TAXONOMIC STATUS OF MYOTIS (CHIROPTERA: VESPERTILIONIDAE) IN PARAGUAY

Transcription

1 Joural of Mammalogy, 82(1):138, 2001 TAXONOMIC STATUS OF MYOTIS (CHIROPTERA: VESPERTILIONIDAE) IN PARAGUAY CELIA LÓPEZ-GONZÁLEZ,* STEVEN J. PRESLEY, ROBERT D. OWEN, AND MICHAEL R. WILLIG Departmet of Biological Scieces, Texas Tech Uiversity, Lubbock, TX (CLG, RDO) Program i Ecology, Departmet of Biological Scieces ad Museum of Texas Tech Uiversity, Lubbock, TX (SJP, MRW) Direcció de Ordeamieto Ambietal, Miisterio de Agricultura y Gaadería, Sa Lorezo, Paraguay (RDO) Qualitative ad quatitative variatio i morphology was assessed for species of Myotis from South America to determie which taxa occur i Paraguay, characteristics that allow for their discrimiatio, ad the degree of geographic ad secodary sexual variatio that occurs i Paraguaya forms. Secodary sexual dimorphism ad geographic variatio were evaluated from uivariate ad multivariate perspectives. Multivariate morphometric differeces i craial morphology amog taxa, idepedet of size, ad mesural characters that best separate species were determied usig pricipal compoets aalysis followed by size-adjusted discrimiat fuctio aalysis. Five species, M. albesces, M. igricas, M. riparius, M. ruber, ad M. simus, occur i Paraguay ad ca be distiguished usig combiatios of craial ad exteral characteristics. No sigificat sexual dimorphism or geographic variatio was detected i these taxa of Myotis i Paraguay. M. levis has ot bee recorded for Paraguay as previously reported, but it may occur i the coutry. M. simus, a species previously cosidered to be restricted to the Amazo Basi, occurs as far south as Paraguay ad orther Argetia. Although M. simus varies sigificatly i size across its rage, highly differetiated craial ad exteral morphology allows for recogitio of this species across its rage. Key words: taxoomy Chiroptera, geographic variatio, morphometrics, Myotis, Paraguay, sexual dimorphism, Bats of the geus Myotis occur i most terrestrial biomes throughout the world. The geus is diverse, with 4 subgeera ad 84 species curretly recogized (Koopma 14). Noetheless, species of Myotis rarely have eviced sufficiet morphologic differetiatio to allow allocatio of idividuals to taxa i a uambiguous maer. Those ihabitig the South America tropics probably are amog the least differetiated (LaVal 173). No comprehesive work o taxoomic status of Myotis i South America has bee attempted sice the revisio by LaVal (173). He examied * Correspodet: celialg@prodigy.et.mx most material available i collectios ad recogized 14 species of Myotis for South America. Four (M. albesces, M. igricas, M. riparius, ad M. ruber) were recorded for Paraguay. Myotis simus, a species believed to be cofied to the Amazo Basi (LaVal 173), was reported later from Paraguay (Myers ad Wetzel 17) ad Bolivia (Aderso 17). Baud ad Meu (13) examied a sample of Myotis from Paraguay ad adjacet coutries ad cocluded that 1 of their Paraguaya specimes represeted M. levis, a ew record for the coutry, ad that M. simus did ot occur i Paraguay. Also, they referred those specimes cosidered by Myers ad Wetzel 138

2 February 2001 LÓPEZ-GONZÁLEZ ET AL. MYOTIS IN PARAGUAY 13 (17) as M. simus to M. ruber. They further redefied M. simus, ad agai restricted its distributio to the Amazo Basi, but did ot discuss status of M. riparius. Therefore, accordig to those authors, oly 4 species of Myotis occur i Paraguay (M. albesces, M. levis, M. igricas, ad M. ruber Baud ad Meu 13). Recet collectig i Paraguay by persoel of Texas Tech Uiversity (López-Gozález et al. 18; Willig et al. 2000) produced large samples of Myotis, icludig a specime from Departameto Misioes tetatively idetified as M. simus (sesu Baud ad Meu 13, except color of pelage) ad a umber of idividuals cosidered to be M. riparius (sesu LaVal 173). Upo compariso of this ew material with specimes of Myotis from Paraguay ad adjacet coutries, a differet picture emerged regardig umber of species ad degree of variatio i Myotis from Paraguay. Our objective was to reassess taxoomic status of Paraguaya Myotis by reevaluatig qualitative characters traditioally used to distiguish species. Additioally, we used a quatitative uivariate ad multivariate approach to describe ad compare craial variatio i size ad shape of species occurrig i Paraguay ad assess validity of morphometric data as taxoomic characters to distiguish taxa. Although our assessmet focuses o Paraguaya populatios, comparisos with specimes from other regios ad iclusio of those specimes i our aalyses provided a wider perspective o the degree of morphologic variatio of Myotis i cetral ad souther South America. MATERIALS AND METHODS Specimes examied. Taxoomy ad omeclature were based o the revisio of Neotropical Myotis by LaVal (173). A total of 413 specimes of South America Myotis represetig the species cosidered by previous authors to occur i Paraguay (M. albesces, M. levis, M. igricas, M. riparius, M. ruber, ad M. simus) was examied. Variatio i Paraguaya samples was quatified ad compared with samples from the Amazo Basi (Brazil, Colombia, Ecuador, ad Peru), Argetie Chaco, souther Brazil, Bolivia, ad Uruguay; areas hereiafter referred to as localities. Two subspecies of M. levis curretly are recogized, M. l. levis ad M. l. diellii (Aderso 17; LaVal 173). Specimes of each geographic race were treated as belogig to a sigle locality i all aalyses. Quatitative ad qualitative itraspecific differeces betwee easter ad wester Paraguaya bats have bee reported (López-Gozález 18; Myers ad Wetzel 183); therefore, whe possible, samples from each regio were treated separately i aalyses. Referece material cosisted of stadard museum skis ad skulls, or specimes i spirits with extracted ad cleaed skulls. Oly adults (phalages ad basispheoid suture well ossified) were icluded i aalyses. Specimes (Appedix I) are deposited i the America Museum of Natural History (AMNH), Field Museum of Natural History (FMNH), Museum of Comparative Zoology (MCZ), Muséum d Histoire Naturelle, Geeva, Switzerlad (MHNG), Museo Nacioal de Historia Natural del Paraguay (MNHNP), Museum of Vertebrate Zoology, Uiversity of Califoria, Berkeley (MVZ), Museum of Texas Tech Uiversity (TTU), Museum of Zoology, Uiversity of Michiga (UMMZ), ad Uited States Natioal Museum of Natural History (USNM). May specimes were ot cataloged; those are listed by field umber (TK) ad are deposited at TTU or MNHNP. Qualitative data. A set of qualitative characters was selected to distiguish amog taxa. Attributes discussed here are a subset of those deemed importat to distiguish amog species of Myotis by previous authors (Hadley ; Miller ad Alle 8; Thomas 1, 2), ad that have bee useful i distiguishig Neotropical species i LaVal s revisio of Myotis (LaVal 173). The poit of isertio of the plagiopatagium was cosidered as a artifact by LaVal (173) but was recogized as a useful character i a subsequet aalysis of Paraguaya Myotis (Baud ad Meu 13); therefore, it also is discussed. Extremes of variatio i these characters are give i paretheses; isertio of plagiopatagium (at akle, at toes), texture of hair (silky, woolly), legth of dorsal hair at midlie o rump (3 mm, 5 mm), positio of P3 (displaced ligually ad almost hidde betwee P2 ad P4 whe see laterally, molariform teeth i a row), sagittal crest (preset, abset), ad frige

