This discussion was first published on Dec 1 2010 as part of the 2010-2011 Red List update, but remains open for comment to enable reassessment in 2012.
Initial deadline for comments: 31 January 2012.
Madagascar Fish-eagle Haliaeetus vociferoides is listed as Critically Endangered under criterion C2a(ii) on the basis that the species has a population of fewer than 250 mature individuals, which was suspected to be in rapid decline owing to a number of threats. The most recent population estimate put the number of breeding pairs at c.120 (R. Watson in litt. 2010), which corresponds to a likely population of c.240 mature individuals. Recent evidence, however, suggests that the population is stable and may have been so at least since the early 1990s (Tingay, 2005, Johnson et al. 2009, R. Watson in litt. 2010).
Extremely low genetic diversity in the species may indicate that it has persisted with a small effective population for hundreds to thousands of years, rather than having suffered a recent genetic bottleneck (Johnson et al. 2009). Despite these findings, the threat level of Critically Endangered has been maintained as a precautionary approach given the severity of likely threats. Deforestation, soil erosion and the conversion of wetland areas to rice-paddies have caused the loss of nesting and foraging habitat (Rabarisoa et al. 1997, Berkelman et al. 1999a, Watson and Rabarisoa 2000). The species is threatened by direct human competition for fish-stocks (Watson 1998, Watson and Rabarisoa 2000), persecution through the taking of nestlings and shooting of adults, accidental entanglement in fishing-nets, disturbance at breeding sites by human activities and, according to local people, use of eagle body parts in food and traditional medicine (Rabarisoa et al. 1997, H. R. Ratsimba in litt. 2006). Water pollution poses a potential threat (H. R. Ratsimba in litt. 2006), given the species’s reliance on fish and the tendency for pollutants to accumulate in prey tissues. Current conservation efforts for this species include environmental education and habitat protection (R. Watson in litt. 2010).
In light of evidence suggesting that the population is stable, further information is requested in support of this view, as well as up-to-date information on the severity of likely threats and their probable impact on the species.
Berkelman, J., Fraser, J. D. and Watson, R. T. (1999) Lake selection by Madgascar Fish-eagles. Auk 116: 976-983.
Johnson, J. A., Tingay, R. E., Culver, M., Hailer, F., Clarke, M. L. and Mindell, D. P. (2009) Long-term survival despite low genetic diversity in the critically endangered Madagascar Fish-eagle. Molec. Ecol. 18: 54-63.
Rabarisoa, R., Watson, R. T., Thorstrom, R. and Berkelman, J. (1997) Status of the Madagascar Fish-eagle Haliaeetus vociferoides in 1995. Ostrich 68: 8-12.
Tingay, R. E. 2005. Historical distribution, contemporary status and cooperative breeding in the Madagascar Fish Eagle: implications for conservation. Ph.D. dissertation, University of Nottingham, Nottingham, UK.
Watson, R. (1998) The plight of the fish eagle: people, eagles and wetlands’ conservation in Madagascar. Africa – Birds & Birding 3: 34-41.
Watson, R. T., and Rabarisoa, R. (2000) Sakalava fishermen and Madagascar Fish Eagles: enhancing traditional conservation roles to control resource abuse that threatens a key breeding area for an endangered eagle. Ostrich 71: 2-10.