Ra. Griffiths et Jp. Foster, THE EFFECT OF SOCIAL INTERACTIONS ON TADPOLE ACTIVITY AND GROWTH IN THE BRITISH ANURAN AMPHIBIANS (BUFO-BUFO, B-CALAMITA, AND RANA-TEMPORARIA), Journal of zoology, 245, 1998, pp. 431-437
Tadpoles of different species of frogs and toads display different ten
dencies to aggregate. We investigated some of the costs and benefits o
f aggregating in three British species by examining their behavioural
responses to the presence of conspecifics, and by monitoring the perfo
rmance of tadpoles under different levels of social interaction with o
ther individuals. The common toad (Bufo bufo), an aggregating species,
displayed higher levels of activity than the natterjack toad (B. cala
mita) and common frog (Rana temporaria), two species that form aggrega
tions less frequently. Moreover, out of the three species, only B. buf
o increased activity in the presence of conspecifics. In all three spe
cies, increased interaction between individuals resulted in increased
variation in size. However, average growth rate was affected only in B
. bufo, which grew faster when raised in isolation and not interacting
with other individuals. Under certain conditions intraspecific compet
ition therefore seems to tie more important than social facilitation,
but may lead to average size at metamorphosis being larger within the
population. The consequences of intraspecific competition within aggre
gations mag therefore be different for individuals and populations.