It is at once both far too specific to be of use to others, and too broad. The number of people in the world who want to travel and see squirrels specifically is, I would suggest, far smaller than the number who want to see penguins or elephants or moose. The number, out of that small group, who for some reason insist that the squirrels be on a small island must not be much more than one.
Yet it is a broad question: hundreds, even thousands of islands meet this criteria. Europe and North America are full of islands. There's an area near me called "The 30,000 Islands" and it by no means contains the majority of North American islands. What's more, some very small islands might not have any squirrels on them, but might be near a mainland or other island that does, and then you could see the squirrel. Heck, I could throw a rock a few feet into the lake and balance on it with one foot and see a squirrel. Is that rock now the correct answer to the question? Of course not. In fact, there is no correct answer to the question, or there are thousands, which is the same thing.
How can you improve the question? Ask for something bigger or smaller than your actual desire. Two examples:
- how can I predict my chances of seeing particular wildlife on a given trip? You can use your squirrel-viewing needs as an example, and list a handful of towns or parks or other places-smaller-than-a-country you are thinking of visiting. Good answers here will lead you not just to resources like websites or guidebooks, but teach you how to use those to find out what you want. You may also get some outside-the-box answers like searching on Instagram for pictures of the wildlife and then looking at the geotags. This is a bigger question than you asked, but it's useful to more people, so might stay open.
- is it possible to reach the islands in [specific lake or park] [by bridge, in rented canoes, whatever]? This wouldn't mention squirrels but would focus on the mechanics of your journey. The information would be useful to people who wanted to reach those islands for other reasons, such as a picnic. By making the question smaller, you make it useful to more people.
I can't guarantee either approach will produce a question that will stay open. And you simply must reduce your scope from the entire planet. I think Europe and North America are actually out of scope for you given your location. This should be clear in the question if you intend to still ask "where can I see" type questions. But it would be better to choose the city/region first and then ask questions about that region. You may end up deciding not to visit that region if it's not squirrel-dense enough for you, but the question and answers can still be useful to others.