Breeding calls of all species and subspecies of _Ptychohyla_ were
recorded in the field. Obtaining series of calls of _Ptychohyla_ is
difficult because these frogs call mostly from vegetation along
roaring mountain streams and only by locating a calling frog some
distance from the water or along a quiet stretch of the stream can
good recordings be obtained. For example, four individuals of _P.
spinipollex_ were recorded, but only one recording was sufficiently
free of background noise to be analyzed.
Analysis of breeding calls supports the division of the genus
_Ptychohyla_ into two groups of species. The call of each member of
the _Ptychohyla euthysanota_ group consists of a single long note,
whereas the call of species in the _Ptychohyla schmidtorum_ group
consists of a series of short notes. Since no differences were found
between the calls of subspecies of any given species, the following
discussion of breeding calls pertains to species. These calls are
described briefly below and at greater length in the systematic
accounts farther on. Audiospectrographs of the breeding calls are
shown in Plate 11, and comparisons of the characteristics of the calls
are given in Table 3.
[Illustration: PLATE 11
Audiospectrographs of the breeding calls of the
five species of _Ptychohyla_:
(A) _P. spinipollex_ (KU Tape No. 41),
(B) _P. euthysanota macrotympanum_ (KU Tape No. 48),
(C) _P. leonhardschultzei_ (UMMZ Tape No. 525),
(D) _P. schmidtorum chamulae_ (KU Tape No. 52),
(E) _P. ignicolor_ (UMMZ Tape No. 526).]