Aythya nyroca | UAE National Red List of Birds

Taxa
Aythya nyroca | (Güldenstädt, 1770)
Location
Countries in Assessment
United Arab Emirates
Country ISO code(s)
ARE
Does the assessment cover a marine EEZ area(s)?
Off
Scope (Assessment)
National
Taxon
Taxonomic Group
Vertebrates
Taxonomic Group Level 2
Birds
Assessed taxon level
Species
Taxon distribution as listed in assessment
The majority of occurrences of this species within the UAE are likely to be of wintering birds or migrant individuals on passage to and from the breeding grounds (Pedersen et al. 2017). Numbers are highest between mid-October and February or early March, when the species is uncommon at wetlands throughout the country (Richardson 1990, Aspinall and Porter 2011, Pedersen et al. 2017). Occasionally, individuals are recorded in the summer months (Pedersen et al. 2017).
Habitats and Ecology
Ecological system type
Terrestrial system
No
Freshwater system
No
Marine system
No
Habitat
Habitat details as listed in assessment
This species occurs at fresh or brackish wetlands overgrown by vegetation (Jennings 2010, Aspinall and Porter 2011). It inhabits ponds, reservoirs, water treatment plants, dams and ornamental lakes, but also sometimes sheltered coastal creeks and lagoons (Richardson 1990, Jennings 2010). It requires shallow water 30-100 cm deep(del Hoyo et al. 1992,;Kear 2005). The species is rather shy and is only found at undisturbed wetlands (Jennings 2010). It forms small groups of usually less than five individuals (Richardson 1990). There is no information available about its diet in the UAE; elsewhere it is omnivorous, but plant material such as seeds, roots and vegetative parts of aquatic plantsdominate its diet (del Hoyo et al. 1992, Kear 2005). Animal matter taken includes worms, molluscs, crustaceans, adult and larval insects, amphibiansand small fishup to 3 cm long (Brown et al. 1982, del Hoyo et al. 1992, Kear 2005). The species is migratory, but little is known about its migratory routes (del Hoyo et al. 1992, Scott and Rose 1996). Individuals wintering in or passing through the UAE may breed in south-central Eurasia. The breeding season lasts from April or May until late June (Madge and Burn 1988, del Hoyo et al. 1992).
Is there a map available in assessment?
Yes
Assessed status
Asessment status in full
Critically Endangered
Assessment status abreviation
CR
Assessment status criteria
D
Assessment rationale/justification
This species has a tiny regular non-breeding population within the UAE. It is assessed here though because it is listed globally, and within the Arabian Peninsula, as Near Threatened. The population trend within the UAE is essentially unknown, although the number of records is increasing, with the creation of new wetland habitats, but with its tiny population size the species qualifies as Critically Endangered under Criterion D, without regional adjustment due to the poor status both globally and within the Arabian Peninsula, as well as with habitat quality potentially deteriorating within the UAE too.
About the assessment
Assessment year
2019
Assessors/contributors/reviewers listed
UAE National Red List Workshop
Affliation of assessor(s)/contributors/reviewers listed on assessment
Government
IGO
Assessor affiliation specific
Government|IGO
Criteria system
Criteria system specifics
IUCN v3.1 + Regional Guidelines v4.0
Criteria system used
IUCN
Criteria Citation
IUCN. 2012. IUCN Red List Categories and Criteria: Version 3.1, Second edition. IUCN, Gland, Switzerland and Cambridge, UK. iv + 32pp pp. And IUCN. 2012. Guidelines for Application of IUCN Red List Criteria at Regional and National Levels: Version 4.0. Gland, Switzerland and Cambridge, UK: IUCN. iii + 41pp.
Endemism
Endemic to region
Not_assigned
Endemism Notes
Is an endemic?: Not_assigned
Conservation
Threats listed in assessment
Within the UAE the main threats to the species are likely from land-use changes and possibly oil pollution, but the severity of these threats are essentially unknown.Across its global range the species faces a large number of threats, outlined below; but it is highly uncertain to what extent such threats impact individuals that visit the UAE.The species is threatened by the degradation and destruction of well-vegetated shallow pools and other wetland habitats(Vinicombe 2000,;del Hoyo et al. 1992,;Kear 2005, Robinson and Hughes 2006)(e.g. changes to the vegetation community, disruption of water regimes, siltation, and increased water turbidity [Robinson and Hughes 2006]) as a result of excessive drainage and water abstraction(Vinicombe 2000,;Grishanov 2006, Robinson and Hughes 2006), peat extraction(Grishanov 2006), eutrophication (from inadequate sewage treatment and nutrient run-off [Robinson and Hughes 2006]), oil pollution(Grishanov 2006), dam and barrage construction, the building of infrastructure on flood-plains (Vinicombe 2000, Robinson and Hughes 2006) and river canalisation(Kear 2005). Changing land management practices such as reed cutting and burning during the breeding season (Petkov 2006), over-grazing (Robinson and Hughes 2006) decreased grazing and mowing of wet meadows(Grishanov 2006), and abandonment (causing succession to scrub) or intensification (causing reversion to open water) of extensively managed fishponds(Vinicombe 2000,;Kear 2005, Petkov 2006, Robinson and Hughes 2006) also threatens the species. The introduction of non-native species has caused further habitat degradation. For example the stocking of lakes with and accidental introduction of Grass Carp Ctenopharyngodon idella has resulted in reductions in macrophyte biomass and corresponding reductions in invertebrate biomass(Kear 2005, Robinson and Hughes 2006), and in Bulgaria an introduced shrub (Desert False Indigo Amorpha fruticosa) is changing the ecological character of wetlands (Robinson and Hughes 2006). Introduced predators such as the Wels Catfish Silurus glanis (Kazakhstan) that predate ducklings, and the Muskrat Ondatra zibethicus (Aral Sea region) have also caused population declines (Robinson and Hughes 2006). Increased drought due to global climate change may pose a threat to the species in part of its range(Vinicombe 2000, Robinson and Hughes 2006). Disturbance by fishing boats and anglers alongside fringe vegetation could cause abandonment of the breeding sites or disrupt the timing of breeding (N. Petkov in litt. 2008). Hunting is another serious threat to the species(Vinicombe 2000,;del Hoyo et al. 1992, Robinson and Hughes 2006). Large numbers are shot on passage in the autumn (e.g. through the Volga delta) and on some wintering grounds<sup>;</sup>(Kear 2005, Balmaki and Barati 2006). Other lower-level threats include lead poisoning (from ingestion of discarded lead shot), fires in areas of reed thickets, peat bogs and woods (Grishanov 2006), entanglement and drowning in fishing nets (Robinson and Hughes 2006<strong style="""">)<strong style=""""> and hybridisation with native species (e.g. Tufted Duck Aythya fuligula and Common Pochard Aythya ferina in Switzerland [Leuzinger 2010]).
Conservation Measures

Conservation measures:
Conservation measures notes:
Required conservation measures:

Further information
History
There are very few records for 1996. The species is thought to have been first recorded in 1986, with slow increases in subsequent years. The species is thought likely to have been Critically Endangered in 1996 on the basis of very small population size, but with no data on trend.
Scientific Name Kingdom Phylum Class Order Family Genus
Aythya nyroca Animalia Chordata Aves Anseriformes Anatidae Aythya