This readme.txt file was generated on <20260220> by Recommended citation for the data: Etterson, M., A. Grinde, M Kuitunen, P. Kuitunen, T. Hollenhorst, and G. Niemi. 2026. Least Flycatcher Nest Success Increases at Sites with Extensive Northern Hardwood Cover at the Landscape Scale. Journal of Field Ornithology. DOI pending ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset : Least Flycatcher Nest Survival Data in Forests in Northeastern Minnesota in 1996 2. Author Information Principal Investigator Contact Information Name: Matthew Etterson Institution: US Environmental Protection Agency Address: Great Lakes Toxicology and Ecology Division, 6201 Congdon Boulevard, Duluth, MN 55804 Email: etterson.matthew@epa.gov ORCID: 0000-0002-9279-6258 Associate or Co-investigator Contact Information Name: Alexis Grinde Institution: Natural Resources Research Institute Address: 5013 Miller Trunk Hwy, Duluth, MN 55811 Email: agrinde@d.umn.edu ORCID: Associate or Co-investigator Contact Information Name: Gerald Niemi Institution: Department of Biology, University of Minnesota Duluth Address: 1035 Kirby Drive 207 Swenson Science Email: gniemi@d.umn.edu ORCID: 3. Date published or finalized for release: 20 February 2026 4. Date of data collection (single date, range, approximate date) 19960601 - 19960801 5. Geographic location of data collection (where was data collected?): Northern Minnesota 6. Information about funding sources that supported the collection of the data: Funding for the project was appropriated by the Minnesota State Legislature from the Environmental Trust Fund as recommended by the Legislative Commission on Minnesota Resources. 7. Overview of the data (abstract): These data represent nest monitoring data for Least Flycatcher (Empidonax minimus) collected during the summer of 1996 in seven forest plots in Northern Minnesota, USA. The data consist of days on which nests were visited (V1 - V14) together with covariates measured at each nest and/or site. The outcome (Fate) of each nest is also provided. The data are formatted for analysis using the program MCestimate, which can be downloaded freely from https://www.epa.gov/chemical-research/markov-chain-nest-productivity-model-estimating-tool. -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: No license or restriction is placed on the data 2. Links to publications that cite or use the data: Pending. 3. Was data derived from another source? No. If yes, list source(s): 4. Terms of Use: Data Repository for the U of Minnesota (DRUM) By using these files, users agree to the Terms of Use. https://conservancy.umn.edu/pages/policies/#drum-terms-of-use --------------------- DATA & FILE OVERVIEW --------------------- 1. File List A. Filename: MN_LEFL_data_1996.csv Short description: These are the data described in the Overview above. 2. Relationship between files: N/A -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: In 1996, from mid-May to the end of July, teams of two to four individuals systematically searched each site at two-to-three-day intervals. The location of each nest was marked with flagging placed at least 10 m from the nest. Nests were monitored every three to four days until just before fledging, when they were checked daily. The following data were gathered at each nest:(1) species of tree or shrub used for nesting; (2) measured height of nest; (3) estimated height of nest tree; and (4) measured diameter at breast height (dbh) of nest tree or shrub. Canopy cover types surrounding each nest within a 100-m radius circle (31,400 m², 3.14 ha) were identified and classified into one of three cover types, i.e., northern hardwood, aspen-birch, or other, using GIS. 2. Methods for processing the data: data provided are in their original unprocessed form. 3. Instrument- or software-specific information needed to interpret the data: Analyses of the data for the associated publication used the software MCestimate, which can be downloaded freely from https://www.epa.gov/chemical-research/markov-chain-nest-productivity-model-estimating-tool. 4. Standards and calibration information, if appropriate: N/A 5. Environmental/experimental conditions: data were collected under ambient weather conditions at the time of monitoring. No experimental manipulations or conditions were applied. 6. Describe any quality-assurance procedures performed on the data: Data were initially handwritten on nest cards. Data entry was done subsequently by the research team associated with the publication. Outliers and data entry errors were diagnosed using QA/QC checks within the MCestimate software. 7. People involved with sample collection, processing, analysis and/or submission: Chris Brown, Darren Cohen, Mary Hammer, JoAnn Hanowski, Rita Hawrot, Jason Lang, Kent Montgomery, and Michael North assisted with finding and monitoring nests. M. Kuitunen, G. Niemi, M. Etterson, A. Grinde, and T. Hollenhorst were responsible for data analysis. ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: N_LEFL_data_1996.csv ----------------------------------------- 1. Number of variables: 24 2. Number of cases/rows: 172 (including headers) 3. Missing data codes: Empty cells represent missing data for all variables except those with header "Vn", where n is an integer between 1 and 14. Empty cells in the latter columns represent unneeded monitoring days because the nests were no longer active. 4. Variable List A. Name: Nest Description: identification variable ranging from 1:153 used to uniquely identify each nest B. Name: Site Description: Categorical variable giving the name of the site at which the nest occurred. Acceptable values of Site are: Tofte1, Tofte2, OakPt, LkErin, Tobique, PineCty, or BldrLk C. Name: NestTree: Categorical variable giving the species of tree in which the nest occurred. Acceptable values of NestTree are: sugar_maple, paper_birch, or other D. Name: NestHt: Continuous variable giving the height of the nest above ground in meters. Range 1.35m - 20.3m E. Name: PlantHt: Continuous variable giving the height of the nest tree in meters. Range 3m - 31m F. Name: DBH: Continuous variable giving the diameter at breast height of the nest tree in cm. Range 2.75cm - 125cm G. Name: PctTotFor10K: Continuous variable giving the percent of total forest within a 10 km buffer on the landscape surrounding the site at which the nest was located. This variable was calculated excluding open water from the denominator. Range 45.9% - 85.4% H. Name: AspenBirch: Continuous variable giving the area in square meters of AspenBirch forest, within a 100 m radius of each nest. Range: 0m^2 - 26,790m^2 I. Name: NorthernHardwoods: Continuous variable giving the area in square meters of Northern Hardwoods forest, within a 100 m radius of each nest. Range: 0m^2 - 31,721m^2 J. Name: Fate: Categorical variable giving the outcome of each nest. Acceptable values are success or depredated. Fate is known to have occurred between the penultimate and final visit, the dates of which are given in the variables V1-V14 below. K - W: Names: V1 - V14. Date variables giving the dates on which nests were visited. V1 always gives the date of the earliest visit on which the nest was known to have either eggs or nestlings. Following V1, all subsequent visits to the nest are recorded sequentially, up to V14, as needed, to document the survival of the nest until it was known to have either fledged (Fate = success) or failed (Fate = depredated).