A Fighting Chance 
Tuesday, September 1, 2009 at 11:00
City Parrots in Amazona vittata - Puerto Rican Amazon, Captive breeding, Conservation, Release

An ambitious recovery project is giving the Puerto Rican parrot, one of the world’s ten most endangered birds, a new lease on life. Images: Marie and Mark Stafford

Taino Indians called the Puerto Rican parrot iguaca, a name that captures the essence of its raucous call, a combination of squawk and car horn about as soothing as the sound of fingernails on a blackboard. “Once you hear it, there’s no other call out here like it,” whispered Tom White, a U.S. Fish and Wildlife Service biologist with the Puerto Rican parrot recovery program. We had been huddled in this canvas blind for more than three hours, looking at the jungle through a tiny tinted window. Forty yards away, lashed to a broken trunk of a palo colorado tree, was a nesting box constructed of a PVC drum with a four-foot-long, periscope-shaped entryway. We heard parrots around us. Guawk, guawk. Guawk, guawk. The sound grew louder and then receded into the forest. “Messin’ with us,” White muttered.

Our location was about 2,000 feet above sea level, 30 miles southeast of San Juan, in the Caribbean National Forest, known as El Yunque. We had climbed a muddy trail by headlight to the two-note serenade of coquís, the various species of tree frog known as the symbol of Puerto Rico, and slipped into the blind at first light. The purpose was to monitor the progress of one of only four nesting pairs of wild Puerto Rican parrots.

The parrot has been called one of the ten most endangered birds in the world. “Don’t ask me what the other nine are,” said White, as if to emphasize the futility of comparing endangerment when so many birds, including several parrot species, are on the verge of disappearing in the wild. The Puerto Rican is certainly the rarest of the 30-plus Amazona parrot species. Despite fierce efforts to protect a wild flock and reintroduce captive parrots, the El Yunque population has hovered below 50 for decades.

The birds battle their twin nemeses: red-tailed hawks and (even in the tropics) hypothermia. “This is not the area that they chose as a refuge; this is what they were left with,” White said of their high-altitude redoubt. “This is the rainiest, most humid part of Puerto Rico. Chicks that fledge either during or before a major rainfall event have a much higher mortality rate than chicks that fledge during drier periods. If we stopped management efforts with this particular population, in a matter of years it would probably be gone, because there are so many environmental factors working against it. That’s why it’s imperative to establish additional populations in Puerto Rico.”

And that is exactly what has happened. With the release of captive birds in Río Abajo, at the opposite end of the island, the Puerto Rican parrot finally has a chance to expand its territory and increase its numbers. “If the parrot is to survive,” said White, “its future depends on new reintroductions elsewhere on the island.”

Here in El Yunque, White and his colleagues climb to these remote nests at least three times a week during nesting season. We timed our visit this particular morning to coincide with the parents’ first forage run of the day. “What you don’t want to do is disturb the nesting pair,” White whispered. At the moment, they were up to a mile away, gorging on the ripening, fat-rich berries of the sierra palm. The nest was wired with an infrared camera and microphone. On a tiny solar-powered monitor, we watched two chicks huddle together, big heads bobbing awkwardly as they clutched like wrestlers. When the more developed of the two began to beat its stubby naked wings, the speaker buzzed with wing beats.

The monitors alert biologists to problems in the nest. “If one chick hatches late and is always behind, it tends to get further and further behind,” White explained. A week earlier White’s colleagues realized that a third chick in this nest box was missing feedings. They rescued it and took it to the nearby aviary. “When they have three, four chicks in the nest, the last one to hatch usually doesn’t make it. When you’re dealing with a large population, it’s not a problem. When you’re dealing with a critically endangered species, every single individual is important.”

The hungry youngsters on the monitor began to complain. Harsh calls of adult parrots surrounded us, growing louder, fading, and then growing louder again. A series of guawks built to a piercing level until an emerald male with a red forehead and blue flight feathers—surely the rarest wild creature I had ever seen—suddenly alighted on a branch near the nest. It still wore bands and a radio from its release (in either 2001 or 2002). Seconds later the female swooped in and dropped down the periscope. The male briefly chased a pearly-eyed thrasher that ventured near and then dropped down the tube after the female. On the monitor we watched as each parent thrust its own beak down that of a chick and violently regurgitated, as though feeding with a jackhammer. Within minutes the chicks’ crops bulged. Then the adults climbed out and, with a series of harsh guawks, flew off.

