As Aged Po`ouli Dies, Authorities Rethink Plans to Save Birds in Captivity

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About 4:20 on the afternoon of Thursday, September 9, 2004, a team of biologists who had set out to capture one of the rarest birds in the world snared their prey: a po`ouli, one of the last three individuals of its species (Melamprosops phaeosoma) thought to survive in the rain forests of East Maui.

For the next 11 weeks, the hopes of hundreds of researchers, thousands of birders, and tens of thousands of people in the general public who track the march of endangered species into recovery or oblivion were pinned to this tiny bird, which tipped the scales at less than an ounce.

Although it was missing an eye and thought to be at least eight years old, judging from the last time anyone had seen a po`ouli show signs of breeding, it seemed in overall good health. And for eight weeks, the government scientists and private aviculturists who were at the helm of the recovery program directed at this species were optimistic. The bird had a healthy appetite, and biologists in the field were frantically trying to capture at least one of the two other remaining wild po`ouli in hopes of establishing a breeding pair in captivity.

After two months in an aviary at the state’s Olinda facility for propagating endangered birds, the po`ouli was described as not being “its usual perky self.” It had been placed on an anti-fungal medication and was also being given a broad-spectrum antibiotic, apparently as a precautionary measure. A few days later, after a blood test for malaria came up positive, anti-malarial drugs were administered, as were fluids and B vitamins.

In the middle of the bird’s obvious struggle, staff with the Zoo Society of San Diego pulled its tail feathers, in hopes that the bird would grow new “blood feathers” that in two weeks’ time could be “harvested” and added to the zoo’s cryogenic library of tissues from endangered species.

Close to midnight on November 26, 11 weeks, one day, and six hours after the bird was found in the mist nets of Hanawi, it died. Since then, efforts to capture the remaining po`ouli have been put on hold, although the search for them continues, so scientists can know if either one is still alive. One was last sighted in December 2003 and the other was last seen in February 2004. The biologists are also spending time in other areas of East Maui forests on the ever so slight chance they might find po`ouli that have so far managed to escape detection.

An Auspicious Start
With the po`ouli’s known population now down to two, and even that number based on sightings no more recent than a year ago, it might well be that the captive po`ouli was the last of its species. Here is a report of its final days, based on documents obtained from the U.S. Fish and Wildlife Service:

The bird, which was caught after flying into a mist net, was gently carried to a holding tent that had been set up near its home range — in this case, Home Range 2. With dusk less than two hours away, the bird was held overnight in a small, cloth-covered cage. Shortly after 7 a.m. Friday, a helicopter transported the bird from Hanawi Natural Area Reserve, in East Maui, to the Maui Bird Conservation Center at Olinda, on the north slope of Haleakala National Park.

At Olinda, the bird was placed into the care of personnel with the Hawaii Endangered Bird Conservation Program of the Zoo Society of San Diego, which runs the captive propagation facility under contract to the state Department of Land and Natural Resources. By six p.m., Alan Lieberman, who heads up the zoo’s Hawai`i operations, reported that the bird “seems to be adjusting. It is eating mealworms, waxworms, olapa berries, and perhaps other items from the food pan. (It is difficult to tell when the bird does the hully-gully in the food dish.)”

In an email broadcast to staff with the DLNR, U.S. Fish and Wildlife Service, and other agencies, Lieberman said, “we won’t change its immediate cloth cage environment for several days after which it will go into a similar dimension cage without the cloth, then several days later we’ll consider the full aviary… Next week, depending on the bird’s behavior, we’ll give the bird a physical to include blood for sexing and the etc. The etc. will depend on how much blood we can get without compromising the bird.”

‘A Real Survivor’
In its report on activities at both the Maui and the Big Island captive propagation centers for the week ended September 12, the Zoo Society of San Diego, which runs both centers, said the po`ouli continued to do well “in a ‘howdy’ cage lined with cloth… The bird only has one eye so its ability to negotiate an aviary with large flight distances will be compromised.” Kirsty Swinnerton, one of the field biologists who helpedl capture the po`ouli, had noticed at the time of capture that the bird had just one good eye. Earlier pictures of the bird, caught in 1997, showed that the bird had both eyes then, Swinnerton noted in an email response to a question from Marilet Zablan of the Fish and Wildlife Service. The fact that the bird had managed to survive such an injury was seen as a good omen by Swinnerton. “Quite unbelievable that this little bird could have survived a traumatic injury like that, hopefully a real survivor.”

Already, though, the bird seemed to be losing ground — or at least weight. By September 15, Lieberman reported that the bird “is doing well. It is holding its weight between 22 and 23 grams. We’d like to see it get back to its field weight (25-26 grams).” Still, he added, the bird seemed to be eating well, chowing down on live food (the worms) as well as olapa berries. And “its behavior is steady. When the bird reaches its field/capture weight we’ll arrange for a physical exam to include a blood sample to confirm sex.”

The weekly reports from the Hawaii Endangered Bird Conservation Program dated October 3, October 10, October 17, October 24, and October 31, indicate that the po`ouli “continues to do well.”

The first hint of trouble comes in the November 7 report. “The po`ouli was moved from its howdy to a larger aviary to accommodate the pending capture of a second bird. The po`ouli is not as ‘comfortable’ in this new set-up. The bird lost weight (26 to 23 grams) and has been moved back to its previous howdy-cage accommodation. The bird has now been in captivity for 59 days.”

