Chlidonias hybrida -- (Pallas, 1811) ANIMALIA -- CHORDATA -- AVES -- -- Common names: Whiskered ; Guifette moustac 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., Tarzia, M., Wheatley, H. & Wright, L. Assessment Rationale European regional assessment: Least Concern (LC) EU27 regional assessment: Least Concern (LC)

In 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 increasing, 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 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). For these reasons the species is evaluated as Least Concern in the EU27. Occurrence Countries/Territories of Occurrence Native: Albania; Armenia; Austria; Azerbaijan; Belarus; Bosnia and Herzegovina; Bulgaria; Croatia; Cyprus; Czech Republic; France; Germany; Greece; Hungary; Italy; Latvia; Lithuania; Macedonia, the former Yugoslav Republic of; Moldova; Montenegro; Poland; Portugal; Romania; Russian Federation; Serbia; Slovakia; Spain; Switzerland; Turkey; Ukraine Vagrant: Belgium; Denmark; Finland; Iceland; Ireland, Rep. of; Luxembourg; Malta; Norway; Sweden; United Kingdom; Gibraltar (to UK) Population The European population is estimated at 66,300-108,000 pairs, which equates to 133,000-215,000 mature individuals. The population in the EU27 is estimated at 29,500-41,500 pairs, which equates to 59,100-82,900 mature individuals. For details of national estimates, see Supplementary PDF. Trend In Europe the population size is estimated to be increasing. In the EU27 the population size trend is unknown. For details of national estimates, see Supplementary PDF. Habitats and Ecology This species utilises a variety of wetland habitats but shows a preference for freshwater marshlands with scattered pools, particularly where the surrounding vegetation is grazed by cattle or horses (Richards 1990). It frequents inland lakes, rivers, marshes, artificial fish-ponds and drainage-ponds covered with water-lilies (e.g. in Italy) (Gochfeld and Burger 1996), swamps, river pools, reservoirs, large dams, sewage-ponds, flooded saltmarshes (Gochfeld and Burger 1996, Higgins and Davies 1996) and rice-fields. The species breeds from May to early-June (Richards 1990) in monospecific colonies of 10–100 pairs.

