Table Of ContentGreatBasin Naturalist56(1), © 1996,pp.38-47
ARIZONA DISTRIBUTION OF THREE SONORAN DESERT
ANURANS: BUFO RETIFORMIS, GASTROPHRYNE OLIVACEA,
AND PTERNOHYLA FODIENS
Brian K. Sullivan1, RobertW. Bowker^, Keith B. Malmos^, and ErikW. A. Gergus'^
—
Abstract. We surveyed historic collecting localities in south central Arizona diningJuK, August, and September
1993-94 to determine the presence of3 little-known Sonoran Desert anurans, Biifo retifoniiis. Gastrophnjne olivacea,
and Pternoliylafodiois. All 3 species were present at most historic localities visited under appropriate conditions (fol-
lowing rainfall in JuK' and August). Pternohijlafodiens was restricted to San Simon Wash and associated tributaries in
south central Pima County. Gastrophnjne olivacea ranged from Vekol Valley in extreme southern Maricopa County
south tothe Mexicanborder, andsoutheastnearTucson and Nogales in Pimaand SantaCruzcounties. Bitfo retifonnis
occuiTcd over the widest area, from southern Rainbow Valley in Maricopa Coimty southwest to the vicinit>' ofOrgan
PipeCactus National Monument,andsoutheasttothevicinityofTucsonandSasabein PimaCounty.
Key tcords: Bufo retifonnis, Gastrophiyne olivacea, Pternohyla fodiens, historic distribution, present distribution,
ainpliibiandecline,Arizona, SonoranDesert.
Three relatively little-known anurans, Bufo Cruz counties, Arizona. First, we describe
retiforDiis, Gastrophnjne olivacea, and Pterno- methods used in conducting the suney. Then,
hylafodiens, occur in the Sonoran Desert in for each target species sun^eyed, we describe
south central Arizona. Although placed in sep- distinguishing acoustic characteristics and out-
arate families (Bufonidae, Microhylidae, and line historic and present distributions. Last,
Hylidae, respectively), they are superficially we present observations on breedingbehavior.
similar in behavioral ecology. Each is inactive
for more than 10 mon each year, emerging Materials and Methods
only to reproduce and forage following intense
Suney Methods
rainfall during the summer "monsoon' season.
Allexhibit "explosive" breedingbehavior(Wells All surveys were conducted along paved
1977) inwhich males form high-density aggre- roads throughout the known ranges of the 3
gations for a few nights (sometimes only one) target species following rainstorms during
following a major rainstorm and call to attract July, August, and September 1993-94. Given
females. WithinArizonaall3 species arelargely the highly unpredictable and variable nature
restricted to a small portion of the Sonoran of summer rainfall and the need for monitor-
Desert in the extreme south central part ofthe ing the entire south central portion ofArizona,
state, so it is perhaps not suiprising that they we could only crudely estimate (e.g., weather
are relatively unknowii. Indeed, Bufo retifonnis reports) the appropriateness of field condi-
was described in 1951 based on specimens tions (i.e., le\el of rainfall) for anuran activit\
collected southeast of Ajo in 1948 (Sanders prior to each field excursion. Whenever suffi-
and Smith 1951), and Pternohylafodiens was cient rainfall appeared to have fallen in the
firstdocumentedin Aiizonain 1957 (Chrapliw>' study area, we traveled to that particular area
and Williams 1957, Williams and ChraplivvT on the night of the rainfall exent, or the fol-
1958). lowing night, to surve\' for amphibians along
Given limited information on these Arizona roadways. Frequently, 2-3 nights ofsurveying
aniuans, this investigation was undertaken in occurred for each rainfall exent. Occasionally,
1993 and 1994 to ascertain th(>ir present dis- siu\'e\- plans were adjusted to take advantage
tribution in Maricopa, Pima, Pinal, and Santa oflocal conditions (e.g., localized flooding).
I|)i-pai(iiit'iilofLifeSciences,ArizonaStateUniversit\-West,PC)Box37101).Phoeni.v,.\/.85069.
-DepartmentofBiolosy,ClendaleComnuniit>'College,Glendale.AZ85302.
^DepartmentofZoology;ArizonaStateUniversity',Tenipe,AZ85287.
