Effects of Weather on Fall and Winter Waterfowl Habitat on Inland Agricultural Lands in the Gulf Coast Joint Venture

To help understand variation in wintering waterfowl habitat the Gulf Coast Joint Venture (GCJV) sought to determine if one or more weather parameters might explain the abundance of ephemeral shallow wetland habitats on inland agricultural lands. This effort was conducted for several Initiative Areas in the GCJV region which span from south Texas to central Louisiana including: the Laguna Madre, the Texas Mid-Coast, the Texas portion of the Chenier Plain, and the Louisiana portion of the Chenier Plain. Estimates of waterfowl habitat were obtained from cloud-free satellite imagery from 2007 to 2015 for three different time periods for each fall/winter (i.e., early [16 Aug–31 Oct], middle [1 Nov–15 Jan], late [16 Jan–31 Mar]). We obtained gridded climate data from the West Wide Drought Tracker (http://www.wrcc.dri.edu/wwdt/) to provide multi-variable weather data from three indices: the Palmer Drought Severity Index, the Standardized Precipitation Index, and the Standardized Precipitation Evapotranspiration Index. Additionally, we used gridded climate data from the PRISM Climate Group (http://www.prism.oregonstate.edu/) to compute average daily temperature and total precipitation. We used correlation analysis (Pearson's and Spearman's) to understand the relationship between weather variables and waterfowl habitat abundance. We analyzed effects of weather variables by period, but also pooled all of the assessments over all periods for each Initiative Area. For variables that were significant with both correlation tests, we used linear regression to determine the relationships between waterfowl habitat abundance and weather variables. Due to small sample sizes in many periods (≤8 samples) these results should be viewed as preliminary. Weather parameters explained 25 to 62 percent of the variation in flooded acres in the GCJV region. There appears to be a pattern where precipitation is correlated to flooded acres in southern Initiative Areas while temperature seems to be correlated to flooded acres in wetter northern areas. However, northern areas may have other confounding factors influencing wetland habitat abundance, such as crawfish farming and rice production.