Intraspecific and Interspecific Variation in the Cryptotis nigrescens Species Complex of Small-Eared Shrews (Insectivora: Soricidae), with the Description of a New Species from Colombia

32 Pages·1993·12.8 MB·

by  Neal Woodman

Intraspecific and Interspecific Variation in the
Cryptotis nigrescens Species Complex of
Small-Eared Shrews with the
(Insectivora: Soricidae),
New
Description of a Species from Colombia
Neal Woodman and Robert M. Timm
Abstract
The Cryptotis nigrescens species complex ofsmall-eared shrews previously was considered
to consist ofa single, wide-ranging species with three subspecies distributed from southern
Mexico to Panama. Our study ofthe patterns ofmorphological variation within this complex
indicates that it is much more diverse and speciose than earlier believed. The group includes
populationsthat occuronly at high elevations(> 500 m)as well as theonly taxon in thegenus
restricted to elevations below 100 m. Based on our investigations, we recognize five species:
C. mayensisoccursontheYucatanPeninsulaandisknownfromanisolatedlocalityinGuerrero;
C. merriami has a patchy distribution from Chiapas, Mexico, to northern Costa Rica; C.
nigrescensinhabitsconterminoushighlandsin Costa Ricaand Panama; C. meraisknown from
two isolated mountaintopsalongthe Panama/Colombia border; and wedescribea new species
from theCentral CordilleraofColombia, which extendsthe knowndistributionofthecomplex
to the southeast. In addition, recent studies indicate that C. hondurensis and C. magna may
be imbedded phylogenetically within the C. nigrescenscomplex.
Resumen
Cryptotisnigrescenses un complejodeespeciesque soliaconsiderarsecomouna solaespecie
con tres subespecies distribuidas a lo largo de America Latina desde el sur de Mexico hasta
Panama. Nuestro estudio de patrones de variacion morfologica en estecomplejo indica que es
diversoycon masespeciesde lasque se habia pensadoantes. Elgrupo incluye poblacionesque
habitan solamente en elevaciones por encima de los 500 m, y tambien el unico taxon en el
genero que esta restringido a elevaciones bajo 100 m. Basados en nuestras investigaciones,
reconocemoscincoespecies. La primera, C. mayensis, seencuentraen la Peninsulade Yucatan
yenunalocalidadaisladaenGuerrero, Mexico. Lasegunda,C. merriami, tieneunadistribucion
discontinua desde Chiapas en Mexico hasta el norte de Costa Rica. La especie C. nigrescens
habita en las cordilleras de Costa Rica y Panama. Se sabe que C. mera vive en las cimas de
dosmontanasaisladasen la fronteraentre PanamayColombia. Laultimaesunaespecienueva
que describimos en esta publication y que mora en la Cordillera Central de Colombia y que
extiende la distribucion del complejo hacia el sureste. Ademas, estudios recientes indican que
las especies C. hondurensis y C. magna pueden estar relacionadas filogeneticamente con el
complejo C. nigrescens.
Introduction America. The genus reaches its greatest diversity
in Mexicoand Central America. Hall and Kelson
Small-eared shrews ofthegenus Cryptotis have (1959) recorded 25 species ofCryptotis in thisre-
a wide distribution, occurring in parts of North gion. InhisrevisionoftheMiddleAmericanCryp-
America,CentralAmerica,andnorthwesternSouth totis, Choate (1970) recognized eight species of
FIELDIANA: ZOOLOGY, N.S., NO. 74, SEPTEMBER 30, 1993, PP. 1-30 1
small-eared shrews in Mexico and Central Amer- in m3 (Choate, 1970). However, there is much
ica, and his taxonomy has been followed by most variationinthesecharactersbothwithinthistaxon
subsequentauthors, includingHall (1981), Hona- and within the genus, and their polarizations are
cki etal. (1982), Corbetand Hill (1991), and Wil- difficult to define.
son and Reeder(1993). We (Woodman & Timm, SystematicrelationshipswithinthegenusCryp-
1992,submitted)recognizedfouradditionalspecies totisremain mostlyunresolved. Woodman(1992)
fromGuatemala,Honduras,andMexico,bringing showedthatthe C. nigrescensgroup maybepara-
the total to 12 species. phyletic with respect to C. hondurensis and C.
