Friday, August 05, 2005
Potential Breeding Interference among Native Frogs by Introduced American Bullfrogs
The American bullfrog, native to eastern North America, is now common in western lowland areas where it was introduced decades ago. Bullfrogs can negatively affect native frogs through competition and predation, and by increasing their susceptibility to predators. Little work has examined other interactions between bullfrogs and native frogs of the family Ranidae, several of which are species of conservation concern. A recent paper by USGS biologist Christopher Pearl and colleagues discusses one such previously uninvestigated interaction: breeding interference. The authors report observations of amplexus (the pairing of ranid frogs during breeding) between bullfrogs and natives at six sites around the Pacific Northwest. These observations included two species of native frogs, the red-legged frog and Oregon spotted frog. The authors discuss hypotheses about conditions under which the presence of bullfrogs could reduce the number of male native frogs available to mate with females of the same species.
Pearl, C.A., Hayes, M.P., Haycock, R., Engler, J.D., Bowerman, J., 2005, Observations of Interspecific amplexus between western North American ranid frogs and the introduced American bullfrog (Rana catesbeiana) and an hypothesis concerning breeding interference: American Midland Naturalist, v. 154, p. 126-134. [Abs] [FullText] Catalog No: 1379
Contact:
Christopher
Pearl,
FRESC,
541-750-1011,
christopher_pearl@usgs.gov
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