Fossorial behavior and ecology of the chorus frog Pseudacris ornate

Abstract

The chorus frog Pseudacris ornata is a fossorial species that uses its forelimbs to burrow in the substrate. This is highly unusual as the great majority of burrowing frogs dig backwards with their hind feet. Pseudacris ornata is quite similar in manner of forelimb burrowing to its nearest relative Pseudacris streckeri. However, P. ornata shows greater hesitancy to burrow and thus is intermediate between the highly fossorial P. streckeri and another species, Pseudacris triseriata, which is not known to burrow . In morphological adaptations of the forelimb for burrowing, P. ornata is also intermediate between the other two species. Pseudacris ornata spends much of its time underground outside its breeding season, and is associated with easily penetrated sandy soils. Pseudacris ornata occasionally communicates underground by vocalization. This type of communication may be of an aversive nature. Forward burrowing may have evolved in salientians to facilitate subterranean feeding or other behaviors requiring efficient orientation using sensory structures on the anterior half of the body.