AVJNF: Vilsted Sø, Odonata survey

Study Extent

The lake Vilsted Sø, North Jutland, Denmark and its vicinities.

Sampling

Dragonfly and damselfly fauna of the lake Vilsted Sø in North Jutland, Denmark was surveyed in five monitoring rounds from May to September 2021. In each round, the investigation took three field days, during which six to eight fixed routes (transects) were thoroughly surveyed (from kayak or in waders). The survey was carried out at the time of day when the activity of the insects is highest, between 10 am and 5 pm (daylight saving time), on days when the following weather conditions were met: - The weather is dry (no precipitation). - The wind speed is max. 4 Beaufort = 8 m / sec. - The temperature is min. 17o C in case of cloudy weather (> 50% cloud cover). - The temperature is min. 13o C in case of sunny weather (<50% cloud cover). The method of registration was: 1) Species identification of all individuals of dragonflies and damselflies seen (within a distance of up to 25 meters from the transect line) using binoculars with low close focus distance (1 meter). 2) Counting the number of individuals. When the density of animals is high (especially the case with certain species of damselflies), a qualified estimate of the order of magnitude is made. 3) Continuous data entry in a mobile phone app. Each entry contains the following data: coordinates, date, species, sex, behavior (where relevant) and number of individuals. In addition, dragonflies and damselflies were registered outside the fixed routes, in order to make the distribution maps of individual species more complete.

Quality Control

N/A

Method steps

1. N/A

1. Odonata
   common name: Dragonflies & Damselflies rank: order

Denmark, North Jutland, Vilsted lake near Ranum and Vilsted