38
1996] SONOIUN DksertAnuiuns 39
To conduct surveys we drove slowly (40-65 with a Weber quick-recording thermometer
kniph) along paved roadways scanning for within 5 sec of recording the final advertise-
anurans on the road surface and listening lor ment call or release call. Water and air tem-
chorus acti\'it\' adjacent to the roadway. Most peratures were generally within 3°C] ofcloacal
roads in the study area are located in valley temperatures during field recordings.
floodplains crossedbynumerouswashes so that
AcousticAnalysis
collection of large lain pools immediately ad-
jacent to roadways occurs commonly. If insuf- Advertisement calls were digitized with a
ficient rainfall had occurred so that anuran DATA Precision model 610 plug-in digitizerat
surface activity was initiated but no chorusing a sampling rate of 10 kHz (Nyquist frequency
activit\' was apparent (i.e., no calling or breed- = 5 kHz) and analyzedwith a DATA Precision
ing), we continued driving, scanning for and 6000 waveform analyzer. Release calls were
recordingall anurans foimd on the road. When digitizedatacapturerateof22kHzonaMacin-
activitywas relatively high (e.g., >20 anurans/ tosh LC computer using a Farallon Corpora-
km) and/or associated with an area ofinterest tion MacRecorder and analyzed with Sound-
(e.g., historic or suspected locality for one of Edit software (version 2.03). Call durations
the target species), we recorded eveiy individ- were measured to the nearest 0.01 sec with
ual anuran seen on the roadway (foraminimum the Waveform analyzer (<2 sec) orwith a stop-
of 1 km) until lack of moisture resulted in watch. Pulse rates ofadvertisement calls were
reduced anuran activity (e.g., <5 anurans/km). measured over a 0.5-sec interval spanning the
Wheneverwe detected choiaisingactivity or call midpoint; all pulses were counted to deter-
pools ofwater along the roadway, we stopped mine the pulse rate of release calls using the
and scanned the area adjacent to the roadway. oscilloscope mode ofSoundEdit. Dominant fre-
If none of the target species were detected quencies were estimated to the nearest 10 Hz
either visually or acoustically, we resumed the over a 0.25-sec intei^val spanning call mid-
road survey. Iftarget species were present, we points using the waveform analyzer. Neither
attempted to record a series of voucher calls advertisement nor release calls are frequency
(seebelow) and collecta small series ofvoucher modulated to any large extent in any ofthe 3
specimens {N < 10). Unfortunately, summer anurans under study. For each male used in
rainfall in south central Arizona was below analysis of advertisement and release calls,
average during the sui-vey period, resulting in mean values were generated for each ofthe 3
few actual breeding aggregations. All speci- call variables from 3 ormore calls.
mens are deposited in the ASU Vertebrate
Historic Distributions
Collection.
We obtained specimen listings from the fol-
Field Observations lowing institutions: American Museum ofNat-
Each target species possesses distinctive ural Histoiy (AMNH), Arizona State Univer-
vocalizations. Advertisementcallswererecorded sity (ASU), Brigham Young University (BYU),
in the field with a Marantz PMD 430 stereo California Academy ofSciences (CAS), Carne-
recorder and Sennheiser ME 80 microphone gie Museum ofNatural Histoiy (CMNH), Los
with K3-U powermodule, ora SonyWM-D6C Angeles County Museum (LACM), Museum
cassette recorder and Sony ECM-909 stereo of Vertebrate Zoology (MVZ), University of
microphone. Males generally ceased calling Arizona (UA), University ofMichigan Museum
when they were approached {Gastrophryne ofZoology (UMMZ), University ofNew Mex-
and Pternohyla were easily disturbed); only if ico (UNM), and United States National Muse-
the observer remained relatively motionless um (USNM). It is important to note that we
would apparently normal calling behavior be examinedonly specimens deposited in theASU
resumed. Release calls were recorded either collection and a portion ofthose housed at the
in the field or in the laboratoryby gently com- USNM. We assume that anurans listed by the
pressing the sides of a male held between other institutions are conectly identified. Given
thumb and forefinger directly above a micro- that these 3 anurans are quite distinct from
phone (following Sullivan 1992). Only slight other Sonoran Desert forms and therefore un-
pressure was necessary to elicit a series ofre- likely to be misidentified, it seems reasonable
lease calls. Cloacal temperatureswere measured to accept these listings in lieu of a physical
40 Great Basin Naturalist [Volume 56
