New Species of Hydrolaetare (Anura, Leptodactylidae) from ... - BioOne

Journal of Herpetology, Vol. 41, No. 4, pp. 724–732, 2007 Copyright 2007 Society for the Study of Amphibians and Reptiles

New Species of Hydrolaetare (Anura, Leptodactylidae) from Bolivia with Some Notes on Its Natural History ´ LVAREZ,3 MARTIN JANSEN,1,2 LUCINDO GONZALES A 1

AND

GUNTHER KO¨HLER1

Forschungsinstitut und Naturmuseum Senckenberg, Senckenberganlage 25, 60325 Frankfurt am Main, Germany 3 Museo ‘‘Noel Kempff Mercado’’, Casilla de Correo 2489, Santa Cruz, Bolivia

ABSTRACT.—We describe a new species of Hydrolaetare from the eastern lowlands of Bolivia. The new species differs from the other two congeners in (1) Finger II and III with lateral fringes only on the inner side; (2) relative length of first finger; (3) palmar tubercle distinctly larger than thenar tubercle; (4) toes semiwebbed; and (5) coloration. Moreover, the advertisement call of the new species differs from that of its congeners. Some information about its natural history is given. RESUMEN.—Se describe una nueva especie de rana perteneciente al geńero Hydrolaetare proveniente de las tierras bajas del este de Bolivia. La nueva especie se diferencia de sus dos congeńeres en (1) dedos II y III de las manos con franjas laterales uńicamente en su parte interna; (2) longitud relativa del primer dedo de la mano; (3) tube´rculo palmar distintivamente ma´s grande que tube´rculo tenar; (4) membrana parcial entre los dedos de los pies; y (5) coloracioń. Ma´s auń, las vocalizaciones de la nueva especie difiere de la de sus congeńeres. Se incluye cierta informacioń de su historia natural.

Although many species of frogs have been described recently, there are still genera poorly known and not well represented in museum collections. Gallardo (1963) described the genus Hydrolaetare with Hydrolaetare schmidti (Cochran and Goin) as its only member. A diagnostic definition of the genus was provided by Gallardo (1963), Cochran and Goin (1970), and Lynch (1971). Heyer (1970) had placed Leptodactylus dantasi (Bokermann 1959) in the Leptodactylus melanonotus group. However, De Souza and Haddad (2003) redescribed that species from the first adult specimens, and transferred it to Hydrolaetare and included a new diagnostic character of the genus (i.e., serrated fringes of fingers and fringes and webbing of toes, which can be keratinized). Information about and specimens of Hydrolaetare are rare, and we are aware of only about 40 specimens or literature records for H. schmidti (e.g., Gallardo, 1963; De Souza and Haddad, 2003) and eight specimens of Hydrolaetare dantasi (Bokermann, 1959; De Souza and Haddad, 2003). Hydrolaetare schmidti has a ‘‘Spotty distribution in the Amazon basin from the Madeira (Brazil) to Colombia, Peru, Bolivia, and French Guiana’’ (Frost, 2006). However, the 11 Brazilian specimens of H. schmidti examined by Gallardo (1963) all lack precise locality data (i.e., two specimens: ‘‘Mato Grosso,’’ eight specimens: ‘‘sem procedencia’’ [without locality], one spec2 Corresponding Author. E-mail: martin.jansen@ gmx.net

imen ‘‘sem procedencia, Amazonia’’). Hydrolaetare dantasi is only known from three localities in the state of Acre, Brazil (De Souza and Haddad, 2003; see Fig. 1). The occurrence of H. schmidti and H. dantasi (as L. dantasi) in Bolivia was suspected by De la Riva et al. (2000) and Ko¨hler (2000). The first record of H. schmidti for Bolivia was published by Padial and De la Riva (2005). They stated, that ‘‘Ce´lio F. B. Haddad (Rio Claro, Brazil; in litt.) has observed another specimen from Bolivia that differs from H. schmidti and H. dantasi but due to bad preservation it could not be assigned with certainty to a new species’’ (Padial and De la Riva, 2005:65). Unfortunately, no locality data were provided by the authors. Little is known about the natural history of these nocturnal, aquatic frogs (see Rodriguez and Duellman, 1994; Lescure and Marty, 2000; De Souza and Haddad, 2003). Ho¨dl and Gollmann (1986) described the distress call of H. schmidti, and Lescure and Marty (2000) provided parameters and graphs of its advertisement call. De Souza and Haddad (2003) provided a description of the advertisement call and distress call of H. dantasi. Photographs or drawings of H. schmidti were provided by Cochran and Groin (1959), Gallardo (1963), Rodriguez and Duellman (1994), and Lescure and Marty (2000); photographs or drawings of H. dantasi were provided by Bokermann (1959) and De Souza and Haddad (2003). In November 2005, L. Gonzales and O. Helmig (Museo Noel Kempff Mercado, Santa Cruz, Bolivia) found one frog on Caparu´ Ranch,