3 140 JOURNAL OF MAMMALOGY Vol. 82, No. 1 of hair at edge of uropatagium (preset, abset). Descriptios of fur ad membrae color follow LaVal (173). Quatitative data. Fourtee craial ad 2 exteral characters were measured usig a digital caliper: greatest legth of skull, icludig icisors; codylocaie legth; codylobasal legth, icludig icisors; mastoidal breadth; zygomatic breadth; breadth of braicase; iterorbital costrictio, least width of skull at postorbital costrictio; breadth across upper caies; breadth across upper molars; legth of rostrum, take as perpedicular distace betwee breadth across caies ad breadth across molars; legth of maxillary toothrow; legth of upper molariform toothrow; legth of madibular toothrow; legth of lower molariform toothrow; legth of forearm; legth of 3rd metacarpal. Values were rouded to the earest mm. Other stadard exteral measuremets (total legth, legth of tail, legth of foot, legth of ear, ad weight) were ot icluded i aalyses because data were missig for several specimes ad iterpreparator variatio may have obscured results. Exteral measuremets for Paraguaya specimes of Myotis were reported i Myers ad Wetzel (183) ad López-Gozález (18). Morphometric aalysis. Specimes were assiged to species based o characters described above. For descriptive ad comparative purposes, mea, stadard deviatio, ad rage of each character were calculated for each species by locality (Appedix II). Ratio of breadth across caies to iterorbital costrictio was calculated for all specimes ad a approximatio to the craial idex ((iterorbital costrictio breadth of braicase) greatest legth of skull/2) ad maxillary idex ((breadth across caies breadth across upper molars) legth of rostrum/ 2) of Baud ad Meu (13). I subsequet aalyses, data were log-trasformed to liearize them. Secodary sexual dimorphism, geographic variatio i size, ad their iteractios were tested i a uivariate fashio usig 2-way aalysis of variace whe samples were sufficietly large ( idividuals/locality at 1 locality). A posteriori uivariate comparisos were performed usig Tukey s multiple-rage tests whe iterlocality differeces were sigificat. Sigificace of multiple uivariate comparisos was adjusted usig the Boferroi sequetial adjustmet (Rice 18) to maitai experimet-wise error rate at 0.05/set of tests, by species. Aalogous multivariate aalyses of sexual dimorphism ad geographic variatio were coducted o craial characters usig multivariate aalysis of variace (MANOVA). For multivariate aalyses, missig data were estimated usig the estimatio-maximizatio algorithm of Little ad Rubi (187). Pricipal compoets aalysis (PCA) ad discrimiat fuctio aalysis (DFA) were used to facilitate comparisos of species. Although overall size may be a effective taxoomic character to distiguish amog taxa, it may obscure other morphologic characters potetially useful i their separatio. Therefore, a size-adjusted discrimiat fuctio aalysis (DFA) was performed to determie how species differ i traits ot related to size ad to idetify which characters were more useful i reflectig those differeces. Size-adjusted discrimiat fuctios were calculated usig residuals from regressios of each variable separately o the pooled-withi-group pricipal compoet 1 (PC1). This approach was effective i accoutig for differeces amog populatios by elimiatig potetially cofoudig effects of geographic ad itrapopulatioal variatio i size (dos Reis et al. ). Structure coefficiets or vector correlatios (i.e., Pearso s correlatio betwee a variable ad each discrimiat fuctio) were calculated as a measure of how closely a variable ad a discrimiat fuctio were related. Such correlatio reflected relative importace of a variable o each discrimiat axis (Bryat 184; Kleka 180). Statistical validity of iterspecific differeces was assessed by a MANOVA amog species o size-adjusted residuals. Cofidece limits for percetages of explaied variace ad vector correlatios were estimated by bootstrappig (resamplig with replacemet from the origial data set) the DFA 1,000 times to create samplig distributios of parameters. The sample from Paraguay icluded the specime idetified by Baud ad Meu (13) as the 1st record of M. levis for Paraguay. That idividual was idetified subsequetly as a large M. albesces (López-Gozález 18). The specime was ot icluded i ay aalyses but was classified subsequetly usig the miimum Mahalaobis distace to species cetroids. The traiig set (all observatios mius M. levis from Paraguay) was bootstrapped 1,000 times to estimate the frequecy distributio of classificatio. Levels of sigificace for statistical tests

4 February 2001 LÓPEZ-GONZÁLEZ ET AL. MYOTIS IN PARAGUAY 141 FIG. 1. Schematic represetatio of diagostic variatio i width of plagiopatagium at its isertio o the leg of Paraguaya Myotis: a) at toes (all South America Myotis except M. simus); b ad c) at the akle (M. simus). were Statistical aalyses were performed usig SAS statistical software (SAS Istitute Ic. ) ad Matlab for Widows (The MathWorks, Ic. 14) usig fuctios ad script files writte by C. López-Gozález or R. E. Strauss. Script files ad fuctios are available upo request from C. López-Gozález ad R. E. Strauss. RESULTS Qualitative variatio. Myotis simus was described by Thomas (1) based o 1 specime from Peru. Wigs attached to the akle was 1 of the distictive characteristics of the type specime. Noetheless, isertio of the plagiopatagium at the akle i M. simus istead of at the toes, as i other species of Neotropical Myotis, was cosidered by Hadley () ad LaVal (173) to be a artifact of preparatio. I cotrast, Baud ad Meu (13) argued that it was ot a artifact ad emphasized that it represeted 1 of the most importat features that separated M. simus from other Neotropical Myotis. We cocur with Baud ad Meu (13); isertio of the plagiopatagium at the akle is ot a artifact, although the character varies across the rage of the species, with o apparet geographic patter. Examiatio of M. simus available to us, icludig specimes from Ecuador, Brazil, Bolivia, Peru, ad Paraguay, showed that i most idividuals, the membrae arrows as it exteds distally, so that at the level of the akle it is oexistet or extremely arrow (Fig. 1b). However, i some specimes, the membrae may be as wide as 1.5 mm at the akle (e.g., AMNH 1473 from Amazoas, Brazil; Fig. 1c). That coditio differed from other Paraguaya Myotis i which the membrae greatly broadeed as it departed from the base of the toes (Fig. 1a; Table 1). I geeral, Paraguaya species of Myotis correspod i fur characteristics to those described by LaVal (173; Table 1). The exceptio was M. riparius, which i Paraguay had slightly loger fur tha specimes from orther areas, makig distictio from M. igricas difficult. Nevertheless, i most cases, the woolly texture of the fur was sufficiet to separate M. riparius from the silkier M. igricas. Myotis simus was described by LaVal (173:31) as usually bright orage or somewhat duller, varyig from ciamobrow to ciamo; tips ot cotrastig; below, hairs loger, tips yellow, bases