OnepoorlyunderstoodCentralAmericangroup magna. Cryptotis hondurensis recently was de-
ofCryptotis is the C. nigrescens complex, which scribed from montane pine forests in Honduras
was known to occur from Guerrero, Mexico, (Woodman&Timm, 1992). Cryptotismagnawas
through Central America to the Panama/Colom- described by Merriam (1895) from mountains of
bia border. Most species of small-eared shrews southernOaxaca,Mexico.Amorecomprehensive
that occur from central Mexico through northern redescription of this species was provided by
South America are high-elevation forms, inhab- Choate(1970),anditwasillustratedbyRobertson
iting regions over 500 m. The C. nigrescenscom- and Rickart (1975), who summarized its biology.
plex,whichincludesbothhigh-elevationandlow- In thispaper, we usethe"C nigrescensgroup" to
elevation taxa, is an exception. Choate (1970) refer informally to only those shrews previously
provided the only recent comprehensive treat- called C. nigrescens.
ment ofthe taxonomy and distribution ofC. ni- The purposes ofthis paper are to (1) revise the
grescens. He recognized one widely distributed taxonomy and delineate the distributions oftaxa
species, C. nigrescens, which included three sub- previously included in C. nigrescens; (2) describe
species: C. n. mayensis, occurringon the Yucatan and illustrate a species new to science; and (3)
Peninsula and known from one locality in Guer- reviewtheavailableinformationonreproduction,
rero, Mexico; C. n. merriami, which Choate de- elevationaldistribution,andhabitatforthemem-
scribed and is distributed from Chiapas, Mexico, bers ofthis complex.
toHondurasandElSalvador;andC. n. nigrescens,
inhabitingCostaRicaandPanamatothePanama/
Colombia border. Of the previously recognized
species, Choate (1970) synonymized C. mera, C. Methods
C
micrura, C. tersus, and zeteki with C. n. ni-
grescens. Cryptotismayensiswasreducedtoasub- Cranialandmandibularmeasurementswerere-
mm
species ofC. nigrescens. cordedtothenearest0.1 usingeitheranocular
In his review ofthe Cryptotis ofMiddle Amer- micrometerin a binocular microscope ora hand-
ica,Choate(1970)hadfewcompletespecimensof helddialcaliper. Skin measurementsarethosere-
C. nigrescens. Ofthe 237 C n. mayensisavailable corded by the collector, except forhead and body
atthattime, allbut 10were mandiblesandpartial length (HB), which we calculated by subtracting
crania from owl pellets, cave deposits, or Mayan therecordedtail length (TL)fromthetotal length.
ruins. Similarly, 15 ofthe 25 specimens available All measurements are in millimeters. Dental ter-
forC. n. merriamiwerefromowlpellets,andonly minology follows Choate (1970). The following
24 skins with accompanying skulls of C. n. ni- craniomandibularmeasurements(fig. 1)wereused
grescens were available for study. Recent collect- inouranalyses:condylobasallength,notincluding
inginMexicohasaddedimportantnewspecimens the upper incisors (CBL); cranial breadth (CB);
C
of n. mayensis and C. n. merriami, and work breadth of zygomatic plate (ZP); interorbital
in Panama and Costa Rica has tremendously in- breadth (IO); breadth of palate across first uni-
creasedthenumberofC. n. nigrescensinmuseum cuspids(U1B); breadth ofpalate acrossthirduni-
collections. This wealth ofnew material led us to cuspids (U3B); breadth of palate across second
review this complex more thoroughly than was molars(M2B);palatallength(PL);uppertoothrow
possible previously. length, Ul to M3, parallel to the long axis ofthe
Cryptotis nigrescens was considered to be dis- skull (TR); unicuspidtooth rowlength, parallel to
tinguishedbyitsshortrostrum;bulbousdentition; theunicuspidtoothrow(UTR); molariformtooth
equal devMelopment ofanteriorand posteriorpor- row length, P4 to M3, parallel to the lMong axis of
tMions of 1; unrecessed posterior margins ofP4, the skull (MTR); posterior width of 1, across
1,andM2;simpleM3;andlackofanentoconid hypocone and metastyle (WM1); mandibular
FIELDIANA: ZOOLOGY
length, from inferior sigmoid notch to posterior Museum ofNatural History, New York (amnh);
