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palila

1

Meeting Endangered Birds on a Tropical Island Getaway

The view as we drove the winding road to the Maui Bird Conservation Center was stunning!

The view as we drove the winding road to the Maui Bird Conservation Center was stunning!

As a senior animal trainer at the San Diego Zoo, I always tell our guests that San Diego Zoo Global has dozens of conservation projects worldwide. But until recently I had never gotten to experience any of our off-site programs. While planning a vacation to the islands of Lanai and Maui in Hawaii, I realized “Hey—we have that bird facility over there!” I had heard about the Maui Bird Conservation Center (MBCC) and the work they do with critically endangered Hawaiian bird species, and I was lucky to be able to visit the MBCC, even though the facility is typically closed to the public.

At left are the bird holding areas.

At left are the bird holding areas.

My companion and I drove straight from the Lanai ferry up an exceedingly narrow and twisty road with some amazing vistas to the Maui Bird Conservation Center, stopping first to pick up some thank-you donuts for the staff. If there’s one thing I know about zoo folk, they love surprise yummy treats, and the reception the donuts got was very gratifying! The MBCC has only a few permanent staff, supplemented by a handful of post-college interns each year. They do everything themselves, including mowing the lawn and caring for the two back-up generators. The interns live on site and are allowed to borrow the car to go into town just twice per week.

We were met by Michelle Smith, who gave us a fantastic tour of the facility and answered all of our questions. The first thing I learned was that the MBCC’s facility is a former minimum-security prison! Its clinic is located in the prison’s old dentist’s office and is fully equipped with an X-ray machine and a complete stock of medicines regulated and monitored by San Diego Zoo veterinarians. Michelle told us that they are able to contact a vet 24-hours per day, and one visits every six months to do a comprehensive check-up on all the birds. Most of the day-to-day medical issues are handled by the MBCC staff, and they’ve even had emergency procedures narrated to them over the phone by the Zoo’s veterinarians!

An intern prepares bird diets at the MBCC, a task I can relate to!

An intern prepares bird diets at the MBCC, a task I can relate to!

Although it was not breeding season for any of the birds, Michelle was able to show us their old but functional incubators. Eggs are transported from the nest to the incubator in a warm thermos full of millet seed! There is also an intensive care unit, like an incubator for premature human babies, where the young chicks grow. Alala and kiwikiu chicks are fed with a hand puppet so they don’t associate food with humans. Eggs that are hand-incubated are cared for intensively and every change recorded in detail. Rate of water loss is very important to monitor, and a machine called an Egg Buddy can even sense and record the heartbeat of the unborn chicks. Michelle explained the hatching process and some of the interventions that the staff has to do to help chicks hatch.

We peeked in on an intern making diets, a process that I am very familiar with! The birds eat mostly fruits and some insects. The alala get some mice because in the wild they would eat eggs and nestlings, though they eat much more fruit than other species of crows. The birds’ diets are put in bowls and served up on stainless-steel trays left over from the prison!

We saw a handsome adult male and three juvenile palila. In the wild, they eat only the pods and grubs found on the mamane tree and are very tenacious about their territory; that is, you can't move them from a dangerous area, because they'll just go back.

We saw a handsome adult male and three juvenile palila. In the wild, they eat only the pods and grubs found on the mamane tree and are very tenacious about their territory; that is, you can’t move them from a dangerous area, because they’ll just go back.

To actually see the birds, we walked down a dirt pathway past a (nonnative) pine grove. The air was surprisingly cool and fresh, due to our elevation on the northwestern slope of Mount Haleakala above the “cowboy town” of Makawao. The MBCC is on state-owned land, and the developed part is about eight acres. We got to enter “Forest Bird Barn I” to see three small forest bird species. I was interested to learn that the four species at the MBCC are from all around Hawaii, not just Maui itself.

The palila is a pretty little gray bird with a yellow head, found only on the high-elevation slopes of Mauna Kea on the Island of Hawaii. The puaiohi or small Kauai thrush is an un-prepossessing brown bird. Puaiohi are easy to raise, and are the species that new staff gets to work with first. The kiwikiu was called the Maui parrotbill until recently, when it was given a Hawaiian name. It’s a really cute little bird with a big bill reminiscent of a parrot’s.

