Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
Ecology, 83(9), 2002, pp. 25422551 2002 by the Ecological Society of America
 

Summary: 2542
Ecology, 83(9), 2002, pp. 2542­2551
2002 by the Ecological Society of America
PREDATOR-INDUCED LIFE-HISTORY PLASTICITY UNDER TIME
CONSTRAINTS IN POOL FROGS
RES ALTWEGG1
Institute of Zoology, University of Zu¨rich, Winterthurerstr. 190, CH-8057 Zu¨rich, Switzerland
Abstract. The mere presence of predators often decreases the growth rate of prey
individuals, which devote energy and time to predator avoidance mechanisms. However,
if time constraints are present, the prey individuals might be forced to neglect predators
in order to grow faster. Amphibian larvae lower their activity when exposed to predators,
which increases their survival probability but lowers their growth rate. I investigated how
time constraints affect the growth strategies of pool frogs (Rana lessonae) in the presence
and absence of caged (i.e., nonlethal) predators, and what the consequences are for their
survival during the larval and the subsequent terrestrial life stage. In two outdoor exper-
iments, I limited the available development time by delaying the hatching date, and by
simulating pond drying. Tadpoles whose hatching date was experimentally delayed reduced
their development and their activity less in the presence of predators than did control
tadpoles. The survival consequences of caged predators was similar for early- and late-
hatched tadpoles. Tadpoles exposed to falling water level increased their developmental

  

Source: Altwegg, Res - Avian Demography Unit, Department of Statistical Sciences, University of Cape Town

 

Collections: Environmental Sciences and Ecology