SF Zoo has an adorable fluffy newborn attraction - and more may be on the way

For the past nine years, the flamingos at the San Francisco Zoo have displayed plenty of pink plumage - but no passion.

That changed this spring, when the flamboyance of 41 adult birds rediscovered its romantic side. The result? Four fluffy white chicks hatched last week, with more potentially on the way. 

Zoo officials are attributing the chick boom to new netting that covers the Chilean flamingo habitat. The mesh roof, which allows the birds to move around at will day and night, has apparently created the conditions they needed to breed.

Previously, the birds were kept in an open-air enclosure during the day, then brought into night quarters under a protective roof. This kept them safe from predators, zoo officials said - but it also disrupted their routines, which kept them from mating. 

"The (new) mesh enclosure allowed us to keep the flock outside, rather than inside their night quarters, and it made a difference in their behavior, allowing them to act more naturally," said Quinn Brown, curator of birds. "We had no expectations of chicks this year, but wanted to see if they would behave differently once they had unlimited outdoor access." 

And they did: This spring, the flamingos began engaging in a mating ritual that hadn't been seen since they last laid eggs, in 2017. 

According to Brown, that was the year concerns about avian flu prompted the construction of the night enclosure to protect the birds against potential outbreaks. It was also the year the zoo stopped pinioning newly hatched flamingo offspring, requiring them to be brought into the holding at night for protection against both the flu and predators. 

The zoo added the overhead net last August so the flamingos could remain capable of flight without escaping, reflecting evolving national animal welfare practices for captive birds. The netting is 20-25 feet high and covers the entire quarter-acre habitat.

The night quarters are still there, but the birds don't have to use it - and that was apparently the game changer.

In April, birdkeeper Liz Gibbons suddenly noticed that the males were standing up tall and shaking their heads left to right. "They were showing off and marching back and forth in unison, an indicator that we are leading up to breeding season," Gibbons said.

Flamingo pairs build their own nesting mounds in shallow water to keep the eggs from going under during high tide. In the wild, the mounds are made of mud, feathers and stones. But at the zoo, DuraPitch clay was added for the first time, giving the flamingos the same fine mixture to work with that covers the infield in Major League ballparks. The dirt is loose so the birds can kick it around the way ballplayers do.

To get them started, staff built a few raised mounds and gave the flamingoes the choice to occupy them immediately. But the birds chose to build their own mounds out of the DuraPitch that had been spread around the beach area. They also chose to build in a corner of the exhibit closest to the viewing area.

"They built their nests there because it is the safest, with bamboo walls around them," Gibbons said. To give them privacy, part of the viewing area was cordoned off and a fence buffer was built to resemble a tiki hut, with viewing windows for the public. 

On July 13, the first chick was spotted by Gibbons, having cracked out of its shell and taken comfort under the pink wings of its mother atop the nesting mound. By the end of the week there were three more chicks from different sets of parents, for a total of four. Two more eggs are still being incubated, a process that takes between 28 and 32 days.

"The chicks are so far doing well and being cared for by their parents," said Quinn Brown, curator of birds, noting that the upswing in amorous activity appeared to be the direct result of the netting. 

"There's nothing sweeter than seeing a flamingo chick having other flamingo chicks to grow up with," said Brown.     

The chicks will soon be out paddling around in the zoo's flamingo pond, and after 65 to 70 days they'll be able to fly - unlike the flock's pinioned adults.  

It will take another two to three years before their feathers turn the distinctive shade of pink the species is known for, and about six years before they can breed - bringing the adult population into the high 40s and 50s if all goes well.

"I'm totally floored by the success of this breeding season, after not seeing much for the last eight years," Gibbons said. "How the flock acted about a year ago is totally different than how they act now. They go in the water more, they swim, they hang out on their island. They are more comfortable in their environment and exhibit more of their natural behavior since we put the netting up."

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