LC
Snow Bunting Plectrophenax nivalis



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). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely 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.40,000,000 individuals (Rich et al. 2004). The European population is estimated at 1,230,000-2,310,000 pairs, which equates to 2,470,000-4,630,000 mature individuals (BirdLife International 2015). Europe forms approximately 20% of the global range, so a very preliminary estimate of the global population size is 12,350,000-23,150,000 mature individuals, although further validation of this estimate is needed.

Trend justification
This species has undergone a large and statistically significant decrease over the last 40 years in North America (-63.6% decline over 40 years, equating to a -22.3% decline per decade; data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007). The European population trend is unknown (BirdLife International 2015).

Ecology

The species is found in treeless, uncultivated barren rocky terrain, usually near snow. It also uses sea cliffs and commonly nests near or even in human settlements. Outside the breeding season it occupies open fields, shingle beaches, saltmarshes, sand dunes, and stubble fields. In Greenland pair formation occurs by late May. It breeds from mid-May to July in Iceland, late May in Scotland and pair formation occurs in early June in Canada. It is monogamous and the nest is a thick cup of dry grass and moss, lined with finer grasses, fur and feathers. It is sited in a variety of places, often in a crevice or crag in some rocks, but will also use artificial sites such as buildings and nestboxes. Clutches are two to eight eggs. The diet is primarily seeds but in the breeding season it will take small invertebrates. The species is migratory (Rising 2016).

Threats

Declines in Europe of birds wintering in coastal areas of the southern North Sea since c. 1970 are attributed to huge embankment projects and intensified grazing, which have destroyed saltmarshes (the preferred foraging habitat of the species) (Rising 2016). The species is also likely threatened by future climate change (Virkkala et al. 2008).

Conservation actions

Conservation Actions Underway
Bern Convention Appendix II. Since 1990 grazing around the southern North Sea has been greatly reduced and no further embankment projects are planned, which has allowed this species to begin to recover (Rising 2016).

Conservation Actions Proposed
To minimise the impacts of climate change large areas of continuous habitats should be preserved and protected in a connected reserve network (Virkkala et al. 2008).

Acknowledgements

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


Recommended citation
BirdLife International (2017) Species factsheet: Plectrophenax nivalis. Downloaded from http://www.birdlife.org on 23/10/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 23/10/2017.