examination ofall specimens. We did, however, lematic. No B. debilis have been recorded from
obtain detailed information from collectors for appropriate habitat spanning the 240 km be-
anyspecimencollectedoutsideorondieperiph- tween Vekol Valley and the otherwisewestern-
eryoftherange (e.g., San Xavierregion). most previous locality for this eastern relative
ofB. retiformis (near Benson, Arizona). Unfor-
Results and Discussion tunately, we were unable to sui'vey Vekol Val-
ley when conditions were suitable for anuran
Bufo retifonnis
activity. —
Relative to other toads (genus Bufo) found Present distribution. In 1993-94, we
in south central Arizona, B. retifonnis pos- obsei^ved B. retiformis at or near most historic
sesses an unusually high-pitched, short-dura- localities, except San Xavier and Vekol Valley,
tion advertisement call, often described as an and at additional sites (Fig. 1). They were
"insect-like buzz" (see Stebbins 1985, Hulse especially abundant along Indian Route (IR)
1978). However, given similarities in adver- 15, 0-40 km north ofQuijotoa, associatedwith
tisement calls ofB. retiformis and G. olivacea, the Santa Rosa Wash floodplain. Surveys in
identification based on calls can only be confi- which every anuran was identified along a
dently determined with analysis of signals in roadway segment (1-65 km) revealed that B.
the laboratory (Sullivan unpublished data). On retiformis constituted up to 63% ofall anurans
average, B. retiformis calls are longer (/x = 3.0 sighted on this route (Table 1), whereas they
sec, range = 2.0—4.3 sec at approximately 26° were absent or composed a small proportion
C body temperature) and lower in frequency (<1%) oftotal anurans sighted on roadways on
ilJL = 3112 Hz) than calls of Gastrophryne the peripheiy oftheir distribution near Mobile
(typically 1-2 sec duration a—t =4000 Hz). and Sasabe (Table 1). Similarly, this toad was
Historic distribution. Bifo retiformis is not abundant along State Route (SR) 85 near
known from west central Sonora and south Organ Pipe Cactus National Monument. Din-
central Arizona (Hulse 1978; Fig. 1). Since it ing 1993 and 1994 we never obserxed this
was described in 1951, this anuran has been species on SR 85 or SR 86 in this westernmost
obsei-ved in Arizona at sites ranging from near portion of the range. Philip Rosen (personal
San Cristobal Wash, just west of Organ Pipe
communication) has observed only a few B.
Cactus National Monument, north to tribu-
retifonnis near the international border, and a
taries ofWaterman Wash near Mobile, south-
number ofindividuals nearWhy, Arizona, dur-
east to the vicinity ofTucson (San Xavier Mis-
ing the course of extensive fieldwork near
sion), and southwest to the international bor-
Organ Pipe Cactus National Monument over
dernear Sasabe. Across this region it occurs in
the past 6 yr
creosote flats, upland saguaro-palo verde asso-
ciations, and relatively high-elevation (>900 Contraiy to the suggestion ol Hulse (1978;
m) desert grassland. see also Nickerson and Mays 1968), Bufo reti-
One historic locality deserves special dis- formis does not appear to be expanding its
cussion: southern Vekol Valley, Pinal Count)'. range northward into areas ofagricultural activ-
At this site Jones et al. (1983) reported bodi B. ity (e.g., soutiiern Pinal County). We conducted
retiformis and B. debilis. We have examined many sin"\eys in southern Pinal County: south
the single voucher specimens for B. retiformis ofStantield and south ofArizona City, 2 areas
(USNM 252797) andB. debilis (USNM 252776; directly north of known localities for B. reti-
SVL = 43 mm, reproductive female) and deter- formis (Fig 1). We also extensively surveyed
mined by comparison with juvt-niles in the the Avra Valley region, Pima County, immedi-
ASU collection (ASU 23099-23102) that the atelywestofTucson, and the \icinity ofMobile,
putative B. debilis is not simply a juvenile B. Maricopa County. These habitats are similarto
retijormis. Using the morphometric methods areas inhabited by B. retiformis directb' to the
proposed 1)\ Ferguson and Lowe (1969), we south or west, except that agricultural activity
scored diis indixidual close to B. debilis in all is relati\t'K higher in these areas. It appears
respects; hence, the B. debilis individual can- that B. retiformis is less conmion on die periph-
not be disnussed as a simiije nnsidentification eiyofits range: nearOrgan Pipe Cactus Nation-
orhybrid. The presence of/i debilis well with- al Monument in the west, near Mobile in the
in the range ofR retiformis is especially prob- noitli, and in AltarVallev in the east.
