To assess the context dependence of kin discriminating
behavior, I examined kin-biased aggregation behavior in tadpoles
of R. cascadae in different ecological conditions. I manipulated food
distribution, predator presence, thermal heterogeneity, and
relatedness in a multifactorial mesocosm experiment. All four
factors interacted to influence tadpole dispersion. My results
suggest that kinship is an important factor in aggregation behavior
dependent upon ecological conditions.
Kin-biased predator defense mechanisms have been proposed
as a possible functional explanation for kin discrimination in
anuran larvae. Tadpoles may better cooperate in predator
vigilance while in kin groups or release kin specific alarm
pheromones when attacked by a predator. I examined predator
avoidance and alarm response behavior in tadpoles of the Cascades
frog (Rana cascadae) and tested whether such behavior is
influenced by kinship factors. I found no evidence of an alarm
response behavior in R. cascadae. My results suggest that crushed
tadpoles appear to initiate a feeding response rather than an alarm
response as has been previously proposed.
Kin-biased competitive interactions have been proposed as a
possible functional explanation for kin discrimination in anuran
larvae. Tadpoles may direct competitive interactions away from
kin. I examined the role of kinship in growth and development of
tadpoles of the Cascades frog (Rana cascadae) in both laboratory
and field studies. In the laboratory, individuals reared in kin
groups had a significantly smaller mass at metamorphosis than
individuals reared in mixed groups. However, kinship effects in
the field depended upon the treatment context. Depending upon
tadpole density and access to flocculent substrate, tadpoles
survived better (after adjusting for differences in mass) in kin
groups than in mixed groups.
My results demonstrate that kinship factors can affect growth
and development in tadpoles, depending upon the ecological
conditions. Furthermore, my results provide a functional
explanation for the kin discriminating behavior observed in R.
cascadae and suggest why such behavior may be context
dependent. / Graduation date: 1995
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/34950 |
| Date | 18 August 1994 |
| Creators | Hokit, D. Grant |
| Contributors | Blaustein, Andrew R. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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