5 142 JOURNAL OF MAMMALOGY Vol. 82, No. 1 TABLE 1. Diagostic characteristics for species of Myotis that occur or may occur i Paraguay. Quatitative characters are give as mea (rage). Acroyms of characters as i Table 4. Species Character M. albesces M. levis M. igricas M. riparius M. ruber M. simus Attachmet of plagiopatagium At toes At toes At toes At toes At toes At akle Legth of fur Log ( 4 mm) Log ( mm) Log ( 5 mm) Short (3 5 mm) Short ( 4 mm) Short ( 3 mm) Texture of hair Silky Silky Silky Woolly Silky Woolly Color of hair Pale to dark brow, tips frosted Frige of hair o edge of uropatagium Positio of P3 Usually o toothrow Dark brow bases, yellow to brow midparts, tips frosted i dark specimes Black to sady brow, tips with darker bases Dull brow, uicolored or bases slightly darker Bright ciamo, uicolored or bases slightly darker Preset Preset Abset Abset Abset Abset Usually o toothrow Usually o toothrow Ofte crowded to ligual side Bright orage (fresh), or ochraceous to ciamo O toothrow Crowded to ligual side Sagittal crest Abset Abset Abset Preset Preset Preset Breadth across upper 1 mm 1 mm 1 mm 1 mm 1 mm 1 mm caies Iterorbital costrictio 0.87 ( ) mm 0. ( ) mm 0. ( ) mm 1.03 (0.3 1.) mm 1.0 ( ) mm 1.03 ( ) mm Craial idex 77.8 (7 8) 80. ( ) 8. (2. 7.) 70.0 (4. 7.1) 81.8 (78.4 8) 7.8 ( ) Maxillary idex 25. ( ) 30. (2.0 3.) 25. ( ) 28.1 (2 31.1) 34.8 (33.5 3) 31.1 ( )

6 February 2001 LÓPEZ-GONZÁLEZ ET AL. MYOTIS IN PARAGUAY 143 somewhat darker. I cotrast, i their redefiitio of the species, Baud ad Meu (13) cosidered that the ochraceous coloratio might be a effect of preservatio rather tha a atural feature. Specimes they studied were all mummy-brow ad ever ochraceous. The specime of M. simus collected by us at Ayolas, Misioes, Paraguay, was a bright orage aimal whe alive. After a year of storage, the dry ski became ochraceous-brow, the same color as i some of the series from the Amazo Basi at AMNH (Appedix I) ad specimes from Bolivia. Dark, ciamo-red idividuals also occurred (e.g., TTU 4348 from ear Tigo María, Peru), ad the red coloratio remaied after years of storage i a museum. Other specimes (dry skis) from the same areas were dull brow, as described by Baud ad Meu (13). We detected o geographic patter to color variatio, although apparet lack of a patter may have resulted from chage i color of specimes across time. Frige of hair at the edge of the uropatagium was a diagostic feature withi species. It separated M. albesces ad M. levis, which have a friged uropatagium, from all other Paraguaya species. Some Paraguaya specimes of M. igricas ad M. riparius had a few hairs at the edge of the uropatagium that were sparse ad required magificatio to be see. Presece or absece of a sagittal crest was a useful character to separate species i Paraguay (Table 1). Itraspecific variatio i degree of developmet of crests was miimal. All Paraguaya M. riparius had a crest, as did all examied specimes of M. ruber ad M. simus. I a large sample of M. simus examied by LaVal (173), oly 8 of 7 specimes lacked a sagittal crest. The P3 crowded to the ligual side was a diagostic character for M. simus (Thomas 1); oly 1 specime of M. simus examied by us lacked that coditio. Although M. riparius was described based o specimes with a crowded P3 (Hadley ), much variatio i that trait occurred i that species. I Paraguay, oly 1 of 5 specimes examied had P3 crowded to the ligual side, whereas 84 of 8 specimes from Cetral ad South America (excludig Paraguay ad Uruguay) had a crowded P3 (LaVal 173). No geographic patter i crowdig was detected. This coditio also occurred sporadically i M. igricas. No sigle character sufficietly differetiated species of Myotis i Paraguay, except for isertio of the plagiopatagium at the level of the akle, which separated M. simus exterally from other species of Neotropical Myotis. The remaiig species could be separated by a combiatio of the aforemetioed pelage characteristics ad craial features (Table 1). However, combiatios of character states cosidered as diagostic of species were ot preset i all specimes, reducig ability to make positive idetificatio usig oly qualitative characters. Quatitative variatio. Because of small samples, secodary sexual dimorphism was ot examied i M. ruber. Sexual differeces i craial morphology were ot sigificat i ay remaiig species based o uivariate or multivariate aalyses, but sex by locality iteractio was sigificat for greatest legth of skull, codylobasal legth, ad legth of maxillary toothrow i M. levis (sequetial Boferroi adjustmet, P 0.001). The correspodig effect also was sigificat i the multivariate test (Table 2). Iterlocality differeces also were sigificat i the multivariate test for M. levis (Table 2). Sigificat geographic differeces cosistetly were foud for codylocaie legth, mastoid breadth, zygomatic breadth, iterorbital costrictio, ad legth of maxillary toothrow (P 0.001). M. riparius differed sigificatly across localities accordig to MANOVA. However, uivariate results were sigificat oly for 1 character after adjustmet; specimes from the Amazo Basi were larger for breadth across upper molars (P 0.001). The locality effect was highly sigificat i the MANOVA for M. simus (Ta-

