Swedish Bird Survey: Fixed routes (Standardrutterna)

Study Extent

Geography and habitat: In total there are 716 Fixed routes systematically distributed across Sweden in a 25 by 25 km grid. This means that all main habitats are surveyed in a representative manner. Timing and frequency: The survey should be carried out in the main breeding season for the majority of species. Hence the date for the survey will vary across the country (approximately 20 May-5 July). Start time should be 04:00 (+/-30 min), but no earlier than 30 minutes before sunrise. Each route should ideally be surveyed once per year, but each year there are routes that were not surveyed. These are prioritised the following year.

Sampling

General layout: A fixed route consists of eight 1km-line transects and eight 5minute-points, along a 2 by 2 km square. Line transects and points should be considered as two separate surveys. (NOTE: some routes consist of less than eight lines and/or points. This is the case when lines/points end up e.g. in a lake or the sea due routes being distributed in a standardised grid. However, a particular route has the same number of lines and points each year it is surveyed.) A given animal can occur on one point and one line, but double-counting the same animal on two points or two lines should be avoided. All birds (excluding young of the year) and mammals (including young of the year, but see the species list) seen or heard are registered no matter how near or far from the line or point they are. Line transects: Counting is carried out while slowly walking, stopping to listen and watch as necessary, during approximately 30-40 minutes per km depending on the terrain. Point counts: Birds and mammals are counted while standing still for 5 minutes at each point.

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. Since 2011, also the following mammals (approximately, all larger than rodents) are included in the survey: Western European hedgehog, Eurasian red squirrel, Eurasian beaver, European hare, mountain hare, European rabbit, Eurasian lynx, grey wolf, red fox, brown bear, stoat, least weasel, American mink, western polecat, pine marten, wolverine, Eurasian otter, Eurasian badger, wild boar, moose, European roe deer, red deer, fallow deer, harbor seal, grey seal and ringed seal. Species with a security class 4 or higher (according to the Swedish species information centre (Artdatabanken)) are not shown in this dataset at present. Currently these species are: Lesser white-fronted goose (fjällgås; Anser erythropus), Golden eagle (kungsörn; Aquila chrysaetos), White-tailed eagle (havsörn; Haliaeetus albicilla), Pallid harrier (stäpphök; Circus macrourus), Montagu’s harrier (ängshök; Circus pygargus), Peregrine falcon (pilgrimsfalk; Falco peregrinus), Gyrfalcon (jaktfalk; Falco rusticolus), Eagle owl (berguv; Bubo bubo), Snowy owl (fjälluggla; Bubo scandiacus), White-backed woodpecker (vitryggig hackspett; Dendrocopos leucotos), Eurasian lynx (lo; Lynx lynx), Brown bear (brunbjörn; Ursus arctos), Wolverine (järv; Gulo gulo) and Arctic fox (fjällräv; (Vulpes lagopus).

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

All data is collected within Sweden.