The parrot once ranged throughout Puerto Rico, including the outlying islands of Mona, Culebra, and Vieques, and as far east as St. Thomas in the U.S. Virgin Islands. When Columbus landed in 1493, scientists guess, as many as a million lived in a variety of wet and dry forests and nested in the natural cavities of old trees. With Spanish settlement, logging, and farming, the birds dwindled. By the early 1900s, a few years after the United States took control of Puerto Rico, 80 percent of the main island’s forests had vanished. Loggers even high-graded rugged El Yunque, removing the mature trees the parrots needed for nesting. Parrots survived in only five isolated pockets.

As habitat became scarce, so did the parrots themselves. Farmers shot them as crop raiders. Collectors robbed nests for the pet trade. Hurricanes in 1899, 1928, and 1932 decimated whole flocks. By 1940 the bird clung to life only in El Yunque. Even as the parrots joined the federal endangered species list in 1967, their downward slide continued until 1975, when the population bottomed out at 13 birds, with as few as three breeding pairs.

Since the 1950s, with the decline of sugar production and the waning importance of agriculture, forest has reclaimed much of rural Puerto Rico. Unfortunately, the parrots didn’t respond, partly because there were still few old trees to form nesting cavities and the areas where the birds resided were isolated from other suitable habitat. So in the 1970s biologists began rehabbing natural sites and erecting artificial nesting cavities. The work paid off: Parrots chose the boxes and improved cavities over trees. The population grew to nearly 50.

But disaster stalked the birds. In 1989 Hurricane Hugo whipped eastern Puerto Rico with winds of up to 138 miles per hour. Of 31 species of trees in the nesting area, specimens of only eight remained standing. Gone were most of the sierra palm, tabonuco, cupey, maricao, and camasey—sources of the parrots’ favorite foods. Fruits of standing trees had been knocked to the ground. Many parrots were blown away or starved. The wind-damaged forest provided little shelter, and red-tailed and broad-winged hawks picked off many of the birds. Parrot numbers dropped by half.

Fortunately, wildlife managers were having success raising parrots in captivity. A federal aviary in El Yunque was started in 1973 with birds hand-raised from eggs taken from wild nests. Two years ago the birds were moved to a new aviary in the foothills nearer Río Grande, providing drier, more habitable conditions. The captive flock has grown to more than 90.

Cage-raised chicks are sometimes slipped into the nests of wild parents. Wildlife managers have also reintroduced live adults, beginning in 2000 with 10 parrots outfitted with transmitters. Additional reintroductions followed. A captive-reared male, released in 2001, paired with a wild female, and they fledged two chicks in 2004.

The current parrot recovery plan, approved this year, sets a goal of two self-sustaining and growing flocks. Wildlife managers have a long way to go. The wild El Yunque flock has hit a wall. The most recent count (spring 2009) put the population at only 25 to 28, based on a census by researchers in treetop platforms. Tracking the radio-collared birds provides a way to verify the accuracy of the counts. “They’re detecting about 98 percent,” said White. “We don’t believe there’s a whole bunch of birds out here we don’t know about.”

The steps to launch a second wild population began in 1993, when biologists established another captive flock at a new aviary. Located 60 miles west of El Yunque in the karst hills of Río Abajo Commonwealth Forest, the Jose L. Vivaldi Memorial Aviary is vital for two reasons. First, it harbors a second captive flock a safe distance from the first, so it’s unlikely that all the birds will be wiped out by a hurricane or epidemic. Second, the drier environment should increase the odds for captive and released birds. Said White, “For the long-term viability of this species, the karst area is going to be critical.”

