Justification of Red List Category
This species is listed as Endangered because it has a small and declining population, which faces a number of threats that may increase in severity in the future. Renewed logging and planned housing developments may result in further declines in available breeding habitat.
Smith and Smith (1989) previously estimated a global population of 2,400 pairs, i.e. 4,800 mature individuals. Anecdotal evidence suggests that the population has declined substantially since then and available survey data suggests the species occurs at low densities, even in apparently suitable habitat (Lloyd and Slater 2011); consequently we cautiously assume a population of 1,000-2,499 mature individuals. This equates to 1,500-3,749 individuals in total, rounded here to 1,500-4,000 individuals.
Frequency of encounters with this species appear to have declined substantially in recent years in several parts of its range, though no empirical evidence is available to support this. It is presumed to have declined in line with modest habitat loss and degradation, plus pressure from invasive species. Planned housing developments could eliminate 8% of remaining breeding habitat (Allen 1996), and an increase in hurricane frequency owing to climate change may further degrade remnant habitats in the future.
Tachycineta cyaneoviridis breeds on Grand Bahama, Great Abaco and Andros in the northern Bahamas (AOU 1998, Raffaele et al. 1998). It may be extinct as a breeding bird on New Providence (Raffaele et al. 1998), but a few birds are seen each breeding season suggesting the presence of a relict but severely threatened population (A. White in litt. 1999). The winter distribution is poorly defined, but there are a number of records from the southern Bahamas and eastern Cuba, and small numbers appear to be resident on the breeding islands (A. White in litt. 1999). On migration, it occurs irregularly in the lower Florida Keys and through southern Florida, USA (AOU 1998). The area of breeding habitat is c.2,000 km2 (Allen 1996), and a population of 2,400 pairs was crudely estimated in the late 1980s (Smith and Smith 1989). There are no empirical data to confirm population trends, but anecdotal reports suggest that the species has declined considerably in numbers and is now a scarce species even in suitable habitat (J. Lloyd in litt. 2009, D. Moore in litt. 2009, F. Rivera-Milan in litt. 2009, Lloyd and Slater 2011).
It nests in natural cavities and old woodpecker holes in pine Pinus caribaea woodlands (Smith and Smith 1989). It also occurs locally in towns and around human habitation, where it nests in artificial cavities and other human structures (Allen 1996). It tends to feed in open areas such as clearings in woodland, marshes, fields and along coastlines (Turner and Rose 1989). Breeding takes place in April-July (Turner and Rose 1989, Allen 1996). Movements are poorly known, but some birds undertake small-scale migrations during winter.
Logging of pines in the northern Bahamas has probably had a major impact (Smith and Smith 1989). Logging was terminated in the early 1970s, but much of the secondary forest is now approaching maturity and there are opportunities for renewed logging (Allen 1996). Planned housing developments could eliminate 8% of remaining breeding habitat (Allen 1996) and there is potential for considerable future building developments on Grand Bahama (L. Gape in litt. 2009), though in recent decades habitat loss has been modest (J. Lloyd in litt. 2009). There is competition for nest-sites with introduced cavity-nesters such as House Sparrow Passer domesticus and European Starling Sturnus vulgaris (Allen 1996). The small area of remaining habitat exacerbates the risk of hurricane-induced habitat loss (Allen 1996); the only notable habitat loss in recent years has resulted from saltwater intrusion associated with large storm surges following hurricanes in 2004 (J. Lloyd in litt. 2009). The frequency of hurricanes within the species's range may increase in coming years as a consequence of global climate change. Fire management may be important for the species as fire suppression may render areas of forest unsuitable over time (J. Lloyd in litt. 2009).
Conservation Actions Underway
A nest box scheme was initiated on Grand Bahama in 1995 to remedy the lack of suitable nest-holes (Allen 1996, A. Mitchell in litt. 1998). A total of 227 boxes were erected at several sites and three were occupied (Allen 1996, A. Mitchell in litt. 1998).
15 cm. Blue, green and white swallow. Dark green crown, nape and mantle, bluish-green rump, blue wings and forked tail, white underparts. Female duller with less pure white underparts. Similar spp Tree Swallow T. bicolor is more metallic with darker, blackish wings and less forked tail. Juvenile T. cyaneoviridis is greyer on back and head with less brown on breast than T. bicolor. Voice Sharp, metallic chep or chi chep. Hints Often feeds high and glides. Most active in evenings and cloudy weather.
Text account compilers
Bird, J., Isherwood, I., Pilgrim, J., Pople, R., Sharpe, C J, Wege, D., Symes, A. & Wheatley, H.
Gape, L., Lloyd, J., Mitchell, A., Moore, D., Rivera-Milan, F., Stahala, C., Wardle, C., White, A. & Wunderle, J.
BirdLife International (2017) Species factsheet: Tachycineta cyaneoviridis. Downloaded from http://www.birdlife.org on 17/12/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 17/12/2017.