NEW SPECIES OF HYDROLAETARE FROM BOLIVIA

FIG. 1. Type localities (white symbols) and distributional records (black symbols) for the species of Hydrolaetare. Circles: Hydrolaetare schmidti; squares: Hydrolaetare dantasi; triangle: Hydrolaetare caparu. Literature records of specimens without precise locality data (i.e., those from ‘‘Mato Grosso,’’ ‘‘Amazonia,’’ and ‘‘Rıó Jurua´, AC, Brazil,’’ cited in Gallardo, 1963; De Souza and Haddad, 2003) have not been plotted on the map.

Department of Santa Cruz, and identified it as a member of the genus Hydrolaetare. The area of the Caparu´ Ranch encompasses a variety of vegetation types, such as large seasonally inundated grassland, Cerrado woodland, rain forest, and seasonally flooded gallery forests of the Cerrado forest formation. The average annual precipitation is between 1,100 and 1,500 mm, and average annual temperature is 25–30uC. A temperature data logger showed an average temperature of 26uC between September 2005 and February 2006. The dry season is between August and November, rainy season and season of inundation between December and July ( J. Rozenman, pers. comm.). In February 2006, M. Jansen (Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt, Germany) and A. A. Diego (Museo Noel Kempff Mercado, Santa Cruz, Bolivia) found nine additional specimens of Hydrolaetare sp. at the same locality and studied some aspects of the ecology of that species. In January 2007, M. Jansen collected four more specimens of this frog at the same locality. Comparisons with literature data of the two known species of Hydrolaetare demonstrated that the Caparu´ specimens represent an undescribed species. Herein, we describe that new species and provide data on its vocalizations and natural history.

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MATERIALS AND METHODS Specimens of the new species were collected at Caparu´ Ranch (14u54.6479S; 61u04.3539W), Provincia Velasco, Department of Santa Cruz, Bolivia, from December 2005 to January 2007. Specimens were deposited at the Museo Noel Kempff Mercado, Santa Cruz, Bolivia (MNKR) and the Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt, Germany (SMF). Comparative data were taken from Bokermann (1959), Cochran and Goin (1959), Gallardo (1963), Lescure and Marty (2000), and De Souza and Haddad (2003). For recording temperature, a HOBO Pendant temperature 64 K data logger (HOBO Data Logger Company, Massachusetts) was situated at Caparu´ Ranch between 27 September 2005 and 24 February 2006. Geographic coordinates were taken with a handheld GPS navigator (Model etrex summit, Garmin International, Inc., Kansas). Calls were recorded with a Sony Hi-MiniDisc-Walkman (MZ-NH90) and a ME80 microphone by Sennheiser electronic GmbH, Wedemark, Germany. Recordings were analyzed with Adobe Audition 1.5, using 256 sampling points. Visual Encounter Surveys (VES) and aural encounter surveys (AES) were worked along seven 100-m transects along a path through a riparian forest. The transects have been searched 1–3 times in three nights, about 30 min per transect. The width of the transect was approximately 5 m for the VES and up to 25 m for the AES. Measurements (in millimeters) using calipers follow Cei (1980) and Duellman (2001): SVL (snout–vent length), HL (head length), HW (head width), ED (eye diameter), END (eye–nostril distance), IND (internasal distance), TD (tympanum diameter), TL (tibia length), and FL (foot length). Means are given 6 1 SD. Webbing formula follows Savage and Heyer (1997). Sex was determined by the presence or absence of vocal slits. The specimens collected for this study were preserved with an injection of formalin and ethanol (5 ml full strength formalin in 1 liter of ethanol) and stored in 70% ethanol. Drawings of the holotype were made using a Leica MZ12 stereomicroscope with a drawing tube. The distribution map (Fig. 1) is based on specimens examined by the authors and on additional records taken from Bokermann (1959), Cochran and Goin (1959), Rodriguez and Duellman (1994), Lescure and Marty (2000), De Souza and Haddad (2003), and Padial and De la Riva (2005). RESULTS Hydrolaetare caparu new species Figures 2–3