edge ofmental foramen (ML); height ofcoronoid AngeloStateNaturalHistoryCollections,SanAn-
process (HCP); height ofcoronoid valley (HCV); gelo,Texas(asnhc); EscuelaNacionaldeCiencias
height ofarticular condyle (HAC); breadth ofar- Biologicas, Mexico(encb); Field Museum ofNat-
ticular condyle (BAC); articular condyle to pos- ural History, Chicago (fmnh); Instituto de Biolo-
terior edge ofm3 (AC3); lower tooth row length, gia, Universidad Nacional Autonoma de Mexico,
p3 to m3 (TRD); and length oflower first molar MexicoCity (ibunam); Instituto Nacional de Bio-
(mlL). Unless otherwise stated, univariate statis- diversidad,SantoDomingodeHeredia,CostaRica
ticsaremean ± standarddeviation.Allcapitalized (iNBio); University ofKansas Museum ofNatural
colornamesfollowRidgway(1912).Localitiesand History, Lawrence(ku); Los AngelesCounty Mu-
elevationswere takendirectly from specimen tags seum, Los Angeles (lacm); Museum ofCompar-
and represent the descriptions ofthe original col- ative Zoology, Harvard University, Cambridge
lectors. Correctionsandadditionsare provided in (mcz);MuseumoftheHighPlains,FortHaysState
brackets. We did not convert distances measured University, Hays, Kansas (mhp); James Ford Bell
in milesorelevationsmeasured in feettothemet- Museum ofNatural History, University of Min-
ric system to avoid inferring a level ofaccuracy nesota, Minneapolis (mmnh); Museo Nacional de
greater than that originally recorded by the col- Costa Rica, San Jose (mncr); Museum ofVerte-
lector. Specimens from archeological or paleon- brate Zoology, University ofCalifornia, Berkeley
tologicalcontextswerenot used in statisticalanal- (mvz); Royal Ontario Museum, Toronto (rom);
yses orplotted on maps because ofthe possibility University ofIowa Museum ofNatural History,
oftemporal variation in size, shape, orgeographic Iowa City (sui); Departamento de Biologia, Uni-
distribution. Number ofspecimens from archeo- versidad Autonoma Metropolitana Iztapalapa,
logical or paleontological sites is calculated as the Mexico (uami); University ofMichigan Museum
minimum number ofindividuals. ofZoology, Ann Arbor (ummz); Universidad Na-
Multivariate analyses were used to look at pat- cional Autonoma de Honduras, Tegucigalpa
ternsofvariation in overall similarityamongspe- (unah); and U.S. National Museum, Washington,
cific members ofthe C. nigrescens complex. Al- D.C. (usnm).
though these analyses often are useful for
distinguishing among known groups, and occa-
sionally pointout variables useful fordistinguish-
ing taxa, they were not relied upon to determine Sexual Variation
species or provide taxonomic diagnoses. In gen-
eral, members ofthe C. nigrescens complex were Male and female Cryptotis are difficult to tell
found to be very conservative in overall form, apart, and fewtests forsexual dimorphism within
particularly as determined by principal compo- the genus have been carried out, at least in part
nentsanalyses(PCA),whichisadescriptiverather becausethereare fewgood seriesofindividualsof
than a discriminatory tool. Most variation de- knownsex. Thetwostudiesthathaveinvestigated
tected by PCA was in size rather than shape. De- sexual dimorphism in Cryptotisindicate that sex-
spite this similarity in shape, species differ dis- ual differences in mensural variablesare minorat
tinctly in their possession of specific characters, most.Choate(1970)foundonlyoneofseven vari-
and we used these characters to separate them. ables (length ofmaxillary tooth row) that he ex-
Analysesofvariance(ANOVA),correlationma- amined to be significantly different between the
trices, and multivariate analyses were carried out sexesinhismorphometricanalysisofC. mexicana
using BMDP on the University of Kansas Aca- from nearJalapa, Veracruz, Mexico. Only 1 of 19
demic ComputingServices' IBM VM/CMS com- variablesdiffered significantlybetween malesand
putersystem. All datawere log-transformed prior females ofC. gracilis in Costa Rica and Panama
to carrying out these analyses. (Woodman, 1992);zygomaticplatelengthwassig-
Elevationalandgeographicdistributionsand the nificantly longer in females.
