History, status, and productivity of the Red-crowned Amazon Amazona viridigenalis in the Lower Rio Grande Valley of Texas

Abstract

Summary Newly established populations of endangered species can help mitigate declines elsewhere and can be a valuable genetic reservoir. When these populations are located within anthropogenic habitats, they may also help mitigate the potential biodiversity loss created by urbanization. The Red-crowned Amazon Amazona viridigenalis is an endangered species that has become naturalized in multiple urban areas throughout the United States and Mexico, and these populations may currently outnumber the population within their historical habitat. While these urban populations may hold the majority of this endangered species, very few studies have analyzed the status and trends of this species, or of threatened parrots in general, in urban areas. Our study focuses on an urban Red-crowned Amazon population in the Lower Rio Grande Valley (LRGV) of Texas: the only parrot population currently recognized as native to the United States. To determine a timeline of Red-crowned Amazon arrival and growth in the LRGV, we reviewed published literature and online citizen science databases. To quantify current population levels and trends, we conducted 412 surveys at all known roost sites throughout the LRGV from January 2016 through April 2019. We also quantified the ratio of adult and juvenile parrots at roosts. Our data suggest the species has been present in the LRGV consistently since the 1970s and showed rapid growth from the mid-1990s through roughly 2016. Roost counts suggest there is currently a minimum LRGV population of about 680 and the population has been relatively stable over the last 3.5 years. Productivity averaged 19% over three breeding seasons, suggesting successful internal reproduction. This study provides important baseline information for the management and conservation of Red-crowned Amazons in the region and provides a valuable timeline on the beginnings and trends of this recently established urban population of Amazona parrot.

Convergent niche shifts of endangered parrots (genus Amazona) during successful establishment in urban southern California

“…The ability of introduced Amazona parrots to thrive under novel environmental conditions, though striking, still does not fully explain why they have been so successful in establishing outside their native range, especially in cities. In addition to the populations discussed here, Red‐crowned Parrots have also become established in Hawaii and Puerto Rico (Kiacz et al., 2021). It is hard not to notice that these introductions have all occurred in densely populated areas with relatively benign climates.…”

“…One, each introduction to a new area seems to result in a unique kind of niche shift, similar to findings from other species with multiple geographic introductions (Pili et al., 2020; Tingley et al., 2016). For instance, the Texas population of Red‐crowned Parrots is so geographically close to the native range that some have considered whether it might be a natural range expansion (summarized in Kiacz et al., 2021). Still, our results suggest that the Texas population inhabits a divergent environmental niche from the native population, one with higher temperatures and less seasonal rainfall, combined with much less vegetation greenness and tree cover, as expected for an urban area.…”

“…We used eBird data for these populations to increase sample size and because Red‐Crowned Parrots are the overwhelmingly dominant species in these areas. There is debate whether the Texas population in the Lower Rio Grande Valley is of native or introduced origin, but it seems likely that human introductions were at least partly responsible for its establishment (Kiacz et al., 2021). To account for variability in detectability, for all eBird data, we filtered observations based on effort variables for more consistent observation methods.…”

Movimientos vespertinos de la lora nuca amarilla (Amazona auropalliata) en la ciudad de San Salvador, El Salvador

“…Las poblaciones de Psitácidos en diferentes ciudades del mundo, no solo en los países de su distribución, están generando nueva literatura sobre estos y su ecología urbana, incluyendo abundancia (Álvarez-Castillo et al, 2022), modelaje de corredores (Jezuíno et al, 2021), tendencias poblaciones, datos históricos, ciencia ciudadana (Kiacz et al, 2021), comportamiento (Ibarra Portillo, 2019) y fuentes de alimento (Herrera & Rodríguez, 2022), entre otros.…”

Modelling Red–Crowned Parrot (Psittaciformes: Amazona viridigenalis [Cassin, 1853]) distributions in the Rio Grande Valley of Texas using elevation and vegetation indices and their derivatives

“…Further study is needed to better understand the patterns and processes of suburban adaptation to develop strategies that support their persistence and make urban landscapes more attractive to a wider diversity of "desirable" species [9]. Interestingly, the populations of Endangered Red-crowned Parrots (Amazona viridigenalis [Cassin, 1853]) found in the southern United States of America (USA) are typically absent from natural areas but instead seem to prefer certain highly-modified urban areas [10][11][12][13][14] and are found in cities in least three states (i.e., California, Florida, Texas) [15]. Those found in the Rio Grande Valley of Texas are the focus of this study.…”