Visitors to Ara Manzanillo’s Great Green Macaw Reintroduction Station in southeastern Costa Rica, just miles from the Panama border, are met by an unholy racket. The local f lock of Great Greens has arrived for its daily snack.
If it’s tropical tranquility you were seeking, forget it: The Ara ambiguus, among the largest of the macaws and similar in length to Bald and Golden Eagles, is no retiring wallf lower. You’d have to think that the genus name derives directly from the high-decibel blasts coming from the nearby treetops — Ar! Ar! Ar! — heard even as we walk up the drive to the center. It’s enough to drown out our guide’s voice as he explains some basic parrot facts. In fact, the name comes from the indigenous Tupi language of Brazil: a’rara.
Some of the avian aural assault is coming from customized plastic trash bins situated 100 meters up a massive almond tree, an example of the successful artificial nests Ara Manzanillo has contrived for the birds. Since 2010, approximately 60 captive-raised birds have been successfully reintroduced, and 15 active artificial nests have been in use since 2014.
The nest box solution was a must for this critically endangered species; fewer than 1,000 individuals exist between southern Honduras and northern Ecuador, while a tiny subspecies hangs on in southern Ecuador’s dry forests.
It was a challenge finding the right material for the artificial homes. Roopak Bhatt, our volunteer guide, says the sharp-billed birds went through wood boxes “like a chew toy” and that metal nests tended to rust in the damp Caribbean climate.
The nest boxes have produced positive results in the Manzanillo population: nine breeding couples and 22 chicks in the past five years. The macaws lay one to four eggs each November or December. In three to four months, the chicks are full size; however, there is an 80 percent mortality rate, and the birds don’t reach breeding age until four or five years. VANISHING HABITAT A major concern for conservationists is the rapid disappearance of the Great Greens’ preferred nesting site: mountain almond trees.
“This tree provides 90 percent of the birds’ nests, but 90 percent of them in Costa Rica have been cut down,”
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says Sam Williams of the Macaw Recovery Network (MRN). The loss of habitat is in part attributed to oil palms replacing native trees. “Great Greens prefer an intact forest,” he notes.
One problem is that ideal nesting sites tend to fall down because of age. “The palms have to have time to age, not merely grow,” Williams explains. (The artificial box we saw at the entrance of Manzanillo was attached to an almond tree more than 300 years old.)
Williams is resigned to a somewhat unnatural method of growing the macaw population. “Since the mountain almond grows slowly, I’m comfortable with the nest boxes. We have to increase the numbers any way that we can,” he says.
In addition to its ample nesting cavities, the tree’s almonds are crucial to the birds’ diet. Great Greens use their huge, powerful bills like massive can openers. “I’ve tried to crack these almonds with a machete and could not,” Bhatt says. The Great Green’s head and jaw are enormous compared to the Scarlet Macaw, which cannot eat the same almonds. (The largest macaw, Brazil’s mighty Hyacinth, is also a big fan of the hard-to-crack
RARE BIRDS: Great Green Macaws perch in a Costa Rican forest. The global population is between 500 and 1,000 birds.
M a c a w R e c o v e r y N e t w o r k