CR
Bahama Nuthatch Sitta insularis



Justification

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 a hurricane in 2016. The remaining population is extremely small and continuing to decline. For these reasons, the species is listed as Critically Endangered.

Population justification
In 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 2018, a further series of surveys recorded a single individual (N. Collar verbally 2018). The small number of recent sightings suggests that the population size of Bahama Nuthatch may now be extremely small. The population is therefore placed 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 lack of records during intensive surveys over four days in January 2018 and the single record during further surveys in Spring 2018 indicate that the population has declined (B. Harris in litt. 2018, Reid 2018) and is now estimated to number no more than 50 mature individuals. This represents a population reduction of over 90% over the past three generation lengths (12 years).

Distribution and population

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 km(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 2018 a further series of surveys recorded a single individual (N. Collar verbally 2018). The small number of recent sightings suggests that the population size of Bahama Nuthatch may now be extremely small.

Ecology

This species inhabits mature Caribbean pine Pinus caribaea forests (Emlen 1977, del Hoyo et al. 2018).

Threats

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).

Conservation actions

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).

Acknowledgements

Text account compilers
Wheatley, H., Ekstrom, J., Butchart, S., Westrip, J.

Contributors
Harris, B., Collar, N., Lebbin, D.


Recommended citation
BirdLife International (2018) Species factsheet: Sitta insularis. Downloaded from http://www.birdlife.org on 15/12/2018. Recommended citation for factsheets for more than one species: BirdLife International (2018) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 15/12/2018.