Date of Award
2011
Publication Type
Master Thesis
Degree Name
M.Sc.
Department
Earth and Environmental Sciences
Supervisor
Aaron Fisk
Supervisor
Trevor Pitcher
Rights
info:eu-repo/semantics/openAccess
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Abstract
This dissertation demonstrates that diet discrimination factors (DDF) have a strong negative correlation with stable isotope values in food for d15N (slope=-0.59±0.02, r2=0.95) and d13C (slope =-0.56±0.02, r2=0.94). Based on these results, a reliable DDF was used to evaluate the influence of predation on the trophic ecology of wild guppy populations in Trinidad. The trophic position of the guppies was 2.7 and did not differ between high- and low-predation sites (p=0.77). Nevertheless, high-predation populations had significantly higher proportions of the fatty acids associated with algae than low-predation populations which had higher proportions of fatty acids associated with invertebrates (p= 0.005). Additionally, standard ellipse area, a measure of isotopic niche width, was greater at high-predation sites compared to low-predation sites within Quare (p<0.001), Turure (p=0.003) and Tacarigua/Tunapuna (p=0.016) but not Aripo (P=0.19). Therefore, low-predation guppy populations appear to have diets more specialized on invertebrates, while high-predation guppies consume resources more indiscriminately.
Recommended Citation
Dennis, Caroline, "The influence of predation on the feeding ecology of trinidadian guppies using chemical tracers" (2011). Electronic Theses and Dissertations. 5586.
https://scholar.uwindsor.ca/etd/5586