The road to the aviary winds up through rugged limestone hills draped with cascading plants. When wild parrots lived in these hills, some reportedly nested in natural cavities in the cliffs. “The real bosses here are the birds,” explained aviary manager Ricardo Valentín. “We pay a lot of attention to what they tell us.” You wouldn’t guess by Valentín’s Helly Hansen raincoat and high rubber boots, but Río Abajo’s rainfall is half of El Yunque’s. The parrots have responded to the combination of drier climate and Valentín’s constant doting. The Río Abajo aviary has built a captive flock of about 140 parrots. I had wanted to accompany Valentín as he checked nests. No way, he said. “We have an unwritten contract with the birds about what is permissible in the breeding areas during the breeding season, and they expect it to be followed to the letter,” he warned in an e-mail. “This means that only employees trusted by the parrots can enter the breeding areas and only at certain times of the day. The parrots react violently and viciously to intruders around their nests and have been known to abandon chicks and break eggs if provoked.”

The burgeoning captive flock has provided members for the much-needed second wild population. Release candidates were toughened up through flight conditioning, explained Iván Llerandi, the release project’s leader. And because hawks in Río Abajo, as elsewhere, were too widespread to control, the parrots went through raptor boot camp, a four-step process developed at El Yunque. First they heard a hawk’s whistle call as a hawk silhouette passed over their cage. The aviary staff noted which birds froze or hid, and which continued to squawk and eat.

A bit later the parrots heard the same call as the silhouette again flew overhead. Suddenly a trained red-tail attacked the parrot cage. Then, in full view of the Puerto Rican parrots, the hawk was set loose on a Hispañola parrot. (The closely related but more common and expendable Hispañolas are often used as stand-ins for their Puerto Rican relatives when aviary managers want to check for the presence of pathogens or try out a novel food.)

The first time they tried the attack, Valentín explained, the parrot attacked the hawk on its perch. “The hawk had to be rescued.” Finally, the traumatized Puerto Rican parrots were once again exposed to the hawk whistle and silhouette. This time, nearly all froze in place, hid, or scanned overhead for danger.

In November 2006, 22 parrots fitted with radio transmitters were set loose. Llerandi and his staff set out feeders to keep the newly freed birds near their caged cohorts. Radio telemetry monitoring during the first week told a sobering, but not entirely unexpected, tale. Six birds died almost immediately, picked off by red-tailed or Puerto Rican broad-winged hawks (also an endangered species). “The birds that clumped together around the aviary survived,” Valentín said. “The ones that went their own way didn’t survive.” Parrots find protection in a flock, with plenty of eyes to the sky.

When I visited in spring, survivors of the release continued to hang around the aviary, but as the flock size increases, the birds are slowly extending their range. (Already six free birds had mated and laid eggs, producing six hatchlings.) As we toured the facilities, two of the new releases, their transmitters visible, perched in a tree above the cages. “When I am checking the nests the birds get really upset, and the released birds, they come to see what I am doing,” said Valentín. “They interact a lot.”
Twenty-four birds were released in 2006 and 21 in 2007, and the aviary released 18 additional birds in 2008. The researchers plan to release between 16 and 18 in December. As of July, nine birds have survived from the first release, 17 from the second, and 15 from the third. “I have had the extreme fortune to see a flock of between 15 and 20 birds fly over the aviary, probably one of the largest flocks seen in the last 40 years,” Valentín wrote in an e-mail. “The fact that the birds have been flocking appears to have had a protective effect, so losses to predators have been happily lower than last year.

“People are so proud of the parrot and like the parrot,” continued Valentín. That is important on an island like Puerto Rico, where more than 4 million people are spreading from the seashore up the valleys and into the hills and mountains. “The parrot has strength of laws that protect it, so it can be used to justify protecting areas that otherwise would be covered with cement,” says Valentín.

Puerto Rico’s Río Grande, which includes El Yunque rainforest, is the municipality most associated with and most boastful of its Puerto Rican parrots. One is emblazoned on its flag. Two appear on the city’s coat of arms. Along Highway 3, the congested east-west route that runs through town, a monument portrays a small band of parrots. Someday, conservationists hope, Puerto Ricans will be able to look to their forested hills with a realistic chance of seeing their emblematic bird for real.

Article originally appeared on (http://cityparrots.org/).
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