Thursday, 31 January 2008
New Bd ecology paper
A new paper from Bosch & Rincon, on the first evidence of an indirect effect of chytridiomycosis in the field, is in press in Diversity and Distributions. We have documented how the disease may indirectly influence community structure by altering biotic interactions in which affected species participate. In Peñalara Natural Park (Central Spain), the common toad (Bufo bufo) has significantly increased its number of breeding sites after chytridiomycosis nearly extirpated the midwife toad (Alytes obstetricans). An experiment demonstrated that breeding B. bufo adults strongly avoided laying eggs in water containing A. obstetricans tadpoles, accounting for observed patterns of pond use. Bufo bufo is far less severely affected by Bd, spends less time in the water and has higher fecundity than A. obstetricans. So, inter-specific differences in the severity of the effects of the pathogen may modify their biotic interaction indirectly favouring one of them.
We think this kind of indirect effect may be a relatively frequent consequence of chytridiomycosis, and further attention must be paid to this to fully understand the deep effects of the disease on amphibian communities.