1996J SoNoiUN DesertAnuiuns 41
a) Historiccollecting localitiesfor Buforetiformisin south central Arizona.
b) Recentcollecting localitiesfor Buforetiformisin south central Arizona.
Fig. 1. Mapofa)historicdistribution(•)andb)presentdistribution(•)ofBuforetifoniminsouthcentralArizona.
—
Breeding ACTiviri'. Like many explosive B. ulvarius, B. cogmitus, B. punctatus, Gastro-
breeding desert anurans, B. retiformis will take phnjneolivacea, Pternohylafodiens, Scaphiopus
advantage ofavarietyofwatersources forrepro- concha, and Spea multipUcata. We never ob-
duction. We observed chorusing activity in served B. retiformis breedingin the absence of
—
cattle tanks and roadside pools associated with other anurans minimally, B. cognatus and S.
washes. We obsei-ved B. retiformis breeding in concha bred sympatricallywith B. retiformis.
the same pool with all other explosive breed- Male B. retiformis typically call positioned
ing anurans that occurin south central Arizona: beneath vegetation (e.g., small shrubs orgrass),
42 Great Basin NATUii\LiST [Volume 56
Table 1. Numbersofanurans individualK'identifiedonroadsurfaceoveraspecifieddistance. Bal = B. alvarius, Bco
= B. cognatus, Bpu = B. punctatiis. Ere = B. rctifonnis, Sco = Scaphiupus cotichii, IR = Indian Route, SR = State
Route. MM = milemarker
1996] SoNORAN DesertAnurans 43
as active searchingand satellitebehaviorcan in- observed a small chorus near Lukeville, just
crease the probability ofheterospecific crosses north ofthe international boundaiy, a site that
since these tactics subvert active choice by extends the range of Gastrophryne approxi-
females. Second, although B. retifonnis is typi- mately 58 km southwest ofthe previous west-
cally found in desert flats and B. punctatus ernmost locality (San Simon Wash, SR 86) in
generally occurs in rockier, upland regions, the United States. Philip Rosen (personal com-
the "hybrid zone" along IR 15 (MM 6-12) rep- munication) suggests thatGastr()})hryne is more
resents a transition between lowland (Lower abundant in Mexico to the south and southeast
Colorado River Subdivision) and upland (Ari- ofLukeville. The absence ofprevious distribu-
zona Upland Subdivision) desert habitats that tional records from Organ Pipe Cactus National
would allow coexistence ofboth species. Third, Monument substantiates the notion that G.
habitat modification at the site, namely, road olivacea reaches its northwestern range limit
construction and development ofcattle tanks, in this area.
may overcome ecological separation between We were unable to document G. olivacea
the species and provide opportunities for anywhere along SR 286 (Altar Valley, Buenos
hybridization. Aires Refuge) in spite of apparently adequate
habitat and the presence ofG. olivacea to the
Gastrophryne olivacea
east. Philip Rosen (1994 personal communica-
As noted above, the advertisement call of tion) obsei-ved a number ofG. olivacea breed-
G. olivacea can be confusedwith B. retifonnis. ing choruses in southwestern Santa Cruz
In the hand, this small, narrow-mouthed toad County, just east of the Buenos Aires Refuge
cannot be confused with any other species boundary, during summer 1994. Hence, this
found in Arizona (Nelson 1972a, 1972b, 1973, species likely occurs in the area but, like B.