Leaving the Forest Bird building, we went to look at the stars of the MBCC: the alala or Hawaiian crows, which are Extinct In The Wild. I capitalized that because I felt awestruck to get to see these birds. There are only 114 alala on the planet, 42 of which are at the MBCC, and the rest of which are on the Island of Hawaii at MBCC’s sister facility, the Keauhou Bird Conservation Center, with one exception. They are strikingly different from regular crows in size, and they made a variety of startlingly loud and odd vocalizations the whole time we were there.

It is considered the only Kauai forest bird with a stable population – even though that population is only 500 individuals. This bird is not being bred at the MBCC very much, because they are stable in the wild - however, observations of the wild birds are very important to ensure that the population is truly sustainable.

The puaiohi is considered the only Kauai forest bird with a stable population, even though that population is only 500 individuals.

The only alala not in Hawaii is Kinohi, who lives in California at the San Diego Zoo Institute for Conservation Research! He is extremely valuable genetically because his mother, a founder, has no other offspring and neither does he. If we can get babies from Kinohi, it will increase the genetic pool by a whole other crow. The problem is that Kinohe is imprinted and not willing to breed with female crows. Scientists at the Institute have been working to get semen samples from him, but Kinohi has been producing only low concentrations of sperm. (see post Alala: We’re Getting Closer.) Michelle was hopeful that they will one day be able to try artificial insemination with a sample from Kinohi. The odds are stacked against it, but I think that if anyone can do it, our scientists can!

I was very impressed by the facility, which was clean and neat. The staff was so kind and excited about having us, I felt like a VIP! It was really special to get to see the birds and hear all about them, especially since the MBCC is typically closed to the public. At the same time, it was sad to hear about the challenges that these species face across all the islands but heartening to hear the determination and enthusiasm shared by the staff. I would encourage anyone to visit during the MBCC’s annual open house if you find yourself on Maui early next November!

Susan Patch is a senior animal trainer at the San Diego Zoo.

1

A Dusty Day Off

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.

3

Have Bird, Will Travel!

Alala chicks settle in at the KBCC.

My time as an intern and seasonal research associate at the Maui Bird Conservation Center (MBCC) from 2006 to 2007 left quite the impression, so I jumped at the chance to return as a research associate in February 2012. It’s been a nonstop first six months as the newest staff member at MBCC, filled with trips to the Big Island, exciting experiences, and many hungry chick mouths to feed!

The Maui parrotbill breeding season was in full swing upon my arrival at MBCC, and the first chick I participated in raising for the Hawaii Endangered Bird Conservation Program was a tiny Maui parrotbill (kiwikiu). A month later, one of our kiwikiu breeding pairs produced another chick. The transfer of this kiwikiu chick to the Keauhou Bird Conservation Center (KBCC) on the Big Island presented the perfect opportunity for me to visit KBCC for the first time. Little did I know that I would be visiting the Big Island facility three times within my first five months!

Natalie carefully holds her precious cargo at the airport.

While I have relocated chicks before, this chick was my first transfer via airplane, and it came with its own unique challenges. Kiwikiu are altricial birds, which means that they are entirely reliant upon their parents for food, warmth, and protection when they hatch. Being a 13-day-old altricial bird weighing in at only 14 grams (0.49 ounces), the kiwikiu chick was unable to completely thermoregulate (maintain his own body temperature) by the day of his journey. A miniature heating pad inside his travel carrier provided him warmth throughout the trip. Constantly monitoring the bird’s well-being, making sure all the correct paperwork was present for security purposes, and the plane ride itself made the trip an exciting and nail-biting experience! All of the pieces fit together perfectly, and the short flight to the Big Island went smoothly.

The need to transfer an alala chick from MBCC at the end of June doubled as a chance to stay a bit longer at KBCC to assist staffers with their many alala chicks. Although the MBCC alala chick was a couple of days younger than the kiwikiu chick, she weighed nearly 10 times as much as the kiwikiu! The size of this not-so-little female helped her maintain body heat, and I actually focused on making sure she didn’t overheat during her travels. Frequently checking to make sure she wasn’t too hot resulted in drawing a fair bit of attention from the Hawaiian Airlines flight attendants and fellow passengers. All of this curiosity made an excellent opportunity for educating the public and sharing about the plight of the alala! This second visit to KBCC was filled with great experiences, from the chance to educate the public about the alala to the opportunities to learn about hand-rearing of various ages of chicks and managing the many alala breeding pairs.

