NT
Blue-headed Hummingbird Riccordia bicolor



Taxonomy

Taxonomic note
Previously listed as Cyanophaia bicolor (del Hoyo and Collar 2014), but moved to current genus following a recent overhaul of all genera by NACC, based on McGuire et al. (2014), Stiles et al. (2017a, b) and others. Monotypic.

Taxonomic source(s)
Handbook of the Birds of the World and BirdLife International. 2022. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 7. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v7_Dec22.zip.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2024 Near Threatened A2c+4c; B1b(iii)
2016 Least Concern
2012 Least Concern
2009 Least Concern
2008 Least Concern
2004 Least Concern
2000 Lower Risk/Least Concern
1994 Lower Risk/Least Concern
1988 Lower Risk/Least Concern
Species attributes

Migratory status not a migrant Forest dependency high
Land-mass type Average mass 4 g
Range

Estimate Data quality
Extent of Occurrence (breeding/resident) 4,000 km2 medium
Area of Occupancy (breeding/resident) 2,464 km2
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 25000-150000 mature individuals medium estimated 2023
Population trend decreasing - suspected 2017-2027
Rate of change over the past 10 years/3 generations (longer of the two periods) 10-29% - - -
Rate of change over the past & future 10 years/3 generations (longer of the two periods) 10-29% - - -
Generation length 2.35 years - - -
Number of subpopulations 2 - - -
Percentage of mature individuals in largest subpopulation 1-89% - - -

Population justification: The species is described as fairly common, but patchily distributed (Stotz et al. 1996, Kirwan et al. 2019). The density of this species has been calculated with very different outcomes, perhaps reflecting significant variation at different altitudes. On Martinique, density of 'at least 3-4 individuals/km2' noted at unknown elevations (Schuchmann and Boesman 2021), while surveys in 1996 found it the 7th commonest bird on Martinique in favoured montane forest, at a density of 3.5-7.7 individuals/ha (equivalent to 350-770 birds/km2) (De Mercey 1996). The lower estimate of Schuchmann and Boesman (2021) is suspected to be overly precautionary (P. Feldmann in litt. 2024) and at least at higher elevations the density calculated by De Mercey (1996) is probably more realistic. If the De Mercey (1996) density is used for high-elevation forests on Martinique, the population size on this island alone greatly exceeds 10,000 mature individuals with similar numbers from Dominica. These numbers do not account also for the species' (scarce) presence in the lowlands. Accordingly the global population size is estimated to number 25,000-150,000 mature individuals.

Trend justification: Difficult to interpret, but suspected to be declining in response to habitat loss and degradation, and potentially climate-induced shifts in habitat extent. There are reports that this species is particularly sensitive to hurricanes: it reportedly became substantially rarer on Dominica due to hurricanes in the 1980, from which it apparently recovered only slowly (Schuchmann and Boesman 2021). Likewise, in the aftermath of Hurricane Maria on Dominica in 2017, the species' abundance dropped drastically (Fairbairn et al. 2022, see also eBird 2023). However, hummingbirds on Guadeloupe recovered quickly after Hurricane Hugo in 1989 (P. Feldmann in litt. 2024) and given the Lesser Antilles is a region with a naturally high occurrence of hurricanes, it is assumed this species has some resistance to these threats. But it is projected that the intensity and probably the frequency of hurricanes will increase as a consequence of climate change (Knutson et al. 2010, Walsh et al. 2016). It can therefore not be ruled out that the rate of habitat loss and mortality may begin to rise faster than these recoveries take place, and the species may begin to decline in the long-term (rather than undergo fluctuations in response to hurricanes). It is also possible that climate change may induce habitat extent shifts upslope, thereby reducing the total area of suitable habitat available to this species, which evidently is much commoner at higher elevations.
Over the last ten years, 18-20% of tree cover has been lost in this species' range (Global Forest Watch 2023, using Hansen et al. [2013] data and methods disclosed therein). However, this high rate is largely driven by the impacts of Hurricane Maria on Dominica, which caused a total rate of tree cover loss of over 18% in 2017 (Global Forest Watch 2023). On Dominica alone, tree cover loss amounted to 36-37% over the past ten years (Global Forest Watch 2023). Forest cover on Martinique however has remained largely stable over the past two decades (Global Forest Watch 2023). In the years prior to and after Hurricane Maria, tree cover loss has been very low at <0.1% per year (Global Forest Watch 2023). Based on the overall rate of tree cover loss and reports of direct mortality, the rate of population decline is suspected to have been between 10-29% over the past ten years. It is however noted that this is largely driven by declines of the subpopulation on Dominica, while the subpopulation on Martinique is likely stable.


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Dominica extant native yes
Martinique (to France) extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Dominica Morne Diablotin National Park
Dominica Morne Trois Pitons National Park
Martinique (to France) Forêts du Nord et de la Montagne Pelée
Martinique (to France) Pitons du Carbet

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Lowland suitable resident
Forest Subtropical/Tropical Moist Montane major resident
Altitude 0 - 1300 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation
Climate change & severe weather Storms & flooding Timing Scope Severity Impact
Past, Likely to Return Majority (50-90%) Rapid Declines Past Impact
Stresses
Indirect ecosystem effects, Ecosystem degradation, Ecosystem conversion, Species mortality

Recommended citation
BirdLife International (2024) Species factsheet: Blue-headed Hummingbird Riccordia bicolor. Downloaded from https://datazone.birdlife.org/species/factsheet/blue-headed-hummingbird-riccordia-bicolor on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/12/2024.