Morphology and burrowing energetics of semi-fossorial skinks (Liopholis)

Abstract

Burrowing is an important form of locomotion in reptiles, but no study has examined the energetic cost of burrowing for reptiles. This is significant because burrowing is the most energetically expensive mode of locomotion undertaken by animals and many burrowing species therefore show specialisations for their subterranean lifestyle. We examined the effect of temperature and substrate characteristics (coarse sand or fine sand) on the net energetic cost of burrowing (NCOB) and burrowing rate in two species of the Egernia group of skinks (Liopholis striata and Liopholis inornata) compared with other burrowing animals. We further tested for morphological specialisations among burrowing species by comparing the relationship between body shape and retreat preference in Egernia group skinks. For L. striata and L. inornata, NCOB is 350 times more expensive than the predicted cost of pedestrian terrestrial locomotion. Temperature had a positive effect on burrowing rate for both species, and a negative effect on NCOB for L. striata but not L. inornata. Both NCOB and burrowing rate were independent of substrate type. Burrows constructed by skinks had a smaller cross-sectional area than those constructed by mammals of comparable mass, and NCOB of skinks was lower than that of mammals of similar mass. After accounting for body size, retreat preference was significantly correlated with body shape in Egernia group skinks. Species of Egernia group skinks that use burrows for retreats have narrower bodies and shorter front limbs than other species. We conclude that the morphological specialisations of burrowing skinks allow them to construct relatively narrow burrows, thereby reducing NCOB and the total cost of constructing their burrow retreats.

Cryptic diversity and molecular systematics of the AegeanOphiomorusskinks (Reptilia: Squamata), with the description of a new species

“…In lizards, ecomorphological traits are often correlated with similar niche envelopes but not correlated with neutral molecular variation (Camargo, Sinervo, & Sites, ). This could be especially evident in burrowing or semi‐burrowing lizards, such as the Greek limbless skink, as the construction of burrows requires a high level of specialization (Wu, Alton, Clemente, Kearney, & White, ).…”

Small, rare and trendy: traits and biogeography of lizards described in the 21st century

“…Because fossorial habits entail much greater energetic costs of locomotion (e.g. Wu et al ., ) fossorial animals are expected to be dispersal limited (although they may be more likely to disperse by rafting, Townsend, Leavitt & Reeder, ), and to have small ranges. These conditions should be ideal for allopatric speciation, and I thus predict that their actual taxic diversity is relatively higher than current numbers suggest, and indeed current description trends reveal.…”

Peer Review #3 of "Large mammal burrows in late Miocene calcic paleosols from central Argentina: paleoenvironment, taphonomy and producers (v0.1)"

“…Body mass estimates of the producers of the burrow on the basis of the cross-sectional 249 area (using the method by Wu et al, 2015) suggest that there are two ranges (Table S1) (Fig. 10D).…”