Justification of Red List Category
This species qualifies as Vulnerable because it is estimated to have a small population which is suspected to be declining as a result of forest loss.
Its status and population size are very poorly known, owing to its apparent scarcity, the species's restricted range and identification difficulties. Its total population may include c.2,500-5,000 mature individuals (K. Sivakumar in litt. 2012). This equates to c.3,700-7,500 individuals, assuming that mature individuals account for around 2/3 of the total population.
A moderate and on-going population decline is suspected on the basis of rates of habitat loss, but this requires further documentation.
Accipiter butleri is endemic to the Nicobar Islands in the Bay of Bengal, India, where it is only known with certainty from Great Nicobar, Little Nicobar, Pilo Milo, Kamorta, Teressa, Bompoka, Tillanchong, Katchall and Nancowry islands (Sankaran 1995, BirdLife International 2001, A. P. Zaibin in litt. 2012). As many islands in the archipelago are poorly studied, it is possible that it is more widely distributed. It is evidently very scarce: during three years of surveys, R. Sankaran sighted 20-25 individuals of this species in its entire known range, and no sightings of this species were obtained in the coastal habitats of the Nicobar Islands during fieldwork in 2006 (K. Sivakumar in litt. 2012), whilst fieldwork from March 2009 to August 2011 produced only two sightings of single birds on Nancowry Island (A. P. Zaibin in litt. 2012). The impact of the 2004 tsunami on this species has not been studied (K. Sivakumar in litt. 2012).
This species is apparently restricted to forested habitats. There is very little information available about its breeding and feeding ecology. Lizards and insects have been recorded as food items.
The primary threat to this species appears to be habitat loss and degradation, and this has accelerated since the arrival of migrants from mainland India in the late 1960s. Clearance for agriculture and development have increased and have exacerbated soil erosion problems. This may also bring this species into conflict with humans as it will take poultry chicks, and airguns are almost ubiquitous on the islands (S. Pande in litt. 2016). The impacts of the tsunami in 2004, which destroyed significant areas of habitat across the islands, have not been investigated for this species, and it may have had secondary consequences such as increased agricultural encroachment (K. Sivakumar in litt. 2012).
Conservation Actions Underway
The species is protected under Indian Wildlife legislation. No targeted conservation measures are known to have been implemented.
30 cm. Medium-sized forest-dwelling hawk. Adult males have pale grey upperparts; dark primaries; dark sub-terminal band to the tail and pale underparts with rusty breast and flank barring. Females and immatures are rich rufous brown with 3-5 dark bands on the uppertail.
Text account compilers
Benstead, P., Bird, J., Crosby, M., Taylor, J., Westrip, J.
Sivakumar, K., Zaibin, A., Pande, S.
BirdLife International (2022) Species factsheet: Accipiter butleri. Downloaded from http://www.birdlife.org on 30/06/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 30/06/2022.