Stebbins 1985). Identification based on calls retifonnis, may be less abundant along SR
(insect-like buzz) alone must be corroborated 286. We did not find G. olivacea in the vicinity
bylaboratoiyacoustic analysis. of San Xavier Mission or along SR 289,
Although Lowe (1964) listed G. carolinensis although we visited these sites after rainfall on
from the mountains near Nogales, Arizona, several occasions. Our failure to document
Nelson (1972a, 1972b) showed that these indi- Gastrophryne in areas with appropriate habi-
viduals do not differ significantly from nearby tat may be an artifact of its secretive habits
populations of G. olivacea from lower-eleva- (i.e., individuals may not come on road sur-
tion sites. Having examined specimens from faces) and small size (i.e., they are difficult to
throughout the range in Arizona, we concur detectwhen on aroad)—.
with Nelson that only a single taxon occurs Breeding activit\'. Gastrophnjne olivacea
north ofthe international bo—undary. aie usually well concealed in vegetation when
Historic distribution. The range of G. calling and possess a call that is extremely dif-
olivacea largely overlaps that of B. retifonnis ficult to localize. They call next towatersources
(Fig. 2), except in Santa Cruz County (e.g., or from floating vegetation. Male satellite
near Pena Blanca) where Gastrophryne occurs activitywas not observed. Although G. olivacea
farther east. Of the 3 anurans surveyed, this has been observed in choruses with all other
species occurs in the widest variety ofhabitats sympatrically breeding anurans (see above list-
in Arizona, ranging from low-elevation cre- ing underB. retifonnis), on many occasions we
osote flats through grasslands to oak-woodland observed it in large, relatively monotypic
MM
communities near Ruby, Arizona (>1200 m). aggregations (e.g., 26.7 and 35, IR 15). In
Wake (1961) reported calling G. olivacea these areas Gastrophryne often breeds in dense
4.8 km southeast ofAjo. Because no individu- stands ofmesquite shrubs growingin the flood-
als were visually confirmed and because ofthe plain ofSanta RosaWash.
difficulty of identifying this species by call, Choruses of Gastrophryne are easily de-
we are inclined to discount—the record. tected, and we were led to a number ofnew
Present distribution. In 1993-94 we Gastrophryne localities by their distinctive
obsei-ved G. olivacea at most historic localities vocalizations. Because oftheir secretive nature,
except those on the eastern margin of the we neverobservedpairs in amplexus, and thus
study area (San Xavier and vicinity of Pena no definitive estimates ofpopulation size were
Blanca), and at some new sites (Fig. 2). We obtained for breeding choruses ofG. olivacea.
44 Great Basin Naturalist [Volume 56
a) Historiccollecting localitiesfor Gastrophryneolivaceain south central Arizona.
b) Recentcollecting localitiesfor Gastrophryneolivaceain south central Arizona.
Fig.2. Mapofa) historic'distrihutioii (•)aiulh) present distriliiition (•)ofGastrophryneolivacea in sonthcentralAri-
zona.
Bywalking the perimeter oi rain-formed i)o()ls, \ille (8/9/94) ouK- 5 calling males were present
we obtained rough estimates of >2()() ealling in a small pool (5 X 10 X 0.25 m). Rain had
males at 2 sites along IR 15, 43 and 56 km fallen the previous 2 nights (8/7-8/8), and sev-
north of Quijotoa, respectively, on recent eral small egg masses were obseiA'ed.
(8/9/93) and previous sinveys (19(S4: Sulh\an
and Bowker impublished). UnfortunateK, since Ptcniohylafodicns
these pools contained considerable vegetation Hie advertisement call oi Ptcrnohijlafodiens
(mesquite shrubs, grass), chorus sizes can onl> is a distinctixe "wonk" repeated at a relatively
be considered approximate (individual toads high rate (2/sec: "wonk-wonk-wonk ," etc;
. . .
were notvisually verified). B\ contrast, at Luke- see Trueb 1969). Males also produce a call,
SoNOiuN DesertAnukans 45
19961
a) Historiccollecting localitiesfor Pternohylafodiensin south central Arizona.
b) Recentcollecting localitiesfor Pternohylafodiensin south central Arizona.
