I found a fascinating information about Carolina Parakeet in captivity, and not only: apparently a free-living breeding group existed in Germany for over 40 years:
"Carolina Parakeet Conuropsis carolinensis † At the end of the 18th and beginning of the 19th century, the Carolina parakeet was one of the most common parrots on the German bird market (D. Hoppe, pers. comm.). In the 19th century, there were several free-flight experiments in Germany with this species, which also resulted in breeding [group] established in the Seebach TH area (von Berlepsch 1874). The numbers were drastically decimated by shooting e.g. around 1876 and in the 1920s, and finally wiped out. The species is now extinct worldwide."
https://club300.de/publications/010_neozoa/Bauer_Woog_2008_Neozoen_in_Deutschland.pdf
"Carolina Parakeet Conuropsis carolinensis † At the end of the 18th and beginning of the 19th century, the Carolina parakeet was one of the most common parrots on the German bird market (D. Hoppe, pers. comm.). In the 19th century, there were several free-flight experiments in Germany with this species, which also resulted in breeding [group] established in the Seebach TH area (von Berlepsch 1874). The numbers were drastically decimated by shooting e.g. around 1876 and in the 1920s, and finally wiped out. The species is now extinct worldwide."
https://club300.de/publications/010_neozoa/Bauer_Woog_2008_Neozoen_in_Deutschland.pdf