Eternal sunshine on the flower-spotted ground : Investigating diel rhythms during midnight sun on high-Arctic pollinators

Abstract: With over 600 articles about terrestrial invertebrates in Svalbard we still lack basic knowledge about pollinator-plant interactions in this part of the high-Arctic. It has never before been investigated how the activity of pollinators varies over a 24-hour timeframe in the high Arctic. Insects in the lower Arctic have been shown to have their peak foraging around noon but as Svalbard experiences midnight sun during the whole summer season pollinators could potentially forage any time during the 24-hour day. In this study pictures were taken every minute over cushions of Silene acaulis, capturing visiting pollinators during 5 days around the beginning of July 2019. Pollinators showed no higher abundance around noon. Instead, no significant difference in the abundance of pollinators was found between the hours of the 24-hour timeframe. No significant connection between the abundance of insects and temperature was found as well as no significant connection between the abundance of insects and wind. The results in this study can contribute to fill the knowledge gap of pollinator-plant interactions in Svalbard and show the need for more research about pollinators temporal dynamics in the high-Arctic.