these features may be greatly reduced, or absent. Distribution and habitat The European tree frog (Hyla arborea) is common in the middle and south of Europe, and its range extends into Asia and North Africa. North America has many species of the family Hylidae, including the gray tree frog (Hyla versicolor) and the American green tree frog (H. cinerea). The spring peeper (Pseudacris crucifer) is also widespread in the eastern United States and is commonly heard on spring and summer evenings. Behaviour and ecology Species of the genus Cyclorana are burrowing frogs that spend much of their lives underground. Breeding Hylids lay their eggs in a range of different locations, depending on species. Many use ponds, or puddles that collect in the holes of their trees, while others use bromeliads or other water-holding plants. Other species lay their eggs on the leaves of vegetation hanging over water, allowing the tadpoles to drop into the pond when they hatch. A few species use fast-flowing streams, attaching the eggs firmly to the substrate. The tadpoles of these species have suckers enabling them to hold on to rocks after they hatch. Another unusual adaptation is found in some South American hylids, which brood the eggs on the back of the female. The tadpoles of most hylid species have laterally placed eyes and broad tails with narrow, filamentous tips. Feeding Hylids mostly feed on insects and other invertebrates, but some larger species can feed on small vertebrates. Gallery References This article incorporates text from the Collier's New Encyclopedia (1921).Further reading "Amero-Australian Treefrogs (Hylidae)". William E. Duellman. Grzimek's Animal Life Encyclopedia''. Ed. Michael Hutchins, Arthur V. Evans, Jerome A. Jackson, Devra G. Kleiman, James B. Murphy, Dennis A. Thoney, et al. Vol. 6: Amphibians. 2nd ed. Detroit: Gale, 2004. p225-243. External links Amnh.org: Amphibian Species of the World Amphibian families Extant Thanetian first appearances Taxa named by Constantine Samuel Rafinesque