7 144 JOURNAL OF MAMMALOGY Vol. 82, No. 1 TABLE 2. P-values of multivariate aalysis of variace (MANOVA) tests for sexual dimorphism, geographic variatio, ad their iteractio i South America Myotis. NT, effect ot tested. Species of Myotis M. albesces M. levis M. igricas M. riparius M. ruber M. simus MANOVA Sex Locality Sex by locality NT * Sigificat after sequetial Boferroi adjustmet by species ( 0.05) * * NT 0.001* * 47 3 NT 0.51 ble 2). Specimes of M. simus from the Amazo Basi were sigificatly smaller tha those from outside the Basi i 7 characters, ad Bolivia specimes were sigificatly larger tha those from Paraguay i 4 of those characters (Table 3). Neither geographic variatio or sexual dimorphism was detected for M. igricas or M. albesces. The PCA illustrated major treds i craial morphology for populatios examied (Fig. 2a). PC1 accouted for 70% of total variatio i the sample ad represeted a geeral size axis. Smaller taxa (M. albesces, M. igricas, ad M. riparius) had low or egative scores, whereas larger species (M. levis, M. ruber, ad M. simus) had high, positive scores o that compoet. Because withi-species variace was large compared with itertaxo differeces for most variables, size aloe did ot discrimiate amog those species, with the possible exceptio of M. ruber. PC2 ad PC3 idicated shape differeces amog taxa (Fig. 2b). Based o shape, 3 distict groups of specimes were formed, M. albesces, M. simus, ad the 4 remaiig species (M. levis, M. igricas, M. riparius, ad M. ruber). First ad 2d axes i the size-adjusted discrimiat fuctio aalysis showed about the same relatioship amog species as did PC2 ad PC3, except that, as expected, groups were more distict (Figs. 2 ad 3). The first 3 discrimiat axes accouted for.7% of total variatio amog taxa after size adjustmet (Table 4). That aalysis also allowed recogitio of 3 distict craial morphologies: M. albesces, M. simus, ad the remaiig species as a group (Fig. 3). Relatioships amog M. levis, M. igricas, M. ruber, ad M. riparius were less clear, suggestig little speciesspecific differetiatio i shape amog those taxa. A relatively broad iterorbital TABLE 3. A posteriori comparisos of sample meas (Tukey s test) for populatios of Myotis simus with a sigificat geographic variatio i uivariate tests ( 0.05). Values of meas are give i millimeters; meas sharig a asterisk are ot sigificatly differet from each other by locality. Locality Character Codylocaie legth Mastoid breadth Breadth of braicase Legth of rostrum Legth of maxillary toothrow Legth of upper molariform toothrow Legth of madibular toothrow Bolivia Paraguay Amazo Basi.* * 5.7*.8* * *

8 February 2001 LÓPEZ-GONZÁLEZ ET AL. MYOTIS IN PARAGUAY 145 FIG. 2. Projectio of idividual scores for samples of species of South America Myotis i pricipal compoets space: a) PC1 ad PC2; b) PC2 ad PC3. Species codes are 1, M. albesces; 2, M. levis; 3, M. igricas; 4, M. riparius; 5, M. ruber;, M. simus. Numbers i paretheses idicate percet variatio amog species explaied by each pricipal compoet. costrictio ad craial vault ad a short rostrum placed M. albesces ad M. simus o the egative side of discrimiat fuctio 1 (DF1) ad separated them from the remaiig species. Large values of greatest legth of skull, codylocaie legth, codylobasal legth (idicative of a log braicase), small zygomatic breadth, ad breadth FIG. 3. Size-adjusted discrimiat fuctio aalysis of 14 craial variables from species of South America Myotis: a) projectio of idividual scores o discrimiat axes 1 ad 2; b) vector correlatios of particular characters with discrimiat axes. Numbers i paretheses idicate percet variatio amog taxa explaied by each discrimiat fuctio; acroyms of variables as i Table 4 ad species codes as i Fig. 2.

9 14 JOURNAL OF MAMMALOGY Vol. 82, No. 1 TABLE 4. Size-adjusted loadigs of craial characters o each of 3 size-adjusted discrimiat fuctios (DFs) costructed to distiguish amog taxa of Myotis i Paraguay. Numbers i paretheses correspod to bootstrapped 5% CI for the vector correlatio betwee each character ad the correspodig DF. DF1 DF2 DF3 Greatest legth of skill (GLS) 4 ( 0.00) 0.70 ( ) 0.0 ( ) Codylocaie legth (CCL) (0.00 ) 0.55 ( 0.8) 2 ( ) Codylobasal legth (CBL) 3 ( 0.02 ) 0.44 (7 0.57) 1 ( 0.41) Mastoid breadth (MAB) 0.71 ( 0.78 to 0.2) 0.45 ( 0.55 to 0.05) 0 ( ) Zygomatic breadth (ZYG) 4 ( 0.40 to 0.08) 0.1 ( 0.72 to 5) 7 ( ) Breadth of braicase (BBC) 0.83 ( 0.87 to 0.77) ( to 1) 3 ( ) Iterorbital costrictio (INC) 0.5 ( 0. to 0.8) 8 ( 0.0 3) 0.02 ( 8 4) Breadth across upper caies (BAC) 0.53 ( to ) 0.73 ( ) 0 ( ) Breadth across upper molars (BAM) 0.01 ( 2 5) ( ) 0 ( ) Legth of rostrum (LNR) 0. ( ) 0.08 ( 8 1) 0 ( 4) Legth of maxillary toothrow (MAX) 0.77 ( ) 7 ( ) 5 ( 2 3) Legth of upper molariform toothrow (UML) 0.0 ( ) 0.54 (1 0.73) ( 0.55) Legth of madibular toothrow (MTR) 0.7 ( ) 0.08 ( 8 1) 0.0 ( 7 1) Legth of lower molariform toothrow (LML) 0.52 (5 0.5) 7 (0 0.53) 4 ( ) Percet of variace explaied (4.5 5.) 2 ( ). ( ) across upper molars separated M. albesces from M. simus, which also had a wider rostrum ad base of skull. M. igricas, M. riparius, M. ruber, ad M. levis had log rostrums (large legth of rostrum ad legth of madibular toothrow) ad arrow craial vaults (small iterorbital costrictio ad breadth of braicase). M. ruber ad M. riparius were idistiguishable i shape of skull; their relatively short braicase (small greatest legth of skull, codylocaie legth, ad codylobasal legth) ad large breadth across upper molars ad zygomatic breadth separated those 2 taxa from the rest of the log-faced Myotis (Fig. 3). Based o discrimiat fuctios obtaied from the aalysis, specime MHNG from Arroyo Pirayu-i, 40 km N Capitá Meza, Itapua, idetified as M. l. levis by Baud ad Meu (13), was classified as M. albesces i 0% of 1,000 iteratios i the bootstrapped DFA. DISCUSSION Ulike may vespertilioids, i which females are larger tha males (Myers 178; Ralls 17; Williams 178; Williams ad Fidley 178), o sigificat differece i size betwee sexes was foud for ay species of Myotis from Paraguay. Although Myers ad Wetzel (183) foud sigificat sexual dimorphism i Paraguaya M. albesces, they cosidered differeces to be sufficietly small to allow for poolig sexes i morphometric aalyses. Similarly, Willig (183) foud o sigificat sexual dimorphism i M. riparius from ortheaster Brazil. Sigificace of the locality by sex i-

