Study finds exotic parrots aren't impacting native bird populations in South Florida
In a neighborhood on the outskirts of Miami, a red-bellied woodpecker made two individual nests in two neighboring dead palm trees. It picked one. A red-masked parakeet moved into the other. Over the summer, they shared alarm calls when strangers approached. They would fly to the same tree when Joshua Diamond examined their nests. This was when he learned they were both parents, raising their young, side by side, without any competition or interference.
This kind of relationship between a native bird and an exotic species is rare. In other parts of the world, parrots can cause problems, especially during breeding season. Because they cannot build their own nests, they interfere and compete for nesting space. Diamond discovered this isn't happening in South Florida. While conducting research on parrot breeding populations, he found native species and parrots are getting along.
"This research is important because it clarifies which parents are actually breeding here, since many are escaped or released pets looking for a safe place to rest," said Diamond, an FIU instructor who graduated with his Ph.D. in environmental science. "It's also highlighting the difference between an invasive species and an exotic one. Parrots are exotic, but they aren't invading our natural areas or causing massive disruption, like the Burmese Python in the Everglades."
Diamond's research on parrots grew out of his work on woodpecker nesting habits in South Florida. While examining nests in dead palms, he sometimes came across parrots. He wanted to understand how many were actively breeding and not just using the nests as a safe place to sleep.
Other studies have examined parrot breeding in Miami, but relied on ground observations of parrots moving in and out of nests. Diamond's study is the first to provide concrete evidence. Using a long, collapsible pole with a camera mounted on the top, he could glimpse inside the nests to see whether there were eggs or babies inside.
For two years, he explored urban, suburban and rural areas across Miami-Dade, as well as Fort Lauderdale and the upper Keys. In total, he explored nearly 4,000 nests and found parrots preferred nests in dead palms. All of the nests were created by red-bellied woodpeckers and pileated woodpeckers.
Diamond found the red-masked parakeet and orange-winged parrot are the top species breeding in South Florida. When a woodpecker moved out, they moved in. After they raised their young, they didn't want to take valuable nest space from native birds. They moved out and other species, such as screech owls, would take their place.
Parrots aren't likely to enter the Everglades or disrupt the balance of this threatened ecosystem, said Diamond. Throughout his study, he found that parrots prefer urban areas. They have nests available to them. They also have their pick of their favorite fruit and seeds that grow on trees in people's backyards. The parrots have no reason to leave. They've already found their paradise.
The findings were published in Avian Research.
More information: Joshua M. Diamond et al. Exotic parrots breeding in urban tree cavities: nesting requirements, geographic distribution, and potential impacts on cavity nesting birds in southeast Florida, Avian Research (2019). DOI: 10.1186/s40657-019-0176-3
Provided by Florida International University