On November 12, day 63, Lieberman emailed a “po`ouli update” to staff with the DLNR and the Fish and Wildlife Service. “The po`ouli has been in captivity now for 63 days. The last few days, the bird has not been its usual perky self. In consultation with Dr. Pat Morris, the bird was started on itraconazole (anti-fungal against Aspergillosus), but back in its original ‘howdy’ cage (restricts unnecessary movements) and given a heat lamp for the evening hours. A wide-spectrum antibiotic was initiated as a precaution.”

The aspergillus fungus is ubiquitous in soil and almost all birds, wild or in captivity, are exposed to it. When birds are stressed or in poor healthy, they are most vulnerable to infection, which can be deadly.

By November 14, things had taken a turn for the worse. “Although stable, this bird is not behaving ‘normally’,” according to the weekly Hawaii Endangered Bird Conservation Program report. The po`ouli “continues to favor the heat lamp and appears fluffed and is not as alert as it was during its first 60 days in captivity. It is on broad spectrum antibiotic and anti-fungal therapy… Fluids and B [vitamin] complex were administered.” The situation was sufficiently grave to warrant a veterinarian, Dr. Beth Bicknese, flying out from San Diego on November 7.

Diagnosis Malaria
From the blood samples drawn in September, Sue Jarvi, a professor of biology at the University of Hawaii at Hilo, and avian malaria expert Carter Atkinson of the U.S.G.S. Biological Research Division in Volcano, Hawaii, determined that the captured po`ouli was infected with malaria. Most probably the infection occurred while the bird was in the wild, Atkinson wrote in an email to Lieberman. “Otherwise, you would have likely seen some clinical signs early on.”

Atkinson and others had done tests for the presence of the malaria parasite in blood of birds at Hanawi about a decade earlier. He continued, “The limited surveys that we did … did pick up a few malaria infestations… During Thane Pratt’s work on `Akohekohe [crested Maui honeycreeper] and parrotbills, he recorded seasonal presence of mosquito larvae up to about 5300 feet. Hence, maybe it’s not a complete surprise that a bird this old was possibly infected on its home range.”

The November 21 weekly report notes the visit of veterinarian Bicknese. She confirmed the diagnosis of malaria “and the bird is being treated with chloroquine and primaquine. Weight is low but stable. Heat is being provided via heat lamp and external heater in aviary. Fluids are being given daily with treatment. Itraconizole will continue to be part of [treatment]. Tail feathers were removed to promote blood feather regrowth which will be harvested in 12-14 days for attempts to grow cells by CRES Genetics Lab. Although the bird is struggling, all attempts are being made to address its infection through treatment and environmental support.” (The San Diego Zoo’s Center for the Reproduction of Endangered Species — sometimes called the Frozen Zoo — preserves frozen genetic material from endangered species.)

Five days later, the beleaguered bird died. The November 26 weekly report of the San Diego Zoo took brief notice of the event: “Mortality: Po`ouli found dead at ~11:30 p.m. on Friday night, 11/26/04.” In a November 26 email Lieberman broadcast to all who had been closely involved with the po`ouli, he wrote: “This is to inform you that the po`ouli has died. The critical tissues are being prepared for shipment to CRES early this morning (Saturday)…. The body will be held for necropsy.”

‘An Interesting Case’

On November 30, Bruce Rideout, a veterinarian with the San Diego Zoo, conducted a necropsy on the po`ouli. “This is an interesting case,” he wrote in his report. “The immediate cause of death is multifactorial,” with poor body condition, kidney and liver necrosis, and growth apparently resulting from Aspergillus infection among the contributing factors. Other conditions in the bird’s body suggested “that this was an aged, and likely geriatric, bird,” Rideout continued. “It is therefore possible that old age was a major contributing factor in the bird’s initial decline.” Aspergillosis “was likely a later event … but still would have significantly contributed to the bird’s final decline.”

The malaria seems not to have played a major role in the bird’s demise. “Although most native Hawaiian forest birds do not tolerate Plasmodium [malaria] infections well, this individual seems to have been surviving with a low-level parasitemia for some time,” Rideout wrote. “Surprisingly, there was not gross, cytologic [cell], or histologic [tissue] evidence that the infection was causing clinical problems.”

What’s Next?
Scott Fretz, chief wildlife biologist for the Delpartment of Land and Natural Resources, said that as of mid-February, no decision had been made as to whether to continue captive-propagation efforts for the po`ouli. Still, “the crews are continuing predator control in east Maui and searching for the birds.”

Agencies involved in the effort were scheduled to get together in late February to “lay out what we know and don’t know,” he said, with a decision expected sometime this month.

“The lesson right in front of our faces is to make sure we don’t get in this same situation with the Maui parrotbill, palila, and other birds” whose numbers are low, he continued. “Captive propagation has helped the puaiohi [small Kauai thrush] and the nene — whose numbers were down near 30 at one point,” he said. “It’s do-able but does take a lot of focused effort and money.”

Fretz noted that the state gets funds for much of its habitat protection work through the Natural Area Reserves partnership program, “but we’re looking at federal cuts for the more intense single-species work, such as captive propagation. Our funds for field crews also come from federal grants. Those are at risk now, too.”

— Patricia Tummons

Volume 15, No. 9 March 2005

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