Complex sentence: In summer it has a distinctive breeding plumage, with a pinkish breast, grey head and pale supercilium (Alström & Mild, 1996); the Rock Pipit's subspecies "littoralis" in summer plumage is very close in outward appearance to the Water Pipit however.
Split into simpler sentences: In summer it has a distinctive breeding plumage, with a pinkish breast, grey head and pale supercilium (Alström & Mild, 1996). The Rock Pipit's subspecies "littoralis" in summer plumage is very close in outward appearance to the Water Pipit however.