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FIG. 2. (A) Holotype of Hydrolaetare caparu (MNKA 8302); (B) portrait of paratype SMF 86647.

Holotype.—MNKA 8302, adult male from Caparu´ Ranch (14u48.7959S, 61u09.6029W; 158 m), Provincia Velasco, Department of Santa Cruz, Bolivia; collected on 16 February 2006 at 0130 h by M. Jansen and A. A. Diego. Paratypes.—Three males, three females, three subadults, four juveniles: SMF 86646, adult male; MNKA 8303, adult female, approximately 14u48.7969S, 61u09.6779W, collected on 16 February 2006 between 0200 and 0215 h by M. Jansen and A. A. Diego; SMF 86647, adult female (14u48.8009S, 61u09.7139W); MNKA 8304, subadult (14u48.7909S, 61u09.6079W); MNKA 8305, juvenile; MNKA 8308, juvenile; SMF 86649, juvenile (14u48.7849S, 61u09.8499W), all collected on 17 February between 2200 and 0300 h by M. Jansen, Q. Vidoz, and A. A. Diego; SMF 86648, subadult, collected on 24 February 2006 by M. Jansen and A. A. Diego; MNKA 8274, subadult (14u48.7489S, 61u09.6319W), collected 12 December 2005 at 2355 h by L. Gonzales and O. Helmig; SMF 86651, juvenile; MNKA 8309, adult male, all approximately 14u48.7979S, 61u09.6759W, collected on 28 January 2007 between 2300 and 0100 h by M. Jansen; SMF 86652, adult female; MNKA 8310, adult

male, all approximately 14u50.3959S, 61u10.6089W, collected on 31 January 2007 between 2200 and 0200 h by M. Jansen. Diagnosis and comparisons with other species.— Medium-sized aquatic frogs (male SVL 82.7– 86.5 mm; N 5 4; female SVL 83.1–93.9 mm; N 5 3), with robust body and limbs; head broad and depressed; eyes large and directed dorsolaterally (Figs. 2,3); pupil elliptical; tympanum diameter about 0.7 times eye diameter; first finger much longer than second; relative finger lengths II , IV , I , III; broad lateral fringes restricted to inner side of second and third finger; toes long, pointed and semiwebbed; fringes and webbing of fingers and toes finely serrate, serrate edge keratinized; palmar tubercle two times larger than thenar tubercle, rounded, sometimes not distinct; males without nuptial pads on thumbs; subgular sac not externally expanded; vocal slits present; premaxillary and maxillary teeth present, vomerine teeth in two arched series of 11–13 teeth, situated on ridges between choanae, laterally reaching to almost level of midchoanae. The new species differs from the other species of Hydrolaetare in the following characters: (1) reduction of fringes: Fingers II and III with lateral fringes only on the inner side, Fingers I and IV without fringes, although a series of denticulations usually present (Fingers II and III with broad lateral fringes in other Hydrolaetare); (2) relative length of Fingers I and III: when adpressed, tip of Finger I reaches well beyond distal subarticular tubercle of Finger III, usually to joint of first and second phalanx in H. caparu (reaches only to distal subarticular tubercle in H. schmidti, and only slightly beyond in H. dantasi); (3) relative length of Finger I and II: Finger I reaches to a point below joint of first and second phalanx (Finger I only slightly longer than second in H. schmidti; Finger II reaches approximately joint of first and second phalanx in H. dantasi); (4) relative size of palmar tubercle: about twice the size of thenar tubercle (palmar tubercle and thenar tubercle about the same size in H. dantasi, palmar tubercle distinctly smaller than thenar tubercle in H. schmidti); (5) webbing of toes: toes semiwebbed (toes webbed basally in H. dantasi and fully webbed in H. schmidti); (6) coloration: dorsum with dark brown blotches (without blotches in H. dantasi and H. schmidti); dark middorsal longitudinal band in other Hydrolaetare reduced to interorbital bar in H. caparu. Lacking large dark rectangular mark on dorsum (present in H. dantasi). Pale dorsolateral longitudinal stripes absent in H. caparu, present in congeners. Venter dark greyish-brown to nearly black with white spots, some individuals more greyish, but never yellowish-white (like in H. dantasi). The new


