In the northeastern part of Kansas at least, rocky slopes in open woods
seem to provide optimum habitat conditions. This type of habitat has
been described by several earlier workers in this same area, Dice (1923:
46), Smith (1934: 503) and Freiburg (1951: 375). Smith (1950: 113)
stated that in Kansas this frog is found in wooded areas, and that rocks
are the usual cover, but he mentioned that outside of Kansas it is often
found in mesquite flats that are devoid of rocks. Freiburg's field work
was done almost entirely on the Reservation and was concentrated in
"Skink Woods" and vicinity, where much of my own field work, both before
and afterward, was concentrated. On the Reservation and in nearby
counties of Kansas, the habitat preferences of the ant-eating frog and
the five-lined skink largely coincide. In an account of the five-lined
skink on the Reservation, I have described several study areas in some
detail (Fitch, 1954: 37-41). It was on these same study areas (Quarry,
Skink Woods, Rat Woods) that most of the frogs were obtained.
Although _G. olivacea_ thrives in an open-woodland habitat in this part
of its range, it seems to be essentially a grassland species, and it
occurs throughout approximately the southern half of the Great Plains
region. Bragg (1943: 76) emphasized that in Oklahoma it is widely
distributed over the state, occupying a variety of habitats, with little
ecological restriction. Bragg noted, however, that the species is
rarely, if ever, found on extensive river flood plains. On various
occasions I have heard _Gastrophryne_ choruses in a slough two miles
south of the Reservation. This slough is in the Kaw River flood plain
and is two miles from the bluffs where the habitat of rocky wooded
slopes begins that has been considered typical of the species in
northeastern Kansas. It seems that the frogs using this slough are not
drawn from the populations living on the bluffs as Mud Creek, a Kaw
River tributary, intervenes. The creek channel at times of heavy
rainfall, carries a torrent of swirling water which might present a
barrier to migrating frogs as they are not strong swimmers. The frogs
could easily find suitable breeding places much nearer to the bluffs.
Those using the slough are almost certainly permanent inhabitants of the
river flood plain. The area in the neighborhood of the slough, where the
frogs probably live, include fields of alfalfa and other cultivated
crops, weedy fallow fields, and the marshy margins of the slough. In
these situations burrows of rodents, notably those of the pocket gopher
(_Geomys bursarius_), would provide subterranean shelter for the frogs,
which are not efficient diggers.
The frogs may live in many situations such as this where they have been
overlooked. In the absence of flat rocks providing hiding places at the
soil surface, the frogs would rarely be found by a collector. The volume
and carrying quality of the voice are much less than in other common
anurans. Large breeding choruses might be overlooked unless the observer
happened to come within a few yards of them. Most of the recorded
habitats and localities of occurrence may be those where the frog
happens to be most in evidence to human observers, rather than those
that are limiting to it or even typical of it.
On September 20, 1954, after heavy rains, juveniles dispersing from
breeding ponds were in a wide variety of situations, including most of
the habitat types represented on the Reservation. Along a small dry
gully in an eroded field formerly cultivated, and reverted to tall
grass prairie (big bluestem, little bluestem, switch grass, Indian
grass), the frogs were numerous. Many of them were flushed by my
footsteps from cracks in the soil along the gully banks. In reaching
this area the frogs had moved up a wooded slope from the pond, crossed
the limestone outcrop area at the hilltop edge, and wandered away from
the woods and rocks, out into the prairie habitat. In this prairie
habitat there were no rocks providing hiding places at the soil surface,
but burrows of the vole (_Microtus ochrogaster_) and other small rodents
provided an abundance of subterranean shelter. In the summer of 1955 the
frogs were seen frequently in this same area, especially when the soil
was wet from recent rain. When the surface of the soil was dry, none
could be found and presumably all stayed in deep cracks and burrows.
Anderson (1954: 17) indicated that _G. carolinensis_ in Louisiana
likewise occurs in diverse habitats, being sufficiently adaptable to
satisfy its basic requirements in various ways.