A pesar de su uso generalizado, se ha centrado relativamente poco en cómo la digestión influye en la detección del ADN de las presas y en la descripción de la dieta de un depredador. La meta codificación de barras de ADN es una herramienta popular para los estudios de la dieta animal que permite abordar una variedad de temas de investigación en todas las disciplinas y taxones. With no clear benefit to using stomach contents, we conclude that fecal samples are the preferred sample type for avian metabarcoding diet studies, unless research goals necessitate otherwise. We found no difference in the description of diet based on sample type at the population level, but our results show that comparing stomach and fecal samples from the same individual can reveal distinct foraging bouts. The relative read abundance of common prey families remained consistent between sample types, suggesting that while less DNA may survive digestion, the proportions of prey remain largely unaffected.
However, these differences did not influence the description of diet, as similar measures of richness and diversity were found in both sample types. Stomach contents produced ~2.5 times greater DNA concentrations than fecal samples and-while this difference in DNA concentration was not statistically significant-stomach contents produced significantly more read identifications than fecal samples. To explore how digestion affects the recovery and detection of prey DNA in passerines, we used DNA metabarcoding to compare the recovery of prey DNA from paired stomach contents and fecal samples in Seaside Sparrows ( Ammospiza maritima). This is especially pertinent for avian diet studies, which have widely adopted the use of fecal samples as a proxy for overall diet. However, these samples may provide incomplete or inaccurate descriptions of diet because of differential digestion and DNA degradation across prey taxa during gut passage.
Fecal samples are a compelling source of dietary DNA because they are collected non-invasively. Despite its widespread use, there has been relatively little focus on how digestion influences prey DNA detection and the description of a predator’s diet. This lens is about 20% thinner than High Index 1.67.DNA metabarcoding is a popular tool for animal diet studies to address a variety of research topics across disciplines and taxa.
We recommend this lens to patients with a medium high prescription to a high prescription. High Index 1.74 is the absolute thinnest lens available anywhere.This lens is about 20% thinner than polycarbonate. High Index 1.67 is great for patients with a medium to medium high prescription.Anti-reflective coating is included with a 2-year warranty that covers any damage. We recommend this material for patients with a low to medium prescription. This material is the most lightweight and provide the most clarity. Trivex is the newest material available on the market.We recommend this material for patients with a low to medium prescription. It is shatter & scratch resistant, and is lighter & thinner than plastic. Polycarbonate is the most common material used for patients.This lens has no shatter or scratch resistance. We recommend this lens for patients with low prescriptions due to the thickness and weight of CR-39. Plastic (CR-39) is our most basic material.