My wife and I are birders and we walked down a street with a sig

Town Bank - My wife and I are birders and we walked down a street with a sign that said 'Crest Place.' We wanted to see the many birds that were down by Cox Hall Creek. Someone asked us what we were doing there. We explained that we only wanted to see the egrets. Why would that person ask us that, when we were on a public street, not private property? Aren't we permitted on a street without being harassed?