1 '
-MARICOPACOUNTY
46 Great Basin Naturalist [Volume 56
More than the other target species, P.fodiens central Arizona. We documented range exten-
is found in associationwith washes. The 2 new sions to the northwest and southeast for B.
locahties we documented are both associated retiformis (Mobile/SR 286) and to the south-
with small tributaries of Sells Wash, a tribu- west for Gastrophryne olivacea (Lukeville).
taiy ofSan Simon Wash. These forms probably occur at all historic
During the preparation of this report, localities, since our inability to verify their
Thomas R. Jones and Ross J. Timmons (per- presence at some sites undoubtedly resulted
sonal communication) found a single male P. from the absence of sufficient rainfall. It is
fodiens near Santa Rosa Wash, 1 km north of critical to note that our survey methods,
the Pinal County line and west of IR 15 (12 although allowing rapid coverage of a rela-
July 1995). This record confirms the presence tively large area, were limited by unpredict-
ofP.fodiens in Santa Rosa Wash, well north of able rainfall and the secretive nature of the
the San Simon Wash system. target species (especially Pternohyla and Gas-
Pteniohylafodiens is only rarely found on trophryne). Unless chorusing activity was
road surfaces, although specimens can be taken undei^way when we visited an area, the pres-
nearwashes when roads are wet (e.g., SR 86 at ence of any of the 3 forms may have been
San Simon Wash). Similar to Gastrophrync, overlooked. In the absence ofchorusing activ-
Pternohyla can be easily missed unless chorus ity, Bufo retiformis was the only target species
activity is underway when a survey is con- regularly found on road surfaces.
ducted. Because of their extremely explosive Minimally, the presence ofthese anurans at
breeding habits and the lack ofsufficient rain- most historic localities suggests no widespread
fall near Sells during the survey period, it is declineas experiencedbyotheranuranamphib-
not surprising thatwe obsei-ved no Pternohyla
ians in the United States (e.g., ranid frogs of
at the historic localities along Sells Wash near
the Southwest; Michael Sredl personal com-
SRB8r6.eeding activit\\—We observed breed- munication). Future work should address esti-
mation of population levels through mark-
ing aggregations ofPternohylafodiens only in
recapture methods in conjunction with inten-
rain-formed pools associated with washes.
Calling males are always in or near water, and sive monitoring of single sites throughout as
of the 3 survey anurans Pternohyla seems many consecutive activity' periods (June—Sep-
more dependent on heavy rainfall to initiate tember) as possible. An understanding of fac-
breeding activity. This species appears to tors contributing to variations in species abun-
exhibit the most explosive mating system of dance will require long-term study.
the 3 species. We never obsei"ved Pternohyla
chorusing more than 36 h after rainfall; by Acknowledgments
contrast, both Gastrophryne and Bufo were
observed in chorus activity 1-4 nights follow- This research was supported by an IIPAM
ing rainfall. award (192004) from the Arizona Game and
The only significant Pternohyla chorusing Fish Department Heritage Fund. We grate-
that we observed occiured near Hickiwan fulK' acknowledge the assistance ofthe Tohono
(7/13/93) and San Simon Wash (7/13/93). O Odham Nation, especially the Department
Although direct coimts were not possible, esti- ofPublic Safety personnel. In addition, Henn'
mates from chorusing intensities suggest that Ramon of the Hickiwan District, Norbert
dozens, ifnot hundreds, ofcalling males may Manuel of the Sells District, and Madeline
have been present at San Simon Wash along Sakiestewa and Jefford Francisco ofthe Babo-
SR 86; however, only a single pair in amplexus quivari District were especially helpful in co-
was obser\'ed. Large aggregations of Pterno-
ordinating activities. Mike Demlong, Robert
hyla have been observed at these sites regu- Dudley, Matthew Goode, Matthew Flowers,
larly over the past 30 yr (Sullivan and Bowker
and Michael Sredl pro\'ided assistance with
unpublished).
field observations. Randy Babb, Darrel Frost,
Summary JeffHowland, K. BniceJones, Thomas R. Jones,
Cla\t()n Ma\, Phil Rosen, Cecil Schwiillie, Nonn
Oui- siu-\ey indicates that all 3 target species Scott, and Michael Sredl graciousK' shared
are present at most historic localities in south their field records and experiences.
