DNA-based diet analysis for any predator.

Area of Science:

• Molecular Ecology
• Genetics
• Wildlife Biology

Background:

• Current prey DNA detection methods for dietary analysis are limited by the need for a priori diet knowledge or ad hoc designs.
• A generalized approach is presented to overcome these limitations for diverse prey detection in predator samples.

Purpose of the Study:

• To develop a versatile DNA-based methodology for identifying a wide range of prey species in predator digestive tracts or feces.
• To provide a transferable approach applicable to various predator-prey systems in ecological research.

Main Methods:

• Utilizes the restriction enzyme Pac I, targeting a site present in Odontoceti (toothed whale) mtDNA but absent in many prey taxa.
• Predator DNA is cleaved and excluded using Pac I, allowing prey-selective PCR amplification with novel universal primers.
• Method optimized and validated using fecal samples from captive and free-ranging bottlenose dolphins with known diets.

Main Results:

• Successfully detected up to five prey species from two phyla in single fecal samples from captive dolphins.
• Identified 13 prey taxa from eight teleost families in free-ranging bottlenose dolphin scat.
• The method demonstrated high efficacy, detecting all but one minor prey item in controlled feeding trials.

Conclusions:

• The presented methodology offers a broadly applicable DNA-based technique for predator diet analysis.
• This approach facilitates the rapid transfer of technology to diverse zoological study systems.
• Enhances the utility of DNA-based diet techniques for a wide variety of ecological research.