10 February 2001 LÓPEZ-GONZÁLEZ ET AL. MYOTIS IN PARAGUAY 147 teractio i M. levis may represet differet expressios of sexual dimorphism i each subspecies, but because of small samples available ad the high degree of overlap i size betwee them (Appedix II), these results must be iterpreted with cautio. Sigificat, albeit slight, geographic differeces i craial ad exteral characters have bee reported i M. igricas ad M. albesces from Bolivia, Chaco Boreal, ad easter Paraguay (Myers ad Wetzel 183). Lack of sigificace for M. igricas ad M. albesces examied here may be the result of ot icludig Bolivia specimes, which were the most differetiated i samples examied by Myers ad Wetzel (183). I their aalysis, differeces betwee east ad west were oly margially sigificat, with Chacoa specimes averagig 1 2% larger tha easter specimes. M. igricas ad M. albesces show opposite clial treds i size south of the Amazo Basi (LaVal 173); M. igricas is smaller to the south, whereas M. albesces icreases i size with latitude. Geographic variatio reported by Myers ad Wetzel (183) may reflect these clial treds because the specimes used i their aalyses were from a sample that largely followed a trasect from the Bolivia Chaco south southeast to easter Paraguay. No geographic variatio i size has bee detected i M. riparius from Veezuela to easter Peru to Uruguay (LaVal 173). Specimes from wester Paraguay were smaller tha idividuals from the easter regio i previous aalysis (Myers ad Wetzel 183). However, small samples precluded powerful statistical aalysis of geographic variatio i M. riparius. Our results reflect those of previous authors, although multivariate results were sigificat, oly 1 of the variables examied was sigificat, ad o patter is apparet i variatio of characters examied. Geographic differeces may exist amog populatios of this species across its rage, but available evidece is ot sufficiet to draw icotrovertible coclusios or to determie if a patter exists. Geographic variatio i M. simus had ot bee recorded previously. Specimes from the Souther Coe were larger tha those from the Amazo Basi (Appedix II). I tur, Bolivia ad Paraguaya specimes differed sigificatly i craial measuremets. Noetheless, we believe desigatio of subspecies i this taxo is ot warrated because o matchig geographic patter occurs i differeces i coloratio or ay other exteral features examied so far. A comprehesive study of the etire rage of the species would be ecessary to evaluate the extet of iterpopulatioal variatio. Despite variatio i size, shape of skull is cosistet across populatios withi species. Neither PCA or DFA suggested ay distict populatios below the specific level. Five species are recogized for Paraguay: Myotis albesces, M. igricas, M. riparius, M. ruber, ad M. simus. DF1 was correlated highly ad positively with characters related to legth of rostrum ad toothrows ad egatively correlated with width of craial vault ad iterorbital costrictio. M. albesces ad M. simus have a short rostrum, broad craial vault, ad wide iterorbital costrictio, whereas the remaiig species have the opposite characteristics. Scores o DF2 were related to relative legth of braicase with respect to total legth of skull. DF2 was correlated egatively with characters related to width of rostrum ad braicase. M. albesces ad M. simus are essetially idistiguishable alog the 1st axis but differed alog the 2d axis; M. simus has wider base of skull, wider rostrum, ad shorter braicase. M. albesces has a comparatively arrow base of skull, which, together with the wider vault, cofers the characteristic, globose appearace of its braicase. We cocluded that M. levis has ot bee documeted for Paraguay. The oly specime from Paraguay previously idetified as M. levis (MHNG ) has the craial morphology of M. albesces. Additioally, dorsal pelage of this idividual is log ad dark, with frosted tips. Although the spec-

11 148 JOURNAL OF MAMMALOGY Vol. 82, No. 1 ime is relatively large (Appedix II) ad frosted hair-tips occur i M. l. levis from São Paulo, Brazil (e.g., FMNH 140, , ), the specime has a short rostrum, globose braicase, ad wide iterorbital costrictio, which firmly place it withi M. albesces. Noetheless, the kow distributio of M. levis i orther Argetia ad souther Brazil (LaVal 173) suggests that it may occur i Paraguay. Although differet i size ad coloratio, M. l. levis ad M. l. diellii are similar i craial shape. Degree of craial resemblace is comparable to that betwee M. igricas ad M. riparius (Fig. 3), which are cosidered distict species. I fact, M. levis ad M. diellii were described origially as species ad subsequetly relegated to subspecies of M. chiloesis by Miller ad Alle (8), assiged by Cabrera (8) to M. ruber, ad referred to as M. levis (distict from M. ruber) by LaVal (173). Uder LaVal s defiitio (followed here), M. levis occurs i southeaster Brazil, Uruguay, ad Argetia. He recogized 2 major groups, M. l. levis from southeaster Brazil to Uruguay ad M. l. diellii from orthwester ad souther Argetia. LaVal (173) distiguished the 2 forms by size ad color ad remarked that differeces betwee them were strikig. M. l. levis is large with broad color variatio across its rage (so much so that LaVal [173] suggested the possibility that his sample represeted 2 species). M. l. diellii, coversely, is smaller, with log, silky, strogly bicolored fur (bases black, tips reddish brow to blod). Noetheless, differetiatio of these 2 forms is far from clear. Specimes from Argetia ca be separated by size (Barquez et al. 1). However, specimes from Etre Ríos Provice, Argetia, were itermediate betwee M. l. levis ad M. l. diellii (LaVal 173). Our samples, which icluded specimes from Bolivia, Brazil, Argetia, ad Uruguay, were sigificatly differet i size for oly 4 of 14 craial characters. We icluded specimes from Bolivia ot available to LaVal, which exteded the rage of size measuremets for M. l. diellii to overlap with that of the omiate subspecies i most measuremets. LaVal (173) suggested the existece of a itergradatio zoe betwee the 2 forms, or else possibility that they represeted differet species, but o data were available from itermediate areas to draw defiitive coclusios. However, exterally, the Bolivia material shows the characteristic coloratio of M. l. diellii (Aderso 17). Although more material is available ow, sample sizes are still isufficiet to assess geographic variatio i M. levis with statistical reliability. Clearly, populatios ow icluded as M. levis await thorough examiatio; additioal, omorphologic iformatio may help clarify taxoomic boudaries. Quatitative idices have bee used to distiguish amog Paraguaya species of Myotis. Craial ad maxillary idices (Baud ad Meu 13) describe differet aspects of the skull (Table 1). Maxillary idex is a measure of size of rostrum; thus, M. albesces has smaller maxillary idex, whereas M. levis would have large values. Craial idex is a measure of breadth of braicase ad craial vault; M. igricas has small craial idices, whereas M. albesces ad M. ruber have large values. Clearly, these idices reflect overall craial size. As such, they show a high degree of overlap ad by themselves are of little use i separatig species. Baud ad Meu (13) used them i combiatio, creatig biplots of maxillary versus craial idex. Such biplots successfully separated M. ruber (actually a mixture of M. ruber ad M. simus) from the remaiig species. LaVal (173) used ratio of breadth across caies to iterorbital costrictio as a taxoomic character to separate species. This ratio is useful to separate M. albesces from the remaiig species i most cases, although ot cosistetly so (Table 1). This ratio is helpful i distiguishig M. riparius ad M. igricas. Other species are better idetified by a combiatio of craial ad exteral

