The evolution of jumping performance in anurans: morphological correlates and ecological implications

Abstract

We investigated the evolution of anuran locomotor performance and its morphological correlates as a function of habitat use and lifestyles. We reanalysed a subset of the data reported by Zug (Smithson. Contrib. Zool. 1978; 276: 1–31) employing phylogenetically explicit statistical methods (n = 56 species), and assembled morphological data on the ratio between hind‐limb length and snout‐vent length (SVL) from the literature and museum specimens for a large subgroup of the species from the original paper (n = 43 species). Analyses using independent contrasts revealed that classifying anurans into terrestrial, semi‐aquatic, and arboreal categories cannot distinguish between the effects of phylogeny and ecological diversification in anuran locomotor performance. However, a more refined classification subdividing terrestrial species into ‘fossorials’ and ‘non‐fossorials’, and arboreal species into ‘open canopy’, ‘low canopy’ and ‘high canopy’, suggests that part of the variation in locomotor performance and in hind‐limb morphology can be attributed to ecological diversification. In particular, fossorial species had significantly lower jumping performances and shorter hind limbs than other species after controlling for SVL, illustrating how the trade‐off between burrowing efficiency and jumping performance has resulted in morphological specialization in this group.

Leaping towards a saltatorial lifestyle? An unusually long-legged new species of Rhombophryne (Anura, Microhylidae) from the Sorata massif in northern Madagascar

“…Hindlimb length is significantly associated with habitat and mode of life in frogs (Gomes et al 2009). Longer legs relative to body length result in greater relative leaping performance (Zug 1978, Choi et al 2003, Gomes et al 2009).…”

“…Longer legs relative to body length result in greater relative leaping performance (Zug 1978, Choi et al 2003, Gomes et al 2009). In general, fossorial frogs have the poorest jumping performance, while arboreal and semi-aquatic frogs are the strongest jumpers (Zug 1978).…”

The diversity and evolution of locomotor muscle properties in anurans

“…Anuran locomotor performance in tasks such as jumping and swimming is readily tested, varies widely across species (Zug, 1978;Richards, 2010), strongly correlates with habitat and morphology (Zug, 1972(Zug, , 1978Emerson, 1988;Gomes et al, 2009), and can be linked to fundamental aspects of muscle physiology (Lutz and Rome, 1994;Richards and Biewener, 2007). Furthermore, anurans show numerous convergences and divergences in locomotor performance and associated morphological traits across their phylogeny ( Fig.…”

Morphological diversity and community organization of desert anurans

“…1, Appendix H), and separated species based on habitat use with clusters of fossorial species (Bufonids, Scaphiophids, and the Microhylid Gastrophryne olivacea), terrestrial but non-fossorial (Craugastor augusti and Eleutherodactylus guttilatus), and semiaquatic species (Hylids: Acris crepitans, Hyla arenicolor, and Ranids: Lithobathes spp.) (see Discussion below and Gomes et al (2009) for further classification and explanation). PC1 described a gradient that reflected morphological differences in limb and head lengths.…”

“…Blair (1976) proposed that desert anurans cope with limited and unpredictable water availability in one of two ways: 1) becoming restricted to the vicinity of permanent waters in the desert, or 2) becoming highly fossorial. These adaptations are reflected in the morphological traits of anurans, particularly hindlimb length (Gomes et al, 2009), thus given that morphology partly reflects the evolutionary influences of environmental conditions, we would expect variation in morphological traits to be reflected amongst habitat types, especially in desert habitats where anuran occurrence appears correlated with physical conditions (e.g., vegetation, soils) of the habitats (Dayton et al, 2004;Boeing et al, 2013). These studies have primarily examined species diversity of Chihuahuan Desert anurans in relation to vegetation type (Boeing et al, 2013) or vegetation and soil type (Dayton et al, 2004).…”