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In nocturnal songbird migrants, total speed of migration is determined by the time birds stay at stopovers, where they replenish fuel reserves used during previous flights, and by their travel speed. In contrast to factors influencing stopover duration, little is known about individual variation in travel speed which is a combination of birds' ground speed and the time spent flying. The latter is directly affected by nocturnal departure time. Ground speed can be easily tracked, e.g., by radar, but not much is known about when migrants set off within the night, let alone factors influencing its variation. Studying how factors cause variation in nocturnal departure time requires an experimental setup that allows transferring results from indoor experiments, where environmental conditions can be controlled for or manipulated, to the behavior of free-flying birds. Here, we show that the start of nocturnal migratory restlessness "Zugunruhe^of caged songbirds was significantly positively related to their radio-tracked nocturnal departure time the following night. We can now start identifying factors causing individual variation in the start of nocturnal migratory restlessness and transfer these results to departure times within the night. This will improve our understanding of why travel speed, and with that total speed of migration, varies individually and how it is affected by environmental changes.

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Facing increasing human demands on Earth, understanding how endangered species may survive in isolated remnants of natural habitat within heavily transformed landscapes is key to contemporary conservation biology. Against this background we here investigate the factors affecting pond occupancy in the endangered European tree frog (Hyla arborea L.) within an urban landscape, being located in north‐eastern Germany where the species is still fairly common. Our survey revealed that 58 out of 122 ponds were occupied by H. arborea. Ponds with a higher percentage of floating vegetation, being deeper and surrounded by higher percentages of crop fields and forests were more likely to be occupied, while factors associated with urbanization such as the percentage of built‐up area were strongly detrimental. Habitat requirements of H. arborea were complex as occurrence was simultaneously affected by different spatial scales, including the landscape scale, the immediate surroundings of ponds and the ponds themselves. H. arborea avoided highly urbanized areas, but occurred frequently in agricultural areas surrounding the city. The latter suggests that this species is fairly tolerant towards human‐induced transformations, and that vast arable fields yielded positive rather than negative effects on H. arborea occurrence. We conclude that the most important conservation issues for supporting H. arborea populations at the periphery of urbanized areas are (1) maintaining an open (agricultural) landscape structure, (2) providing undisturbed overwintering habitats, and (3) maintaining pond quality by halting shrub and tree encroachment.