A palila chick gets weighed at KBCC.

Less than two weeks later, staff members at KBCC had their hands full of hungry (and LOUD—ear protection required!) alala chicks and needed an extra pair of hands… another chance for me to visit the Big Island and get more experience! By this point, I had the chick routine down and jumped right in to help out. In addition to the large number of alala chicks, KBCC had successfully hatched a palila chick. When the opportunity arose to take a break from feeding the “mob” of alala chicks, I assisted in hand-rearing the young palila. Working with the palila chick allowed me to gain invaluable hands-on experience with this intriguing species.

It’s been an amazing start to my position here at MBCC, and I’m looking forward to many more years working with and learning about these remarkable and unique species!

Natalie Staples is a research associate at the Maui Bird Conservation Center, operated by San Diego Zoo Global.

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Hawaiian Birds: Pallets of Pellets

Palila specialize in eating the seedpods and flowers of the mamane shrub.

Special birds have special tastes… or more appropriately, they have special nutritional requirements.

Operating managed-care bird propagation centers in the relatively remote location of the Hawaiian Islands comes with its own set of challenges; one of the major challenges is providing our birds with the specialist diets they require to keep them healthy and productive. With the exception of the nene, all the focal species of the San Diego Zoo’s Hawaii Endangered Bird Conservation Program can be described as “softbills,” a loose, general term to describe birds that consume fruit, animal protein, and nectar, or somewhere within that spectrum. For instance, in the wild, `alala are recorded as consuming a wide variety of native fruits, invertebrates and their larvae, as well as the eggs and nestlings of other birds. As another example, Maui parrotbills primarily consume invertebrates and their larvae, as well as nectar and fruits.

A delivery of Kaytee pellets is unloaded.

While it may not be possible to replicate wild diets exactly, we aim to provide a representation of the wild diet that offers the same balanced nutritional composition, and this is where it becomes challenging. Catering to insectivorous tastes, we import mealworms and crickets from a company in Oahu, as well as laboriously culture waxmoth larvae in-house. These insects are particularly important for providing animal protein to stimulate breeding, build up a bird’s resources for egg-laying, and to fuel the growth of chicks. For `alala, we import mice (adult mice, “fuzzies,” and “pinkies”) from the mainland, which come shipped overnight on dry ice in insulated boxes. For the palila, which specialize in eating the seedpods and flowers of the mamane shrub, this means frequent treks up into the sub-alpine zone on the slopes of Mauna Loa and Mauna Kea to harvest the crucial food source.

A food pan prepared for 'alala.

`Alala are generalists, using that famous corvid intelligence to opportunistically forage for a wide variety of food types. One of the most effective ways to offer a generalist softbill a healthy diet in managed care is to provide softbill pellets as a significant proportion of their diet. These softbill pellets are an all-in-one meal with a balance of carbohydrates, fats, amino acids, vitamins, and minerals. This is where we are very fortunate to have the wonderful support of Michelle Goodman and the Kaytee Learning Center, the educational wing of the Kaytee animal nutrition company. For several years, Kaytee has generously donated its Exact Mynah/Toucan pellets to support our `alala program, as well as covering shipping costs from Wisconsin to Hawaii. This is no mean feat—with now over 90 `alala in the flock, that is a lot of beaks to feed, and the most recent shipment weighed half a ton!

Richard Switzer is the conservation program manager of the San Diego Zoo’s Hawaii Endangered Bird Conservation Program. Read his previous post, ‘Alala Season Begins with a Flurry.

1

Endangered, Elusive Palila

A palila perches on a mamane tree at the KBCC.

Over the course of three weeks in January and February 2011, staff members from the San Diego Zoo’s Hawaii Endangered Bird Conservation Program trekked up to Pu`u Mali, on the northern slopes of Mauna Kea (the tallest mountain on the Big Island of Hawaii). Our objective was to carry out some preliminary research on the small population of wild and released palila that reside at this location.

