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Hostert_MS_Thesis_Final.pdf (1.73 MB)
ETD Abstract Container
Abstract Header
The role of individual variation in the consumption of non-native prey: implications for the evolution of diet specialization and biological invasions
Author Info
Hostert, Lauren Elizabeth
Permalink:
http://rave.ohiolink.edu/etdc/view?acc_num=osu1408940623
Abstract Details
Year and Degree
2014, Master of Science, Ohio State University, Environment and Natural Resources.
Abstract
Abundant non-native species frequently cause changes in natural environments by altering the composition and abundances of native species. One explanation for why non-native species are able to reach higher densities outside of their native range is because they escape their natural enemies (i.e. Enemy Release Hypothesis). Although the release of non-native species from their natural enemies may be due to lower densities or diversity of predators, parasites or pathogens, there are many alternative mechanisms that can reduce the predation pressure that a non-native species may experience following introduction into a new environment. In this study, I examined how individual variation in diet, morphology, competitive ability (i.e. aggression) of a native predator (common mudcrab,
Panopeus herbstii
), along with the relative energetic value of alternative prey contributes to the consumption of a recently introduced, non-native prey species (green porcelain crab,
Petrolisthes armatus
). Specifically, I: 1) quantified within-population variation in diet breadth and competitive ability of native
P. herbstii
predators, 2) evaluated the influence of competitive ability on within-population variation in diet and the consumption of non-native prey,
P. armatus
, and 3) compared the relative caloric densities of the native prey species of
P. herbstii
(
G. demissa
,
C. virginica
, and
E. depressus
) with that of the non-native prey
P. armatus
. AIC model comparisons indicated that predator sex, aggression, and competitor presence were the most important factors influencing diet specialization of
P. herbstii
predators, wherein predators that exhibited specialist diets were female and more aggressive. Individual
P. herbstii
predators also tended to exhibit specialist diets in the presence of a competitor. Individuals that specifically specialized on
P. armatus
were also female and more aggressive, but additionally, larger individuals. Individual
P. herbstii
predators generally, displayed more specialized diets on
P. armatus
in the absence of a competitor. The total number of
P. armatus
consumed was best explained by sex and size, whereby females and larger individuals consumed greater numbers of
P. armatus
. Also, in the presence of no alternative prey, females and smaller individuals consumed great quantities of
P. armatus
. Results from the oxygen bomb calorimetry analysis indicated that non-native
P. armatus
and native ribbed mussels
Geukensia demissa
have similar specific energies that are significantly greater than native eastern oysters
Crassostrea virginica
and depressed mud crabs
Eurypanopeus depressus
(which are not statistically different from one another). Overall, these results demonstrate that there is considerable individual variation in diet (i.e. some individuals are specialists, some generalists) and the consumption of
P. armatus
among the tested population of
P. herbstii
predators.
P. armatus
is a considerably profitable prey type compared to native prey yet only a sub-set of the population including females consumes
P. armatus
in large proportions. This gives some insight as to why
P. armatus
has been able to establish and maintain high population densities in this area but it produces more questions regarding why some individuals continue to not consume this abundant, profitable prey item.
Committee
Lauren Pintor, PhD (Advisor)
Elizabeth Marschall, PhD (Committee Member)
Mazeika Sullivan, PhD (Committee Member)
Pages
106 p.
Subject Headings
Behavioral Sciences
;
Biology
;
Ecology
;
Environmental Science
Keywords
non -native prey
;
optimal foraging theory
;
diet breadth
;
enemy release hypothesis
Recommended Citations
Refworks
EndNote
RIS
Mendeley
Citations
Hostert, L. E. (2014).
The role of individual variation in the consumption of non-native prey: implications for the evolution of diet specialization and biological invasions
[Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1408940623
APA Style (7th edition)
Hostert, Lauren.
The role of individual variation in the consumption of non-native prey: implications for the evolution of diet specialization and biological invasions.
2014. Ohio State University, Master's thesis.
OhioLINK Electronic Theses and Dissertations Center
, http://rave.ohiolink.edu/etdc/view?acc_num=osu1408940623.
MLA Style (8th edition)
Hostert, Lauren. "The role of individual variation in the consumption of non-native prey: implications for the evolution of diet specialization and biological invasions." Master's thesis, Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1408940623
Chicago Manual of Style (17th edition)
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Document number:
osu1408940623
Download Count:
676
Copyright Info
© 2014, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.