Birds on this list fall into several categories. Breeding may even occur, but these species have never been abundant here. A host of other birds qualifies for this category, and could be added to the table, producing a very different looking situation on paper. The Ipswich sparrow, once considered a separate species, is now classified as a lighter coloured race of the savannah sparrow. The world population of Ipswich sparrows spends its breeding season in parts of Nova Scotia.
Roseate terns exist here at very low population levels.
Longs bulrush and piping plover are examples of species threatened globally. The Acadian whitefish is endangered, with the world population located in a few Nova Scotian watersheds. The short-tailed swallowtail butterfly is thriving in Cape Breton, but is listed since that is the sole place where one can find them. This committee, which represents government and private agencies, reviews scientific reports on species found across Canada. Threatened species are likely to become endangered if the pressures from human or natural causes that make them vulnerable are not reversed.