1894
Oct. 11 to
Nov. 21
Concord, Massachusetts.
Resumè of Field Observations.
  Mammals. Musk rats have been exceptionally numerous in
the river this autumn and thus far they have not been
molested to any extent by the shooters while I do not
think that any traps have been set for them. The unusual
number and size of their houses attracts general attention
and comment among the farmers and others who have seen
them. These houses line the river banks all the way from
Fairhaven Bay to Ball's Hill. There are five in one group
and three in another on the Beaver Dam Rapid. Two of
them are at least five feet high and each would make
nearly or quite a full load for a tip cart. Some of the
older farmers & gunners tell me that they have not seen
so many or so large houses on this river for fifteen years
& this is also my own impression.
[margin]Musk rats[/margin]
  Of all the creatures that inhabit the river at this season
the Musk rats are by far the most interesting. I have seen a
great deal of them this autumn for I have almost invariably
started up river at about the time when they were beginning
their nightly wanderings. One evening I counted eighteen
between Ball's Hill and the Minute Man and I frequently
saw twelve or fourteen. As far as I can make out they
all spend the day in holes in the banks and visit their
houses and feeding grounds only after twilight has begun
falling. Many of them have to cross the river for this
purpose and I have noticed that each individual
regularly crosses in the same place. The first come out
of their holes soon after sunset if the weather is clear,
earlier if it be stormy or cloudy. Some evenings they
are very bold – in fact perfectly fearless – swimming about
on the open water in every direction and allowing me