You are welcome to answer questions posted in the Ask a Teacher forum as long as your suggestions, help, and advice reflect a good understanding of the English language. If you are not a teacher, you will need to state that clearly at the top of your post. Please note, all posts are moderated by our in-house language experts, so make sure your suggestions, help, and advice house the kind of information an international language teacher would offer. If not, and your posts do not contribute to the topic in a positive way, they will be subject to deletion.
Would you pls explain for me this sentence:
Kittiwakes defeacate over the edge of the nest, which keeps it clean, but this practice, as well as their tendency to leave the nest littered with eggshells, makes its location very conspicuous.
A kittiwake is a kind of seabird. They nest on rocky ledges. To keep the nest free of excrement, the birds do not use the nest for a toilet, but go to the bathroom over the edge of the nest. This leaves conspicuous discoloration around the nest. Pieces of eggshell are also left in the nest after the young hatch. The white eggshell and discoloration make the nest area quite visible and easy to locate for predators like larger gulls and mammals.
.
How to understand? 
Linear Mode
