Justification of Red List Category
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The population is suspected to be in slow to moderate decline owing to the expansion of intensive agriculture and trapping for trade (Juniper and Parr 1998).
Psittacara holochlorus is distributed from southern Texas, USA, and northern Mexico (including subspecies brevipes on Socorro Island) south through the Middle American isthmus to south-western Nicaragua, and occurs in a variety of wooded habitats (Juniper and Parr 1998). An overall decline in the population is thought to have occurred in recent decades owing to the expansion of intensive agriculture, and the species is known to be traded in small numbers locally and internationally (Juniper and Parr 1998). However, its use of modified habitats probably buffers the population to some extent against the negative impacts of the degradation and fragmentation of natural habitats.
Subspecies brevipes is endemic to Socorro in the Revillagigedo Islands, Mexico, and is regarded as highly threatened. The population was estimated at 400-500 birds within c.35 km2 of suitable habitat in 1991. Numbers were considered stable and did not decline subsequently in the early 1990s (Rodríguez-Estrella 1995, Rodríguez-Estrella et al. 1996). However, there may have been some contraction in range since c.1960. Surveys from 2006 and 2007 estimated a population of c.300 individuals, suggesting a population decline from previous population estimates (J. E. Martínez-Gómez in litt. 2007).
Subspecies brevipes is threatened mainly by erosion, habitat degradation and the inhibition of forest regeneration caused by heavy sheep-grazing, which is compounded by habitat damage caused by locust outbreaks (J. E. Martínez-Gómez in litt. 2007). The introduction of rats remains a potential threat to brevipes (B. Tershy in litt. 2007).
Conservation Actions Underway
A captive-breeding programme for subspecies brevipes has been instigated for potential reintroduction (R. Rodríguez-Estrella in litt. 1999), and activities have been conducted to control sheep and cats on Socorro (J. E. Martínez-Gómez in litt. 2007, B. Tershy in litt. 1998, 1999, 2007), with nest-boxes also provided (J. E. Martínez-Gómez in litt. 2007).
Conservation Actions Proposed
Monitor the population of subspecies brevipes, and develop a captive-breeding programme, while completing the eradication of invasive species on Socorro and nearby Clarion Island and preventing further introductions (B. Tershy in litt. 2007).
Text account compilers
Bird, J., Butchart, S., Symes, A. & Taylor, J.
Martínez-Gómez, J., Rodríguez-Estrella, R. & Tershy, B.
BirdLife International (2019) Species factsheet: Psittacara holochlorus. Downloaded from http://www.birdlife.org on 23/09/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 23/09/2019.