This species is listed as Endangered because it has a very small population which is undergoing continuing declines owing to overexploitation and loss and degradation of its wetland habitats (Collar and Stuart 1985).
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.
Distribution and populationArdea humbloti
100 cm. Large, solitary heron. Upperparts mostly mid-grey, with darker cap, cheeks and flight feathers. Massive, pale straw-coloured bill, tending to orange in breeding season. Paler grey underparts, pale flesh or greyish legs and feet. Similar spp. From Grey Heron A. cinerea and Purple Heron A. purpurea by solid dark cap, uniform grey plumage lacking white or rufous, and more massive bill. Hints Often on mudflats adjacent to mangroves, or on fringes of large lakes.
breeds only in Madagascar
but is also recorded as a vagrant from the Comoro Islands
and Mayotte (to France)
. In 1973, it was reported to have declined alarmingly and to be facing extinction unless completely protected. More recently it was found to be fairly common (though patchily distributed) in parts of north and west Madagascar, and uncommon in the south (Langrand 1990). It has also been seen regularly at Lake Alaotra (ZICOMA 1999). The total population was recently estimated to number 1,000-3,000 individuals (F. Hawkins in litt.
2002 to Wetlands International 2002), although since then survey data from 2003 and 2004 combined with past literature has resulted in an estimation of no more than 1,500 individuals (Andrianarimisa et al.
in press). It is now judged to be restricted to western Madagascar, where it is sparsely distributed, with its stronghold being the Antsalova region (Andrianarimisa et al.
in press). Population justification
Survey data from 2003 and 2004 combined with past literature suggests that there are no more than 1,500 individuals, roughly equivalent to 1,000 mature individuals.Trend justification
This species's population is suspected to be decreasing in line with levels of egg-collection and hunting, cutting of nesting-trees, conversion of remaining wetlands to rice-paddies, and siltation of wetlands as a result of watershed deforestation. The likely rate of population decline, however, has not been estimated.EcologyBehaviour
There is no evidence of migration in this species, but it is prone to long-distance wandering in search of suitable habitat (Kushlan and Hancock 2005; Hancock and Kushlan 1984). It is usually seen alone, sometimes with other herons (Langrand 1990). It breeds mainly in small groups of a few pairs in mixed species colonies but also solitarily (Langrand 1990; del Hoyo et al
. 1992). Various independent observations suggest that nesting takes place year-round (Langrand 1990; ZICOMA 1999; Andrianarimisa et al.
in press). There are observations of grey heron Ardea cinerea
and A. humbloti
chicks occupying the same nests; though there is no evidence of mixed pairings or hybridisation, and this interaction between the two species is not understood (Andrianarimisa et al.
in press). Habitat
The species prefers coastal areas (including coral islets, mangroves, tidal mud flats and estuaries) (Kushlan and Hancock 2005; Hancock and Elliott 1978) but also frequents freshwater lakes (particularly those that persist through the dry season and are in close proximity to other lakes (Andrianarimisa et al.
in press)), rivers and, more rarely, rice-paddies (Kushlan and Hancock 2005; Hancock and Elliott 1978). It forages in clear, shallow waters (Langrand 1990; Hancock and Elliott 1978) and among floating vegetation (Hancock and Elliott 1978; del Hoyo et al
. 1992). Habitat suitability depends on water clarity, shoreline areas with shallow water and the availability of large fish (Andrianarimisa et al.
in press). Diet It feeds chiefly on medium to large fish (up to 20cm (del Hoyo et al
. 1992)) and crustaceans (Langrand 1990; Morris and Hawkins 1998). Breeding Site
It nests in tree-tops or hollows in rocks, and has also been reported to nest on the ground (Kushlan and Hancock 2005; Hancock and Kushlan 1984). Its clutch-size is three. Threats
Natural wetlands have been degraded by modification and conversion for human use, particularly for rice cultivation (Stattersfield et al
. 1998 ; Andrianarimisa et al.
in press), and by siltation as a result of watershed deforestation
(Stattersfield et al
. The former wetlands of the central highlands may once have been important refuges for immature birds
(Andrianarimisa et al.
in press). At the nest it is especially vulnerable to disturbance, egg-collection and the capture of nestlings by local villagers for food
(ZICOMA 1999; Andrianarimisa et al.
in press). These pressures are likely to reduce its numbers as the human population of western Madagascar continues to increase
(ZICOMA 1999), however the establishment of a local community association resource management process (Gestion Local Securisee
or GELOSE) has significantly decreased these activities in these zones (Razafimanjato et al.
