DOI: 10.5061/dryad.w9ghx3g29
title: Resurveying breeding forest bird communities in Western Oregon after 50 years: comparing 1968–1970 and 2020–2021

description: 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.
description: # 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 * RecordID: Sequential
 numbering of data rows. * English Name: Contains the English species name
 of each bird species following the American Ornithological Society 2024
 species names
 ([http://checklist.americanornithology.org](http://checklist.americanornithology.org)). Chesser, R.T.; Billerman, S.M.; Burns, K.J.; Cicero, C.; Dunn, J.L.; Hernández-Baños, B.E.; JimÈnez, R.A.; Johnson, O.; Kratter, A.W.; Mason, N.A.; et al. AOU Checklist of North and Middle American Birds Available online: [https://checklist.americanornithology.org/taxa/](https://checklist.americanornithology.org/taxa/) (accessed on 11 September 2024). If no birds were detected (passerine sp entered for English Name) * Scientific Name: Contains the scientific species name of each bird species following the American Ornithological Society 2024 species names ([http://checklist.americanornithology.org](http://checklist.americanornithology.org)). Chesser, R.T.; Billerman, S.M.; Burns, K.J.; Cicero, C.; Dunn, J.L.; Hernández-Baños, B.E.; JimÈnez, R.A.; Johnson, O.; Kratter, A.W.; Mason, N.A.; et al. AOU Checklist of North and Middle American Birds Available online: [https://checklist.americanornithology.org/taxa/](https://checklist.americanornithology.org/taxa/) (accessed on 11 September 2024). * Direction: To help observers keep track of different individual birds detected within a survey, direction was noted based on the location of each bird at its initial detection. East=e, West=w, North=n, South=s, North-northeast=nne, Northeast=ne, East-southeast=ese, Southeast=se, South-southeast=sse, South-southwest=ssw, Southwest=sw, West-northwest=wnw, Northwest=nw, North-northwest=nnw. Direction not noted (cell filled with NA). * Distance: Distance between the observer and each bird at its initial point of detection was estimated and measured, when possible, to the nearest 5 m up to 50 m, the nearest 10 m up to 100 m, and the nearest 25 m at greater distances when possible. Detections within 20 m were noted to within 1 m if the bird was seen. A few records above 20 m were also measured more precisely if the bird was seen or if circumstances allowed more precise measurements, such as recognizing that a bird must be in a specific tree. Distance not noted (cell filled with NA) if no birds were detected (passerine sp entered for English Name). * cfsvd: Detection cues. The cues by which each bird was detected are noted, including calls (c ), song (s), drumming by woodpeckers (d), visuals (v), and fly-over (f). More than one cue can be noted for any given bird. * Time intervals information. Surveys were 2 back-to-back 5-min surveys totaling 10 min each. Within each 5-min count, each bird was given a detection-no detection (dnd) history based on whether or not it was detected in each of 5 one-minute intervals (column headers interval1_1, interval1_2...interval1_5). A 1 indicates the bird was detected (irrespective of detection cue type) within that interval. A 0 indicates it was not detected. Thus, dnd histories are strings of five 0s and/or 1s with one entry of a 1 or 0 per interval. An exception was for 1512 records where the dnd histories included just 2 total intervals for a 10-min count (column headers interval5_1 and interval5_2). In the latter case, if a bird was detected during the first 5 min of the 10 min count, it was noted as 1 in the min1 interval, and if it was not detected, it was noted as 0 in the min1 interval. Likewise, for the second 5-min of a 10-min count, if a bird was detected, it was noted as 1 in the min2 interval and 0 if it was not. Interval columns were left blank when not applicable; that is, when one-minute interval data were available, the interval5_1 and interval5_2 columns were left blank, and when data were only available for the interval5_1 and interval5_2 columns, cells for the one-minute intervals were left empty. * interval1_1: Noted as 1 if a bird was detected and 0 if it was not during the first one-minute interval of a 5-min count. * interval1_2: Noted as 1 if a bird was detected and 0 if it was not during the second one-minute interval of a 5-min count. * interval1_3: Noted as 1 if a bird was detected and 0 if it was not during the third one-minute interval of a 5-min count. * interval1_4: Noted as 1 if a bird was detected and 0 if it was not during the fourth one-minute interval of a 5-min count. * interval1_5: Noted as 1 if a bird was detected and 0 if it was not during the fifth one-minute interval of a 5-min count. * interval5_1: Noted as 1 if a bird was detected and 0 if it was not during the first five-minute interval of a 10-min count. * interval5_2: Noted as 1 if a bird was detected and 0 if it was not during the second five-minute interval of a 10-min count. * Time: Start time of each 5-min count period. Time is reported in numeric format (e.g., 635 means 06:35 am; 1415 means 2:15 pm). * Lat: Latitude in decimal degrees. Measured to 10 m accuracy with a hand-held GPS unit, typically a Garmin eTrex 10. * Long: Longitude in decimal degrees. Measured to 10 m accuracy with a hand-held GPS unit, typically a Garmin eTrex 10. * Plot: Anderson plot within which survey stations were located. Each survey location is noted with latitude and longitude coordinates. Each location is the plot where stationary (point) counts were surveyed. Plots begin with the abbreviation AP (Anderson Plot) followed by a number between 3 and 9, because we included Anderson's original plots that he numbered 1-10. We excluded plots 1, 2, and 10 because of radical changes in habitat composition since his original surveys (usually clear-cutting) or dominance by oaks instead of coniferous trees. * CountLoc: Survey point locations and whether they were within the quarter-sections originally designated by Anderson as his plots or not. In = latitude and longitude coordinates, place the survey location within his original plot. Out = latitude and longitude coordinates place the survey location outside his original plot but within 250 m of its boundary and containing habitat that, when viewed on satellite imagery taken within a year of our surveys, had similar habitat to that in the nearby plot. * Date: DD/MM/YYYY on which each bird was detected. * obs: Observer who conducted the bird surveys. Nolan M. Clements (nmc) and W. Douglas Robinson (wdr). * notes: An additional notation indicating that 1512 records used two 5-min time intervals instead of 5 1-min intervals in back-to-back 5-min counts is made. Cells for the rows with one-minute interval data are intentionally left empty, as no notes were added. * Crediting data use: A request is entered: If using any record(s) from this dataset, please consider citing as: Clements, N. M. and W. D. Robinson. 2025. Re-surveying breeding forest bird communities in western Oregon after 50 years: comparing 1968-1970 and 2020-2021. Biodiversity Data Journal doi:10.3897/BDJ.13.e162862 ## Code/software n/a ## Access information Other publicly accessible locations of the data: * none Data was derived from the following sources: * none