Swedish Bird Survey: Winter point count routes (Vinterpunktrutterna)

Study Extent

Geography: The winter point count routes are distributed across the whole of Sweden, and there are routes present in all of the 21 Swedish counties. However, the routes are concentrated to the more populated southern half of the country. Point count routes are personal and the position of the route (and the 20 individual points) is determined by the surveyor who initiates it (a so called “free choice” monitoring scheme). Timing and frequency: The winter season is divided into five survey periods, each lasting for 21 days including three weekends. 1: 5–25 October 2: 10–30 November 3: 19 December – 8 January (the main survey period) 4: 24 January – 13 February 5: 1–21 March The project leaders recommend the surveyor to choose one of three survey plans depending on the amount of time and effort he or she is able to spend (but all survey data are accepted regardless of when within the five periods they are collected): Plan 1: The winter point count route is surveyed just once, and then during period no. 3. Plan 2: The route is surveyed twice, and then during periods no. 3 and 5. Plan 3: The route is surveyed during all five periods. Surveying during all five periods allows the tracking of invasions and other movement patterns. It can potentially also allow calculations of winter mortality. Surveying during period no.5 can also be regarded as an early spring survey of breeding non-migrants as well as provide information about changes in the arrival of early migrants. Surveys should preferably be undertaken +/- 5 days of when it was done in year 1. Surveying should start at the same time in relation to sunrise as on the first occasion it was surveyed, +/- a maximum of 30 minutes, and it is recommended to start early morning. The 20 points should be surveyed in the same order every year. A route does not have to be surveyed every year. Since the routes are (in the vast majority of cases) personal, they are no longer counted once the surveyor stops counting this particular route. Following the same principle, new routes can be initiated.

Sampling

Winter point count routes consist of 20 separate positions (points), situated around 300 m or more apart in dense forest and around 400 m or more apart in open terrain, to minimize the risk of double-counting. Birds are counted while the surveyor is standing still for 5 minutes at each point. All birds seen or heard shall be registered no matter how near or far from the point they are. Only birds identified to species shall be included, except crossbills that may (when necessary) be registered at the genus level. The surveyor’s method of transport between points is also registered (on foot or skis, by bike or moped, by car or motorcycle, other). The amount of snow on the ground is also registered (bare ground, snow covered ground, very thin or patchy cover of snow).

Quality Control

Data is checked and validated by the project leaders, specifically species identity, numbers and geographical location. Confidence in the data is good.

Method steps

1. See sampling description.

All bird species in Sweden occurring naturally in the wild are included in the survey. Species with a security class 4 or higher (according to the Swedish species information centre (Artdatabanken)) are not shown in this dataset. Currently these species are: Lesser white-fronted goose (fjällgås; Anser erythropus) Golden eagle (kungsörn; Aquila chrysaetos) Spotted eagle (större skrikörn; Clanga clanga) White-tailed eagle (havsörn; Haliaeetus albicilla) Pallid harrier (stäpphök; Circus macrourus) Peregrine falcon (pilgrimsfalk; Falco peregrinus) Gyrfalcon (jaktfalk; Falco rusticolus) Barn owl (tornuggla; Tyto alba) Eagle owl (berguv; Bubo bubo) Snowy owl (fjälluggla; Bubo scandiacus) White-backed woodpecker (vitryggig hackspett; Dendrocopos leucotos)

1. Animalia
   common name: Animals rank: kingdom
2. Chordata
   common name: Chordates rank: phylum
3. Aves
   common name: Birds rank: class

All data is collected within Sweden.