We
correlation of character states to these distribu- tested for secondary sexual variation in C.
tions were examined for all members of the C. nigrescens using our two largest series of sexed
nigrescensgroup. individuals. One included 17 males(14crania, 16
Specimensused in ouranalysesare listed in the skins) and 16 females (12 crania, 16 skins) from
SpecimensExaminedsection. Thesespecimensare Monteverde, Costa Rica, and the otherconsisted
deposited in the following institutions: American of 13 males (13 crania, 9 skins) and 10 females
WOODMAN & TIMM: SMALL-EARED SHREWS
CBL
Fig. 1. Cranialandmandibularmeasurementsusedinthisstudy.Abbreviationsofvariablesareexplainedinthe
Methodssection oftext.
(1 crania, 8 skins)fromnearSanFelix(including tected alpha values were not used despite a lack
Cerro Bollo), Panama. A correlation matrix was ofindependence among the variables tested, be-
calculatedfor 19craniomandibularvariables(CBL, cause protected values would have increased the
CB, ZP, IO, U1B, M2B, PL, TR, UTR, MTR, likelihood of making Type II errors (i.e., incor-
WM1, ML, HCP, HAC, BAC, TRD, mlL, AC3, rectly accepting no difference between males and
HAV).Becausesamplesizesweredifferentforskin females or between localities).
variablesandforcraniomandibularvariables,skin Onlyonevariable,UTR(P-0.0042),exhibited
measurements (HB, TL) were not included in the a statistically significantdifference between sexes,
correlation matrix. Variables then were culled so with females larger than males. In addition, CBL
thatnotwovariablesintheremainingdatasethad (P = 0.0566) was close to being significantly dif-
a correlation coefficient of 0.75 or greater. This ferent;again, femaleswerelargWerMthanmales. Five
yielded eight variables (CBL, ZP, UTR, MTR, ofthe 10variables(ZP, MTR, 1, BAC, HCV)
WM1, HAC, BAC, HCV); allothervariablescor- had P > 0.30, indicating no distinction between
relatedstronglywithCBL,exceptHCV,whichwas thesexes. Theremainingthreevariables(HB, TL,
strongly correlated with HAC. A two-way ANO- HAC) had probabilities falling between 0.10 and
VA was calculated for each ofthese eight cranio- 0.30, providing no clear evidence of whether a
mandibular variables and the two skin variables. differenceexistedbetween malesandfemales. Fe-
Both sex and locality (Monteverde vs. San Felix) males averaged slightly larger than males for five
were tested as sources ofvariance to separate ef- measurements in the groups from both Monte-
fects ofsexual dimorphism and geographic vari- verde (TL, CBL, ZP, UTR, HAC) and San Felix
ation.Statisticalsignificancewasdeterminedusing (CBL, UTR, MTR, HAC, mlL), although notfor
aBrown-Forsythetestforequalityofmeans,which all the same variables. Males from Monteverde
does not assume equality ofthe variances. Pro- were larger than females for HB, and males from
FIELDIANA: ZOOLOGY
San Felix were larger for HB and TL. However, shape axes. In the PCA of specimens from San
actualdifferencesbetween maleand femalemeans Felix, factor 1 represents size and factor 2 is a
in both groups were small (table 1). Ifwe use the contrast between shape ofthe articularcondyleof
differences, taken to fourdecimal places, between the mandible (HCV and HAC) vs. a negatively
the male and female means for the eight cranio- weighted mlL(table 3). In theplotoffactor 1 and
mandibular variables, we find that they average factor 2 scores for these specimens (fig. 3), males
0.0470(range=0.0169-0.0892)forthespecimens and females exhibit complete overlap along the
fromSanFelixand0.0926(range-0.0107-0.4630) shape axis. Along the size axis, however, there is
for specimens from Monteverde. Most are below separation ofthetwosexes. Malesrangealongthe
our ability to measure accurately. entire length of factor axis 1 but are more con-
Incontrasttothesex term, 9ofthe 10 variables centrated at the lower end ofthe scale. Females
tested were significantly different between locali- all cluster toward the upper end ofthe scale.
