y on warm,
sunny afternoons. Often several were calling within an area of a few
square yards, answering each other and maintaining a regular sequence.
In the last week of May rains were frequent, and the precipitation
totalled 2.09 inches. On June 1 and 2 also, there were heavy rains
totalling 2.26 inches. On the evening of June 2 many frogs were calling
at a pond 1/2 mile south of the Reservation, and one was heard at the
pond on the Reservation. By the evening of June 4, dozens were calling
in shallow water along the edge of this pond in dense _Polygonum_ and
other weeds. There was sporadic calling even in daylight and there was a
great chorus each evening for the next few days, but its volume rapidly
diminished.

In mid-June a system of drift fences and funnel traps was installed 200
yards west of the pond in the dry bottom of an old diversion ditch
leading from the pond. The ditch constituted the boundary between
bottomland pasture and a wooded slope, and therefore was a natural
travelway. The object of the installation was to intercept and catch
small animals travelling along the ditch bottom. The drift fence was
W-shaped, with a funnel trap at the apex of each cone so that the
animals travelling in either direction would be caught. The numbers of
frogs caught from time to time during the summer provided information as
to their responses to weather in migrating to the pond.

TABLE 1. NUMBERS OF FROGS CAUGHT WITHIN TWO DAYS AFTER RAIN IN FUNNEL
TRAPS IN 1954, FROM MID-JUNE, TO THE TIME OF FIRST FROST.

Date Precipitation No. of
in inches caught frogs
July 1 2.02 8
July 10 .11 none
July 16 1.26 none
July 20-21 .94 3
July 24 .38 2
July 28 .29 none
August 1-2 3.22 31
August 6-7-8 2.43 none
August 12 .28 none
August 16 .29 none
August 19-22 .70 none
August 27-28 1.05 none
September 9 .50 none
September 29-30 .38 none
October 4 .74 none
October 12-14 3.51 none

From the positions of the traps and drift fences, it was obvious that
all of the frogs that were caught were travelling toward the pond.
Capture of an equal number moving a