Archived 2011-2012 topics: Madagascar Fish-eagle (Haliaeetus vociferoides): request for information

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.

Link to current BirdLife species factsheet for Madagascar Fish-eagle

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.

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3 Responses to Archived 2011-2012 topics: Madagascar Fish-eagle (Haliaeetus vociferoides): request for information

  1. Dr Ruth Tingay says:

    I think we have produced strong evidence to show that the status of ‘critically endangered’ is unjustified for this species, and that it should be downlisted to ‘endangered’. The hypothesis that this species has “declined rapidly in the last 50 years”, cited by multiple authors since the early 1980s, has been shown to be invalid (see Tingay 2005; Johnson et al. 2009). The evidence that the species’ former distribution was greater than its modern-day range is entirely unconvincing (see Tingay 2005). A further publication to support these findings is due to be submitted for peer review shortly: R.E. Tingay & M.L. Clarke. Re-assessing the population history of the Madagascar fish eagle: a critical evaluation of the historical literature. Our research suggests that this is a naturally small population that has not undergone a population decline since records of its existence first emerged (in 1833). Thus, the quantitative criteria used by IUCN to classify the species as ‘critically endangered’ have not been met. Our data do meet the criteria required for ‘endangered’ status.

  2. Joe Taylor says:

    The following comments were received from Lily-Arison Réné de Roland on 8 February 2011:

    These are the information concerning Madagascar Fish eagle Haliaeetus vocideroides:

    (1) its occupation areas decreased, mainly at the south of Madagascar. Before 2006, this species was seen until Manja district but at the moment, the southern area distribution is at Belo sur Tsiribihina. That means, this species moved about 100 Km to the North compared of its range before.

    (2) This species is absent and abandonned more old areas like the river of Manambolo (from Tsingy of Bemaraha to Ankavandra). In 2005, we recored 5 individuals and in September 2010, no individuals was seen.

    (3) I noted the the quality of its habitat are realy changed such as the quality of the water on the lake (most lake became very small and almost dry), most of forest along the river are cut (like at manambolo river).

    (4) Very few wetland areas in Madagascar are classified as protected areas.

    (5) Only the best areas to protect this species are at Manambolomaty and Mandrozo protected areas.

    So I think that the status of this species must stay at critically endangered.

  3. Joe Taylor says:

    The following comments were received from Lily-Arison Réné de Roland on 31 January 2012:

    Concerning the Madagascar Fish-eagle Haliaeetus vociferoides, I always consider my ideas I sent to the forum last year (diminution of range areas, diminution of wetland habitat able to support this species and the very few wetland habitat classified as New protected areas in madagascar). So this species is very threatened and I always suggested to put it in Critically Endagered (CR) species.

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