12 February 2001 LÓPEZ-GONZÁLEZ ET AL. MYOTIS IN PARAGUAY 14 characters described previously, ad summarized below. KEY TO PARAGUAYAN SPECIES OF MYOTIS PLUS M. LEVIS 1. Fur 3 mm log o dorsum, color bright orage or tawy to ciamo-red o back, legth of forearm 37 mm, P3 crowded ligually, so that it is scarcely visible i lateral view, isertio of plagiopatagium at base of tarsals...m. simus Dorsal pelage 3 mm, color from ciamo red to black, tips may be white, givig a frosted appearace, P3 ot crowded to ligual side, isertio of plagiopatagium at toes Sagittal crest usually preset, ofte well developed, breadth across caies usually greater tha iterorbital costrictio, or if about equal, the iterorbital costrictio usually mm, dorsal pelage silky ad reddish-brow to ciamo, or woolly ad dull to dark brow, fur relatively short ( 5 mm)... 3 Sagittal crest usually abset, or poorly developed if preset, breadth across caies usually less tha iterorbital costrictio, or if ot, the iterorbital costrictio usually mm, dorsal pelage silky, color yellow or sady brow to black, tips of hairs may be white, givig a frosted appearace, fur log ( 5 mm) Fur silky, color ciamo-red, hair o dorsum of uropatagium exteds to or past the kees, greatest legth of skull 14.5 mm, legth of forearm 37 mm... M. ruber Fur woolly, color reddish-brow to dark-brow, hair o dorsum of uropatagium does ot exted to or past the kees, greatest legth of skull 14.5 mm, legth of forearm 37mm M. riparius 4. Pelage strogly bicolored, color brow to almost black at bases of hairs ad silvery o tips, givig a frosted appearace, or dark brow o bases ad yellow to brow o midparts with paler tips. A frige of hair at the posterior edge of uropatagium is preset (may eed magificatio to be observable), breadth of braicase 7 mm, or if smaller, the legth of rostrum 5.7mm... 5 Pelage weakly bicolored, color sady brow (i specimes from orthwester Chaco), to blackish, uropatagium without a frige of hair, breadth of braicase 7 mm, legth of rostrum usually 5.5 mm... M. igricas 5. Dorsal fur brow to almost black at bases of hairs ad silvery o tips, givig a frosted appearace, craial vault ad iterorbital costrictio relatively broad, givig a globose appearace to skull, rostrum relatively short, breadth betwee caies 7 mm or if smaller, the legth of rostrum 5.7mm...M. albesces Dorsal fur with dark bases ad silvery tips givig a slightly frosted appearace similar to that of M. albesces (i M. l. levis), or fur dark brow o bases, yellow to brow o midparts, ad paler o tips (i M. l. diellii), craial vault ad iterorbital costrictio arrow, rostrum relatively log, breadth betwee caies 7 mm, or if wider, the legth of rostrum mm... M. levis SPECIES ACCOUNTS Paraguaya species of Myotis represet 2 subgeera, Leucooe, icludig M. albesces, M. riparius, M. ruber, ad M. simus, ad Selysius, represeted by M. igricas (Koopma 13, 14). Cabrera (8) desigated a mootypic subgeus, Hesperomyotis, to iclude M. simus, based o its high degree of morphologic divergece from cogeers. Our results idicate that degree of differetiatio of M. simus is similar to that i M. albesces or M. ruber. With the evidece at had, we see o reaso to cosider M. simus to belog to a differet subgeus. Myotis albesces (É. Geoffroy Sait-Hilaire, 180) A small species of Myotis, ad the most distictive of those occurrig i Paraguay. Dorsal fur rages from pale to dark brow or almost black, tipped with golde yellow or silvery white, resultig i a frosted appearace. Idividual dorsal hairs are log ( 4 mm); vetral hairs are dark brow with

13 0 JOURNAL OF MAMMALOGY Vol. 82, No. 1 buffy tips. Coloratio of pelage rages from almost black to sady brow, always with frosted tips. Some specimes have 1 patches of rusty-brow or black hair o the dorsum. No differece i color was detected betwee specimes from easter ad wester Paraguay. The plagiopatagium attaches to the toes (Fig. 1a). A frige of hairs is preset o the posterior border of the uropatagium, although it may be difficult to see without magificatio. This character is cosistet throughout Paraguay. The skull is of moderate size (Appedix II), with little forehead slope, ad a arrow, short rostrum. Craial vault ad iterorbital costrictio are wide relative to size of skull. These characters separate M. albesces from all other species (Fig. 3). Exteral characteristics separate M. albesces from all other species of Paraguaya Myotis (Table 1), except for M. levis (which may occur i Paraguay) ad M. igricas, which may have similar coloratio. However, its globose craial vault, short rostrum, ad proportioally wider postorbital costrictio (ratio breadth across caies to iterorbital costrictio 1) suffice to separate it. Distributio. Myotis albesces occurs throughout Paraguay, although it seems more commo i the west (López-Gozález 18; Willig et al. 2000). Remarks. Although clial variatio i size exists for Mato Grosso (Brazil), Paraguay, ad Uruguay, o subspecies have bee recogized (Koopma 14; LaVal 173). Reproductive biology ad atural history have bee described by Myers (177). M. albesces shares roosts with M. igricas i the Paraguaya Pataal. Fidley (13) classified this species as a forest ad clearig aerial isectivore. Myotis igricas (Schiz, 1821) This is the most commo species of Myotis i Paraguay ad o average the smallest (Appedix II). The dorsal pelage is silky. Coloratio rages from black o bases ad tips of hairs i the easter regio, to sady brow o tips with darker bases i the orthwester Chaco. Wig membraes isert at toes (Fig. 1a). Both rostrum ad braicase are arrow, ad upper molariform teeth usually are arraged i a row, although i a few specimes (e.g., TK 0, 0231, 023), P3 is crowded to the ligual side. M. igricas usually lacks a sagittal crest, although some specimes from Fuerte Olimpo, Departameto Alto Paraguay, have a low, barely perceptible sagittal crest. However, pelage characteristics place these specimes i M. igricas. This species is distiguishable exterally from cogeers i Paraguay by color, legth ad texture of hair, ad overall size (Table 1). M. igricas ca be cofused oly with M. riparius; these 2 species are more similar to each other tha to ay other Paraguaya species i size or shape of skull. However, M. igricas geerally is smaller, the ratio of iterorbital costrictio to breadth of caies usually is 1 (as opposed to 1 im. riparius), ad M. igricas lacks a sagittal crest, which is preset i M. riparius. I Paraguay, pelage of M. riparius is ot as distictive as it is i more orther areas of South America ad resembles that of M. igricas. Some Paraguaya specimes reported previously i the literature as M. igricas actually may be referable to M. riparius. Distributio. Widely distributed throughout Paraguay i easter ad wester regios (López-Gozález 18; Willig et al. 2000). Remarks. Four (LaVal 173; Wilso ad LaVal 174) or 5 (Koopma 14) subspecies of M. igricas have bee recogized. Uder either iterpretatio, Paraguaya populatios ca be ascribed to the omiate subspecies. M. igricas has bee foud sharig roosts with M. albesces i the Paraguaya Pataal. Reproductive patters i Paraguay were described by Myers (177). Females give birth i sprig ad summer ad probably cotiue at low frequecy durig autum ad witer. Males are aseasoal with regard to their testis cy-

