the trees alive and healthy that there are not many dead trees available. Not to mention that it would be difficult to actually move those trunks into the exhibit!

Enter the cork nest! The ingenious box was developed by curator Peter Shannon and his team at Albuquerque Biological Park. The nest box has plywood sheets on the top, bottom, and three sides. The fourth side is open, exposing the cork. The idea is that the cork is hard enough to provide the birds a tough substance to chip away at but is soft enough for them to still make progress. Here’s a photo essay and video of what happened…

On February 3, 2014, I used a tool to make a small indent in the hard cork on the front of the nest box and installed the box in the yellow-napped woodpecker’s Picus chlorolophus exhibit, which is just up the hill from the turtle exhibit on Tiger Trail.

#1: On February 3, 2014, I used a tool to make a small indent in the hard cork on the front of the nest box and installed the box in the yellow-napped woodpecker’s Picus chlorolophus exhibit, which is just up the hill from the turtle exhibit on Tiger Trail.

Within hours, the male was clinging to the front of the nest box and was working away at the starter hole I had made! You can see that the woodpeckers are much better at making circles than I am…how embarrassing.

Within hours, the male was clinging to the front of the nest box and was working away at the starter hole I had made! You can see that the woodpeckers are much better at making circles than I am…how embarrassing.

After congratulating myself for thinking about making the starter hole, I walked into work on February 9 to see this. Hmm, obviously I didn’t put the starter hole in the right place and the birds had come up with their own location.

After congratulating myself for thinking about making the starter hole, I walked into work on February 9 to see this. Hmm, obviously I didn’t put the starter hole in the right place and the birds had come up with their own location.

By February 16, though, the birds had come up with an even better spot!

By February 16, though, the birds had come up with an even better spot!

 A week later, the three holes look like a surprised cork ghost...

A week later, the three holes look like a surprised cork ghost…

 ...and by March 16, a scared cork ghost!

…and by March 16, a scared cork ghost!

It has been such a joy these past few weeks to see both of the woodpeckers engaging in their natural nesting behavior. At the time of this writing, the bottom hole is the most extensive cavity that reaches to the very bottom of the nest. The upper right hole is also large but does not extend or break through to the bottom hole. And the top center hole—the one I helpfully started for them—nothing. I think they just worked on it to be nice.

The video below is not the up-close-and-personal video I’ve tried to show in the past. But I think it is great in that it was taken from the guest walkway and is exactly what observant—and lucky—guests might be able to see for themselves! In the video, the woodpecker is “corkpecking” and chipping away at the material. Later in the day, I was delighted to see the female’s pointy beak emerge full of loose bits of cork. She spat the cork out, ducked back into the nest, and emerged seconds later with another mouthful of excavated cork. How cool!

Woodpecker Video

Mike Grue is a senior keeper at the San Diego Zoo. Read his previous post, A Trick up Her “Sleeves.”

11

Orangutan Personalities

Janey bonds with a young Zoo guest.

Janey bonds with a young Zoo guest.

Ever wonder about the personalities of the orangutans and siamangs you watch on Ape Cam? Wonder no more! Here’s a quick guide to help you tell “who’s who.”

Janey is the oldest animal in the exhibit. At approximately 52 years old, her hair is thinning on her back and shoulders, and her toes are curled up (it is painful for her to straighten them out). You may see her crutch-walking on exhibit. She is on medications, due to her age, for pain and gut mobility. She is our only Borean orangutan, born in the wild around 1962. She remains interested in “human items” due to the fact that she was hand raised and in private hands for the first half of her life. Her favorite spots in the exhibit are at the exhibit glass and in her zen/sun spot down the hill. She gets along with everyone in the group. But do not let her old age fool you! She lets her feelings be known, and she stands her ground.

Karen was born at the Zoo on June 11, 1992, and was hand raised. She survived a widely publicized open-heart surgery in 1994. Karen is very short and round (a no-neck girl!). Her hair is shorter than Janey and Indah’s, and her eyes are yellow. She has a LOT of personality, is very stubborn and willful but remains a keeper and guest favorite. Karen likes to twirl around on the sturdy bamboo poles in the exhibit. She also likes to roll around instead of walking when out there (she will and can walk, but chooses not to!).

