From declines to recovery: 52 years of changes in autumn migratory songbird abundance at an island stopover site in southern New England

Migratory birds are declining across North America, and many studies have used long-term datasets to estimate trends in abundance for migratory birds. To most efficiently prioritize at-risk populations, it is critical to know the current trend status of migratory species, which involves accurately assessing the most appropriate timescale for monitoring changes in populations. In this study, we analyzed autumn hatch-year bird banding data from the Block Island Banding Station on Block Island, Rhode Island over a 52-year period (1970-2021) to examine long-term abundance trends for 22 species of migratory songbirds and compared our results to trends from Manomet Conservation Sciences and the USGS Breeding Bird Survey. We ran four models (no change, linear, quadratic, and breakpoint model) for each species and used model selection with AICc to determine the best model. Eighteen of the 22 species were best represented by breakpoint models, indicating that they experienced a sudden change in ..., , # From declines to recovery: 52 years of changes in autumn migratory songbird abundance at an island stopover site in southern New England

Dataset DOI: [10.5061/dryad.h70rxwdwn](10.5061/dryad.h70rxwdwn)

## Description of the data and file structure

The provided R Scripts and data are used to analyze 52 years of autumn bird banding data (hatch-year birds only) from the Block Island Banding Station on Block Island, RI, USA. Specifically, this code runs four models (no change, linear, quadratic, and breakpoint) for 22 species of migratory songbirds, selects the best model, runs a leave-one-out analysis, and classifies each trend based on trend direction.

### Files and variables

#### File: AOU\_species\_codes.csv

**Description:** This file contains taxonomic classifications for each species, downloaded from the American Ornithological Society. 

##### Variables

* SPECIES_ID: Taxonomic order
* AOU: Assigned four-letter AOU code
* SPECIES_NAME: Common name
* spp: Scientific name
* orde...,