Complex sentence: The European Nightjar does not build a nest, and its two grey and brown blotched eggs are laid directly on the ground; they hatch after about 17--21 days and the downy chicks fledge in another 16--17 days.
Split into simpler sentences: The European Nightjar does not build a nest, and its two grey and brown blotched eggs are laid directly on the ground. The eggs hatch after about 17--21 days and the downy chicks fledge in another 16--17 days.