Indah likes to sit in the far right (east) climbing structure. She rarely comes down to the ground, and then only to get food and be at the popular man-made termite mound to grab a snack. Indah is the pretty one of the group with long, flowing hair and a large bump in the middle of her forehead. She is very slow to warm up to new people, but she likes the siamangs and shares her food with them occasionally (an unusual behavior in the primate world!). She was a very doting mother to little Aisha, born in 2013.

Satu is our lone male orangutan and is Aisha’s father. He was born on March 26, 1995. His cheek pads and dreadlocks filled out once his father, Clyde, moved to another zoo. Satu has a sweet disposition and can usually be seen slightly down the hill in a bed of pappas grass. He is quite playful and often plays with the two siamangs that share the exhibit.

Aisha is our newest orangutan, born on October 25, 2013, to mother Indah. So far, her mother is doing a great job of caring for her, and little Aisha is skilled at clinging to Mom’s chest as the pair travel up poles and across the ropes. What fun we’ll have watching her grow!

Of our two siamangs, Unkie is much leaner than Eloise and his face is more angular. Siamangs pair bond for the life of their mate, and Unkie and Ellie have been together since 1987 and can often be heard singing duets.

Unkie, born on October 19, 1983, is usually the instigator with the orangutans; he likes to steal their food, pull on their hair, and swat at them. Eloise, born on April 17, 1981, has a visible belly and a bare chest. There is a discolored line of hair down the middle of her back. She has had five offspring with Unkie. The siamangs both are very sweet, not too aggressive to people or their orangutan roommates.

Now that you know a bit more about them, I hope you’ll continue to enjoy watching all the action on Ape Cam!

Tanya Howard is a senior keeper at the San Diego Zoo. Read her previous post,

7

A Trick Up Her “Sleeves”

What tricks did this bird have up her "sleeves"?

A male blue-crowned hanging parrot has a red “bib” whereas the female does not.

I never stop learning at the San Diego Zoo. It is one of the best things about working here! I am constantly challenged to learn more about the birds I work with, the exhibits I work in, and how I can take better care of both. Sometimes I learn technical skills like how to install a mister system that can be utilized to give the birds a bath. Or I can read up on tips to successfully breed red-billed leiothrix Leiothrix lutea. Many times I learn from simply observing the birds go about their daily routines.

A few days ago, I was doing an end-of-the-day check on the blue-crowned hanging parrots Loriculus galgulus just up the hill from the tiger exhibit. As I was getting a head count, one of the birds caught my eye. It looked like one of the adorable little females had done something to her primary feathers. It seemed as if she had lost some of the barbules at the tips of her long, green feathers; it made her back look spiky. She was perched on a palm frond, chewing on a leaflet, and didn’t seem to be concerned with her odd feathers. After a few moments, she quickly flicked her head back to preen the spiky feathers and then returned to her chewing. A few more moments, another quick flick and preen, and back to the frond.

It's easy to see how the blue-crowned hanging parrot got its name!

It’s easy to see how the blue-crowned hanging parrot got its name!

It was after the third or fourth flick that I started to suspect what the tiny parrot was doing. My first reaction was that I must be imagining it—she surely wasn’t doing what I thought she was doing, was she? I had never heard of such a behavior, and I couldn’t believe she was being so smart…so efficient.

I crouched down in front of the exhibit to get the best vantage possible. I stopped watching her quick flicks, chewing, and preening, and instead focused on her spiky back. With a quick movement, the female turned her head, preened, and went back to her work. But there was a new spiky green “feather” in her back!

She wasn’t preening broken feathers after all! She was snipping little bits off the palm frond, sticking the cuttings onto her back, and using her feathers to hold them in place! I knew these little parrots lined their nests with strips of plant material, but I had never envisioned them using their back feathers as a type of backpack. With only one trip from her nest, this female was able to bring back over half a dozen strips to her nest instead of the paltry one strip she could’ve brought back if she had carried it in her beak.

This behavior has been documented before, but it is not something seen on a regular basis. Indeed, after eight years working with birds, I had never even heard of it. It makes me excited to find out what other tricks these birds have up their sleeves…er, feathers.