The palila Loxioides bailleui is one of the endangered Hawaiian honeycreeper species propagated at the Keauhou Bird Conservation Center (KBCC). The palila uses its strong, finch-like bill for opening mamane Sophora chrysophylla pods to obtain the immature seeds (its primary food source), and the species shares a close ecological relationship with the plant. The introduction of invasive ungulates such as goats, sheep, and cows ultimately led to the vast destruction of mamane forests, which in turn was responsible for decimating the palila population and reducing its range. Currently, the majority of the population is located on the south-western slope of Mauna Kea, but it is declining rapidly. According to the U.S. Geological Survey (USGS), the palila population has dropped from about 4,400 in 2003 to as low as 1,200 birds in 2010. Efforts to expand the palila population back to its historic range at Pu`u Mali have included experimental releases of captive-bred birds from KBCC, as well translocation of wild birds by the USGS.

A release aviary in the heart of palila habitat.

During our fieldwork, we had three goals:
1) To provide supplemental food at the former release site and then record data on the frequency of supplemental food consumption by both captive-released and wild palila. Since food abundance is a limiting factor in the palila distribution and population, we hoped that our previous release birds and even wild birds might return for supplemental food.
2) To conduct surveys of the Pu`u Mali area, in an attempt to get a population estimate of palila currently inhabiting the area, both captive-released and wild.
3) To conduct behavioral observations of wild palila with regard to habitat use, in the hope that this may provide additional, valuable information for application in captive management.

Research staff look for wild palila.

We spent a total of four hours each day observing the feeding stations and another four hours hiking around Pu`u Mali in search of both wild and release birds. Unfortunately, no palila were sighted at the feeding stations, and none of the supplemental food appeared to have been eaten. Luckily, there was a seasonal abundance of mamane pods, so perhaps the palila will be more eager to come in for supplemental food at other times of year, during mamane shortages. More discouraging was the result that scarcely any palila were even sighted at Pu`u Mali, with a maximum of four birds recorded by our team. Worst of all, we documented numerous signs of feral cats (another major threat to the palila) as well as signs of pigs, goats, and sheep.

The results from our field expedition seem to shed a grim light on the current status of the palila population at Pu`u Mali. Although the outcome was not what we would have wished, it did confirm that drastic conservation efforts are still needed to help save this unique bird species. Consequently, we feel even more motivated to continue our own palila recovery activities.

Kyle Parsons is a research associate at the Keauhou Bird Conservation Center.

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1st Hatch of Hawaiian Bird Breeding Season

Puaiohi #311 hatches

Greetings from the San Diego Zoo’s Maui Bird Conservation Center (MBCC)! We are starting to welcome chicks here at the MBCC for the 2010 breeding season. Over the summer, the Hawaii Endangered Bird Conservation Program (HEBCP) hopes to raise four different species of endangered native Hawaiian birds: the `alala (Hawaiian crow), Maui parrotbill, puaiohi (small Kauai thrush), and the palila. I am happy to announce that at 6 p.m. on Tuesday, April 6, we celebrated our first hatch of the season! The puaiohi chick is the 310th puaiohi to be hatched by the HEBCP and tipped the scales at approx 3.8 grams (0.13 ounces).

#310 at one day old

As a new staff member here at the MBCC, this is my first time participating in the breeding season, and I am especially excited to start off the summer with a strong and healthy chick. Hot on the heels of #310 (or should that be “hot on the hocks”?), puaiohi chick #311 hatched at approximately the same time the following evening (see photo). Here’s hoping for many more healthy chicks throughout the season!

Michelle Smith is a research associate for the San Diego Zoo’s Hawaii Endangered Bird Conservation Program. Read a previous post about the program, Nene Awareness Day.

Other Hawaii bird posts:
Training an Alala for an Important Job
Maui Parrotbill Hatches
Puaiohi: 300th Chick
Palila: From Hatch to Wild Home

0

‘Akepa: End of an Era (But What a Life!)

June 29, 2009, was a sad day for the staff of the Hawaii Endangered Bird Conservation Program: the Keauhou Bird Conservation Center (KBCC) experienced the death of the last remaining Hawaii ‘akepa Loxops coccineus in our care. (There are still ‘akepa in the wild.)

Although this marks the end of an era, it gave the program staff a chance to reflect on the remarkable life of this wonderful little bird. Affectionately known as “Studbook #3,” he hatched in May 1999 from an egg collected from the wild—one of the first potential founders of the captive ‘akepa flock. This means that he was just over 10 years old at the time of his death. Not bad for a little guy typically weighing in at 10.2 grams or 0.36 ounces. (When you weigh only 10 grams, those extra 0.2 grams count for a lot!) But this is relatively heavy compared to an ‘akepa chick, which weighs less than 1 gram (0.03 ounces) at hatch—one of the smallest passerine species to have been raised artificially from the egg, and quite a challenge for our team of hand-rearers (see post, A Small but Mighty Akepa).