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FIG. 3. Head (dorsal and lateral view), left foot, and hand of holotype of Hydrolaetare caparu (MNKA 8302). Scale measures 10 mm.

species differs from H. dantasi by its proportionally narrower Finger II; Finger II and Finger IV subequal (Finger IV slightly longer than Finger II in H. dantasi); and snout from above slightly pointed (similar in H. schmidti, rounded in H. dantasi). The new species differs from H. schmidti in Finger II and Finger IV extending to the base of the joint of second and third phalanx of Finger III (Finger II and Finger IV extending only to the base of the penultimate phalanx of the Finger III in H. schmidti). For measurements of Hydrolaetare caparu, see Table 1. Description of holotype.—Adult male; body and limbs robust (see Fig. 2); head broad and depressed, head slightly longer than wide;

snout broad, rounded and slightly pointed in dorsal view, sloping and protruding in lateral view (Fig. 3); nostrils nearer to the tip of the snout than to the eye, separated from each other by a distance slightly smaller than eye–nostril distance and about the same as the distance of nostril to tip of snout; opening of nostril directed anterodorsally; eyes large, protuberant and directed dorsolaterally, diameter larger than distance from eye to nostril; canthus rostralis not prominent; loreal region slightly concave; tympanum annulus distinct and rounded, tympanum membrane about 0.7 times eye diameter; separated from eye about 1.2 times diameter of eye; supratympanic fold starting from posterior corner of the eye, ending

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TABLE 1. Measurements (in millimeters) of adult males, females, and subadults of Hydrolaetare caparu. Males (N 5 4) Range (mean 6 SD)

SVL HL HW ED TD END IND TL FL

82.7–86.5 (85.4 6 1.8) 30.1–35.0 (32.9 6 1.8) 30.0–31.4 (30.7 6 0.6) 7.3–7.6 (7.5 6 0.1) 4.9–5.4 (5 6 0.3) 6.2–6.9 (6.5 6 0.3) 5.0–5.9 (5.4 6 0.3) 33.6–34.0 (33.7 6 0.2) 34.9–38.8 (37.0 6 1.7)

Females (N 5 3) Range (mean 6 SD)

83.1–93.9 (90.0 6 7.1) 30.9–37.8 (34.5 6 3.4) 30.4–34.5 (33.1 6 2.4) 7–7.8 (7.4 6 0.4) 5.1–5.3 (5.2 6 0.1) 6.2–7.5 (7 6 0.7) 5.1–6.3 (5.6 6 0.6) 33.7–37.5 (35.6 6 1.9) 38.6–40.7 (39.2 6 1.3)

Subadults (N 5 3) Range (mean 6 SD)

60.1–64.2 (61.5 6 2.3) 23.3–29.1 (25.7 6 3.0) 21.7–26.5 (25.5 6 2.6) 5.2–5.6 (5.4 6 0.2) 3.9–4.8 (4.4 6 0.5) 4.6–5.5 (5 6 0.5) 3.3–4.2 (3.6 6 0.49) 24.2–28.1 (25.6 6 2.2) 28.2–33.5 (30 6 3.03)

