3 research outputs found
A predator has nonconsumptive effects on different life-history stages of a prey
Through a field experiment, we show that a predator has negative nonconsumptive
effects (NCEs) on different life-history stages of the same prey species. Shortly before
the recruitment season of the barnacle Semibalanus balanoides (spring), we
established experimental cages in rocky intertidal habitats in Nova Scotia, Canada.
The cages were used to manipulate the presence and absence of dogwhelks, Nucella
lapillus, the main predators of barnacles. At the centre of each cage, we installed a tile
where barnacle pelagic larvae could settle and the resulting recruits grow. Mesh
prevented caged dogwhelks from accessing the tiles, but allowed waterborne
dogwhelk cues to reach the tiles. During the recruitment season, barnacle larvae
settled preferentially on tiles from cages without dogwhelks. In the fall, at the end of the
dogwhelk activity period and once the barnacle recruits had grown to adult size,
barnacle body mass was lower in the presence of dogwhelks. This limitation may have
resulted from a lower barnacle feeding activity with nearby dogwhelks, as found in a
previous study. The observed larval and adult responses in barnacles are consistent
with attempts to decrease predation risk. In the fall, dogwhelk cues also limited
barnacle reproductive output, a possible consequence of the limited growth of
barnacles. Overall, the results of this study suggest that a predator might influence trait
evolution in a prey mediated by NCEs on different life-history stages