Resource use and coexistence of two syntopic hylid frogs (Anura, Hylidae)

Abstract

ABSTRACT. The objectives of this study were to measure and compare niche breadth and overlap of males of Hyla nana Boulenger, 1889 and Hyla sanborni Schmidt, 1944 in three neighboring ponds. The measured niche dimensions were seasonal occurrence, call site, and diet. The reproductive season of H. sanborni was longer in permanent ponds, whereas H. nana had a longer reproductive season in the temporary pond. Call site characteristics were similar for both species, however H. sanborni called from higher perches than H. nana. Diptera (Nematocera) were the most consumed item by both species in the three ponds but, in general, H. nana ingested larger prey than H. sanborni. For both species, the consumption of prey types was correlated with the availability in the environment. The multidimensional overlap between H. nana and H. sanborni was higher in the permanent ponds than the temporary pond, in which H. sanborni was rare. These species differed in abundance among ponds, consumed prey of different sizes, and probably fed in different time periods. Moreover, the data obtained suggest that structural differences in the ponds may modify the dynamics of resource partitioning between the two species. Beside the great overlap found in the major niche dimensions analyzed the detected differences may be great enough to allow their coexistence. KEY WORDS. Hyla, multidimensional overlap, niche breadth, niche overlap, resource partitioning.

Bioacústica e sítio de vocalização em taxocenoses de anuros de área aberta no noroeste paulista

“…Apesar de vários estudos criticarem o modelo de equilíbrio em comunidades (e.g., Strong 1982, Strong et al 1984, Wiens et al 1986, Eterovick & Barros 2003 alguns artigos recentes têm demonstrado coexistência baseada em diferenciação de nicho (e.g., Elliot & Mariscal 2001, Menin et al 2005, Verburg & Bills 2007, inclusive entre espécies crípticas (Nicholls & Racey 2006, Wellborn & Cothran 2007.…”

Habitat heterogeneity and use of physical and acoustic space in anuran communities in Southeastern Brazil

“…Nevertheless, only during the last decade quantitative aspects of anuran calling sites were published (Eterovick and Sazima 2000, Rossa-Feres and Jim 2001, Menin et al 2005. These quantitative studies evidenced some exceptions to these patterns, as the differential use of calling sites in open area anuran assemblages (Eterovick and Sazima 2000), and also proposed different approaches concerning the use of advertisement call as a tool assessing how coexisting species use the physical and acoustic space (Martins et al 2006, Santos and.…”

Uso de recursos alimentares e espaciais por dois anuros do gênero Dendropsophus (Anura: Hylidae) de La Selva, Costa Rica.

“…The similarities of the calling sites of Dendropsophus phlebodes and D. ebraccatus may be related to their taxonomic relationship and similar body sizes, as has been shown in related species by Rossa-Feres and Jim (2001) and suggested by Menin et al (2005). However, despite the similarities, there are significant differences in the substrate and leaf sizes used by these species.…”

“…Although the trophic niche is thought to be a less important factor in the maintenance of coexistence, it is relevant to an understanding of interspecific interactions (Duré and Kehr 2001). Moreover, a high availability of environmental resources, along with factors such as vegetation structure, environmental heterogeneity, reproductive modes, and predation influence the use of resources and affect coexistence of species (Donnelly and Guyer 1994, Gordon 2000, Menin et al 2005, Vasconcelos and Rossa-Feres 2008. Toft (1985) reported that the ways in which species use and share the resources are important factors for structuring anuran assemblages.…”