behind the corner of the mouth; no postrictal tubercles present; tongue large, longer than wide; posteriorly serrated. Forearm and arm robust; Fingers I and III relatively long, not webbed; first finger much longer than second; tip of Finger I reaches well beyond distal subarticular tubercle to joint of Phalanx I and II of Finger III; Finger II and IV subequal and extending to the base of the penultimate phalanx of Finger III; only inner side of second and third finger with broad lateral fringes; rounded subarticular tubercles well developed on fingers; palmar tubercle twice larger than thenar tubercle, shape rounded, sometimes not distinct; thenar tubercle elongated. Legs relatively short, robust; toes long, slender and pointed, with well-developed single, protruding, rounded to elliptical subarticular tubercles; small outer and a larger, elongated inner metatarsal tubercle on each foot; webbing contiguous with fringes of toes; toes webbed to the base of phalanx III of Toe IV, to the base of the ultimate phalanx of Toe I, to the outer side of Toe II, slightly above the base of the penultimate phalanx at inner side of Toe V, to the base of the penultimate phalanx on the inner side of Toe II and the outer side of Toe III, and to the base of the third phalanx of the inner side of Toe III; foot webbing formula I1 2 2II1 2 2K III2 2 3 IV32 2 1KV; toe lengths I , II , V , III , IV (Fig. 3). Fringes of fingers and fringes and webbing of toes finely serrate; serrate edge keratinized; no nuptial pads on thumbs. Dorsal skin rugose with denticulations, numerous

small craters on the skin most numerous on posterior portion; scattered warts, predominantly on the flanks and dorsal surfaces of hind limbs; venter smooth. Color in life of holotype.—Dorsum greyishbrown with dark brown blotches; dark interorbital bar; two dark brown narrow bands starting from the tip of the snout, passing through the nostril and ending on the anterior part of the eye; a triangle-shaped bar on the upper lip beneath the eye; bands and bars dark brown with paler edging. Hind limb with dark blotches. Venter dark greyish-brown to nearly black with white spots. Color in alcohol.—Top of head and dorsum very dark brownish-grey; blotches and bands dark brown; paler edging faded to white. Measurements of holotype (in mm).—SVL 85.9; HL 33.3; HW 31.2; ED 7.4; END 6.9; IND 5.9; TD 5; TL 33.6; FL 37.9. Variation.—Complete sets of measurements for the type series are provided in Table 1. Foot webbing formula I(1+ 2 1) 2 2II1 2 (2J 2 2K)III(1K – 22) 2 3IV3 2 (1 – 1K)V. Blotches on greyish-brown dorsum can vary from dark brown to dark green; blotches and bars with paler edging, which varies from yellowishwhite to greenish; snout and interorbital portion reddish in some specimens (SMF 86647, MNKA 8309); venter dark greyish-brown to nearly black with white spots, some individuals more greyish. Vocalization.—Calls heard rarely but regularly. The frog called from dusk (1830 h) to dawn (last call observed: 0400 h on 21 February 2006; 25uC).The advertisement call consisted of a series of single calls, which sound like a row of meows ascending in duration and loudness (Fig. 4 shows one of these single calls). Intervals between advertisement call series ranged from approximately 1–2, rarely 3 or 4 times per 30 min during the AES. However, in most cases, individuals emitted a single call series and then were silent for longer periods. In 12 recorded series, four to eight single calls were emitted per series. The vocalizations usually ascended constantly in volume and duration during the series, at least until the penultimate call. In 10 of 12 series, the final vocalization was the longest and loudest, and the penultimate was the second longest. In two of the 12 series, the penultimate vocalization was the longest (and loudest). Call duration varied from 0.06 (one first call) to 0.64 sec (one last call), mean duration was 0.27 sec (SD 5 0.14; N 5 58). Call duration of the last call varied from 0.3–0.64 sec (0.44 sec 6 0.1; N 5 12), duration of the longest call of every series varied from 0.3–0.64 sec (0.45 sec 6 0.1; N 5 12). Intervals between the calls ranged from 0.7–1.28 sec (0.97 sec 6 0.14;


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FIG. 4. Sound spectogram and waveforms of advertisement call of Hydrolaetare caparu. Air temperature 5 24.4uC; water temperature 5 26.8uC. Specimen not collected.