The nest is a heap of aquatic vegetation or dry grass, placed either on floating and emergent vegetation over water 60–80 cm deep or resting on the bottom of very shallow water. Clutches are two or three eggs. Its diet consists of terrestrial and aquatic insects (e.g. Dytiscidae, adult and larval Odonata, Orthoptera, flying ants (Gochfeld and Burger 1996) and mosquitoes (Richards 1990)), spiders, frogs, tadpoles, small crabs (Gochfeld and Burger 1996), shrimps (Richards 1990) and small fish. Northern breeding populations of this species are fully migratory (Gochfeld and Burger 1996). After breeding it departs for the wintering grounds from late- July to September, returning again between April and May (Richards 1990). The species sometimes forages singly, but is more common in small groups or larger mixed-species flocks on passage and in the winter (Snow and Perrins 1998). Habitats & Altitude Habitat (level 1 - level 2) Importance Occurrence Artificial/Aquatic - Irrigated Land (includes irrigation channels) suitable breeding Artificial/Aquatic - Irrigated Land (includes irrigation channels) suitable non-breeding Artificial/Aquatic - Seasonally Flooded Agricultural Land suitable breeding Artificial/Aquatic - Seasonally Flooded Agricultural Land suitable non-breeding Marine Intertidal - Salt Marshes (Emergent Grasses) suitable breeding Marine Intertidal - Salt Marshes (Emergent Grasses) suitable non-breeding Wetlands (inland) - Bogs, Marshes, Swamps, Fens, Peatlands suitable breeding Wetlands (inland) - Bogs, Marshes, Swamps, Fens, Peatlands suitable non-breeding Wetlands (inland) - Permanent Freshwater Marshes/Pools (under ha) suitable breeding Wetlands (inland) - Permanent Freshwater Marshes/Pools (under ha) suitable non-breeding Wetlands (inland) - Permanent Saline, Brackish or Alkaline Marshes/Pools suitable breeding Wetlands (inland) - Permanent Saline, Brackish or Alkaline Marshes/Pools suitable non-breeding Wetlands (inland) - Seasonal/Intermittent Freshwater Marshes/Pools (under ha) suitable breeding Wetlands (inland) - Seasonal/Intermittent Freshwater Marshes/Pools (under ha) suitable non-breeding Wetlands (inland) - Seasonal/Intermittent Saline, Brackish or Alkaline Marshes/ suitable breeding Pools Altitude max. 2000 m Occasional altitudinal limits Threats This species suffers from the loss of natural wetlands to land reclamation, dry seasons and an increase in drainage schemes (Hagemeijer and Blair 1997), as well as the canalization of rivers (Tucker and Heath 1994). The species suffers nest destruction from the invasive rodent species Myocastor coypus in Italy (Arduin 1997). Increasing tourism and water sports near breeding colonies result in disturbance and the loss of nesting sites (Tucker and Heath 1994) and many nests are lost to adverse weather. Fishermen collect eggs in Ukraine (Gochfeld and Burger 1996). It is affected by water quality and so pollution from insecticides and eutrophication are a threat (Martí and Moral 2004). In addition the intensification of fisheries and bycatch in fishing nets are issues (Golemansky 2011). 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 Indirect ecosystem effects Agriculture & Marine & Timing Scope Severity Impact aquaculture freshwater Ongoing Majority (50-90%) Unknown Unknown aquaculture (scale unknown/ Stresses unrecorded) Indirect ecosystem effects Biological resource Fishing & harvesting Timing Scope Severity Impact use aquatic resources Ongoing Unknown Unknown Unknown (unintentional effects: (large scale) Stresses [harvest]) Species mortality Threats & Impacts Threat (level 1) Threat (level 2) Impact and Stresses Biological resource Hunting & trapping Timing Scope Severity Impact use terrestrial Ongoing Minority (<50%) Slow, Significant Low Impact (intentional use - Declines species is the target) Stresses Species mortality; Reduced reproductive success Climate change & Temperature Timing Scope Severity Impact severe weather extremes Ongoing Unknown Unknown Unknown Stresses Ecosystem degradation; Indirect ecosystem effects Human intrusions & Recreational Timing Scope Severity Impact disturbance activities Ongoing Majority (50-90%) Unknown Unknown Stresses Species disturbance Invasive and other Coypu (Myocastor Timing Scope Severity Impact problematic coypus) Ongoing Majority (50-90%) Causing/Could Medium Impact species, genes & cause fluctuations diseases Stresses Indirect ecosystem effects; Species mortality Invasive and other Unspecified species Timing Scope Severity Impact problematic Ongoing Unknown Causing/Could Unknown species, genes & cause fluctuations diseases Stresses Species mortality Natural system Other ecosystem Timing Scope Severity Impact modifications modifications Ongoing Majority (50-90%) Causing/Could Medium Impact cause fluctuations Stresses Ecosystem degradation; Indirect ecosystem effects Pollution Herbicides and Timing Scope Severity Impact pesticides Ongoing Unknown Unknown Unknown Stresses Indirect ecosystem effects Pollution Industrial & military Timing Scope Severity Impact effluents (type Ongoing Unknown Unknown Unknown unknown/ unrecorded) Stresses Ecosystem degradation; Indirect ecosystem effects Conservation Conservation Actions Underway Bern Convention Appendix II. The species has been included as a target species in three EU LIFE Projects.

Conservation Actions Proposed The species requires the maintenance of a network of water-bodies with well-developed emergent and floating vegetation to provide sufficient breeding habitat. These areas should be protected from disturbance by the establishment of buffer zones around them. Artificial, anchored rafts may be useful in providing nesting sites on intensively managed water-bodies (Tucker and Heath 1994). Bibliography Arduin, M. 1997. The nutria problem. Informatore Agrario 53(29): 69-70. Gochfeld, M. & Burger, J. (1996). Whiskered Tern (Chlidonias hybrida). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/54045 on 1 April 2015). Golemansky V. (ed.) 2011. Red Data Book of the Republic of Bulgaria. Digital edition, Vol. 2, Animals. BAS-MOEW, Sofia, http://e-ecodb.bas.bg/rdb/en/vol2/ Bibliography Higgins, P. J.; Davies, S. J. J. F. 1996. Handbook of Australian, New Zealand and Antarctic birds vol 3: snipe to pigeons. Oxford University Press, Oxford. Martí, R., & del Moral, J. C. (2004). Atlas de las aves reproductoras de España. Parques Nacionales. Richards, A. 1990. Seabirds of the northern hemisphere. Dragon's World Ltd, Limpsfield, U.K. Snow, D. W.; Perrins, C. M. 1998. The Birds of the Western Palearctic vol. 1: Non-Passerines. Oxford University Press, Oxford. Map (see overleaf)