TAVERNIER — Last spring, Jerry Lorenz, state research director with Audubon Florida, closely monitored little roseate spoonbills chicks, the color of strawberry milkshakes, fledging in their nests from his cellphone, not out of convenience but because of rising seas.
Lorenz, along with other biologists at the Audubon’s Everglades Science Center on Plantation Key, installed game cameras and satellite transmitters last year to collect critical data on the threatened bird’s behavior.
Biologists with the Everglades Science Center felt they had to track spoonbills differently because a swelling Gulf of Mexico and to lessen stress on the nests to better their chance of success.
“After eight weeks, after the chicks are gone, we’d have our data and only have to disturb the nests one time. The cameras take a picture every hour. After eight weeks, that’s thousands of photos. The second aspect is that we are putting trackers on these birds,” Lorenz said.
Because this species has a clear relationship with hydrologic conditions in the River of Grass, roseate spoonbills are considered the “canary in the coal mine” for the health of the Everglades and are indicators of restoration success.
“We had 10 cameras set up on nests. We had a late nesting and put five more cameras out so in all we followed 15 cameras,” Lorenz said.
What Lorenz saw was visually stunning.
“The quality of some of these pictures are just beautiful. Nobody is ever going to get these kinds of pictures. It’s a candid shot of what’s going on in the nest with the chicks interacting. One time, I found the neighboring chicks had come over to hang out for a bit.”
What biologists learned was that roseate spoonbill nesting did “so-so” last season.
“The spoonbills did poorly last year in what I saw on the cameras,” Lorenz said. “We were doing a double-blind study. A biologist was traditionally following the colony to track either when the chicks failed or fledged. I was watching the cameras.
“Out of the 15 nests, we had four nests produce chicks. The biologist was following 30 nests all together and found they produced 0.8 chicks per nest, which isn’t bad, but not great either. It’s much better than what I saw with the cameras, but it’s not a hallmark year which is when at least one chick fledges per nest. It wasn’t a great year, but it wasn’t awful either.”
Fledging is the stage of development between hatching and becoming capable of flight.
Climate change and sea-level rise are known culprits for the spoonbill’s declining numbers, said Lorenz.
“It used to be all the way back to 1939 until about 30 years ago, spoonbills nested between Nov. 1 and Dec. 31, when the fish are concentrated during the dry season. Now they’re nesting in January and later and that’s because of sea-level rise. We’ll start our surveys in November and won’t see any nesting activity at least until January,” Lorenz said.
“We counted just about 300 nests in Florida Bay, but compared to what was nesting in the ‘90s, it’s about half. We’re a little worried. We really think Everglades restoration will make a difference. If you increase the freshwater flow, then that wetland becomes much more productive. These birds won’t have to wait for such ideal conditions to nest.”
Since 2010, Lorenz said he’s measured annual sea level increases of a half inch to an inch in the bay. The Gulf of Mexico, which is connected to Florida Bay, is retaining water and steadily rising, and this makes foraging for food more difficult for adult spoonbills. Spoonbill parents alternate finding food for the chicks, and despite having 20-inch legs, the water is often too high for wading.
The Everglades Science Center plans to increase monitoring efforts with more cameras this season.
“Last season was the proof of the concept. This year we’ll have at least 40 cameras, and we are going to set these up in a known sub-colony. We need to figure out how many cameras we will need going forward. This is a work in progress. At the end of a few years, we won’t have to go disturb the colony, which would be ideal. Out of the 40, we’ll only have about five of them with cellular trackers to learn exactly when the chick is done,” Lorenz said.
“The whole goal is to get the information and provide that to the people making the decisions that affect Florida Bay. It’s a net benefit to us and the birds. When we are tracking these birds, most are migrating back to Florida Bay. Adults don’t go that far. Spoonbills come back to where they are hatched. There are about 10% spreaders. That’s how they expand their range, but the vast majority will come back to Florida Bay.”
For more information, visit fl.audubon.org/news.