Mike Grue is a senior bird keeper at the San Diego Zoo. Read his previous post, Sing, Song.

259

Xiao Liwu: Weaning Wrap-up

Xiao LiwuLate last week, we separated Xiao Liwu from his mother for the last time. He remained in the main viewing exhibits for a few days while Bai Yun was shifted out of the area so that they were not across a door from one another. We have found in the past that in the first few days post-weaning, the cub can be quite vocal, calling for mother as it wanders about. This can arouse a response from Bai Yun; therefore, we find it best to put some distance between them to allow our adult female to remain relaxed.

As anticipated, our littlest bear has shown some tendency toward wandering and vocalizing in the last few days. This is normal. As mentioned in a previous post, the cub is always the one most unhappy about the separation and would prefer to prolong his or her relationship with momma bear. The lure of a constant companion, playmate, and milk source is strong! Her absence from the cub’s life is something the youngster clearly responds to. However, past cubs seem to move on from their discontent within about a week or so, and we expect Xiao Liwu will follow suit.

For her part, Bai Yun does not seem to reciprocate the sentiment that “absence makes the heart grow fonder.” Keepers have reported that she is doing very well post-separation. The only restlessness observed with her are those typical of food anticipation, the same bouts observed when the cub was with her daily. Otherwise, Bai Yun is very focused on priority number one: her bamboo and other food. For our matriarch, it’s business as usual. Her job of cub rearing now done, she appears thoroughly content.

Xiao Liwu has been shifted off exhibit to the upper bedroom area where he is closer to his keepers. This is beneficial to the little bear, as the keepers are poised to fill some of the social void left by his mother’s absence. Already, they have had nice sessions with him during which they have been able to hand-feed him apple slices and offer him back scratches. The apple slices are a small victory because, as you may recall, he has been unwilling to eat anything but bamboo to this point. Having a food source over which the keepers can bond with the youngster will enable them to build a stronger relationship. These bonding sessions become an important foundation for future training and husbandry that requires cooperation and mutual trust between keepers and animal.

While Xiao Liwu will be off exhibit for some time to facilitate his keeper-bonding experience, there is a silver lining for some of our panda fans. Patriarch Gao Gao has been shifted back to the main viewing area, where he will remain for the next few months. When you observe the bears, you may notice that both Gao Gao and Bai Yun have small shaved patches now, as both underwent routine veterinary check-ups at the end of last week. With that out of the way, and weaning complete, our panda facility will now settle into a new routine that will be the status quo for the near term.

Suzanne Hall is a senior research technician for the San Diego Zoo Institute for Conservation Research. Read her previous post, Weaning Xiao Liwu: Leafy Greens.

111

Weaning Xiao Liwu: Leafy Greens

Xiao Liwu is surrounded by leafy greens.

Xiao Liwu is surrounded by leafy greens.

After many days of short separations, giant pandas Bai Yun and Xiao Liwu were doing well. Both bears had a few hours each morning to be on their own, and both spent that time eating heartily. Reunions between them at the midday feed were non-events. Although occasional nursing bouts were observed, it did not appear that the frequency of nursing had been accelerated. Further, the duration of observed nursing bouts was very short, lasting only about two minutes. This suggested that either mother Bai Yun’s milk supply had begun to dwindle or that the nursing was more about comfort-seeking than calorie-seeking on the part of our youngster, Xiao Liwu.

Since no other comfort-seeking behaviors had been observed, we opted to move forward with our weaning protocol. Last week, we lengthened the time the two bears are separated. The two are no longer reunited at midday and instead are separate still as they are served lunch. Access to each other is now delayed until the end of the workday, when the last keeper is ready to head home.

Did you notice? Probably not, since the bears showed no overt response to this change. We have only one report of “Wu” knocking on the door that separated mother from son, and it was a brief event. They are both taking this change very much in stride. In fact, by all accounts, Wu seems to be handling this separation better than any of his siblings. He is a very relaxed bear.

