Justification of Red List category
This species has an extremely 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). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely 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.
Partners in Flight estimate the global population to number 180 million mature individuals (A. Panjabi in litt. 2017), however this was before the taxonomic split of Vireo chivi. Nevertheless, the population size is extremely large.
This species has undergone an increase over the last 50 years in North America (44% increase between 1966 and 2015 based on the North American Breeding Bird Survey (Sauer et al. 2017), or 43% increase between 1970 and 2014 based on Partners in Flight (A. Panjabi in litt. 2017)). Recent trends suggest a large, significant increase of 14.5% over the last three generations (Sauer et al. 2017).
This migratory species overwinters in South America, east of the Andes, in Colombia, Venezuela, Ecuador, French Guiana, Guyana, Suriname, Brazil, Peru, Bolivia, Paraguay, Uruguay and northern Argentina. It spends the summers and breeds in North America, in the USA and Canada, with passage through Central America and the Caribbean.
On its breeding grounds, the Red-eyed Vireo favours areas of deciduous forest or mixed deciduous-coniferous forest; in coniferous areas, it usually occurs along streambeds where deciduous trees are present. It is more abundant in the forest interior than at the edge, and usually requires substantial understorey, however, the species does occur in substantially modified areas, such as parks or cemeteries, as long as there are large trees present. At the northern edge of its range in Canada, it occupies groves of aspen (Populus) and alder (Alnus). On migration, the Red-eyed Vireo uses a wider variety of habitats, but these are usually still deciduous-dominated. On the wintering grounds in South America, the species occupies various forest types, including rainforest, mangrove swamps, várzea, dry forest and plantations (Brewer 2019).
There is no evidence to suggest that there are currently any substantial threats to this species.
Conservation Actions Underway
No targeted conservation actions. Monitoring covered by North American Breeding Bird Survey.
Text account compilers
Elliott, N., Hermes, C., Ekstrom, J., Butchart, S., Palmer-Newton, A.
BirdLife International (2023) Species factsheet: Vireo olivaceus. Downloaded from http://datazone.birdlife.org/species/factsheet/red-eyed-vireo-vireo-olivaceus on 29/09/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://datazone.birdlife.org on 29/09/2023.