Data and code from: DNA metabarcoding reveals dietary divergence among sympatric swallows and flycatchers

Aerial insectivore (AI) populations have been in steep decline in North America since the 1970s, with swallows, swifts, and nightjars declining more rapidly than flycatchers. As AI share a common diet of flying insects, reductions in insect abundance are likely one of the major factors driving population decline. Previous studies have shown major dietary differences between swallows and flycatchers; flycatchers have exhibited more diverse, generalist diets than swallows. However, no study has directly compared the diets of sympatric swallows and flycatchers using the same method of dietary analysis. To investigate these differences, we compared the diets of six AI species living in sympatry during the breeding season. We collected fecal samples from adult Riparia riparia (Bank Swallow), Hirundo rustica (Barn Swallow), Petrochelidon pyrrhonota (Cliff Swallow), Tachycineta bicolor (Tree Swallow), Empidonax alnorum (Alder Flycatcher), and E. minimus (Least Flycatcher). We used DNA metabarc..., We caught adult birds of Hirundo rustica (Barn Swallow), Riparia riparia (Bank Swallow), Petrochelidon pyrrhonota (Cliff Swallow), Tachycineta bicolor (Tree Swallow), Empidonax minimus (Least Flycatcher), and E. alnorum (Alder Flycatcher) during the 2022 breeding season in New Brunswick, Canada. Birds defecated in paper bags, banded (with morphology data such as age, sex, wing chord, etc. also taken), and released. 
Fecal samples were stored at -20 °C until packaged in 1.5ml microcentrifuge tubes and sent to the Canadian Centre for DNA Barcoding (CCDB) at the University of Guelph (Guelph, ON) for DNA metabarcoding analysis. DNA fragments extracted from each sample were amplified using arthropod-specific primers described by Zeal et al. (2011), which target a 157 base-pair section of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene. Two polymerase chain reaction (PCR) replicates were performed for each sample. The amplified DNA was sequenced alongside ..., , # Data and code from: DNA metabarcoding reveals dietary divergence among sympatric swallows and flycatchers

[https://doi.org/10.5061/dryad.573n5tbj3](https://doi.org/10.5061/dryad.573n5tbj3)

## Description of the data and file structure

Data package includes 5 comma-separated values files:

1. Birds2022.csv
2. Diet2022.csv
3. FecalSampleTransfer.csv
4. 2022CivilTwilight.csv
5. LarvalHabitat.csv

### Files and variables

#### File: PRN_Data_Package_MS_24_088.zip

**Description:**

Data file 'Birds2022.csv' contains all banding data and fecal sample bag IDs, with the following variables:

⦁ Bag_ID: Individual marker, when combined with species, differentiating the fecal samples collected in paper bags. Must be combined with species when linking to the secondary fecal sample IDs in the data files 'FecalSampleTransfer.csv' and 'Diet2022.csv'.

⦁ Bander: Initials of the personnel who applied the CWS issued aluminum band for individual identification of birds.

⦁ Code: Status of band appl...,