BETA-FOR_SP9_BreedingSuccess_2022/2023

one-time sampling + rapid assessment 2023 ################ In 2022 we monitored 360 nest boxes and in 2023, 216 nest boxes. Two nest boxes were installed in each patch, with a minimum distance of 20 m between them. The nest boxes were attached to the trunk of a randomly selected tree at a height ranging between 1.50 m and 1.70 m. In patches with forest gaps, the nest boxes were mounted on tree trunks at the edge of the gap approximately 15 m from the gap center and within the first tree line of the surrounding closed forest. The orientation of the entrance hole of the nest boxes was not standardized to imitate the random distribution of natural tree cavities. The commercially available nest boxes were made from wood concrete and featured a front door opening, a nest chamber of 12 cm in diameter, and an entrance hole of 32 mm in diameter (produced by SCHWEGLER Vogel- u. Naturschutzprodukte GmbH, Germany, nest box type 1B). Nest boxes were placed at the beginning of March and surveyed bi-weekly from the beginning of May until the end of July following the inspection procedure described by Hochrein et al. (2022). We counted eggs (alive/ dead) and noted if they were warm (incubated) or cold as well as the number of nestlings (alive/ dead) and their development stage (1= no plumage, 2= developing plumage, 3= complete plumage). The species was identified visually by the adult bird or fully developed nestling or by egg characteristics (relative size and color). Breeding success variables were determined by interpreting registered events, e.g. we assumed that nestlings had fledged when nests with previously incubated eggs or nestlings were empty and at least 14 days had passed since potential hatching (Hochrein et al. 2022). ################ We greatly acknowledge the help of: Michael Junginger, Andrea Ingrosso, Katharina Kallnik, Manuel Mauermann, Kim Zimmermann, Noelle Demuth, Adèle Kieffer, Interns of the Bavarian Forest Nationalpark and all other assistants