Predator-prey interactions between introduced trout and long-toed salamanders and ways to mitigate nonconsumptive effects

dc.contributor.advisorChairperson, Graduate Committee: Andrea Litten
dc.contributor.authorKenison, Erin Kennedyen
dc.contributor.otherAndrea R. Litt, David S. Pilliod and Thomas E. McMahon were co-authors of the article, 'Nonconsumptive effects of introduced trout predators on long-toed salamanders: changes in morphology and life history' submitted to the journal 'Journal of herpetology' which is contained within this thesis.en
dc.contributor.otherAndrea R. Litt, David S. Pilliod and Thomas E. McMahon were co-authors of the article, 'Adding vegetation structure to reduce nonconsumptive effects of introduced trout: a novel method for amphibian conservation?' submitted to the journal 'Journal of herpetology' which is contained within this thesis.en
dc.date.accessioned2015-01-25T17:50:50Z
dc.date.available2015-01-25T17:50:50Z
dc.date.issued2014en
dc.description.abstractPredators can increase prey through mortality, but also have the capacity to alter behavior, morphology, and life history through nonconsumptive effects. In many historically fishless lakes in western North America, trout have been introduced for recreational fishing and are associated with reducing and extirpating populations of amphibians, including long-toed salamanders (Ambystoma macrodactylum). Salamanders and trout may coexist in some lakes, as larvae are able to alter foraging behavior by avoiding open water, foraging at night in shallow water, and hiding in cover to avoid predation. However, salamanders may experience nonconsumptive effects due to these behavioral changes. We sought to estimate the nonconsumptive effects of trout on morphology and life history of larval salamanders. We caught salamander larvae using minnow traps in northwestern Montana during the summers of 2012 and 2013 and compared body morphology measurements and size at and timing of metamorphosis between lakes with and without trout. Salamanders in lakes with trout were smaller: they weighed less, had shorter body lengths, and had shorter and narrower tails. Salamanders in lakes with trout were also less likely to metamorphose, did so later in the summer, and had smaller total and tail lengths at metamorphosis. These changes in morphology and life history likely were a result of reduced foraging to avoid predator attacks. We conducted a field experiment in 2013 to investigate whether adding vegetation structure could reduce nonconsumptive effects of trout on salamander larvae by providing refugia and reducing perceived risk of predation. We constructed field enclosures in lakes with and without trout and quantified changes in salamander growth and differences in size at metamorphosis with and without added structure. Salamanders appeared to detect trout cues because they grew more slowly in lakes with trout, even though trout had no ability to consume salamanders. Added vegetation structure did not influence growth rates, but did increase the probability of salamanders that reached metamorphosis. Future research efforts should investigate whether adding vegetation structure to whole lakes can mitigate the nonconsumptive effects of trout, provide a feasible alternative to fish removal, and facilitate coexistence between salamanders and trout.en
dc.identifier.urihttps://scholarworks.montana.edu/handle/1/3418en
dc.language.isoenen
dc.publisherMontana State University - Bozeman, College of Letters & Scienceen
dc.rights.holderCopyright 2014 by Erin Kennedy Kenisonen
dc.subject.lcshPredation (Biology)en
dc.subject.lcshIntroduced fishesen
dc.subject.lcshSalamandersen
dc.titlePredator-prey interactions between introduced trout and long-toed salamanders and ways to mitigate nonconsumptive effectsen
dc.typeThesisen
thesis.catalog.ckey2674431en
thesis.degree.committeemembersMembers, Graduate Committee: Thomas E. McMahon; David Pillioden
thesis.degree.departmentEcology.en
thesis.degree.genreThesisen
thesis.degree.nameMSen
thesis.format.extentfirstpage1en
thesis.format.extentlastpage100en

Files

Original bundle

Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
KenisonE0814.pdf
Size:
5.2 MB
Format:
Adobe Portable Document Format
Copyright (c) 2002-2022, LYRASIS. All rights reserved.