14 February 2001 LÓPEZ-GONZÁLEZ ET AL. MYOTIS IN PARAGUAY 1 cle, o storage of sperm has bee foud i either males or females. Fidley (13) classified M. igricas as a forest ad clearig aerial isectivore. Myotis riparius (Hadley ) Myotis riparius has short ad woolly fur, buffy-brow dorsum, ad idividual hairs slightly burished at the tips ad slightly grayer toward the bases (Hadley ). Ciamo-red specimes also may exist (LaVal 173). The wig membrae attaches to the base of toes (Fig. 1a). The type specime is large i exteral measuremets (legth of forearm, 3.2 mm), but with a comparatively small skull (greatest legth, 14.2 icludig icisors, as measured by C. López-Gozález). The skull is log ad arrow, ad well-developed sagittal ad lambdoidal crests are preset. P3 is crowded to the ligual side i the type specime. Broad variatio i size exists amog Paraguaya specimes. Noetheless, M. riparius averages larger tha M. igricas. Dorsal pelage may ot be as short ad markedly woolly as it is i more orther specimes, ad P3 is ot always crowded to the ligual side i Paraguaya M. riparius. Moreover, P3 is crowded i some M. igricas, which may make idividuals difficult to idetify. However, presece of a sagittal crest (always abset i Paraguaya M. igricas where the 2 species are kow to occur i sympatry), the ratio iterorbital costrictio to breadth across caies 1, ad shorter fur, are sufficiet to distiguish M. riparius from M. igricas whe both ski ad skull are available. M. riparius is distiguished easily from other species of Myotis i Paraguay by coloratio ad skull proportios. Distributio. Most Paraguaya specimes have bee collected i forested areas of the easter regio, although a few have bee caught i the lower Chaco (López- Gozález 18; Willig et al. 2000). No records are kow from the dry Chaco. Remarks. Little geographic variatio has bee detected i this species across its rage (LaVal 173), ad o subspecies are recogized. Accordig to LaVal (173), the holotype of Myotis guaycuru, a specime from Mato Grosso (curretly Mato Grosso do Sul), Brazil, may represet a M. riparius as uderstood here. I that case, it would become the seior syoym of M. riparius. The origial publicatio by Proeça (143), describes M. guaycuru as a relatively large bat (legth of forearm 37 mm), with P3 crowded to the ligual side (so much that it is ot visible from the lateral side), with fulvous-yellow fur, ad with isertio of the uropatagium at the level of the tarsals, a character evidet i the origial descriptio (Proeça 143:figure 3). However, M. guaycuru is described as lackig a sagittal crest, a character used by Proeça (143) to distiguish it from M. simus. Despite this purported differece, isertio of the uropatagium at the tarsals ad crowdig of P3 suggest that the type specime of M. guaycuru actually belogs to M. simus as uderstood here, ad, therefore, the ame M. guaycuru Proeça 143 should be cosidered a juior syoym of M. simus Thomas 1. M. riparius has bee cosidered as a water bat (Fidley 13:88) associated with gallery forests that forages over water. Noetheless, LaVal ad Fitch (177) reported 78 idividuals of this species i the raiforest of La Selva, Costa Rica, collected well away from riparia eviromets. Myotis ruber (É. Geoffroy Sait-Hilaire, 180) Myotis ruber is a large distictive bat. Dorsal pelage is bright ciamo-red, relatively short, but silky, ad moocolored or oly slightly bicolored. The dorsal surface of the uropatagium is covered with hair to the level of the kees. The veter is yellowish, with dark brow bases. The plagiopatagium attaches at the toes (Fig. 1a). The skull is robust, large, ad wide at its base; the rostrum is log ad relatively wide, iterorbital costrictio is arrow, ad sagittal crest is well developed. I Paraguay, M.

15 2 JOURNAL OF MAMMALOGY Vol. 82, No. 1 ruber is distiguishable from other cogeers by size ad coloratio (Table 1). Because of similar size, the craium ca be cofused with that of M. simus, which, however, differs i the positio of P3, i havig loger rostrum, arrower craial vault, ad ratio of iterorbital costrictio to breadth across caies 1. Distributio. All kow Paraguaya records are from the southeaster corer of the coutry, Departameto Itapua, ad from Sapucai, Departameto Paraguari. M. ruber ihabits low semideciduous forests ad is a rare bat throughout its distributio (Acosta y Lara 0; López-Gozález 18). Remarks. Baud ad Meu (13) described M. ruber from Paraguay i a maer cosistet with characters give by LaVal (173) ad clearly recogized differeces betwee it ad M. simus. Nevertheless, they assiged 2 clear M. simus (MVZ ad ), uder their ow defiitio ad that of LaVal (173), to M. ruber. Skulls of M. simus ad M. ruber are markedly differet i shape (Figs. 2 ad 3). Both PCA ad DFA placed these 2 specimes withi M. simus. Additioally, both idividuals have the characteristic short wooly pelage of M. simus, ad isertio of the plagiopatagium is ot at the toes. No subspecies are recogized (Koopma 14; LaVal 173). Myotis simus (Thomas, 1) This is a large Myotis with extremely short woolly fur. Dorsal color rages from a bright orage i fresh specimes (which becomes tawy-brow i dry specimes) to ciamo-brow, to ciamo. Tips of hairs do ot cotrast with bases o dorsal pelage. O the veter, hairs are slightly loger, with yellow tips ad slightly darker bases. Membraes are dark brow to black. Ulike other Myotis i Paraguay, the plagiopatagium attaches at the level of the tarsals (Figs. 1b ad 1c). This combiatio of characters exterally distiguishes Paraguaya M. simus from other cogeers. Large size, presece of a well-developed sagittal crest, crowdig of P3 to the ligual side, relatively short, wide rostrum, wide base of skull, ad short toothrow characterize M. simus craially. I Paraguay, M. simus ca be cofused oly with M. ruber because of their similarity i geeral ad size of braicase (mea craial idex 7.8, as opposed to 81.8 i M. ruber), but they differ i shape of rostrum. Other characters useful to distiguish the 2 species are discussed i the accout for M. ruber. Distributio. Scattered records are available from the lower Chaco, the viciity of Asució, ad Ayolas, Departameto Misioes (López-Gozález 18; Willig et al. 2000). Argetie records are available from ear Clorida, Formosa, across the Paraguay River from Asució ad from Isla Apipé, Corrietes, across the Paraa River from Ayolas (Barquez et al. 1; Fores 172). Remarks. Myotis simus was origially believed to be cofied to the Amazo Basi (Hadley ; LaVal 173; Miller ad Alle 8). More recetly, it has bee caught i Bolivia (Aderso 17), Paraguay (Myers ad Wetzel 17), ad Argetia (Barquez et al. 1; Fores 172). Baud ad Meu (13) redefied the species, arguig that some of the most importat characters used to distiguish it, isertio of the plagiopatagium at the tarsal level ad a larger caie, had bee misiterpreted or disregarded by previous authors. Based o a sample of South America Myotis, they cocluded that M. simus was restricted effectively to the Amazo Basi, ad it was ever orage or ochraceous. Furthermore, they assiged Paraguaya M. simus to M. ruber. However, their sample was small ( idividuals) ad, by chace, icluded specimes with brow-colored fur. Specimes AMNH (examied by them) for istace, are certaily ot orage or ciamo-red, as are other idividuals from the Amazo Basi. Nevertheless, texture (woolly) ad legth of fur are homo-

