Living together, sometimes feeding in a similar way: the case of the syntopic hylid frogs Hypsiboas raniceps and Scinax acuminatus (Anura: Hylidae) in the Pantanal of Miranda, Mato Grosso do Sul State, Brazil

Abstract

taxonomically and thus, also tend to share physiological and behavioural traits (see Menin et al., 2005). Therefore, a clear understanding of the relationship on niche overlap, similarity and competition among species is necessary to answer questions on community structure (Lawlor, 1980). IntroductionSyntopic related species are expected to be exposed to a similar array of potential prey, especially if they share activity period, body size and microhabitat features (e.g. Pianka, 1986;Sluys and Rocha, 1998; Guimarães and Bastos, 2003). This may result in considerable overlap of prey consumption, especially if they are closely related AbstractWe studied the feeding ecology of two Hylinae anurans (Hypsiboas raniceps and Scinax acuminatus), living sympatrically and syntopically in the Pantanal of Miranda, Mato Grosso do Sul State, Brazil. The two hylid species had similar relative mouth width but differed in body size. The diet of the two frog species were composed of arthropodan prey. Both species consumed 11 different prey types, of which seven were common among them. Hypsiboas raniceps had a larger niche breadth (B A = 0.64) than S. acuminatus (B A = 0.48). Trophic niche overlap among frog species was 60.7 %. Our data are suggestive that although for many anurans the diet simply tend to reflect prey availability in the microhabitat, these two frog species, despite sharing similar microhabitat and period of activity (thus potentially exposed to a similar array of preys), tends to differ somewhat in diet (about 40%) which may result from some intrinsic ecological aspects to each of them (e.g. ecophysiology) and/or differences in body size.

Diet of Leptodactylus fuscus (Amphibia: Anura: Leptodactylidae) in the Pantanal of Miranda river, Brazil

“…The high importance of agile arthropods such as beetles, crickets, grasshoppers, ants and spiders in the diet of species of the Leptodactylus genus indicate more sit-and-wait feeding strategy (Maneyro et al 2004, Rodrigues et al 2004, Sanabria et al 2005, De-Carvalho et al 2008, Solé et al 2009). However, in some of these studies there is great quantity of larvae or more sedentary groups, which suggest an opportunistic feeding Biota Neotrop.,vol.…”

“…The difference in the most important orders in the diet of L. fuscus found in this study and De-Carvalho et al (2008) can be attributed to opportunistic behavior and differences in prey availability, so that the diet composition is determined by the food availability of arthropods in environments occupied by the population (Das 1996, Hirai & Matsui 2000, Hirai 2004, Lopez et al 2007. Several studies found a relationship between predator and prey size or prey number, based on stomach contents (Maneyro et al 2004, Biavatti et al 2004, Sanabria et al 2005, López et al 2007). In general this relationship is attributed to the fact that larger frogs have larger heads and therefore can eat larger prey, which is evident when assessing the diet of young and adult individuals (Solé & Rödder 2010).…”

“…Dendrobatidae) are specialized in certain type of prey (Biavati et al 2004, Wells 2007). In addition, there are species that feed on small vertebrates (Duellman & Lizana 1994, Sanabria et al 2005 or even on plant material (Silva et al 1989, Das 1996. Amphibians occupy an important trophic position in terrestrial and aquatic ecosystems by controlling populations of many organisms, especially invertebrates, and also serving as prey for many organisms (Toledo et al 2007, Wells 2007.…”

“…Several studies show that the predator size explains the variations in abundance and volume of prey, concluding that larger individuals are expected to feed on larger preys and in larger quantity (Maneyro et al 2004, Biavatti et al 2004, Sanabria et al 2005, López et al 2007). In general, this effect is related to ontogenetic differences in morphology, physiology and behavior (Lima 1998, Lima & Magnusson 2000, Solé & Rödder 2010.…”

“…Most publications about anurans in the Pantanal floodplain refer to species list (Strüssmann et al 2000), diversity (Strüssmann 2011), description of new species (Ávila et al 2010), reproductive biology and behavior , 2002 and endoparasites (Campião et al 2009(Campião et al , 2010. There are only two studies that describe the diet of three anurans species: Leptodactylus podicipinus Cope, 1862 (Rodrigues et al 2004), Hypsiboas raniceps Cope, 1862 and Scinax acuminatus Cope, 1862 (Sabagh et al 2010).…”