Data Zone
Justification of Red List category
This species is restricted to one island and has undergone a severe population decline in recent decades as a result of forest loss, invasive species and severe hurricanes in both 2016 and 2019. Any remaining population is likely extremely small and continuing to decline. For these reasons, the species is listed as Critically Endangered.
Population justification
In 2018, following Hurricane Matthew (2016), four days of intensive surveys for the Bahama Nuthatch, covering all sites where the species has been recorded in recent years, failed to find any individuals (B. Harris in litt. 2018, Reid 2018). Furthermore, once per month for a year, a local bird guide visited one of the main sites where the species was previously recorded, without recording any individuals (B. Harris in litt. 2018). In spring and summer 2018 however, extensive foot surveys by two teams resulted in a small number of sightings of the species with a single report of two individuals being sighted together (UEA 2018, Hermes and Sessa-Hawkins 2019). In late summer 2019 however, another Category 5 hurricane, Dorian, the second largest Atlantic hurricane on record, hit the island of Grand Bahama causing further severe damage to the species's habitat. The species has not been sighted since Hurricane Dorian hit and extensive surveys are urgently required to establish whether the extremely small number of remaining individuals survived this event (Bell 2019). The small number of recent sightings, and possibility that no individuals survived this latest hurricane, mean that any remaining population is likely extremely small; thus it is placed here in the band 1-49 mature individuals.
Trend justification
The population size was previously estimated at 1,800 individuals (equating to approximately 1,200 mature individuals) in 2004 (Hayes et al. 2004). The very few sightings recorded in spring and summer 2018 following Hurricane Matthew (2016), and the absence of records following Hurricane Dorian (2019), indicate that the population has declined rapidly and is now estimated to number no more than 50 mature individuals, and likely considerably fewer (UEA 2018, Bell 2019, Hermes and Sessa-Hawkins 2019). This represents a population reduction in excess of 90% over a ten year period.
S. insularis is found only on Grand Bahama Island of the Bahamas (del Hoyo et al. 2018). The species was reported to be fairly common in 1969, with a density of 8.48 individuals per km2 (Emlen 1977), and in 1978, with a density of 13 individuals per km2 (Emlen 1981). Extensive surveys in 1993 detected only two individuals, leading to the conclusion that the population had declined by 90% since 1969 (Smith and Smith 1994). In 2004 further surveys were carried out using playback of S. insularis calls, leading to a population estimate of 1,800 individuals, but the authors stated that this may have been an optimistic number (Hayes et al. 2004). In 2007, line transect surveys through the pine forests of Grand Bahama recorded only two individuals of S. insularis, with 14 additional adults and seven juveniles located using intensive area searches coupled with broadcast playbacks of recorded vocalizations (Lloyd and Slater 2011). All individuals were located in or adjacent to Lucaya Estates and the species was noted to be very scarce relative to its abundance in the 1960s (Lloyd and Slater 2011). In September 2016, Grand Bahama Island was hit by Category 5 Hurricane Matthew, which caused significant damage (Reid 2018). In January 2018, four days of intensive surveys for the Bahama Nuthatch, covering all sites where the species has been recorded in recent years, failed to find any individuals (B. Harris in litt. 2018, Reid 2018). Furthermore, once per month for a year, a local bird guide visited one of the main sites where the species was previously recorded, without recording any individuals (B. Harris in litt. 2018). In spring and summer 2018 however, extensive surveys throughout over 700 km of pine forest in the Northern Lucayan Estates by two teams resulted in a small number of sightings of the species with a single report of two individuals being sighted together (UEA 2018, Hermes and Sessa-Hawkins 2019). In late summer 2019 however, another Category 5 hurricane, Hurricane Dorian, the second largest Atlantic hurricane on record, hit the island of Grand Bahama, causing yet more devastation. The species has not been sighted since Hurricane Dorian hit and further extensive surveys are required to establish whether the extremely small number of remaining individuals survived this event (Bell 2019).
This species inhabits mature Caribbean pine Pinus caribaea forests (Emlen 1977, del Hoyo et al. 2018).
The species is threatened by habitat destruction and degradation through logging and the development; as well as fires and hurricane damage (Hayes et al. 2004, Lloyd and Slater 2011). Nearly all of the forest on Grand Bahama was logged in the 1950s (Hayes et al. 2004). In September 2016, Grand Bahama Island was hit by Category 5 Hurricane Matthew, which caused significant damage (Reid 2018). Invasive species may also be a threat, either acting as predators (Raccoon Procyon lotor, Corn Snake Pantherophis guttatus) or as competition for this species (e.g. House Sparrow Passer domesticus, European Starling Sturnus vulgaris) (Hayes et al. 2004). The island was also hit by Category 5 Hurricane Dorian in August-September 2019 which caused further extensive, significant damage to the species already extremely limited habitat; it is not yet clear whether the species survived this event (Bell 2019).
Research and Conservation Actions Underway
Surveys are underway on Grand Bahama to relocate and estimate the population size of surviving individuals (D. Lebbin in litt. 2018).
Research and Conservation Actions Proposed
Carry out surveys in order to refine the population estimate. Conduct regular surveys at selected sites to monitor population trends. Monitor rates of habitat loss and degradation. Assess the potential impact of invasive species. Challenge detrimental development proposals and raise awareness of the importance of forest conservation among government officials, businesses and the general public (Hayes et al. 2004). Create a protected area to protect the remaining habitat in the Lucayan Estates area (Hayes et al. 2004).
Text account compilers
Wheatley, H., Everest, J.
Contributors
Butchart, S., Collar, N., Ekstrom, J., Harris, B., Lebbin, D. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Bahama Nuthatch Sitta insularis. Downloaded from
https://datazone.birdlife.org/species/factsheet/bahama-nuthatch-sitta-insularis on 22/12/2024.
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 22/12/2024.