In the Church of England (which I'm not going to begin to explain), vicar is the title given to parish priests. Vicars wear a variety of different vestments but are typically seen in black and white robes like that in the picture. When you see a picture of a vicar, or any other priest type person for that matter, you have an image not only of that person's physical appearance but also of their role in the community.
In Charles Elton's 1927 book on 'Animal Ecology' he says:
"[W]hen an ecologist says 'there goes a badger,' he should include in his thoughts some definite idea of the animal's place in the community to which it belongs, just as if he had said, 'there goes the vicar.'"
This is a very evocative illustration of the 'niche' concept.
I'm sometimes a little reluctant to mention this to American students because I feel obliged to explain a little about vicars and badgers. European badgers are more distinctly black and white striped than their American equivalents so what Elton was saying was that we don't just think of a vicar as a person in black and white clothing, and we shouldn't think of a badger like that. We should try to think of the animals' place in the community.
(Contrary to the opinion of some, there is no such thing as a 'giant man-eating badger'. I almost wished I had spent my life in the British military just so I could have been the person to make the following statement:
UK military spokesman Major Mike Shearer said: "We can categorically state that we have not released man-eating badgers into the area." You can read the full story here.)