WtieMs.Sevenofthesevariables(HB,TL,CBL,UTR, Ouranalysisofsexual variation in C. nigrescens
m1L)1,hHadACP,<B0A.C0)5.hOandlPyZ<P0.s0h0o1w,eadndnotwdiof(feMrTenRc,e ssihzoewwsitnhoincltehairspsaptetcieersn.oAfltsehxouuaglhdfiemmoarlpeshigsemneri-n
between the populations at Monteverde and San ally averaged larger in most craniomandibular
=
Felix (P 0.3531). For all variables, specimens measurements in which thereweredifferencesbe-
from San Felix averaged larger than those from tween the sexes, males averaged larger in HB, es-
Monteverde. In fact, males from San Felix aver- pecially among specimens from San Felix. The
aged larger than females from Monteverde forall overlap between males and females for all mea-
variables except ZP, UTR, and m1L. surementswasgreat. Onlytwo variables weresig-
Theinteractionbetweensexandlocalitywasnot nificant or close to being significant when tested
significantforanyvariables,andP < 0.30foronly for differences between the sexes, and the statis-
TL(P= 0.0734), CBL(P= 0.0947), and ZP(P = ticalsignificanceofthosevariablesmayhavebeen
0.2593). a result of multiple comparison of dependent
Body mass has been shown to be a good cor- means. No other variables tested wereclearlydif-
relate of other estimators of size in some other ferent. PCA indicated a tendency for male and
small mammals (Iskjaer et al., 1989). Average female C. nigrescens from San Felix to separate
weights of males and females from Monteverde out on size, but this was not the case for those
were the same (table 1), giving no indication of from Monteverde, and the size range for males
sexualdimorphism.However,ouruseofbodymass from San Felix overlapped completely that offe-
washamperedbytheimprecisionwithwhichvery males.
smallanimalscanbeweighedinthefieldandsmall These results indicate that any sexual variation
samplesizesavailable. Geographicvariation could that exists is beyond our ability to measure ac-
not be evaluated, because weights were not avail- curately and precisely in these diminutive mam-
able for specimens from San Felix. mals. Differencesbetweensexeswereconsiderably
To test whetherall craniomandibular variables lessthandifferencesbetweengeographiclocalities,
together would show size differentiation between and they did not influence statistical tests among
males and females, we ran PCAs separately for populations or contribute significantly to overall
specimens from Monteverde and from San Felix patternsofgeographic variation in which we were
using the original 19 craniomandibular variables interested. Possessing few sexed individuals from
and the same individuals as for the ANOVAs. each locality, we could not partition our sample
Becauseallvariablesgenerallyloadheavilyonfac- intotooth-wearclasses(Rudd, 1955)andthuspro-
tor axis 1 in a PCA, this axis provides a good portion out possible effects ofage-related differ-
estimatorofoverallsize.Therefore,factor 1 scores ences. However, because sexual variation did not
should prove to be useful in determiningany ob- inhibit our ability to detect geographic variation
vious patterns ofsize differentiation between the within C. nigrescens, we used males, females, and
sexes. InthePCAofspecimensfrom Monteverde, unsexed individuals in all subsequent analyses.
factor 1 estimatessizeandfactor2 isashapescore
representing contrast between a combination of
m1L and WM1 vs. the negatively weighted AC3 Systematic Descriptions
(table 2). A plot offactor 1 and factor 2 scores for
these specimens (fig. 2) indicates nearly complete In the following descriptions, species are ar-
overlapofmalesand femaleson both thesizeand ranged geographically, roughly from northwest to
WOODMAN & TIMM: SMALL-EARED SHREWS
Table 1. Selectedmeasurementsofmaleandfemale C. nigrescensfrom Monteverde,Costa Rica,andSan Felix,
Panama. Abbreviations ofmeasurementsare explained in the Methods section oftext. The statistics presented are
mean ± standard deviation of the mean, and observed extremes. Number of individuals for each species is in
parentheses.
Mont
HB
TL
CBL
CB
ZP
IO
U1B
M2B
PL
TR
UTR
MTR
WM1
ML
HCP
HCV
HAC
Table 1. Continued.
Monteverde
BAC
AC3
TRD
mlL
Weight (g)
2 -
Fig. 4. Dorsal, ventral, and lateral viewsofthe skull and lateral view ofthe skull and mandible ofC. tnayensis
(asnhc6071). Scale bar = 5 mm.
21) and broad, joins mandible at steep angle; Cryptotis hondurensis—C. mayensis is much
viewed posteriorly, horizontal and vertical larger (HB averaging 69 vs. 61 ± 5; table 4) and
branches of articular condyle short and broad; hasmuchpalerpelage; shortertail(averaging41%
lower sigmoid notch very shallow, not extending vs.46%);M3lesscomplex,lackingmetacone;den-
beneath ventral border ofarticular process; pos- titionbulbous;coronoidprocessofmandiblemuch
terior border of lower incisor extends nearly to higher and broader.
