Abstract
Introduced species often encounter novel environments that test their capacity for ecological flexibility and adaptation. We investigated ecological niche dynamics in Nanday Parakeets ( Aratinga nenday ), a naturalized parrot species in Los Angeles, to assess whether their introduced range reflects a shift from their native range in South America. Using principal components analysis and niche overlap tests, we found that the introduced population occupies a distinct environmental space—cooler, drier, and with less tree cover—with no measurable niche overlap. Habitat suitability modeling in Los Angeles suggests that their current habitat is narrowly concentrated in south-facing coastal canyons and not in more arid inland or high-elevation areas. Data from iNaturalist show that Nanday Parakeets roost and feed mainly in sycamore trees. The 2025 Palisades Fire impacted only 3% of suitable habitat, while the 2018 Woolsey Fire impacted 12%, neither with an observable effect on the population. Our results highlight the contradiction apparent in many species introductions: niche flexibility during establishment combined with ecological constraints on later spread.