16 February 2001 LÓPEZ-GONZÁLEZ ET AL. MYOTIS IN PARAGUAY 3 geeous throughout its rage ad distiguish M. simus from all other Myotis, with the possible exceptio of M. riparius i orther South America. M. simus has bee classified as a water bat, a over-water forager ad ihabitat of gallery forests (Fidley 13:88). ACKNOWLEDGMENTS This research was geerously supported by grats from the Natioal Sciece Foudatio to R. D. Owe ad M. R. Willig (DEB-4002) ad by the Office of Research Services at Texas Tech Uiversity (D. Schmidly ad R. Sweazy). The Miisterio de Agricultura y Gaadería del Paraguay provided sigificat fiacial ad logistic support. Persoel of the Museo Nacioal de Historia Natural del Paraguay (MNHNP) ad the Paraguaya office of the Covetio o Iteratioal Trade of Edagered Species (CITES-PY), especially A. L. Aquio, provided cotiual ecouragemet, support, ad cooperatio. I additio, the Direcció de Parques Nacioales y Vida Silvestre (C. Fox), Fudació Moisés Bertoi (R. Gauto, A. Va Humbeeck, A. Yaoski, ad A. M. Macedo), Etidad Biacioal Yacyreta (M. Cubas), Yaguarete Forests (P. Mueller), Uiversidad Católica Nuestra Señora de la Asució (J. Usher), ad the may owers ad admiistrators of the raches we visited provided valuable assistace. H. Amarilla, A. Cadia, R. Fariña, S. Frutos, P. M. Gorrese, S. T. Mezik, M. Mieres, J. Pitos, M. Råberg, R. D. Steves, ad G. Terol were part of the field crews or offered logistic assistace. For their dedicatio to the project ad coscietious efforts i the field, we are especially grateful to I. Mora ad F. Pitos. Fudig for museum work was provided by 2 summer grats from the Departmet of Biological Scieces, Texas Tech Uiversity, ad a Grat-i-Aid of Research from the America Society of Mammalogists to C. López-Gozález. For access to iformatio ad specimes uder their care, we thak R. J. Baker ad R. R. Mok (TTU), F. Baud (MHNG), I. Gamarra de Fox (MNHNP), C. O. Hadley, Jr., ad L. K. Gordo (USNM), P. Myers (UMMZ), J. L. Patto ad B. Stei (MVZ), B. D. Patterso (FMNH), M. E. Rutzmoser (MCZ), ad N. Simmos ad K. F. Koopma (AMNH). Part of this work was accomplished durig M. R. Willig s teure as a sabbatical fellow at the Natioal Ceter for Ecological Aalysis ad Sythesis, Uiversity of Califoria Sata Barbara. We thak R. K. LaVal ad M. A. Boga for their criticisms of a early versio of this paper. LITERATURE CITED ACOSTA Y LARA, E. F. 0. Quirópteros del Uruguay. Comuicacioes Zoológicas del Museo de Historia Natural de Motevideo 58:1 71. ANDERSON, S. 17. Mammals of Bolivia, taxoomy ad distributio. Bulleti of the America Museum of Natural History 231:1 52. BARQUEZ, R. M., M. A. MARES, AND J. K. BRAUN. 1. The bats of Argetia. Special Publicatios, Museum of Texas Tech Uiversity 42: BAUD, F. J., AND H. MENU. 13. Paraguaya bats of the geus Myotis, with a redefiitio of Myotis simus (Thomas 1). Revue Suisse de Zoologie 0: BRYANT, P Geometry, statistics, probability: variatios o a commo theme. The America Statisticia 38: CABRERA, A. 8. Catálogo de los mamíferos de América del Sur. Revista del Museo Argetio de Historia Natural Berardio Rivadavia, Bueos Aires 4: DOS REIS, S. F., L. M. PESSOA, AND R. E. STRAUSS.. Applicatio of size-free caoical discrimiat aalysis to studies of geographic differetiatio. Revista Brasileira de Geética 13: FINDLEY, J. S. 13. Bats, a commuity perspective. Cambridge Uiversity Press, Cambridge, Uited Kigdom. FORNES, A Myotis (Hesperomyotis) simus Thomas, ua ueva especie para la Argetia. Neotrópica 18:87 8. GEOFFROY SAINT-HILAIRE, E Sur les Vespertilios du Brésil. Aales des Scieces Naturelles 3: HANDLEY, C. O., JR.. Descriptios of ew bats from Paama. Proceedigs of the Uited States Natioal Museum 2: KLEKA, W. R Discrimiat aalysis. Sage Uiversity Paper Series, Quatitative Applicatios i the Social Scieces 1:1 71. KOOPMAN, K. F. 13. Order Chiroptera. Pp i Mammal species of the world: a taxoomic ad geographic referece. 2d ed. (D. E. Wilso ad D. M. Reeder, eds.). Smithsoia Istitutio Press, Washigto, D.C. KOOPMAN, K. F. 14. Chiroptera: systematics. Mammalia. Hadbuch der zoologie. Walter de Gruyter, Berli, Germay 8: LAVAL, R. K A revisio of the Neotropical bats of the geus Myotis. Bulleti of the Natural History Museum of Los Ageles Couty :1 54. LAVAL, R.K.,AND H. S. FITCH Structure, movemets, ad reproductio i three Costa Rica bat commuities. Occasioal Papers, Museum of Natural History, Uiversity of Kasas :1 28. LITTLE, R. J. A., AND D. B. RUBIN Statistical aalysis with missig data. Joh Wiley & Sos, New York.