VU
Montserrat Oriole Icterus oberi



Taxonomy

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - D1+2

Red List history
Year Category Criteria
2016 Vulnerable D1+2
2015 Critically Endangered B1ab(i,ii,iii,iv)
2013 Critically Endangered B1ab(i,ii,iii,iv)
2012 Critically Endangered B1ab(i,ii,iii,iv,v)
2010 Critically Endangered B1a+b(i,ii,iii,iv,v)
2009 Critically Endangered B1a+b(i,ii,iii,iv,v)
2008 Critically Endangered
2004 Critically Endangered
2000 Critically Endangered
1994 Lower Risk/Near Threatened
1988 Threatened
Species attributes

Migratory status not a migrant Forest dependency High
Land mass type Average mass 36 g
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 30 medium
Number of locations 2 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 250-460 medium estimated 2012
Population trend Stable medium estimated -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations 2 - - -
Largest subpopulations 1-89 - - -
Generation length (yrs) 6.1 - - -

Population justification: In 2012 the total population was estimated at 307-690 birds (212-1,131, 95% CI), depending on whether the sampling area around each point count was assumed to encompass 100 m or 150 m (Oppel et al. 2014a). The upper estimate comprises 546 (382–897) individuals in the Centre Hills, and 143 (94–234) individuals in the South Soufrière Hills (using a 100 m radius around points); and the lower is based on estimates of 243 (170–399) individuals in the Centre Hills, and 64 (42–104) individuals in the South Soufrière Hills (using a 150 m radius around points; Oppel et al. 2014a). This very roughly equates to 200-460 mature individuals. Previous population estimates were of 460-590 pairs (260-1,190, 95% CI) or 920-1,180 mature individuals, and 5,200 individuals (based on 2004 survey data; Hilton 2008).

Trend justification: A variety of monitoring and analytical techniques indicate annual declines of 8-52% during the period 1997-2000 (Hilton et al. 2003) following a rapid one-off event when a volcanic eruption caused a 60% decrease in range and population in 1996. There was some recovery between 2003 and 2005, and there was no evidence of a continuing population decline between 2000-2013 despite continuing volcanic activity and the presence of native and invasive nest predators, although large uncertainty around trend estimates mean the power to detect a shallow negative trend is very low (Oppel et al. 2014a). Based on the comparison of count data at 42 points, the population in 2013 was 50% of that in 1998 (Oppel et al. 2014a), thus a decline of 30-49% is estimated to have taken place over the past three generations (18 years), but the current population trend is estimated to be stable, as annual monitoring data from 2011-2016 show that the trend is stable or even increasing (S. Oppel in litt. 2016). The probability of extinction after three generations is predicted to be low (2.1% by the year 2028) and future population size is uncertain owing to demographic and environmental stochasticity (Oppel et al. 2014b).


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Montserrat (to UK) N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Montserrat (to UK) Centre Hills
Montserrat (to UK) South Soufriere Hills

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Montane major resident
Altitude 100 - 900 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Small-holder farming Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem conversion
Climate change & severe weather Timing Scope Severity Impact
Ongoing Whole (>90%) Causing/Could cause fluctuations Medium Impact: 7
Stresses
Ecosystem degradation, Reduced reproductive success
Climate change & severe weather Timing Scope Severity Impact
Future Whole (>90%) Unknown Unknown
Stresses
Indirect ecosystem effects, Ecosystem degradation
Climate change & severe weather Timing Scope Severity Impact
Past, Likely to Return Whole (>90%) Very Rapid Declines Past Impact
Stresses
Ecosystem degradation, Reduced reproductive success
Geological events Timing Scope Severity Impact
Past, Likely to Return Whole (>90%) Very Rapid Declines Past Impact
Stresses
Indirect ecosystem effects, Ecosystem degradation, Ecosystem conversion, Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Named species Timing Scope Severity Impact
Ongoing Whole (>90%) Very Rapid Declines High Impact: 9
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Named species - Sus domesticus Timing Scope Severity Impact
Future Majority (50-90%) Slow, Significant Declines Low Impact: 4
Stresses
Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Unspecified species Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Indirect ecosystem effects
Invasive and other problematic species, genes & diseases Problematic native species/diseases - Named species - Margarops fuscatus Timing Scope Severity Impact
Ongoing Whole (>90%) Very Rapid Declines High Impact: 9
Stresses
Reduced reproductive success
Residential & commercial development Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem conversion

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Pets/display animals, horticulture - - International Non-trivial Recent

Recommended citation
BirdLife International (2017) Species factsheet: Icterus oberi. Downloaded from http://www.birdlife.org on 22/10/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 22/10/2017.