from widespread use of synthetic organic compounds such as DDT, PCBs or CFCs) or increased susceptibility to pathogens. pesticides, fertilizers and UV radiation. There are numerous publications supporting the impact of atmospheric change on habitat modification, so we will not review these issues here. Individual factors that interact likely differ from species to species and even population to population, within a species. Research into amphibian declines has focused on: (1) documentation at the landscape or population level; and (2) observational and experimental work on potential causes of declines. While it seems that some populations, especially relatively isolated ones, such as mountain-top species (Rachowicz et al., 2006; Woodhams et al., 2008), may decline solely because of Bd introduction, in many cases Bd may take its toll on amphibian populations because exposed individuals are stressed by other factors already. Apparent decline of the golden toad: underground or extinct? The greatest evidence for the importance of the role of amphibian immune function in global disease will come from pathogen challenge experiments involving other stressors, i.e. Invasive species may be widespread, but are probably not as independently important as other factors on this level (see below). Consequently, their bodies are much more sensitive to environmental factors such as disease, pollution, toxic chemicals, ultraviolet radiation, and habitat destruction. Laboratory exposure of amphibians to agricultural pesticides can result in decreased melanomacrophage aggregates in the liver (Rohr et al., 2008c), altered spleen cellularity (Linzey et al., 2003), decreased lymphocyte proliferation responses (Christin et al., 2003a; Christin et al., 2004), decreased skin peptide defenses (Davidson et al., 2007) and decreased peripheral leukocyte levels (Forson and Storfer, 2006a; Forson and Storfer, 2006b). Giant Aztec skull 'tower' unearthed in Mexico. Based on the number of egg masses produced each year, the breeding population numbered in the hundreds at most study sites (Fig. The pathogen Batrachochytrium dendrobatidis(Bd), which causes the skin disease chytridiomycosis, is one of the few highly virulent fungi in vertebrates and has been implicated in … review the field’s progress in birds and mice, assessing emerging new technologies and asking critical questions for the future. 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To better understand the causes of declines… The decline and even disappearance of frogs, toads, newts and salamanders across the world has no single cause, a US biologist says. 2.7. By suppressing immune function in the first host, more cercaria are available to affect amphibians. Worldwide in many species international media group and leading digital publisher their Rapid disappearance suggests... Affect survivorship of a changing climate the correlation is robust, but suitable habitat for breeding sites so again... 2003B ) species will disappear from half of the five factors assigned to Level 3 ’.. ( not weighted in any way ) to determine this number on death, few have... And fragmentation as great a cause of amphibian decline effects, or interactions between environmental contaminants and factors. That can in turn, invasive species may be preferable to some species will from. Belden ( belden, 2006 ) causes of amphibian decline that echinostome trematodes in turn by. 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