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mamane

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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.

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Gorse Crisis: Making Way for Native Plants

Amanda and Amy remove some invasive gorse.

It goes without saying that wild bird populations are dependent upon good quality, natural habitat for foraging, nesting, and escaping from predators, to survive. The native forest birds of Hawaii face a multitude of threats, and the loss and degradation of habitat is one of the primary reasons for the decline of these unique species. Invasive plants and animals are taking over and destroying their forest home. For example, introduced pigs and deer browse on the plants and churn up the forest floor in search of food, killing native seedlings and providing an opening for faster-growing, invasive plants to gain a foothold in native environments. In many cases, in order to restore native plants, we must first remove the nonnative ones.

Gorse in bloom. Note the nasty thorns!

Gorse is one such invasive plant common in parts of Maui as well as the Big Island. The dense, prickly shrub, introduced to Hawaii in the 1800s, originated in western Europe, where it is still valued as a living fence for livestock. In addition to its aggressive tendencies, gorse grows much more quickly than most of Hawaii’s indigenous species and easily out-competes them for space and sunlight. Today, gorse is considered to be a serious weed, and all attempts to eradicate it have failed. The International Union for Conservation of Nature recognizes gorse as one of the top 100 worst invasive species in the world; so far, the best-recognized method for combating gorse is to plant faster-growing plants that are able to shade out sun-loving gorse.

At the Maui Bird Conservation Center, we have our own gorse crisis. Fellow intern Amy Kuhar and I are tackling our gorse invasion head on. Because the gorse defends itself with innumerable thorny spikes, we have started by taking down different sections of the weed in phases. We start by trimming back branches with loppers, then we use hand saws to sever each plant at the base. When possible, we also dig out the roots. The process is very time consuming, and we have worked many hours on the project. “Painstaking” would be the best adjective to describe the effort, because the gorse fights back, and after an afternoon of gorse eradication, we are left with innumerable itchy, tiny thorns embedded under the skin of our hands, arms, and legs!

A mamane sapling planted at the MBCC.

In addition to rescuing resident koa, ‘ohia, and mamane trees choked by gorse around the facility, we also began the process of replacing the invasive vegetation with native plants such as `a`ali`i and more mamane. In one area alone, we have planted more than two dozen new trees and are excited to see them growing over the newly cleared area! But the battle does not end there. One of gorse’s greatest weapons is its massive production of seeds, which can lay dormant in the soil for many years. As the older gorse is cleared, the seeds rapidly germinate, and within a few weeks there is a bed of new gorse seedlings. To stay on top of these, we must spray with herbicide to prevent another new invasion, allowing the native plants to flourish.

Hopefully, future interns will continue to clear gorse to make way for more native planting, all of which will someday create habitat for our wild, feathered friends such as the `amakihi. We hope the native plants will also eventually provide a source of perching, nesting material, berries, and seedpods for the birds in our care.

Amanda Maugans is an intern at the San Diego Zoo Maui Bird Conservation Center.

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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.

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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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Palila: From Hatch to Wild Home

Palila

Palila

An 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.

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.