Stopover behaviour of migratory songbirds at a small desert oasis in Southern Morocco

Every year millions of migratory birds travel from their breeding grounds in Europe across the Mediterranean Sea and Sahara Desert to their wintering grounds in Sub-Saharan Africa and back. In spring, breeding season follows the northward migration, so an energy-efficient migration or early arrival date at the breeding grounds can prove advantageous for an individual to ensure a successful breeding season. Depending on species and individual factors birds use different migration strategies. Most of these strategies include at least one stationary period, a stopover, to rest and refuel depleted energy reserves. The goal of this thesis was to determine the stopover behaviour of migratory songbirds at a small desert oasis in the Sahara Desert, what structures of the local vegetation they used and to investigate how external factors affected this behaviour. To do so we conducted behavioural observations at the Yasmina oasis near Merzouga in Southern Morocco during the spring of 2024. We surveyed randomly selected tamarisks in the oasis and noted all birds that stayed in this tree during our observation session as well as their behaviour. We compared the occurrences of the different species and our three behavioural categories (Foraging, Movement or Resting) with data on temperature, wind, date, daytime and the characteristics of the tree. The results confirmed findings from Maggini et. al. (1) – we observed the most birds foraging, but they showed more resting behaviour during midday, at high temperatures or strong winds. Additionally, they preferably used high trees with a dense foliage cover.