Andaman Serpent-eagle Spilornis elgini


Justification of Red List category
This species has a small range, in which it is thought to be quite common, but may have a small population with a fragmented subpopulation structure. The forests of the interior of the Andaman Islands are coming under increasing pressure from agriculture and development schemes and this species is likely to decline concurrently. A further threat is hunting. The species is therefore listed as Vulnerable.

Population justification
Although considered quite common in its optimal habitat, the overall population size may in fact be quite small. A total of 62 individuals were recorded on 25 of 45 islands with a total area 3,700 km2 surveyed in 1993-94 (Davidar et al. 1996). Therefore, its density has been considered to be not more than 1 or 2 individuals per km2 (P. Davidar in litt. 2016) with the total number of mature individuals considered to be 4,000 or less (P. Davidar in litt. 2016). Therefore, the population size is placed here in the range 1,000-4,000 mature individuals.

Trend justification
There are no data on population trends; however; the species is suspected to be declining at a slow to moderate rate, owing to habitat degradation and hunting.

Distribution and population

Spilornis elgini is endemic to the Andaman Islands, Indiawidely distributed from the North Andaman to the Little Andaman Islands (Davidar et al. 2007, Koparde and Manchi 2013, Rajeshkumar et al. 2015). It is considered fairly common across its range and preferred habitat (BirdLife International 2001, Vijayan 2009, Clark et al. 2017).


Habitat type and island area are the primary determinants of the species's occurrence pattern. It preferentially occurs on larger islands (>24 km2) and in closed canopy wet evergreen and semi-evergreen forests in the interior of islands (though it does extend to the coasts in some areas [Thiollay 1997, P. Davidar in litt. 2020]), where it is quite common (Rajeshkumar et al. 2015, P. Davidar in litt. 2016), but it can be found in other habitats, including degraded forests (Koparde and Manchi 2013), agricultural land, and potentially wetland and seashore (Rajeshkumar et al. 2015). It is known to feed on rats, lizards and snakes (Rao et al. 2013), as well as crabs and prawns (Pande et al. 2009). It appears to be ecologically separated from Crested Serpent-eagle S. cheela, which inhabits coastal forests on the same island (Thiollay 1997).


Although forest remains extensive on the Andamans, loss and fragmentation of cover continues and is perhaps accelerating. The human population on larger islands, which are suitable for the species (Davidar et al. 2007), is rising rapidly and habitat is consequently under mounting pressure from agriculture, grazing and logging. Hunting is also apparently common on the islands and may affect this species.

Conservation actions

Conservation Actions Underway
CITES Appendix II. Listed in Schedule I of Wildlife (Protection) Act of India, 1972. The Department of Environment and Forests, Andaman & Nicobar Islands has initiated steps to conserve the endemic and threatened bird species of Andaman and Nicobar Islands and the Zoological Survey of India is monitoring the bird population of this archipelago (C. Sivaperuman in litt. 2016).

Conservation Actions Proposed
Conduct research on the species ecology, especially breeding biology and territory size (P. Davidar in litt. 2016, P. Koparde in litt. 2016). Survey to assess the size of the population. Regularly monitor the population at selected sites across its range. Investigate its abundance in forest at different levels of perturbation. Protect significant areas of intact closed canopy forest in the Andaman islands. Quantify the impact of hunting on populations. Conduct awareness campaigns involving local residents to engender pride in the species and prevent hunting.


Text account compilers
Fernando, E.

Benstead, P., Davidar, P., Koparde, P., Mahood, S., Praveen, J., Sivaperuman, C., Taylor, J. & Westrip, J.R.S.

Recommended citation
BirdLife International (2023) Species factsheet: Spilornis elgini. Downloaded from on 01/10/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from on 01/10/2023.