Graduate Thesis Or Dissertation

 

Unpalatability as an antipredator defense in anuran larvae Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/zk51vm28h

Descriptions

Attribute NameValues
Creator
Abstract
  • The tadpoles of several anuran species with groupforming larvae are relatively unpalatable to many of their potential predators. To more fully understand the role of palatability and its relationship to group formation as an antipredator defense in anuran amphibian larvae, I investigated the palatabilities of the larvae of three species of anurans, the Western toad (Bufo boreas), Cascades frog (Rana cascadae) and Pacific treefrog (Hula regilla) to several syntopic insect and salamander predators. Both B. boreas and R. cascadae tadpoles form social aggregations in nature. Salamanders ate proportionately fewer B. boreas than R. cascadae and H. regilla tadpoles of similar size and same developmental stage. Differential predation on B. boreas, R. cascadae and H. regilla tadpoles was probably due to distasteful qualities of B. boreas larvae as opposed to differences in prey size or escape ability. After being captured by salamanders, B. boreas tadpoles were usually released unharmed. Both newly-hatched and mid-developmental B. boreas tadpoles were unpalatable to salamanders whereas R. cascadae and H. regilla tadpoles were palatable at all developmental stages tested. The relative palatability of B. boreas, R. cascadae and H. regilla larvae to insect predators was similar regardless of whether tadpoles were newly-hatched, in mid-larval development or at metamorphic climax. Kin selection may have played a role in the evolution of Bufo unpalatability and group formation in the ancestral population, however, it may not be important for maintaining these traits in extant B. boreas populations. Because group-forming R. cascadae tadpoles are palatable to the predators tested, they may utilize other antipredator defenses to avoid being eaten.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using ScandAll PRO 1.8.1 on a Fi-6770A in PDF format. CVista PdfCompressor 5.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items