Two animals have a similar appearance, consume similar food, and live in a similar environment. can you say that their niches are identical? why or why not?

Well, many times animals may look alike and eat the same food because they are adapting to there invirment. For example there may be many diffrent species of birds that look similar and eat the same food but that does not mean they are of the same kind of bird, over time the birds that have the right body shape to collect food in that invirment will survive while the others perish. This will make the birds look alike while in all they are not of the same species in any way. 
Hope this helps