Sentence:  These are E. olitor, which is similar to E. melanogaster but smaller in size, with dark greyish-brown upperparts with pale <WSD>frosted tips</WSD>; and E. miletus, which is similar in size and colour to E. cachinus but with a relatively shorter tail and higher skull profile. 
Meaning of the word marked with <WSD> tags:  White or light coloration at the ends of darker feathers or fur on a bird or mammal.