N 5 46); the repetition rate ranged from 52.9 calls/min to 75 calls/min (61.6 calls/min 6 6.23; N 5 11). In one case, after one series of calls, a response of another individual could be recorded with an interval of 7.3 sec between the two series. The advertisement call has a dominant frequency ranging from 376–639 Hz (542 Hz 6 105; N 5 8) and consists of two distinct parts: it begins with pulses (6–22; 12.7 6 8.3; N 5 6; frequency range 400–1100 Hz), followed by a louder vocalization that consist of three to six harmonic bands (4.7 6 1.4; N 5 8; frequency range 300–3000 Hz). See Table 2 and Figure 4 for parameters of advertisement call. Some individuals emitted distress calls after being placed in a transportation bag. The calls

were provoked by shaking the bag gently. With this method, 17 calls were emitted by one female (SMF 86647) in a period of 10.66 sec. Distress calls of four individuals (one male, one female, two subadults) were analyzed. This call (Fig. 5) sounds similar to the advertisement call but differs in being louder and with a narrower frequency range. The calls showed clear harmonic structures with various harmonic bands and sound energy distributed over a wide range of frequencies. Duration varied from 0.24– 0.83 sec (0.42 sec 6 0.15; N 5 59). Mean dominant frequency of the distress calls varied from 547 kHz (one adult male) to 1149 kHz (one subadult). See Table 3 and Figure 5 for parameters of the distress call.

TABLE 2. Advertisement call parameters in Hydrolaetare caparu. Means are given in parentheses 6 SD. Call duration [ms]; N 558 min–max (mean 6 SD)

0.065–0.637 (0.273 6 143)

Duration of last call of one series [ms] N 512 min–max (mean 6 SD)

Duration of longest call of one series [ms]; N 5 12 min–max (mean 6 SD)

Call intervals [ms] N 5 46 min–max (mean 6 SD)

Dominant frequency [Hz] N58 min–max (mean 6 SD)

0.304–0.637 (0.444 6 0.099)

0.304–0.637 (0.453 6 0.092)

0.7–1.28 (0.965 6 138)

376–639 (541.63 6 105.4)

Frequency range [Hz]

300–3000

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FIG. 5. Sound spectogram and waveform of distress calls of Hydrolaetare caparu, SMF 86646 (adult male, SVL 86.3 mm).

Natural history.—Hydrolaetare caparu appears to be restricted to seasonally flooded riparian forests of a small river associated with the Rıó Paragua that dries up during the dry season. Occasionally, the species was found in an adjacent flooded grassland area near the borders of the forest. During December 2005, the species was difficult to find (LGA, pers. obs.), and only one subadult could be observed and captured at the border of the forest to the flooded grassland on two nights. The call of the species was not heard during that time. All 17

observations in February 2006 were found near or on small islands formed by roots at the bottom of trees. Twelve individuals have been found in the water, five have been found on the ground. Calling males were observed on sites close to the waterline or half inside the water with high escape distance (approximately 5– 10 m). When disturbed, individuals sitting on the shore escaped into the water. Along the 100m transects, a remarkably high density of this species could be observed: up to three individuals were seen on 11 surveys along the transects

TABLE 3. Comparisons of distress call parameters in Hydrolaetare caparu. Means are given in parentheses 6 SD.

Sex

SMF 86646

male

SVL

86.3 mm

SMF 86647

female

93.1 mm

MNKA 8304

subadult

60.3 mm

SMF 86648

subadult

60.1 mm

Call duration (sec) min–max (mean 6 SD; N)

0.266–0.826 (0.586 6 0.184; 0.309–0.450 (0.366 6 0.042; 0.240–0.533 (0.344 6 0.074; 0.264–0.782 (0.405 6 0.135;

15) 18) 15) 14)

Dominant frequency (Hz) min–max (mean 6 SD; N)

426–747 (547 6 95; 15) 408–1047 (661 6 225; 18) 575–1657 (1087 6 281; 15) 792–1790 (1149 6 272; 11)

