Data Zone
Justification of Red List category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (extent of occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Population justification
The global population has not been quantified given recent taxonomic changes. The last population estimate, from Wetlands International (2021), is 260,000-2,300,000 individuals in total, which equates to roughly 173,000-1,500,000 mature individuals. Most, if not all, of these estimates are from before 2011.
Trend justification
The population is thought to be stable, although some populations may have decreasing trends (Partners in Flight 2019, Wetlands International 2019).
Behaviour The majority of this species is sedentary, although northern breeding populations are migratory and African populations may perform local movements relating to seasonal rainfall (del Hoyo et al. 1992). The timing of breeding varies geographically, but often occurs during the rains in the tropics (del Hoyo et al. 1992, Kushlan and Hancock 2005). The species is highly territorial and often forages and nests singly, occasionally also nesting in loosely spaced single-species groups of 5-15 pairs or even in larger breeding aggregations of several hundred pairs (del Hoyo et al. 1992, Kushlan and Hancock 2005).
Habitat The species shows a preference for forested water margins such as mangrove-lined shores and estuaries, or dense woody vegetation fringing ponds, rivers, lakes and streams (Hancock and Kushlan 1984, del Hoyo et al. 1992, Kushlan and Hancock 2005). Other suitable habitats include river swamps, canals, artificial ponds, salt-flats, mudflats, tidal zones, exposed coral reefs, reedbeds, grassy marshland, pastures, rice-fields and other flooded cultivation (del Hoyo et al. 1992, Kushlan and Hancock 2005).
Diet Its diet varies considerably over its range, but usually consists predominantly of fish as well as amphibians (e.g. frogs), insects (e.g. water beetles, grasshoppers and dragonflies), spiders, leeches, crustaceans (e.g. crabs and prawns), molluscs, earthworms, polychaete worms, birds, small reptiles and mice (del Hoyo et al. 1992, Kushlan and Hancock 2005).
Breeding site The nest is a small, shallow structure of twigs placed well hidden amongst the branches of trees or bushes (especially mangroves Rhizophora spp. and Avicennia spp., or Allocasuarina spp., Myoporum spp., Callistemon spp., Hibiscus spp., Casuarina spp., Syzygium spp. and Inga spp.) 0.3-10 m above the surface of water or above the ground (del Hoyo et al. 1992, Kushlan and Hancock 2005).
The species is threatened by human disturbance, pesticides and habitat destruction, e.g. the loss of mangroves (del Hoyo et al. 1992, Kushlan and Hancock 2005). The species is taken for food in some areas (del Hoyo et al. 1992).
Text account compilers
Hermes, C.
Contributors
Butchart, S., Ekstrom, J., Symes, A., Taylor, J. & Malpas, L.
Recommended citation
BirdLife International (2024) Species factsheet: Green-backed Heron Butorides striata. Downloaded from
https://datazone.birdlife.org/species/factsheet/green-backed-heron-butorides-striata on 22/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/12/2024.