The impact of environmental temperature on larval development and metamorph body condition in the common toad, Bufo bufo

The dates when common toads first started to spawn (1980-2009) and when metamorphs first started to emerge from the natal pond (1984-2009) were recorded annually at a pond in southern England. Data loggers were used to record daily pond water temperatures between 1995-1999 and 2002-2009. The SVL and body mass of newly emerged metamorphs were recorded between 2003-2009. The dates of first spawn deposition varied between years by up to 60 days, from 28th January 2007 to 29th March 2006. The duration of the tadpole stage was negatively correlated with the date of first spawn deposition and with the mean pond water temperature during the tadpole stage. Although the duration of the tadpole stage was longer when spawning was early, compared to when it was late, metamorphs emerged from the pond up to 37 days earlier when spawning was early but with a lower body condition than when spawning was late. The body condition of newly emerged metamorphs was highly correlated with the temperature of the pond water they experienced as tadpoles. The potential benefit of early metamorphosis in providing a longer period of time for toadlet growth, before entering their first hibernation, may be counterbalanced by their poorer body condition when compared with later emerging metamorphs.