I can’t say why it is that he seems so much better able to adapt to the weaning process than his siblings. Perhaps it is because of his penchant for bamboo. He still refuses to eat anything but his leafy greens, despite our keepers’ gallant attempts to offer him something—anything—that he might like as an alternate treat. We know that adult pandas have to spend a lot of time feeding on bamboo to meet their caloric needs. Perhaps Wu is not so concerned about weaning because he, too, is very focused on bamboo feeding. To get his calories, he isn’t relying on carrots and apples and Gao Gao bread and honey-soaked softened biscuits (keepers have been really trying to entice him!), so he has to take in as much bamboo as he can get his paws on, and there is little time to worry about his mother.

In fact, these weaning separations may be helping him to some degree. Our little panda actually gained some weight in the first nine days of our separation protocol. Perhaps having the bamboo all to himself is beneficial to him. It will take some time, and several more weigh-ins, to see if his weigh gain trajectory alters as a result of weaning separations.

In a short time, if both do well, we will be looking to complete the weaning process for Xiao Liwu. Though some of the details have yet to be worked out, be sure that our keeper staff stands ready to provide Wu with the added social support all of our past cubs have needed once he is independent of his mother. All of our previous cubs have incurred a short period of pining for their mother after weaning was complete (generally not reciprocated by Bai Yun, they’d be sad to learn), but perhaps our bamboo boy will pine the least of all. He’s very busy, after all, getting in those leafy greens.

Watch our pandas daily on Panda Cam.

Suzanne Hall is a senior research technician for the San Diego Zoo Institute for Conservation Research. Read her previous post, Weaning Xiao Liwu: Conflict over Calories.

2

Sing, Song

Listen to the red-billed leiothrix's song!

Listen to the red-billed leiothrix’s song below!

Birds can make some of the most beautiful music in the world. The sweet call of the northern cardinal Cardinalis cardinalis tells us spring is coming. The majestic cry of the red-tailed hawk Buteo jamaicensis evokes a sense of being connected to nature—the sound most movies incorrectly play when they have a bald eagle Haliaeetus leucocephalus on the screen. Loons sound so lonely and remorseful, it can make the heart ache. While those sounds evoke a variety of emotions in humans, birds sing and call for different reasons. Sometimes they may sing to announce their territory, to communicate with their mate, or to attract a mate in the first place.

The San Diego Zoo’s beautiful pair of red-billed leiothrix (pronounced LY oh THRIX) Leiothrix lutea in the enclosure just up the hill from the tigers take singing to the next level. The male has a wonderful repertoire of warbling whistles. He has so many notes, and it varies so much, it sounds like a new song every time he sings. To start the duet, the male spends about ten seconds delivering a gorgeous song before he takes a break. Then it’s the female’s turn. In the pause after the song, the female utters a low-pitched chirp, chirp, chirp, chirp. That’s it! Following the female’s contribution, the male picks right back up with another round of lovely notes. Once he finishes…chirp, chirp, chirp, chirp. Another song…chirp, chirp, chirp, chirp.

red-billed leiothrixAt first I couldn’t tell exactly what was going on, but after listening for awhile I noticed a few things:

1) The female never interrupts the male mid-song; she always waits until he is done to deliver her chirps.

2) The female chirps three to five times—with four being the most common.

3) The male starts his song again after her chirps, but waits for her chirps before he starts up again. This became obvious when I heard him finish his song, but the female didn’t call back right away. She was delayed because she was eating and had just swallowed a large piece of fruit! The minute she could, she chirped to complete her end of the duet.

Why does she chirp? Why does the male seem to find her call so important? I don’t know. I haven’t found any literature to suggest that they are actually “duetting” in the formal sense of the term. But when both of the birds seem to take their cue from each other, I think the term is appropriate. Either way, it is extremely interesting and quite cute!

Check out this vocal pair of birds uphill from the tiger exhibit (just next to the turtle exhibit on Tiger Trail).

 

On the audio, we first hear the male producing a short song followed by the female’s lower pitched, encouraging chirps. They continue back and forth for some time with the longest and most impressive song at the end of the recording. The female chirped anywhere from seven to ten times between the male’s song. This is a higher number of chirps than I had heard earlier in the month. I wonder if the female chirps more as the pair gets closer to the breeding season? Something to look forward to listening for as winter passes and spring starts to round the corner.

Mike Grue is a senior keeper at the San Diego Zoo. Read his previous post, Pick on Someone Your Own Size!