Thank you.
A notable feature of Brownsea Island -- for those who like that kind of thing -- is that it and the Isle of Wight (the latter on a much bigger scale and with far greater numbers) are the last genuine havens / refuges in the south of Britain, for the British red squirrel (the alien grey ones can't get across the water).
There is another -- very different -- British island situation, featuring two different populations of less-than-common wildlife species, of interest to naturalists: the two different species there, have had problematic dealings with each other; which matter, and human involvement therewith, has been in the news in the past couple of years -- some controversy involved.
What is the place; and what are the two species of creature, concerned?