Table 3: Best-fit cline model and geographic location of the cline center of the winter moth x Bruce spanworm hybrid zone for the Massachusetts transect for each year from 2007-2018, and Connecticut transect for 2016-2018, estimated using the R package ‘hzar’. The confidence interval two log likelihood units above and below the center and width values are in parentheses. Cline centers and widths for 2009, 2011, and 2012 could not be estimated due to failures in model conversion.