Zonerodius heliosylus 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Pelecaniformes Ardeidae

Scientific Name: Zonerodius heliosylus
Species Authority: (Lesson, 1828)
Common Name(s):
English Forest Bittern
Taxonomic Source(s): del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Lynx Edicions BirdLife International.

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Beehler, B., Bishop, P., Burrows, I., Burrows, R., Gibbs, D. & Mack, A.
Facilitator/Compiler(s): Benstead, P., Derhé, M., Dutson, G., Mahood, S., O'Brien, A., Pilgrim, J.
This species qualifies as Near Threatened because it has a moderately small population which is thought to be undergoing a moderate decline owing to habitat degradation.

Previously published Red List assessments:
2008 Near Threatened (NT)
2006 Near Threatened (NT)
2004 Near Threatened (NT)
2000 Lower Risk/near threatened (LR/nt)
1994 Lower Risk/near threatened (LR/nt)
1988 Lower Risk/least concern (LR/lc)

Geographic Range [top]

Range Description: Zonerodius heliosylus occurs throughout New Guinea (Papua, formerly Irian Jaya, Indonesia and Papua New Guinea) and on the adjacent islands of Salawati and Aru, Indonesia. There are very few recent records and it is such a reclusive species that it is impossible to assess its true population (Coates 1985, Beehler et al. 1986, K. D. Bishop in litt. 1994, D. Gibbs in litt. 1994, Eastwood 1998).

Countries occurrence:
Indonesia; Papua New Guinea
Continuing decline in area of occupancy (AOO): Yes
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 652000
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Continuing decline in number of locations: Unknown
Extreme fluctuations in the number of locations: No
Lower elevation limit (metres): 100
Upper elevation limit (metres): 1430
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Fewer than 10,000 individuals are estimated to survive (unpublished information supplied by Wetlands International Specialist Groups), so it is placed in the band 2,500-9,999 individuals here. This equates to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.

Trend Justification:  There are no data on population trends; however, the species is suspected to be declining slowly, owing to habitat loss and degradation.
Current Population Trend: Decreasing
Additional data:
Number of mature individuals: 1500-7000 Continuing decline of mature individuals: Yes
Extreme fluctuations: No Population severely fragmented: No
Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No

Habitat and Ecology [top]

Habitat and Ecology: It frequents streams, pools and swamps in forest to 1,430 m.

Systems: Terrestrial; Freshwater
Continuing decline in area, extent and/or quality of habitat: Yes
Generation Length (years): 7.4
Movement patterns: Not a Migrant

Threats [top]

Major Threat(s): Although it is not hunted (B. M. Beehler in litt. 1994) and there are still huge areas of suitable habitat left, it may be threatened by the extensive logging of lowland forest (I. Burrows in litt. 1994, R. Burrows in litt. 1994), especially as it occurs along watercourses (A. Mack in litt. 1999).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
None is known.

Conservation Actions Proposed
Survey to better understand the abundance and distribution of the species. Protect large areas of lowland rainforest. Ensure protection of forests along watercourses.

Citation: BirdLife International. 2012. Zonerodius heliosylus. The IUCN Red List of Threatened Species 2012: e.T22697274A38251878. . Downloaded on 29 November 2015.
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