Resurveying breeding forest bird communities in Western Oregon after 50 years: comparing 1968–1970 and 2020–2021

Accurate assessments of changes in breeding bird populations require regular, structured surveys or, alternatively, carefully documented benchmarks that can be precisely repeated. We resurveyed a historic benchmark of forest bird communities in Western Oregon, USA, originally conducted by Stanley Anderson between 1968-1970. Anderson’s thesis uniquely preserves detailed plot locations, species density estimates, vegetation structure summaries, and methodological descriptions—an uncommon level of documentation for the time. To facilitate accurate comparisons and future resurveys, we explain how we aligned our methods with Anderson’s and incorporated modern bird counting techniques. We also provide our raw data, metadata, and methodological details to ensure transparency and reproducibility., , # Resurveying breeding forest bird communities in Western Oregon after 50 years: comparing 1968–1970 and 2020–2021

Dataset DOI: [10.5061/dryad.w9ghx3g29](10.5061/dryad.w9ghx3g29)

## Description of the data and file structure

We re-surveyed forested bird plots in western Oregon, USA, initially surveyed by Stanley Anderson. The initial surveys were in 1968-1970. We established more precisely repeatable survey methods and implemented them by surveying the same plots in 2020-2021. To make the surveys more repeatable, we used stationary counts and provided the GPS locations, time, and dates for which all surveys were conducted. The data file lists all individuals identified to species at each point along with the ancillary information gathered to facilitate distance analyses and detectability adjustments for estimating densities of birds on plots.

### Files and variables

#### File: Clements_Robinson_summerbirdsurvey_OregonCoastRange.csv

**Description:** 4934 records

##### Variables

*...,