SHORT NOTES SHORT NOTES Field observations were made between August 1994 and December 1995 in Fazenda Santa Maria' 2 km HERPETOLOGICAL JOURNAL, Vol. 11, pp. 29-32 (2001) from Nova Itapirema district (2 1° I' S, 49° 4' w), in north-western Sao Paulo State, Brazil. The observa­ PARENTAL CARE BEHAVIOUR IN ti�ns were made in a permanent pond ( 40 m length, 6 m LEPTODACTYLUS PODJCIPINUS width and 0.8 m depth), in an open area with marginal (COPE, 1862) (ANURA, and emergent, grassy vegetation (Poaecea and LEPTODACTYLIDAE) Cyperacea). The "focal animal" method (Martin & �ateson, 1986) was employed, with weekly observa­ !TAMAR A. MARTINS tions made from 1600 hrs to 0200 hrs, using flashli ghts and, when necessary to avoid disturbing the animals Departamento de Biologia - Laborat6rio de Zoologia, red filters. Additional daily visits (n=32) were made t� Universidade de Ta ubate, Siio Paulo, Brazil observe the daytime behaviour of females in relation to eggs and tadpoles. Key words: parental care, anurans, Leptodactylus Each adult specimen found (60 male and 25 female) In anurans, parental care is known in about 10% of was captured and marked according to Martofs (1953) the species and occurs in one form or another in 14 technique of toe amputation. Small egg samples were families (Salthe & Mecham, 1974; McDiarmid, 1978; collected and fixed in 5% formalin. The spawning Wells, 1977, 1981). Parental care, which requires some places were marked with stakes which were numbered investment, may be present in either males or females with reference to the numbers of the corresponding fe­ and may be considered an adaptation to specific eco­ males. The stakes served as reference points to follow logical conditions (Wells, 1977, 1981). McDiarmid the fe male displacements (i.e. movements from one (1978) recognized 12 categories of parental behaviour place to another). in anurans, based on oviposition habitat, the site of pa­ Each female with eggs and/or tadpoles was observed rental care, the nature of larval stage and the sex of the during three daily periods of30 mins each. During each caring parent. Wells (1981) proposed fourbroader cat­ period the fo llowing data were collected: number of egories: (1) caring foreggs, (2) caring fortad poles, (3) pumping motions by the female, timeela psed from one transporting eggs, and ( 4) transporting tadpoles, ex­ pumping motion to the next, time from one displace­ cluding cases in which ovoviviparity or viviparity ment to another and total displacement distance. At the occurs. end of each period a stake was used to mark the last Aquatic care of eggs and tadpoles is rare among resting place of each female and her tadpoles. At each anurans, probably because the habitats of adults and visit, the distance from the last resting place to that ob­ tadpoles are different (McDiarmid, 1978; Wells, 1981 ). served was measured. Small tadpole samples from each Only a few cases of parental care in species with female were collected, killed and preserved in 10% for­ aquatic reproduction have been reported, mainly in spe­ malin for later identification of larval stages. cies with foammass nests and free-living tadpoles. This The following description is based on observations of 11 females. The female laid her eggs in a foam nest phenomenon is more often present in tropical species with terrestrial reproduction and may represent an evo­ within the male's territory. After egg-laying, the male lutionary response to predation in aquatic environments abandoned the spawning site and moved to another. The female caring behaviour began at spawning. She (Salthe & Mecham, 1974; Crump, 1974; Wells, 1981 ). remained beside or partially under the foamnest during One common characteristic of the subfamily the whole embryonic development period, with the Leptodactylinae is egg-laying in a foam mass either head directed towards the mass, but never on it. Occa­ floating at the water's surfaceor in burrows (Downie, sionally, females were observed capturing small 1996). Few reports of egg-care exist for the family spiders and ants on the egg mass; this behaviour was Leptodactylidae. However, care of aquatic eggs and easily observed as the female did not quit her eggs even tadpoles has been observed in adults of two species of in the presence of an observer. the "ocellatus" species group (Heyer, 1969), When the hatchlings began to leave the foam nest Leptodactylus ocellatus (Vaz-Ferreira & Gehrau, 1975) and became free-living, the female remained most of and Leptodactylus bolivianus (Wells & Bard, 1988), the time with her body partially submerged, under or and in two species of the "melanonotus" group (Heyer, beside the foamnest. As the larvae abandoned the foam 1969), Leptodactylus validus and L. leptodactyloides mass and