NEW SPECIES OF HYDROLAETARE FROM BOLIVIA (12 observations; average 1.1 per survey), and up to four individuals could be heard (24 observations on 11 visits; average 2.2 per survey). There is no ontogenetic change in coloration. Other herpetofaunal components recorded at this site were Dendropsophus cf. leali, Leptodactylus chaquensis, Osteocephalus sp. and Rhinella cf. margaritifer. Distribution.—Hydrolaetare caparu is only known from the type locality. Etymology.—The name caparu is a noun used in reference to the type locality where the type series of the species was collected. DISCUSSION Although H. caparu appeared to be very rare in October 2005, the strikingly high densities of H. caparu during the surveys in January 2006 suggest that H. caparu is highly seasonally in its appearance. Hydrolaetare caparu calls from sites near to or half in the water, and none has been observed floating in open water or in mud holes. This is unlike the other species of Hydrolaetare (see Rodriguez and Duellman, 1994; De Souza and Haddad, 2003). Lescure and Marty (2000) stated that H. schmidti in Guyana calls from open water or hidden in flooded burrows and stays in the water during the night, either flat in the water or in a nearly vertical position with only eyes and nostrils above the water. De Souza and Haddad (2003) stated that excavated holes in muddy soil used as calling sites are suggestive of a specialized reproductive mode in this genus. However, this does not agree with our observations in H. caparu. The reported vocalizations of the other species of Hydrolaetare differ from our observations in H. caparu. Instead of a series of ascending meows, the advertisement call of H. dantasi consists of a single call with an initial percussive sound followed by a whistle (De Souza and Haddad, 2003). Moreover, there are differences in call duration and dominant frequency. There is little information in the literature about the call of H. schmidti. Lescure and Marty (2000) did not mention a series of calls of the individual Guayana. They compare the call with a ‘‘beuglement’’ (5 roaring or shouting) and provide sonagram, oscillogram, and call parameters very different to the parameters of H. caparu. Unlike the call of H. caparu, the call of Guayanan H. schmidti consists of a single note lasting 1,700 ms with a dominant frequency of 0.15–2.98 kHz. However, Rodrı´guez and Duellman (1994) stated that the call of Ecuadorian H. schmidti consists of a series of low groans. The distress call of H. caparu is very similar to those of its congeners. The high variability in parameters of distress calls has

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been observed for the congeners as well and may represent different degrees of distress (Ho¨dl and Gollmann, 1986; De Souza and Haddad; 2003). The patchy distribution of H. schmidti (Fig. 1) shows that more research is necessary to evaluate the taxonomic status of the disjunct populations. Acknowledgments.—We thank the owners of Caparu´ Ranch (J. Rozenman and G. Weise) for the invitation to conduct herpetological surveys on their properties. Further, Rozenmann provided useful information about the area. A. A. Diego, Q. Vidoz, O. Helmig, and the coworkers of the haciendas provided invaluable field assistance. We thank A. Jahn for logistic help and useful information about Caparu´ Ranch. Collecting and exportation permits were provided by the Ministerio de Desarrollo Sostenible, La Paz, and Servicio Nacional de Sanidad Agropecuaria e Inocuidad Alimentaria (SENASAG). P. Herrera and A. Justiniano, Museo Noel Kempff Mercado, Santa Cruz, provided valuable assistance with acquisition of these permits. The Spanish translation of the abstract was provided by J. Sunyer. The study was supported by a grant from German Academic Exchange Service (DAAD) and the ‘‘Wilhelm-Peters-Fonds’’ of the Deutsche Gesellschaft fu¨r Herpetologie und Terrarienkunde (DGHT) for M. Jansen. Mayor sponsoring of that study was done by Globetrotter, Frankfurt.

LITERATURE CITED BOKERMANN, W. C. A. 1959. Una nueva especie de Leptodactylus de la region Amazonica (Amphibia, Salientia, Leptodactylidae). Neotropica 5:5–8. CEI, J. M. 1980. Amphibians of Argentina. Monitore Zoologico Italiano (N. S.). Monografia:1–609. COCHRAN, D. M., AND C. J. GOIN. 1959. A new frog of the genus Limnomedusa from Columbia. Copeia 1959:208–210. COCHRAN, D. M., AND C. J. GOIN. 1970. Frogs of Columbia. United States National Museum Bulletin 288:1–655. DE LA RIVA, I., J. KO¨HLER, S. LO¨TTERS, AND S. REICHLE. 2000. Ten years of research on Bolivian amphibians: updated checklist, distribution, taxonomic problems, literature and iconography. Revista Espanola de Herpetologia 14:19–164. DE SOUZA, M. B., AND C. F. B. HADDAD. 2003. Redescription and reevaluation of the generic status of Leptodactylus dantasi (Amphibia, Anura, Leptodactylidae) and description of its unusual advertisement call. Journal of Herpetology 37:490–497. DUELLMAN , W. E. 2001. Hylid Frogs of Middle America. Society for the Study of Amphibians and Reptiles/Natural History Museum of the University of Kansas, Ithaca, NY.

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Accepted: 20 June 2007.