Complex sentence: One of the smallest petrels, Cook's petrel is typically in length with a wingspan and a weight of around 200 g. Its colouration is typical of gadfly petrels: pale grey upperparts with a dark grey "M" on the wings and white underparts.
Split into simpler sentences: One of the smallest petrels, Cook's Petrel is typically in length with a wingspan and a weight of around 200g. Its coloration is typical of gadfly petrels: pale gray upperparts with a dark grey'M' on the wings; white underparts.