Although Hawaii ‘akepa are not one of Hawaii’s most critically endangered bird species, having the ‘akepa flock in managed care has enabled us to develop and refine techniques that we hope to use in the recovery of their more endangered relatives within the subfamily of Hawaiian honeycreepers. The remainder of the managed-care ‘akepa flock were eventually released in 2007, in an initial attempt to reestablish a wild population in a restored patch of forest on the Big Island known as Kipuka 21 (see post, Kipuka 21: A New Home for Our Creeper and ‘Akepa). However, due to an accident in his aviary as a fledgling, which resulted in a major part of one of his legs being amputated, #3 was considered not fully equipped to lead a healthy life in the wild. Instead, he was destined for our education aviary.

It was amazing to see how he thrived in the captive environment on only one leg. “Thrived” is perhaps an understatement, because he was well known to crowds of school children visiting KBCC for his dazzling acrobatics, whether he was hanging upside-down from the roof of his aviary, or a flash of orange feathers hot on the pursuit of fruit flies and moths, only to elegantly alight on a perch with perfect balance on his one good leg (scoring 10 points from the Russian judge).

But ‘Akepa #3 is not the only bird that we believe has set a managed care longevity record for its species. Puaiohi #5, better known as Green Mama, is still going strong at the Maui Bird Conservation Center (MBCC) despite veterinary issues, having hatched in 1996. Puaiohi #9 is only a year behind her and is still siring offspring this season at the age of 12. Not to be outdone, Palila #11 has been laying fertile eggs at the grand old age of 13, while 12-year-old Maui Parrotbill #1 continues to chase females less than half his age.

It is not unusual for tropical bird species to lead long lives, since they do not experience the extreme challenges that the seasons bring for birds in temperate climes. Very often their annual reproductive rate is low, too—the antithesis of “Live fast, die young.” Furthermore, with a consistent, healthy food supply and veterinary care, birds in managed care frequently have the ability to outlive their wild counterparts. Of course, these smaller passerines cannot compete with the larger species, such as corvids, which are renowned for their longevity. Consequently, the Hawaii Endangered Bird Conservation Program honors undoubtedly goes to Kalani, ‘alala studbook #27. At the ripe old age of 28, Kalani is the old man of the program. Although time has certainly mellowed him, he is reputed to be a grumpy old man, at that.

Richard Switzer is the Conservation Program Manager for the Institute for Conservation Research’s Hawaii Endangered Bird Conservation Program.

Read Richard’s previous post, Naming ‘Alala Chicks.

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Hawaii Bird Program: Open House

captionThe Keauhou Bird Conservation Center (KBCC) welcomed visitors on December 6, 2008, to its annual open house. Over 80 people came to see some of the most endangered birds in the world and learn about our role in their recovery efforts.

The visitors learned from the staff about the main problems that are affecting the wild populations of endemic Hawaiian birds. These are introduced predators (mongoose, rats), introduced diseases (pox, malaria), and habitat degradation/loss (much from feral sheep, goats, and pigs).

There were thought to have been 140 species of birds in Hawaii when Europeans first arrived on the islands. Today, one-half of those are extinct. Of the remaining, about one-half are critically endangered, and many of them are presumed extinct.

captionDuring the open house, our guests were given the opportunity to see Hawaiian crows (‘alala), Maui parrotbills, palila, puaiohi, Hawaiian ‘akepa, and elepaio. Even a pair of wild nene made an appearance.

Few people get a chance to see these birds. The ‘alala are extinct in the wild and there are currently 60 at the KBCC and our sister facility, the Maui Bird Conservation Center. The other species at the KBCC are critically endangered and live in hard-to-reach habitats. For example, Maui parrotbills are found in the remote high-elevation rain forests of Maui, and currently less than 500 remain. Puaiohi live in the Alaka’i Wilderness Preserve of Kauai and prefer habitat with steep ravines. The wild population may be as low as 200 individuals.

captionThe visitors were given a look at our kitchen to see what ‘alala, palila, and puaiohi at the KBCC eat. The kitchen contains many foods you might find in your own kitchen, such as apples, melons, and frozen vegetables, and many others you wouldn’t want to find there, like frozen mice, mealworms, and dried fly pupae!

