Recurvirostra Avosetta -- Linnaeus, 1758
Total Page：16
File Type：pdf, Size：1020Kb
Recurvirostra avosetta -- Linnaeus, 1758 ANIMALIA -- CHORDATA -- AVES -- CHARADRIIFORMES -- RECURVIROSTRIDAE Common names: Pied Avocet; Avocet; Avocette à tête noire European Red List Assessment European Red List Status LC -- Least Concern, (IUCN version 3.1) Assessment Information Year published: 2015 Date assessed: 2015-03-31 Assessor(s): BirdLife International Reviewer(s): Symes, A. Compiler(s): Ashpole, J., Burfield, I., Ieronymidou, C., Pople, R., Van den Bossche, W., Wheatley, H. & Wright, L. Assessment Rationale European regional assessment: Least Concern (LC) EU27 regional assessment: Least Concern (LC) In Europe this species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence 10% in ten years or three generations, or with a specified population structure). The population trend appears to be fluctuating, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (30% decline over ten years or three generations). For these reasons the species is evaluated as Least Concern in Europe. Within the EU27 this species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence 10% in ten years or three generations, or with a specified population structure). 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). For these reasons the species is evaluated as Least Concern in the EU27. Occurrence Countries/Territories of Occurrence Native: Albania; Armenia; Austria; Azerbaijan; Belarus; Belgium; Bulgaria; Croatia; Cyprus; Czech Republic; Denmark; Estonia; France; Georgia; Germany; Greece; Hungary; Italy; Macedonia, the former Yugoslav Republic of; Malta; Moldova; Montenegro; Netherlands; Norway; Poland; Portugal; Romania; Russian Federation; Serbia; Slovakia; Slovenia; Spain; Sweden; Switzerland; Turkey; Ukraine; United Kingdom Vagrant: Faroe Islands (to DK); Finland; Iceland; Latvia; Luxembourg; Gibraltar (to UK) Population The European population is estimated at 58,400-74,300 pairs, which equates to 117,000-149,000 mature individuals. The population in the EU27 is estimated at 51,700-59,300 pairs, which equates to 103,000-119,000 mature individuals. For details of national estimates, see Supplementary PDF. Trend In Europe the population size is estimated to be fluctuating. In the EU27 the population size is estimated to be stable. For details of national estimates, see Supplementary PDF. Habitats and Ecology 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 (Pierce and Boesman 2013). The species is present all year round in parts of Western Europe (Hayman et al. 1986, Pierce and Boesman 2013). It breeds from April to August in large colonies (Pierce and Boesman 2013) usually of between 10 and 70 pairs (Johnsgard et al. 1981). The species breeds in flat open areas (Pierce and Boesman 2013) on shallow saline or brackish wetlands (Johnsgard et al. 1981, Hayman et al. 1986, Urban et al. 1986, Snow and Perrins 1998, Pierce and Boesman 2013) 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, pools, coastal lagoons, estuaries, saltpans (Pierce and Boesman 2013), 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). Outside of the breeding season the species inhabits coastal and inland saline lakes and mudflats, lagoons, pools, saltpans, estuaries (Pierce and Boesman 2013), sandy beaches, river deltas and flood-plains (Urban et al. 1986). It rarely occurs on inland freshwater lakes and rivers (Urban et al. 1986, Pierce and Boesman 2013) but may forage on agricultural land (Pierce and Boesman 2013). Its diet consists predominantly of aquatic invertebrates 4–15 cm long including aquatic insects (Pierce and Boesman 2013) (e.g. small beetles, midges and brine flies) (Johnsgard et al. 1981), crustaceans (Pierce and Boesman 2013) (e.g. Corophium spp.) (Johnsgard et al. 1981), oligochaete and polychaete worms, and molluscs, as well and small fish (Pierce and Boesman 2013) (e.g. sole) (Urban et al. 1986) and plant matter (Pierce and Boesman 2013) (e.g. seeds and small roots) (Urban et al. 1986). The nest is a scrape (Pierce and Boesman 2013) 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 and neighbouring nests are usually one