Answer:
The author's purpose in this paragraph is to demonstrate the differences in the nesting habits of gulls, western gulls in particular, and other species of birds. Quinlan also conveys the challenges in the aforementioned nesting habits and leads readers to wonder what the impact of such unusual practices may be on western gulls.
Explanation:
Without context, it's difficult to give a more specific answer, but this seems ot be a reasonable assumption of purpose.