Complex sentence: The valley of Bug river and wet areas are the habitat of many birds endangered with becoming extinct: black stork, common sandpiper, common snipe, Eurasian curlew, grey heron, ruff.
Split into simpler sentences: The valley of Bug River and associated wet areas is the habitat of many birds endangered of becoming extinct. These include the: black stork, common sandpiper, common snipe, Eurasian curlew, grey heron, ruff.