PARENT SESSION
Oral Session # 7: Populations and Genetics.
Presiding: E Sotka
Monday, August 4. 8:00 AM to 11:30 AM, SITCC Meeting Room 106.
Resource level and reproductive frequency in female four-toed salamanders, Hemidactylium scutatum.
Harris, Reid1, Ludwig, Patrice*,2, 1 James Madison University, Harrisonburg, VA, USA2 University of Virginia, Charlottesville, VA, USA
ABSTRACT- Skipping a reproductive event may be selectively advantageous if the reduced reproductive output is balanced by gains in survival and lifetime fecundity. Alternatively, skipping a reproductive event may be due to the effects of resource limitation. Data from a 10-year field study showed that females that did skip reproduction had higher growth, which can translate into higher fecundity, and tended to have higher survival. However, these benefits did not compensate for the absence of reproduction in a year caused by skipping. We experimentally examined whether female four-toed salamanders (Hemidactylium scutatum) skip a reproductive event because of a lack of adequate resources after nesting and before the onset of winter. A manipulation of food level after the nesting period revealed that females fed a high food ration were twice as likely to return the next year to oviposit as females fed a maintenance food level. Females from the maintenance food level treatment that did return were in similar condition to females from the high food ration treatment. This result suggests that a threshold body condition is necessary before reproduction is attempted. We conclude that skipping reproduction in this species is due to the proximate effects of resource limitation.
Key words: Hemidactylium scutatum, reproductive frequency, feeding, life history