LC
Pied Avocet Recurvirostra avosetta



Justification

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.

Population justification
The global population is estimated to number c.280,000-470,000 individuals (Wetlands International 2015). The European population is estimated at 58,400-74,300 pairs, which equates to 117,000-149,000 mature individuals (BirdLife International 2015).

Trend justification
The overall population trend is uncertain, as some populations are decreasing, while others are increasing, stable, or have unknown trends (Wetlands International 2006). In Europe the population size is estimated to be fluctuating (BirdLife International 2015).

Ecology

Behaviour Northern populations migrate south between August and October and return to the breeding grounds between March and May, staging on route in large numbers at certain sites (del Hoyo et al. 1996). The species is present all year round in much of its African range and in parts of Western Europe however (Hayman et al. 1986, del Hoyo et al. 1996). It breeds from April to August in large colonies (del Hoyo et al. 1996) usually of between 10 and 70 pairs (Johnsgard et al. 1981). The species remains gregarious on passage and during the winter, migrating in loose flocks (Hayman et al. 1986), foraging in groups of 5-30 individuals (Urban et al. 1986) and gathering to roost in large flocks of several thousand individuals (Hayman et al. 1986). Habitat Breeding The species breeds in flat open areas (del Hoyo et al. 1996) on shallow saline or brackish wetlands (Johnsgard et al. 1981, Hayman et al. 1986, Urban et al. 1986, del Hoyo et al. 1996, Snow and Perrins 1998) with islands, ridges, spits or margins of bare sand, clay or mud (Snow and Perrins 1998) and sparse short vegetation (Hayman et al. 1986), including inland lakes (Johnsgard et al. 1981, del Hoyo et al. 1996), pools (del Hoyo et al. 1996, Snow and Perrins 1998), coastal lagoons (Johnsgard et al. 1981, del Hoyo et al. 1996, Snow and Perrins 1998), estuaries, saltpans (del Hoyo et al. 1996, Snow and Perrins 1998), saltmarshes, irrigated land and flood-plains in arid areas (Snow and Perrins 1998). The most important characteristics of breeding habitats appear to be water levels which gradually decline over the summer to expose additional feeding areas, and high salt concentrations that prevent the development of excessive emergent and shoreline vegetation (Johnsgard et al. 1981). Non-breeding Outside of the breeding season the species inhabits coastal and inland saline lakes and mudflats (Urban et al. 1986, del Hoyo et al. 1996), lagoons, pools, saltpans (del Hoyo et al. 1996), estuaries (Hayman et al. 1986, del Hoyo et al. 1996), sandy beaches, river deltas and flood-plains (Urban et al. 1986). It rarely occurs on inland freshwater lakes and rivers (Urban et al. 1986, del Hoyo et al. 1996) but may forage on agricultural land (del Hoyo et al. 1996). Diet Its diet consists predominantly of aquatic invertebrates 4-15 cm long including aquatic insects (del Hoyo et al. 1996) (e.g. small beetles, midges and brine flies) (Johnsgard et al. 1981), crustaceans (del Hoyo et al. 1996) (e.g. Corophium spp.) (Johnsgard et al. 1981), oligochaete and polychaete worms, and molluscs, as well and small fish (del Hoyo et al. 1996) (e.g. sole) (Urban et al. 1986) and plant matter (del Hoyo et al. 1996) (e.g. seeds and small roots) (Urban et al. 1986). Breeding site The nest is a scrape (del Hoyo et al. 1996) that may be positioned in a variety of sites including on bare sand (Johnsgard et al. 1981), dried mud, short grass (Urban et al. 1986), dead vegetation and built-up mounds of debris (Johnsgard et al. 1981). The species nests in large colonies, neighbouring nest usually 1 m apart (Hayman et al. 1986) or occasionally as close as 20-30 cm (Urban et al. 1986). Management information Artificially constructed nesting sites in coastal locations such as beaches of bare shingle and islands or rafts covered with sparse vegetation are successful in attracting breeding pairs of this species (Burgess and Hirons 1992). The species responds positively (e.g. breeding numbers increase) to the introduction of cattle grazing on coastal grasslands, possibly as a result of reduced vegetation cover allowing improved predator detection (Olsen and Schmidt 2004).

Threats

The species is threatened in Europe by the pollution of wetlands with polychlorinated biphenyls (PCBs), insecticides, selenium, lead and mercury (del Hoyo et al. 1996). Important wintering sites (e.g. in Portugal or the Yellow Sea) are also threatened by infrastructure development (del Hoyo et al. 1996), land reclamation, pollution, human disturbance and reduced river flows (Kelin and Qiang 2006). The species is susceptible to avian botulism (Blaker 1967, Hubalek et al. 2005) and avian influenza (Melville and Shortridge 2006) so may be threatened by future outbreaks of these diseases.

Conservation actions

Conservation Actions Underway
The species is listed on Annex I of the EU Birds Directive and Annex II of the Bern Convention.

Conservation Actions Proposed
The following information refers to the species's European range only: Artificially constructed nesting sites in coastal locations such as beaches of bare shingle and islands or rafts covered with sparse vegetation are successful in attracting breeding pairs of this species (Burgess and Hirons 1992). The species responds positively (e.g. breeding numbers increase) to the introduction of cattle grazing on coastal grasslands, possibly as a result of reduced vegetation cover allowing improved predator detection (Olsen and Schmidt 2004). Pollution of wetland habitats, land reclamation, infrastructure development and human disturbance at key breeding sites needs to be stopped.

Acknowledgements

Text account compilers
Ashpole, J, Butchart, S., Ekstrom, J., Malpas, L.


Recommended citation
BirdLife International (2017) Species factsheet: Recurvirostra avosetta. Downloaded from http://www.birdlife.org on 23/11/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 23/11/2017.