A video allowed the visitors to see some of our field activities including collecting eggs from wild nests and releasing hand-reared birds as well as parts of the incubation and hand-rearing process that very few get to witness. Everyone learned about the tremendous effort put into each egg and chick and got a peek into a hand-rearing lab through a viewing window.

The grand finale of the tour was the ‘Alala Education Aviary, which is home to three ‘alala (Lilinoe, Lokahi, and Kekoa). Many were surprised at how big the birds are; they are larger than many of the crows found on the mainland. Visitors were also even more surprised to find out that such a large animal only weighs about one pound.

We also had the pleasure of hosting four artists from the Big Island. Jack Jeffery, Emily Herb, Elizabeth Miller, and Margaret Barnaby displayed and sold their bird-inspired artwork as the open house guests snacked on refreshments and had the opportunity to ask questions and talk to the staff.

The open house not only gave the public a chance to learn about our facility, but it also gave our staff a chance to share our excitement and passion for conservation of the rare and wonderful birds we work with daily.

Sara Bebus is a research associate at the San Diego Zoo’s Keauhou Bird Conservation Center.

Visit the Hawaii Endangered Bird Program blog section

3

Palila: From Hatch to Wild Home

PalilaAn endangered palila pauses at the open hatch of its release aviary, taking one last glance at its surroundings before taking its flight to freedom (see image at right). This palila is one of seven that were airlifted by helicopter in early March 2009, up to a site known as Puu Mali, on the northern slopes of Mauna Kea, Hawaii’s tallest volcano. All seven palila were hatched in previous breeding seasons at the Keauhou Bird Conservation Center (KBCC) as part of the Hawaii Endangered Bird Conservation Program’s ongoing effort to restore the palila population and thereby help to prevent the species’ extinction.

Up at Puu Mali, the program’s field crew eagerly anticipated the birds’ arrival and had prepared two release aviaries. For just over two weeks, the palila remained inside these release aviaries while orientating themselves to the mountainside that was soon to become their home. Up at an altitude of 8,000 feet (2,400 meters), Puu Mali experiences surprisingly bitter, cold nights, so this was also an opportunity for the palila to acclimate themselves to the novel temperatures while being fueled by the unlimited food provided by the field crew.

A released palila foraging in the mamane canopy, with bands and radio transmitter visible.The palila Loxioides bailleui is endemic to the Big Island of Hawaii. It is restricted to the dry, subalpine scrubland of Mauna Kea, which supports forests of mamane trees. The mamane is a Hawaiian endemic tree belonging to the pea family that produces seedpods that are a vital food source for the palila. Not only do the palila primarily eat the “beans” of the mamane, but the moth caterpillars lurking inside the pods are thought to supply a valuable source of protein, particular for palila nestlings.

But the mamane forests, and therefore the palila, are under threat from feral cattle, sheep, and goats. These ungulates browse on the mamane saplings, preventing the new generation of mamane trees from establishing, and also strip bark and kill mature trees. The palila’s habitat has become so fragmented that the birds lack “corridors” that would enable them to migrate seasonally around the mountainside, following the fruiting of seedpods at different elevations. Additionally, feral cats and black rats have a major impact on nesting success as nest predators; it is thought that feral cats may even be causing a shift in population demographics, by depredating mature females incubating on the nest. Fortunately for the palila, the majority of its remnant habitat lies above the “mosquito line,” now estimated to be at an elevation of 5,000 feet, so avian malaria has impacted palila less than the many other critically endangered (and recently extinct) species of Hawaiian forest bird.

The majority of the palila population is found on the southwestern slopes of Mauna Kea, but we have been undertaking experimental releases of palila at Puu Mali, within the historic range of the species. In tandem with the releases, a team from the U.S. Geological Survey Biological Resources Division has translocated several cohorts of palila from the southwestern slopes of Mauna Kea. Preliminary evidence suggests that Puu Mali is able to support a population of palila long-term, despite only limited protection of the habitat from exotic predators and ungulates. Furthermore, released captive-bred birds appear to act as a “magnet” for the translocated flock that otherwise appears to have a strong fidelity to the southwestern slopes.

