CALIFORNIA TOAD. Bufo boreas halophilus Baird and
large, adult females being 4-5 inches long (males 3-1/2 inches or less);
skin rough with numerous large 'warts' (pl. 60a); a large raised
gland (parotoid) on each shoulder behind ear region; space between the
two glands broader than width of one gland; pupil round. Upper surface
grayish green, with numerous large irregular spots or streaks of black;
a conspicuous streak of white extends along middle of head and back;
under surface dull yellow, sometimes with numerous small black spots.
Voice: A rather deep-toned prolonged trilling, with rhythm
resident in western part of Yosemite region, below 4500 feet altitude.
Recorded from Yosemite Valley westward to Snelling and Lagrange. Lives
in sheltered situations on or below ground, coming forth at dusk of
evening. Solitary except at spawning time.
43A closely related
subspecies, the Northwestern Toad, Bufo boreas boreas Baird and
Girard, occurs at Walker Lake and near Williams Butte. It is
distinguished from the California Toad by darker coloration and by
having the spread of the hind foot (from tip of first toe to tip of
fifth toe) more than 36 per cent of body length. The habits of the two
subspecies are alike, so far as known.
The California Toad is common in the lowland and
foothill territory in the western part of the Yosemite region, and upon
two occasions it was found on the floor of Yosemite Valley. Its range is
separated from that of the Yosemite Toad by a considerable altitudinal
interval, involving the upper two-thirds of the Transition Zone. East of
the mountains is found a close relative, the Northwestern Toad.
The California Toad, and toads in general (of the
genus Bufo), may be distinguished from other tail-less amphibians
of the Yosemite region by the presence of a large raised area, the
parotoid gland, on each 'shoulder' behind the ear membrane (pl.
60a). The Spade-foot (Scaphiopus) may show a slight
elevation in the same region, but that animal may be recognized
otherwise by its cutting 'spade' on the hind foot and by the elliptical
pupil in the eye. True toads (Bufo) have the pupil circular. The
California and Northwestern toads have the parotoid glands rather long
and widely separated, whereas the Yosemite Toad has these glands but
little longer than broad and separated by about the width of one of the
glands. Locality will serve to distinguish the California and
Northwestern toads, the former occurring only on the west slope of the
mountains and the latter, so far as the Yosemite section is concerned,
exclusively on the east side.
At most localities in the western foothills we found
the California Toad exceedingly abundant, probably in about the same
numbers as were present before the country was settled by the white man.
In most settled districts toads have suffered great decrease from one
cause or another incident to man's activities. Early in the morning the
soft dust of roadways was often closely patterned with tracks where the
toads had been traveling about during the preceding evening. At Pleasant
Valley count was kept on the evening of May 28, 1915, of the toads seen
along a certain quarter-mile of dusty road which passed between a
hayfield and an open pasture. At 7:40 P.M., in early twilight, nine were
counted; upon returning at 8:00 P.M., when the light of day was
practically gone, thirteen toads were checked off.
The California Toad is such a heavy-bodied animal
that it seldom hops in the conventional manner in which toads are
supposed to move. When not frightened it walks in slow fashion, dragging
the hind feet so that the toes are continually in contact with the
ground. The 'track' consists of a series of distinct little pits, 5 in
number, indicating the positions of the toes when the foot is against
the ground, and the successive series of dots are connected by faint
grooves where the toes have been dragged along in the dust.
The difference in size between females and males is
marked in this species. Females are decidedly larger and more heavily
built, and during the breeding season their skin remains rough, whereas
that of the males then becomes quite smooth. The males, during the
breeding season at least, have developed on the 'thumb' and inner sides
of two adjacent 'fingers' areas of rough dark-colored skin, which in
combination with their smaller size makes possible easy distinguishment
of the sexes.
In the late spring months the toads betake themselves
to pools of water for the purpose of laying eggs. The spawning season
had practically passed when our field party arrived at Pleasant Valley
in May, 1915. One animal was noted croaking in the water of Piney Creek
on May 22, and on May 23 the small black tadpoles of this species were
noticed in a small creek near Forty-nine Gap. A majority of the toads
taken on these dates had already deposited their eggs. A few of the
femalesand they were the largest of all, measuring 4 inches or
more in lengthhad not laid their complement of eggs. Whether there
is a differential laying, with the smaller animals coming first, is not
known. Males were encountered in smaller numbers than females, and some
at least of the former had already lost the dark horny patches on their
On several occasions during the hot days of early
summer, California Toads were observed at the entrances to burrows of
meadow mice and ground squirrels. The toads probably make pretty general
use of such burrows as daytime retreats, going greater or less distances
below the surface as may be necessary to escape the heat and dryness of
the mid-day hours.