Population divergence in growth rate and antipredator defences in Rana arvalis.
2006 (English)In: Oecologia, Vol. 147, no 4, 585-595 p.Article in journal (Refereed) Published
Growth and development rates often differ among populations of the same species, yet the factors maintaining this differentiation are not well understood. We investigated the antipredator defences and their efficiency in two
moor frog Rana arvalis populations differing in growth and development rates by raising tadpoles in outdoor containers in the nonlethal presence and absence of three different predators (newt, fish, dragonfly larva), and by estimating
tadpole survival in the presence of free-ranging predators in a laboratory experiment. Young tadpoles in both populations reduced activity in the presence of predators and increased hiding behaviour in the presence of newt and fish.
Older tadpoles from the slow-growing Gotland population (G) had stronger hiding behaviour and lower activity in all treatments than tadpoles from the fast-growing Uppland population (U). However, both populations showed a plastic
behavioural response in terms of reduced activity. The populations differed in induced morphological defences especially in response to fish. G tadpoles responded with relatively long and deep body, short tail and shallow tail muscle,
whereas the responses in U tadpoles were often the opposite and closer to the responses induced by the other predators. U tadpoles metamorphosed earlier, but at a similar size to G tadpoles. There was no evidence that growth rate was
affected by predator treatments, but tadpoles metamorphosed later and at larger size in the predator treatments. G tadpoles survived better in the presence of free-ranging predators than U tadpoles. These results suggest that in these
two populations, low growth rate was linked with low activity and increased hiding, whereas high growth rate was linked with high activity and less hiding. The differences in behaviour may explain the difference in survival between the
populations, but other mechanisms (i.e. differences in swimming speed) may also be involved. There appears to be considerable differentiation in antipredator responses between these two R. arvalis populations, as well as with respect
to different predators.
Place, publisher, year, edition, pages
2006. Vol. 147, no 4, 585-595 p.
Growth rate, Inducible defences, Plasticity, Population differentiation, Predation
IdentifiersURN: urn:nbn:se:uu:diva-31017DOI: doi:10.1007/s00442-005-0301-3OAI: oai:DiVA.org:uu-31017DiVA: diva2:58913