posterior border ofcingulum ofp4; lower denti- Remarks—The pelage ofCryptotis mayensis is
tion wide; only hypoconid in talonid ofm3. paler than in any other member ofthe genus, in-
Comparisons—Cryptotis mayensis has the pal- cludingC.parva. fromwhichthecolorationdiffers
estpelageofanymemberoftheC. nigrescensgroup, in being more gray and less olive. The overall
appearing medium gray (often speckled with appearanceofC mayensisisa medium brownish
C
patchesofwhite)ratherthandark brown toblack. gray. Close inspection ofthe dorsal pelage of
—
Cryptotismagna C. mayensisis much smaller mayensisrevealsthattheindividualhairsarethree-
(HB averaging 69 vs. 86; table 4) and has much banded. The proximal one-halfto three-quarters
paler pelage; much shorter tail (averaging 41% of ofthehairsisamediumgray,followedbyanarrow
HBvs.53%);skullmuchsmallerinalldimensions, bandoflightgray.Thedistaltip(aboutone-eighth
but zygomatic plate relatively broader (averaging ofthe total length) ofthe hair is brownish gray.
1 1.8%ofCBL vs. 10.1% ± 0.6); usually only one The transition between bands is not sharp, with
dorsalforamen;well-developedforamenposterior thecolorsinsteadtendingtogradeintoeachother.
to dorsal articular facet (foramen present but al- Thegreat extent oflighter, basal coloration in the
ways vestigial in C. magna); rarely possesses fo- hairsofthistaxonprobablyaccountsforitsoverall
ramina dorsal to dorsal articular facet; no ento- paler appearance and greater reflectance.
conidintalonidofm3(vestigialentoconidpresent Goldman (1951) described the northern Yuca-
in C. magna). tan habitat around Chichen Itza, from which the
WOODMAN & TIMM: SMALL-EARED SHREWS
Fig. 5. Map ofsouthern Mexico, Belize, and Guatemala showingthedistribution ofC. mayensis.
holotype ofC. mayensiswas collected, as stunted dularareaslacklongguardhairsandunderfurbut
tropical forest about 25-40 ft high with dense, havea sparsecoveringofshort, fine hairs(Wood-
brushyundergrowth. He notedthattheweatheris man&Timm,submitted).Bothmalesandfemales
highly seasonal, with a long, hot, dry season from possesslateralglands,butinfemalestheyaremuch
aboutDecembertoJuneandarainyseasonmarked smaller and more difficult to see (Murariu, 1976;
bytorrentialafternoon showers. Dowlerand EngW- Beeetal., 1980). Itislikelythattheseglandsserve
strom (1988)reportedaspecimenfrom 7.5 km afunctionin sexualcommunication. Eadie(1938)
Escarcega, Campeche, as having been trapped in foundthatthelateralglandsofmaleBlarinashowed
mature, transitional deciduous-evergreen forest. increased activity with enlargement ofthe testes.
In the same area they also collected Hetewmys Cryptotismayensisisrarelycollected, andthere
gaumeri, Ototylomysphyllotis, Peromyscusyuca- are few complete specimens in museum collec-
tanicus, and Oryzomys melanotis. Two C. may- tions. However, it is unlikely that this shrew is
ensis from 60 km SE ofDzibalchen, Campeche, truly rare, because remains from owl pellets are
weretakeninpitfallssetintransitionaldeciduous- abundant. Of 122 specimens examined in our
evergreenforestdominatedbyescobopalms(Cry- study, 76 came from owl pellets, 33 are from ar-
sophila) and Sabal palms (M. D. Engstrom, in cheologicalcontexts,and 13arestandardmuseum
litt.). Alvarez and Martinez (1967) captured a C. specimens.
mayensis along a road in tropical rain forest op- Cryptotis mayensis is distinctive in being the
posite a cornfield, 2 km SE Laguna Chickanka- only member of the genus restricted to lowland
naab, Quintana Roo. areas. OntheYucatanPeninsulathespeciesisnot
FewreproductivedataareavailableforC. may- knowntooccurabove 100m.Theonlyspecimens
ensis, and no pregnant or lactating females have ofC. mayensis from outside ofthe Yucatan Pen-
beenrecorded. Malescapturedon4June,24June, insulaare craniaandunassociated mandiblescol-
and 19 August showed no indications ofhaving lectedbyWilliamLopez-FormentC.in 1969from
lateral glands. When present, these paired glan- belowabarnowl(Tytoalba)roostinMacuiltzingo
10 FIELDIANA: ZOOLOGY