On Wednesday, March 18, 2009, the hatches of the release aviaries were opened for the fourth time since 2003. Within an hour, all seven birds were busy foraging in the canopy of mamane trees. As hoped, this spring appears to have provided a plentiful crop of mamane seedpods and flowers, with the result that the released birds have shown very little interest in returning to the open aviaries where supplemental food continues to be provided. In fact, this has enabled the released birds to forage far and wide, up to six miles (10 kilometers) away from the release site. This is presenting quite a challenge for the field crew who continue to monitor the success and survival of the birds by the use of radiotelemetry: long hikes up the cinder scarp and bumpy drives around the mountainside are a daily activity.

At the moment, the field team reports that five birds are being observed daily, alive and well, while a sixth bird has been proving more elusive to monitor. Unfortunately, the seventh bird was found dead a few days after release, apparently the victim of an introduced predator…a sad reflection of the ongoing threats to the palila population.

Meanwhile, news has just reached the field team that the palila flock at the KBCC has just started nest building. We now intend to intensify our release effort, with the goal of establishing a viable population at Puu Mali, so the program’s biologists eagerly await this season’s hatching of chicks, future recruits for release into the mamane forests on the slopes of Mauna Kea.

Richard Switzer is a conservation program manager for the San Diego Zoo’s Institute for Conservation Research.

Read a previous blog about palila.
Read more blogs from Hawaii Endangered Bird Conservation Program staff.

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Preserving Hawaiian Bird Cell Lines

Palila cellsThere is another side to the Hawaii Endangered Bird Conservation Program that happens at the San Diego Zoo’s Beckman Center for Conservation Research. Our Genetics Division has preserved the genetic material of many Hawaiian birds in the Frozen Zoo®, a large collection of frozen samples, including thousands of cell lines. Most of the cell lines in the Frozen Zoo are grown using a piece of skin tissue from a small biopsy, which can be taken during an animal’s regular veterinary exam.

This is not as feasible for birds due to their fragile skin and small size, so our chance to obtain tissue from Hawaiian birds comes after they have died. Usually we receive an eyeball or a section of trachea. Then that piece of tissue is diced up into tiny pieces and put into an enzyme that digests the connective tissue, freeing up the individual cells.

Andrea places prepared flasks in an incubator.Once the diced tissue has been “digested” by the enzyme for a few hours, we put the remaining material in a tissue culture flask with the appropriate cell culture medium, which is a liquid containing the nutrients cells need to survive, and place them in a heated incubator. We will “feed” the cells every few days by emptying the flask and putting new medium in. If all goes as planned, the cells will attach to the bottom of the flask and will proceed to divide until they take up all the space. When there are enough cells, we will apply another enzyme, called trypsin, that breaks up the bonds holding the cells to the flask so they float freely, allowing us to move the cells into new, larger flasks for continued growth. Eventually the population of cells has doubled several times. It typically takes around a month for this to happen; tissue from younger animals tends to grow more rapidly than from aged animals.

Preserved cells in the Frozen ZooThen it’s time to put them in the Frozen Zoo. Ordinarily, cells die when frozen because the water they contain forms sharp ice crystals, tearing the fragile cell membranes apart. To inhibit crystal formation, we add a chemical called a cryoprotectant (in this case, dimethyl sulfoxide) to the cells. The cells are then placed into several tiny one-milliliter vials and put in a computerized cryogenic freezer that lowers the temperature at a carefully controlled rate. A little over an hour later the cells have reached 80 degrees below zero, and they’re ready to be put into boxes for storage in the Frozen Zoo, where liquid nitrogen keeps them frozen at an even colder temperature: 196 degrees below zero. At any time, they can be pulled out of the liquid nitrogen, thawed, and put back into cell culture medium and they will continue growing! Cells can be kept frozen for many years in this suspended but living state; nobody knows exactly how long because the technology has only been around for a few decades. The Frozen Zoo thus provides a self-renewing source of DNA for researchers studying the genetic makeup of particular species.

Currently there are cell lines from over 45 Hawaiian birds in the Frozen Zoo, including nene, ‘alala, Maui parrotbill, puaiohi, palila, and Hawaii creeper. Sadly, in 2005 the po’ouli became the first extinct species represented in the Frozen Zoo. It will doubtless not be the last, but thanks to all the people working hard on this project, there is reason to hope that no more Hawaiian birds will end up on that tragic list.

Andrea Johnson is a research technician for the San Diego Zoo.