fellinto the water they formed a dense shoal (Downie, 1996). The present paper reports parental car­ near the female's body. The tadpole shoals were found ing behaviour in Leptodactyluspodici pinus. at depths between 3 cm and 19 cm, near the margins, among emergent water plants. The female remained close to the tadpoles and the tadpoles scraped the fe­ Correspondence: I. A. Martins, Departamento de Bio logia - Laborat6rio de Zoologia, Universidade de Taubate - male's postero-dorsal region and hind legs. UNITAU, CEP: 12020-270, Taubate, Sao Paulo, Brazil. E­ The tadpoles always followed the female,who made mail: [email protected] bouts of pumping motions (sensu Wells & Bard, 1988) 30 SHORT NOTES 18 18 45) the distance between the female and the tadpoles 16 A 16 B 14 14 became greater again and the female was often ob­ 12 12 served out of the water, on the vegetation. There was no 10 10 contact between female and tadpoles in the latter pe­ I 8 Ul riod, suggesting that the parental influence on the Q) 4 g offspring had ended. The average duration of larval de­ 2 .l!!Ul 0 velopment, and consequently of parental care by the ii 24-27 c 18 18 Q) female, was28 days (SD = ±3.7 days; range = 25 to 32 E 16 16 D Q) days, n=l 1). u 14 14 ..!ll a. 12 12 Pumping followed by displacement was observed in Ul i5 10 10 all females with tadpoles (n= l l), and usually began about 30 mins after sunset. In broad daylight, the fe­ males remained at more protected sites under the vegetation and the tadpoles were similarly less active, although they kept removing sediments and feeding. The displacements were mostly unidirectional, but on a number of occasions (n=28) the femalemoved forward, FIG. I. Displacement distances of four femaleLeptodacty/us podicipinus and their tadpoles in relation to larval made the pumping movements, returned to the tadpole development stages. Females: A (n=25), B (n=26), C (n=32) shoal, made new pumping movements, and proceeded and D (n=28); n= number of the observations. to the site where she had first made the movements. Most often,this occurred when the female had travelled of the posterior region of the body at the water surface a long distance or was in water more than 20 cm deep. before moving from one place to another. In the pump­ At other times the femaleseemed to return to the shoal ing motion the female arched her back and alternately to reunite the dispersed tadpoles, which had formedtwo lowered and raised the hind legs and the vent above the or three separate shoals. water's surface, producing waves which reached the Trivers (1972) considered parental care to be "any tadpoles. The pumping movements were rhythmic and investment by the parent in an individual offspring that usually, when a series of more than six was produced, increases the offspring's chance of surviving (and the last movements were faster and had a larger ampli­ hence reproductive success) at the cost of the parent's tude than those previous. Soon afterthe female moved, ability to invest in other offspring". the tadpoles moved towards her, taking the same route. Parental care is present in some form in the majority When most of the tadpoles reached the female, she of anuran families and this taxonomic distribution sug­ moved again and made a new series of pumping mo­ gests several independent evolutionary origins within tions. Sometimes the female paused between the order (Salthe & Mecham, 1974). In many anurans displacements until all the tadpoles reached her and parental care is restricted to the females(W ells, 1977). made contact with her body. The number of pumping Work on the genus Leptodactylus demonstrates an movements made by a female during one displacement adaptive tendency towards female parental care (Wells ranged from 1 to 39 and showed no correlation with ei­ & Bard, 1988; Downie, 1996). ther the distance travelled (r=0.117, P>0.10, n=63) or Many leptodactylid species have developed evolu­ the time elapsed between one series of pumping move­ tionary mechanisms that protect the offspring from ments and the next (r=0.081, P>0.10, n=63). The harmful agents (Vaz-Ferreira & Gehrau, 1974). In the distances travelled in each displacement ranged from genus Leptodact}1lus, the more common mechanisms in 10 cm to 80 cm (mean±SD = 29.8±15.8 cm, n=63). this connection are: (1) a floating foamnest; (2) a bur­ The total displacement of females and their tadpoles row with the eggs and embryos in foam; (3) a floating ranged from 6.5 m to 18 m. foam nest with the female caring for the eggs and tad­ The distance travelled by the females with their tad­ poles until metamorphosis (Heyer, 1969; Vaz-Ferreira poles showed a positive correlation with the stage of & Gehrau, 1975; Duellman & Trueb, 1986; Wells & Bard, 1988; Downie, 1996).