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 is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not 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.
Wetlands International (2015) estimate the overall population to be 780,000-2,910,000 individuals. The European population (consisting of individuals from the caspius and porphyrio subspecies) is estimated at 9,600-51,000 pairs, which equates to 19,100-102,000 mature individuals (BirdLife International 2015).
The overall population trend is uncertain, as some populations are decreasing, while others are increasing, stable, or have unknown trends (Wetlands International 2006). The European population is estimated to be fluctuating (BirdLife International 2015).
Behaviour This species is sedentary, nomadic or partially migratory, with many populations making local seasonal movements in response to changing habitat conditions (del Hoyo et al. 1996) (e.g. the drying of marshes) (Taylor and van Perlo 1998). The timing of breeding varies geographically (in relation to peaks in local rainfall) (del Hoyo et al. 1996). It breeds in solitary territorial pairs (del Hoyo et al. 1996, Taylor and van Perlo 1998) (especially in pastures) (Taylor and van Perlo 1998) or in small communal groups containing several breeding males, breeding females and non-breeding helpers (del Hoyo et al. 1996, Taylor and van Perlo 1998) (especially in swamps) (Taylor and van Perlo 1998). When not breeding the species occurs in pairs, small groups of 12 or more individuals (Africa) or in larger congregations of 50 to several hundred individuals (India and New Zealand) (Taylor and van Perlo 1998). The species is mainly crepuscular and forages in the early-morning and late-evening (del Hoyo et al. 1996). Habitat It shows a preference for permanent, fresh or brackish, still or slow-flowing, sheltered, extensive wetlands (del Hoyo et al. 1996) with floating mats of water-lilies (Taylor and van Perlo 1998), tall, dense emergent vegetation (e.g. reeds Phragmites spp., Typha spp., sedge Carex spp., papyrus Cyperus spp. (del Hoyo et al. 1996, Taylor and van Perlo 1998), Scirpus spp. or Eleocharis spp. (Taylor and van Perlo 1998)), muddy or sandy shorelines and patches of shallow water (del Hoyo et al. 1996). It may however occur in saline, eutrophic or turbid wetlands, and may be found on small waters and seasonal or temporary wetlands (e.g. in Africa) (del Hoyo et al. 1996). Suitable habitats include ponds, lakes, dams, marshes, swamps, rivers, flood-plains, artesian wells, sewage farms (del Hoyo et al. 1996) and wet rice-fields (Taylor and van Perlo 1998). The species also extends into open habitats adjacent to wetlands including grasslands, agricultural land, parks, gardens, hedgerows and forest margins (del Hoyo et al. 1996). Diet Its diet consists predominantly of plant matter including shoots, leaves, roots, stems, flowers and seeds (e.g. of Typha spp., Scripus spp., rice, grasses, sedges, Rumex spp., Polygonum spp., water-lilies (del Hoyo et al. 1996), clover Trifolium spp., fern Salvonia repens, bananas, tapioca and yam Dioscorea spp. (Taylor and van Perlo 1998)). It also takes animal matter including molluscs, leeches, small crustaceans (del Hoyo et al. 1996) (Isopods, Amphipods and crabs) (Taylor and van Perlo 1998), adult and larval insects (del Hoyo et al. 1996) (Coleoptera, grasshoppers, Hemiptera, Diptera, Lepidoptera) (Taylor and van Perlo 1998), earthworms (Taylor and van Perlo 1998), spiders, fish and fish eggs, frogs and frog spawn, lizards (del Hoyo et al. 1996), water snakes Natrix maura (Taylor and van Perlo 1998), adult birds, bird eggs and nestlings, small rodents and carrion (del Hoyo et al. 1996). Breeding site The nest is a shallow cup in a large substantial structure of vegetation (del Hoyo et al. 1996) built on a platform of vegetation floating on or standing in shallow water (del Hoyo et al. 1996, Taylor and van Perlo 1998) 30-120 cm deep (Taylor and van Perlo 1998) and concealed in thick vegetation (del Hoyo et al. 1996). Management information There is evidence that the application of rabbit Oryctolagus cuniculus control measures may lead to an increase in nest predation on this species by rabbit-specialising predators (New Zealand) (Haselmayer and Jamieson 2001).
The main threats to this species are habitat loss through wetland drainage (del Hoyo et al. 1996, Taylor and van Perlo 1998), habitat degradation through the introduction of exotic species (e.g. coypu Myocastor coypus) (Taylor and van Perlo 1998), direct mortality from pesticide contamination (del Hoyo et al. 1996, Dowding et al. 1999) (e.g. brodifacoum, a pesticide applied aerially to exterminate rodents) (Dowding et al. 1999), poisoning by cyanobacterial toxins (from dense blooms of cyanobacteria in wetlands) (Alonso-Andicoberry et al. 2002) and hunting (del Hoyo et al. 1996). The species is also susceptible to avian influenza (Melville and Shortridge 2006, Gaidet et al. 2007) and avian botulism so may be threatened by future outbreaks of these diseases (Galvin et al. 1985).
Conservation Actions Underway
EU Birds Directive Annex I. Bern Convention Appendix II. The following information refers to the species's European range only: The species has full legal protection in France, Greece, Portugal, Spain and Italy and is listed in the national Red Lists of Italy, Portugal and Spain. In Italy a large part of the main sites for the species are now legally protected as SPAs and a reintroduction programme is being prepared in Sicily. In Portugal an EU Life-funded, reintroduction programme has begun in the Baixo Mondego region (Coimbra), in the Paul de Arzila and Paul da Madriz Nature Reserves and three successful reintroduction programmes have been completed in Spain. A European Species Action Plan was published in 1999 (de Vergara and Ripoll 1999).
Conservation Actions Proposed
The following information refers to the species's European range only: This species should be fully protected, included in the appropriate category in the national catalogues and have a National Recovery Plan for countries within its European range. Key sites should be adequately protected, as should smaller sites and appropriate restoration, conservation and enhancement measures aplied. Reintroduction programmes have been shown to be successful and should be implemented in areas with fragmented populations or where natural population recovery is unlikely. Restrictions on hunting at important sites are also needed. Monitoring should be standardised throughout its range. Research should focus on mortality caused by lead poisoning and the impact of pesticides. Public awareness of the species and its status should be raised (de Vergara and Ripoll 1999).
Text account compilers
Ekstrom, J., Butchart, S., Malpas, L. & Ashpole, J
BirdLife International (2020) Species factsheet: Porphyrio porphyrio. Downloaded from http://www.birdlife.org on 19/09/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/09/2020.