very well for
their safe harborage, but when it comes to protecting the larger birds
and mammals we see how easily the natural balance of life is by some
chance influence destroyed. A capital instance of this difficulty
which arises when preservation is essayed on small areas has recently
been forced on my attention. In Dukes County, Massachusetts, there is
the vanishing remnant of an interesting bird known from the island to
which it is limited as the Martha's Vineyard prairie chicken. It is
closely related to its better known Western kinsman, yet is a distinct
variety. Although the form has apparently developed on the island and
once abounded there, it has dwindled in numbers until there are but
few surviving. In the hope of providing a safe refuge for the remnant,
I have for a number of years stopped all shooting on a tract of a
thousand or two acres which is well fitted to supply them with food
and shelter. As they still dwindled, it seemed probable that the foxes
were harming them. This appeared the more likely for the reason that
the fox is not a native of the island, but was introduced a few years
ago by some reckless experimenters. These marauders were cleared away
without good results. Further inquiry made it apparent that the real
enemy of these birds was the feralized domestic cat which has gone
wild from the households, especially from the many homesteads that
have been abandoned. This creature has bred in great numbers and is
now threatening the existence of all birds that rear their broods upon
the ground. It is hardly possible to exterminate them, for the reason
that they are wary, and any systematic hunting of them would prove
exceedingly disturbing to the very timid birds. The result is that
nearly all these birds have left my land for certain plains near by
which are covered with scrub oaks and where there is too little ground
life to attract the cats. In that region, though it has an area of
about thirty thousand acres, the food is scanty; the prairie chickens
dwelling there are likely to perish for lack of the rose-hips which,
in the hill country they have been forced to desert, served to
maintain them at times when the ground was covered with snow.

The lesson which may be drawn from the experience above stated is to
the effect that it is necessary to have a protected field of
sufficient area, and in the proper conditions to keep the balance of
life which arises from the exchange of relations betwe