Examining inter-regional and intra-seasonal differences in wintering waterfowl landscape associations among Pacific and Atlantic flyways

The Central Valley of California (CVC) and Mid-Atlantic (MA) in the U.S. are both critical sites for nationwide food security (California Poultry Federation 2016, Prosser et al. 2017), and many waterfowl species annually, especially during the winter, providing feeding and roosting locations for a variety of species. Mapping waterfowl distributions, using NEXRAD, may aid in the adaptive management of important waterfowl habitat and allow various government agencies to better understand the interface between wild and domestic birds and commercial agricultural practices. We used 9 years (2014–2023) of data from the US NEXRAD network to model winter waterfowl relative abundance in the CVC and MA as a function of weather, temporal period, environmental conditions, and landcover characteristics using Boosted Regression Tree modelling. We were able to quantify the variability in effect size of 28 different covariates across space and time within two geographic regions which are critical to na..., We analyzed NEXRAD data from November 1 to March 15 (2014–2023) to estimate waterfowl densities in the Central Valley of California and the Mid-Atlantic. Radar reflectivity, measured in units of Z (mm⁶ m⁻³), was used to quantify waterfowl biomass by assessing the density and size of targets.
To capture waterfowl departing feeding grounds, we analyzed radar scans during evening civil twilight when detection was highest. Data were collected from the lowest elevation sweeps (0.5°) with volume dimensions of 250 m x 0.5°. Scans were manually screened to exclude precipitation and other non-bird sources, using NOAA’s Weather and Climate Toolkit and Amazon Web Services for radar data.
Reflectivity in dBZ was converted to total bird reflectivity (η) [cm² km⁻³] and grouped into 10 m altitude bins to create a vertical profile of reflectivity (VPR). The VPR, derived from the five lowest sweeps (0.5°–5.5° tilt) within 5–20 km of the radar, was adjusted for range bias to calculate vertically integrat..., , # Examining inter-regional and intra-seasonal differences in wintering waterfowl landscape associations among Pacific and Atlantic flyways

## List of Associated Documents and Descriptions of Files

### (1) Screening Spreadsheets

.csv files of days of the winter November 1st to March 15th 2014-2022 for each of the 6 radars (KDAX, KBBX, KHNX, KDOX, KMHX, and KLTX).

File and variables included:

* RADAR = 4 Digit Radar Site Code
* DATE = Day of the Year in Month/Day/Year format
* SEASON = 'Winter' to distinguish from other season in projects dealing with songbirds.
* DOWNLOAD = Purposely left blank, it's filled in with a Yes or No by the data handler depending on the STATUS column
* STATUS = Classed as biological (B), contaminated (C), or No Data/missing (ND) when visually screened using NOAA's Weather Climate Toolkit. Biological days were used for modelling
* CONTAMINATION_TYPE = If STATUS = B, then 'blank', if STATUS = C OR ND, CONTAMINATION_TYPE is listed. P = Precipitation, CL = Clu...