Diet, microhabitat and time of activity in a Pristimantis (Anura, Strabomantidae) assemblage

Phyllomedusa : Journal of Herpetology 12/2008; DOI: 10.11606/issn.2316-9079.v7i2p109-119
Source: DOAJ

ABSTRACT We tested if the richness and abundance of six closely related species of Pristimantis significantly varied among three transects located at different distances from a creek in an Andean cloud forest. We found that richness and abundance of frogs varied significantly among transects, being the transect located at the forest interior the richest in frog species and number of individuals. We chose these more crowded sites to evaluate resource use differences among the species. We evaluated ecological variables such as microhabitat, diet, and time of activity in these speciesthat are similar in morphology and body size, to determine whether they have differences in the use of these resources. Most specimens perch on leaves at heights within 1.5 and 2.0 m of the ground and are nocturnal; only P. douglasi was found with diurnal and nocturnal activity. The species had similar diets, they ingested a wide spectrum of prey sizes that are similar among species, months, and between transects. Almost all collected frogs were juveniles and were found during every single month of sampling suggesting continuous reproduction; however, adults and juveniles of P.douglasi were absent during some of the drier months, indicating seasonality. Thus, we found that most of these Pristimantis species occupy the forest interior and that there is no a strong segregation in the use of the evaluated resources, only one species had a slight difference in activity and reproductive time.

Download full-text


Available from: Martha Patricia Ramirez Pinilla, Aug 31, 2015
1 Follower
  • Source
    • "Este patrón de actividad durante todo el día con picos de actividad nocturnos no es común en anuros, que suelen ser asociados con actividad nocturna (Duellman & Trueb, 1994); sin embargo, otras especies de ranas de hojarasca y del clado Terrarana tienen este mismo patrón (e.j. Pristimantis douglasi Arroyo et al., 2008, P.aff. fenestratus, Waldez, Menin, & Rojas-Ahumada, 2011). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Geobatrachus walkeri is a frog that belongs to a monotypic genus and is endemic to the Sierra Nevada de Santa Marta, Colombia. The species inhabits different microhabitats between 2 000 to 3 500m altitude, including the leaf litter of a pine plantation. To understand its reproductive ecology, we conducted eight frog samplings, covering the rainy and dry seasons, and two habitat types (secondary native forest and pine plantation) during 2010-2011. For this study, we also included data obtained from five previous similar samplings undertaken during 2008-2009. The pine leaf litter was the main microhabitat where frogs were found; we heard choruses of six-ten calling males during all sampled months, and observed the frogs having diurnal and nocturnal activity. Regardless of the year of study, the population consisted of neonates recruited several times of the year, a large number of juveniles with a wide range of body sizes, and fewer adults with a narrower range of body size. The histological analyses of the gonads showed that the size at maturity was near 18mm SVL for males and females, and those adult males and females were reproductive active during all sampling months, suggesting a continuous reproductive activity pattern. However, during the dry season, the seminiferous tubules showed a drastically diminished spermatic epithelium although containing abundant luminal spermatozoa, which suggest a reduction in the sperm production at the end of this season. Similarly, frogs of all age categories were significantly more abundant during the early dry season, whereas were significantly less abundant with the advancement of the dryness suggesting that the intensity of the dry season could temporally stop the activity and reproduction of this population.
    Revista de biologia tropical 03/2014; 62(1):183-99. · 0.61 Impact Factor
  • Source
    • "Feeding characterizations are key to understand different biological aspects such as: the ecological organization in communities and assemblages (Toft, 1980; Toft, 1981; Lima and Magnuson, 1998; Parmelee, 1999; Muñoz-Guerrero et al., 2007; Arroyo et al., 2008), the phylogenetic relationships among species (Santos et al., 2003; Darst, 2005; Grant et al., 2006), and their behavior and physiology (Toft, 1980; Toft, 1981; Lima and Magnuson, 1998). For instance, the diet composition has been showed to be important in the early evolutionary history of some higher taxa (Vitt and Pianka, 2005), influencing the present organization of the communities (Greene, 2005). "
    Herpetology Notes 01/2014;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Pristimantis aff. fenestratus is a common species in non-flooded forests of central Amazonia, Brazil. Herein, we show the reproductive pattern and data on population structure of this species from two sites, using standardized sample methods (visual and auditory surveys), during three rainy seasons. The higher number of males in calling activity was detected in the beginning of the rainy season. However, sporadic male calls were also heard in the dry season. Females were significantly larger than males, and males captured at the end of the rainy season were larger than those captured in other periods. Females with eggs visible through the abdominal wall were found in all samplings at one site, but a larger number of juveniles were found at the end of the rainy season. The size of juveniles was variable and the smallest individuals were found at the end of the rainy season. According to nocturnal visual surveys males were significantly more abundant than females (1.9:1 adult sex ratio). According to data collected on gravid female occurrence, juvenile number variation, and presence of calling males, we suggest that P. aff. fenestratus reproduces during the rainy season showing marked seasonality.
    South American Journal of Herpetology 09/2011; DOI:10.2994/057.006.0202
Show more