This past week, I had a visit from Carlos Ramirez, a part time aviculturist from Puerto Rico and part time collector. Each breeding season, he supplements his livelihood harvesting Canary-winged Brotogeris chiriri and White-winged Parakeets Brotogeris versicolurus from the massive feral flocks; in 2016 he collected 537 chicks. The trapping is legal and is intended to control the rapidly growing feral parrot populations (that also include Blue and Gold Macaws Ara ararauna, countless species of conures, several species of amazons and even Umbrella Cockatoos Cacatua alba).
In Puerto Rico, I personally witnessed as thousands of these little birds congregated in trees for roosting in metropolitan San Juan. It was a noisy spectacle that I have only ever seen in Leticia, Colombia. The two species do not hybridize, though they nest fairly close together. Reports of hybrids are I believe erroneous, as many White-winged Parakeets fledge with some yellow in the wings, which they lose as they mature. This has been the experience of Carlos Ramirez in Puerto Rico and of myself in the feral populations of both species in South Florida.
The Brotogeris in Puerto Rico nest in arboreal termitarium. In South Florida, arboreal termites are not present, so the Brotogeris have adapted to nesting in the trunk of Canary Island Date Palms Phoenix canariensis. The birds select decomposing branches or remains of branches near the top of the palm. Here they tunnel and breed. The fact that the same two species use different nest types in two different parts of the wild illustrates how adaptable parrots are. The only common denominator—and to me the most important—is that they must both excavate the nest.
Brotogeris are as a sociable and species prolific in nature. In Puerto Rico, Carlos has taken as many as 8 chicks from the nest. In Miami the most that I have seen is 5, though pairs can produce two clutches per year. They nest as early as a year of age and seem to remain within the area that they were born. I can state this because in 2011 I color banded the chicks from several nests. These same chicks nested very close to the original nest in 2012. I have seen pairs and their offspring nest in the same palm, in close proximity. This observation was used by a local aviculturist to colony breed the two species. Interestingly when trappers in 2010 removed most of the flock from an area in North Miami Beach, Florida, the remaining three birds (a pair and their progeny, which was still in the nest when the group was trapped) did not nest. It was when several birds were released into that area that the pair nested again.
Based on field observations and breeding results involving many Brotogeris species, I believe that Brotogeris need the vocal stimulus of each other to nest most prolifically; it is easier to breed from them when other members are nearby than when a single pair is kept. The nest should be long, so that it can be filled with pieces of cork (which resembles termitaria, which all the species readily use in the wild) for the birds to tunnel through. I have used vertical nests successfully, but they also had to be filled with cork to be accepted. It is, in my opinion, more important for them to dig than the actual nest shape or size; the digging induces gonadal development and needs to occur over several days. A nest filled with cardboard, for example, is excavated too quickly and soon causes the birds to lose interest. A block of cork is a harder substrate and requires more effort to tunnel through.
When provided with the proper conditions, these small gems are not difficult to breed.