metre apart (Hayman et al. 1986) or occasionally as close as 20–30 cm (Urban et al. 1986). Habitats & Altitude Habitat (level 1 - level 2) Importance Occurrence Grassland - Temperate suitable breeding Marine Coastal/Supratidal - Coastal Brackish/Saline Lagoons/Marine Lakes suitable breeding Marine Coastal/Supratidal - Coastal Brackish/Saline Lagoons/Marine Lakes suitable non-breeding Marine Intertidal - Mud Flats and Salt Flats suitable non-breeding Wetlands (inland) - Permanent Inland Deltas suitable breeding Wetlands (inland) - Permanent Inland Deltas suitable non-breeding Wetlands (inland) - Permanent Saline, Brackish or Alkaline Lakes suitable breeding Wetlands (inland) - Permanent Saline, Brackish or Alkaline Lakes suitable non-breeding Wetlands (inland) - Seasonal/Intermittent Freshwater Lakes (over ha) suitable breeding Wetlands (inland) - Seasonal/Intermittent Freshwater Lakes (over ha) suitable non-breeding Wetlands (inland) - Seasonal/Intermittent Saline, Brackish or Alkaline Lakes and suitable breeding Flats Wetlands (inland) - Seasonal/Intermittent Saline, Brackish or Alkaline Lakes and suitable non-breeding Flats Altitude max. 3000 m Occasional altitudinal limits Threats The species is threatened in Europe by the pollution of wetlands with polychlorinated biphenyls (PCBs), insecticides, selenium, lead and mercury (Pierce and Boesman 2013). Important wintering sites (e.g. in Portugal) are also threatened by infrastructure development (Pierce and Boesman 2013), 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. Threats & Impacts Threat (level 1) Threat (level 2) Impact and Stresses Agriculture & Agro-industry Timing Scope Severity Impact aquaculture farming Ongoing Majority (50-90%) Unknown Unknown Stresses Ecosystem degradation Agriculture & Annual & perennial Timing Scope Severity Impact aquaculture non-timber crops Ongoing Minority (<50%) Slow, Significant Low Impact (scale unknown/ Declines unrecorded) Stresses Ecosystem degradation Threats & Impacts Threat (level 1) Threat (level 2) Impact and Stresses Biological resource Fishing & harvesting Timing Scope Severity Impact use aquatic resources Ongoing Minority (<50%) Slow, Significant Low Impact Declines Stresses Ecosystem degradation Climate change & Droughts Timing Scope Severity Impact severe weather Ongoing Minority (<50%) Slow, Significant Low Impact Declines Stresses Ecosystem degradation Human intrusions & Recreational Timing Scope Severity Impact disturbance activities Ongoing Minority (<50%) Slow, Significant Low Impact Declines Stresses Species disturbance Invasive and other Avian Influenza Timing Scope Severity Impact problematic Virus (H subtype) Future Majority (50-90%) Slow, Significant Low Impact species, genes & Declines diseases Stresses Species mortality Invasive and other Clostridium Timing Scope Severity Impact problematic botulinum Past, Likely to Majority (50-90%) Slow, Significant Past Impact species, genes & Return Declines diseases Stresses Species mortality Invasive and other Unspecified species Timing Scope Severity Impact problematic Ongoing Minority (<50%) Slow, Significant Low Impact species, genes & Declines diseases Stresses Species mortality Invasive and other Unspecified species Timing Scope Severity Impact problematic Ongoing Minority (<50%) Slow, Significant Low Impact species, genes & Declines diseases Stresses Species mortality Natural system Abstraction of Timing Scope Severity Impact modifications surface water Ongoing Minority (<50%) Slow, Significant Low Impact (unknown use) Declines Stresses Ecosystem degradation Natural system Other ecosystem Timing Scope Severity Impact modifications modifications Ongoing Minority (<50%) Slow, Significant Low Impact Declines Stresses Ecosystem degradation Pollution Agricultural & Timing Scope Severity Impact forestry effluents Ongoing Minority (<50%) Slow, Significant Low Impact (soil erosion, Declines sedimentation) Stresses Ecosystem degradation Pollution Herbicides and Timing Scope Severity Impact pesticides Ongoing Majority (50-90%) Slow, Significant Medium Impact Declines Stresses Ecosystem degradation; Species mortality Pollution Industrial & military