1996] SoNORAN DesertAnurans 47
LiTER.\TURE Cited Appendix 1
BOWKER, R. W., AND B. K. SULLlVAN. 1991. Anura: Bitfo Specimen numbers forhistoriccollectinglocalities for
punctatus X B. retiformisnaturalliybridization. Her- Bufo retiformis, GastropJmjne olivacea, and Pternohijla
petological Review22:54. fodiens. Institutional abbreviations: AMNil = American
CnRAPLiwT, R S., AND K. L. Williams. 1957. Aspecies of Museum ofNatural Histoiy, ASU = Arizona State Uni-
frog new to the fauna ofthe United States: Ptemo- versityvertebratecollection, BYU = BrighamYoungUni-
hylafodiens Boulenger. Chicago Academy of Sci- versitycollection,CAS = CaliforniaAcademyofSciences,
ence, Natural Histoiy Miscellaneous Publication CMNH = Carnegie Museum ofNatural History, LACM
160: 1-2. = LosAngelesCountyMuseum, MVZ = MuseumofVer-
Ferguson, H., and C. H. Lowe. 1969. Evolutionaiy tebrateZoology, UAZ = UniversityofArizona, UMMZ =
relatioJn.ships ofthe Bufopunctatus group. American University of Michigan Museum of Zoology, UNM =
MidlandNaturalist81;435-446. University of New Mexico, USNM = United States
Hl'LSE, A. C. 1978. Bufo rctifonnis: Sonoran green toad. National Museum.
Catalogue of American Amphibians and Reptiles
AMNH
207: 1-2. Bufo retiformis: 59189, 60671, 85357-65, 91953-
Jones, K. B., L. Porzer Kepner, and W. G. Kepner. 54, 1022.34-36; ASU 3298-3300, 3894-3902, 3942-48,
1983. Anurans of Vekol Valley, central Arizona. 8002, 8004, 8005, 22775-76, 23099-102, 23252, 24038-39,
SouthwesternNaturalist28:469—170. 24273-74, 25552-53; BYU 42119; CAS 91.501-04, 94390-
CMNH
Lowe, C. H. 1964. Thevertebrates ofArizona. University 95,98055-56, 188354-55; 51562,.53841-42,538.55,
ofArizonaPress,Tucson. 63,520, 89782-95; LACM 26086-88, 64180-84, 88380-400,
Nelson, C. E. 1972a. Gastrophnjne olivacea: western 91833, 105719, 11.5266-314, 12.3234-41, 137788-89; MVZ
narrow-mouthed toad. Catalogue of American 71906-07, 73751-52, 74206-32, 76620-28, 81269, 139130,
AmphibiansandReptiles 122: 1-4. 180219-22, 180358-59; UAZ 12369-75, 14848-49, 25847-
UMMZ UNM
1972b. Systematic studies ofthe North American 48, 31381, 4,3011; 133460, 1,36,395, 134077;
mi.crohylid genus Gastrophnjne. Journal ofHerpe- 30993-995, 31268, 40207, 41686-87; USNM 226443-45,
tology6(2): 111-137. 24,5988,252797,322966.
1973. Gastrophnjne: narrow-mouthed toads. Cat-
. AMNH
alogue ofAmerican Amphibians and Reptiles 134: Gastrophnjneolivacea: 88986,91971-80, 119746;
1-2. ASU 14014, 22059-60, 22224-25, 22969-70, 22771-74,
NiCKERSON, M.A.,ANDC. E. Mays. 1968. Buforetiformis 2,3095, 23411, 24259-60, 25664-66; CMNH 63138-,39;
Sandersand Smithfromthe SantaRosaValley, Pima LACM 26576-81, 91896, 115511, 112480, 12,3293; MVZ
County,Aiizona.JournalofHeipetology 1(1-4): 103. 49479-,504, 58922, 72304-05; UAZ 26993-96, 29101-04,
Sanders, O., and H. M. Smith. 1951. Geographic varia- 29107, 42187-91, 38181, 35163-64, 38179, 38200-01,
tion in toads ofthe dehilis group ofBufo. Field and 38180, 38197-99, 29027; USNM 252817; UMMZ 136400,
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Received4May1995
Accepted1 September1995
