LC
Falcated Duck Mareca falcata



Justification

Justification of Red List category

This species has a very 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 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). The population size is large, and 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 population size of this species is assumed to be moderately large, based principally on coordinated counts from the non-breeding grounds. A previous estimate of 78,000-89,000 (Cao et al. 2008) is now considered too precautionary, with a revised number of at least c.132,500 derived from a count of c.125,000 in the Yangtze River floodplain in 2019/2020 (Meng 2019, Zhang et al. 2020), c.1,100 in the Democratic People's Republic of Korea, 1,500–4,000 in Japan, and c.2,500–6,000 birds in the Republic of Korea; small numbers elsewhere in South-East Asia counted as part of the Asian Waterbird Census total fewer than 50 birds (Wetlands International 2022). On the assumption that these coordinated counts may have missed some—but unlikely many—birds, the total population is estimated here to be 132,500-150,000 birds, or (assuming a ratio of 0.66), 87,000–100,000 mature individuals.

Trend justification
Using WPE5 data (Wetlands International 2012) and that collected subsequently (see Langendoen et al. 2021 for method), the International Waterbird Census determined an uncertain trend that fell into the bracket of likely stable (growth rate c.1.03). In China, studies by Meng (2019) and Zhang et al. (2020) portray a complex picture, where numbers in the Yangtze River floodplain have likely increased (between 2004/2005 and 2019/2020), while those in coastal areas have declined. For example, at repeat-effort sites in the Yangtze floodplain numbers at some localities have surged by more than 50% since 2004/05, but at coastal sites, the species has evidently declined, e.g.: from 5,660 in 2006/2007 to 1,200 in 2018/19 in Hangzhou Wan, Zhejiang (Zhang et al. 2020). The reasons for this increase are unknown, and it is unclear whether these reflect a genuine increase in the global population, or a redistribution of birds from elsewhere in East Asia. The population in Japan is generally considered stable (Kasahara and Koyama 2010) while declines have recently been noticed in South Korea (Moores et al. 2014). Given that the numeric gains observed in the Yangtze floodplain far exceed the plausible losses from South Korea and coastal areas of China, it is difficult to conclude these data are indicative of a global decline over the past three generations (11.5 years: 2011–2023). Evaluating the global trend, Wetlands International (2022) consider the global trend to be stable or increasing; precautionarily the former is accepted here.

Distribution and population

Breeds in south-east Siberia, Russia, south to northern Mongolia, China and Japan. Birds then migrate south, with most wintering in the Korean Peninsula and (especially) China. Smaller numbers winter more widely across south and south-east Asia, from north-east India, Nepal (rare) and Bangladesh east to Myanmar, Thailand, Lao PDR (numerically few records, but probably regular) and Viet Nam.

Ecology

The species breeds by water-meadows and lakes in lowland valleys, both in open and partly wooded areas. It winters on lowland rivers, lakes, flooded meadows, and, less frequently, coastal lagoons and more rarely estuaries (Madge and Burn 1988). Zhang et al. (2020) found different habitat use during different migration periods, with birds in spring more confined to water and more rarely croplands, while those in autumn mostly used grasslands and croplands. In winter, birds were mostly found using open water near emergent vegetation. A large majority of birds (82%) use stopover sites that are inland (i.e. not coastal).

Threats

Hunting for food was probably the biggest threat to this species historically, although this is now likely to affect few birds at only a local scale. A larger threat is likely caused by habitat loss and degradation, particularly the eutrophication and water pollution at some sites in eastern China; land reclamation has also impacted some wintering sites (Zhang et al. 2020). Given that the global population is suspected to be stable, neither habitat loss/degradation, or hunting, are thought to be driving global population declines, although it is acknowledged that in eastern China they may either be causing localised declines, or causing the redistribution of birds to sites further west. 

Conservation actions

Conservation Actions Underway
The species occurs in a number of protected areas. Protected area designations are thought to have benefitted this species, with the Chen Lake and Wang Lake Nature Reserves declared Ramsar sites in 2013 and 2018 respectively (Zhang et al. 2020).

Conservation Actions Proposed
Continue to monitor non-breeding populations (see, e.g., Zhang et al. 2020) and, where possible, breeding ones.

Identification

48-54 cm. Relatively bulky dabbling duck. Breeding male unmistakeable, with grey body, large, maned head with green and bronze iridescence, white throat, buff and black undertail-coverts, and elongated, arched tertials. Female and eclipse plumage male fairly uniform dark brown, with paler buff belly. Similar spp. Female and eclipse male best separated from other Anas species by combination of buff belly, greyish legs, and distinctive shape: relatively short, heavy, but bouyant body with rather long dark grey bill. Voice On breeding grounds, male has a short, low whistle, followed by a wavering uit-trr. Female has a hoarse quack.

Acknowledgements

Text account compilers
Berryman, A.

Contributors
Baral, H.S., Barter, M., Cao, L., Chan, S., Tordoff, A.W., Butchart, S., Taylor, J. & Mahood, S.


Recommended citation
BirdLife International (2024) Species factsheet: Falcated Duck Mareca falcata. Downloaded from https://datazone.birdlife.org/species/factsheet/falcated-duck-mareca-falcata on 22/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 22/12/2024.