Many passerines initiate migration soon after sunset and fly until early morning. It is however unclear how this pattern is affected by the large differences in night length that birds experience at different latitudes and with seasonal progression. Using weather radar data we can identify the start and end of bird migratory movements at 14 different sites in Sweden, ranging from Kiruna to Ängelholm. Comparing the migratory pattern at different night lengths will give us clues to what cues birds use to initiate migration, and what factors shape nocturnal migration. I am now looking for a motivated student to delve into our large dataset of weather radar data to quantify nightly migration activity, and then analyze this data in relation to night length at different sites and times.
Contact: Cecilia Nilsson, cecilia.nilsson@biol.lu.se