Priority effects of the early breeding fire salamander on the late breeding banded newt
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Early breeding intraguild predators may have advantages over late breeding predators via priority effects; early breeding predators may reduce shared prey resources before late breeders appear and may also prey upon the late breeders. Here we show that predatory larvae of the late-breeding predatory banded newt, Triturus vittatus vittatus, occupy the same temporary pond toward the end of the developmental period of the early-breeding predatory fire salamander, Salamandra salamandra, resulting in a large size disparity between larvae of these two species while they co-occur. We conducted outdoor artificial pool experiments to assess priority effects of large larval Salamandra at the end of their larval development period, on recently hatched larval Triturus. We also assessed how artificial vegetation may influence larval Triturus performance in the presence or absence of Salamandra Salamandra, introduced into the experimental pools two weeks prior to the newt larvae, strongly reduced invertebrate prey abundance shared by these two predatory urodeles and with only a one week period of overlap, strongly reduced abundance of Triturus larvae. The artificial vegetation had only a small ameliorating effect on Triturus survival when Salamandra was present. Triturus size at metamorphosis (snout-tail length) was significantly larger in the Salamandra pools, presumably due to a combination of a strong “thinning effect” and greater vulnerability of smaller Triturus individuals to predation by Salamandra. Time to metamorphosis was not significantly affected by Salamandra. These results have conservation implications as T. v. vittatus is listed as highly endangered and may also explain the largely negative spatial association of the two species.
KeywordsHabitat heterogeneity Priority effects Salamandra salamandra Triturus vittatus vittatus Temporary pools Predation
We thank Shai Anuka for technical help, Tamar Krugman and Eden Orion for logistical help, Moshe Kiflawi, Avi Eitam, Naomi Hill, Nir Peleg, Alon Silberbush, Oren Pearlson, Gad Degani and Shirli Bar-David and two anonymous reviewers for critiquing an earlier version of the manuscript. The research was funded by a Vataat doctoral fellowship awarded to O. Segev and U.S.-Israel Binational Science Foundation grants 98–390 and 02–365 awarded to L. Blaustein and M. Mangel.
- Barnett, H. K. & J. S. Richardson, 2002. Predation risk and competition effects on the life-history characteristics of larval Oregon spotted frog and larval red-legged frog. Oecologia 132: 436–444.Google Scholar
- Blaustein, L., N. Engert, E. Steiner, E. Nevo & M. R. Warburg, 1996a. Israel’s endangered Urodele species: Preliminary studies on their distribution across Mount Carmel and their influence on community structure of temporary pools. In Steinberger, Y. (ed.), Preservations of Our World in the Wake of Change. Vol. 6A/B. ISEEQ publishing, Jerusalem, Israel.Google Scholar
- Brodman, R., 1999. Food and space dependent effects during the interactions of two species of larval salamanders. Journal of Freshwater Ecology 14: 431–437.Google Scholar
- Gafny, S., 2004. Threatened amphibians in Israel. In Dolev, A. & A. Perevolotsky (eds), The red book - vertebrates in Israel. Israel Nature and Parks Authority and The Society for the Protection of Nature in Israel, Jerusalem, Israel.Google Scholar
- Turner, A. M. & S. L. Montgomery, 2003. Spatial and temporal scales of predator avoidance: Experiments with fish and snails. Ecology 84: 616–622.Google Scholar
- Warburg, M. R., 1994. Population ecology, breeding activity, longevity, and reproductive strategies of Salamandra salamandra during an 18-year long study of an isolated population on Mt. Carmel, Israel. Mertensiella 4: 399–421.Google Scholar