2007). Cutting of nesting-trees can also be a significant threat, e.g. at Manambolomaty Ramsar Site where this has caused an alarming decline over the last 10 years (ZICOMA 1999). Wetlands in Madagascar have long been in decline as the climate has become progressively drier (Stattersfield et al
, and this has been compounded by the degradation of wetlands
(Stattersfield et al
. The depletion of fish stocks by local fisheries is a potential threat (Andrianarimisa et al.
in press). Conservation Actions Underway
This species is recorded from Ankarafantsika Strict Reserve, Ankarana Special Reserve and Baly Bay National Park, but overall its habitat is poorly protected (Langrand 1990), with c.50% of the population residing outside protected areas (Andrianarimisa et al.
in press). The Malagasy government has ratified the Ramsar Convention, which came into force for the country in 1999, and this may herald improved conservation measures for wetlands. During surveys in the Antsalova region in 2003/2004, the numbers of this species, on average for each site, were found to be significantly higher on lakes in designated Ramsar sites (Lakes Befotaka, Soamalipo, Ankerika and Antsamaka) compared with lakes outsite designated sites (Andrianarimisa et al.
in press). However, this could be due to variations in survey effort, the availability of suitable shoreline habitat, the proximity of the relatively undisturbed Tsimembo Forest, which prevents serious soil erosion, or the proximity of lakes to one another (Andrianarimisa et al.
in press). A survey in 1999 found the species in 20 Important Bird Areas within the West Malagasy Endemic Bird Area (ZICOMA 1999). Conservation Actions Proposed
Locate and protect important breeding colonies. Obtain population estimates for the species (Morris and Hawkins 1998).
Andriamasimanana, R. and Rabarimanana, M. 2011. Analyses de la dégradation du lac Kinkony pour la conservation du Complexe des Zones Humides Mahavavy - Kinkony, Région Boeny, Madagascar. Madagascar Conservation and Development 6(1): 22-28.
Andrianarimisa, A., Bachmann, L., Ganzhorn, J.U., Goodman, S.M. and Tomiuk, J. 2000. Effects of forest fragmentation on genetic variation in endemic understory forest birds in Central Madagascar. Journal fÃ¼r Ornithologie 141: 152-159.
Collar, N. J.; Stuart, S. N. 1985. Threatened birds of Africa and related islands: the ICBP/IUCN Red Data Book. International Council for Bird Preservation, and International Union for Conservation of Nature and Natural Resources, Cambridge, U.K.
del Hoyo, J.; Elliot, A.; Sargatal, J. 1992. Handbook of the Birds of the World, vol. 1: Ostrich to Ducks. Lynx Edicions, Barcelona, Spain.
Hancock, J. and Elliot, H. 1978. Harper and Row, New York, USA.
Hancock, J.; Kushlan, J. 1984. The herons handbook. Croom Helm, London.
Kushlan, J. A.; Hancock, J. A. 2005. The herons. Oxford University Press, Oxford, U.K.
Langrand, O. 1990. Guide to the birds of Madagascar. Yale University Press, New Haven, USA.
Langrand, O.; Goodman, S. M. 1995. Monitoring Madagascar's ecosystems: a look at the past, present, and future of its wetlands. In: Herman, T.B.; Bondrup-Nielsen, S.; Willison, J.H.M.; Munro, N.W.P. (ed.), Ecosystem monitoring and protected areas, pp. 204-214. Science and Management of Protected Areas Association, Wolfville, Canada.
Morris, P.; Hawkins, F. 1998. Birds of Madagascar: a photographic guide. Pica Press, Robertsbridge, UK.
Razafimanjato, G.; Sam, T. S.; Thorstrom, R. 2007. Waterbird monitoring in the Antsalova region, Western Madagascar. Waterbirds 30(3): 441-447.
Stattersfield, A. J.; Crosby, M. J.; Long, A. J.; Wege, D. C. 1998. Endemic bird areas of the world: priorities for bird conservation. BirdLife International, Cambridge, U.K.
ZICOMA. 1999. Zones d'Importance pour la Conservation des Oiseaux a Madagascar.
Further web sources of information
Explore HBW Alive for further information on this species
Search for photos and videos, and hear sounds of this species from the Internet Bird Collection
Species factsheet from HeronConservation - The IUCN-SSC Heron Specialist Group
Text account compilers
Ekstrom, J., Evans, M., Martin, R, Pilgrim, J., Shutes, S., Starkey, M., Symes, A., Taylor, J.
Andrianarimisa, A., Hawkins, F., Langrand, O., Rabenandrasana, M.
IUCN Red List evaluators
Butchart, S., Taylor, J.
BirdLife International (2016) Species factsheet: Ardea humbloti. Downloaded from
http://www.birdlife.org on 06/02/2016.
Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from
http://www.birdlife.org on 06/02/2016.
This information is based upon, and updates, the information published in BirdLife International (2000)
Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004)
Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.
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