Complex sentence: The Great Reed Warbler undergoes marked long-term population fluctuations, and it is able to expand its range quickly when new habitat becomes available, this common and widespread bird is considered a Species of Least Concern by the IUCN.
Split into simpler sentences: The Great Reed Warbler undergoes marked long-term population fluctuations, and it is able to expand its range quickly when new habitat becomes available. This common and widespread bird is considered a Species of Least Concern by the IUCN.