Measurement of Wild Pig Morphometrics

Pigs were captured using various traps baited with corn. Once wild pigs were captured, they were then euthanized (IACUC Protocol No. 14–100 for Mississippi samples). Measurements collected by USDA personnel were done conducted by following several USDA IACUC‐approved studies (Sanders et al., 2020 ; Snow et al., 2019 (link); Snow et al., 2022 ; Snow, Halseth, et al., 2021 (link); Snow & VerCauteren, 2019 ; Snow, Wishart, et al., 2021 (link)). Body mass and other morphometric data were gathered postmortem. Body mass was measured to the nearest kg. In Mississippi, we recorded morphometric measures for: body length, chest girth, ear length, eye to snout length, hindfoot length, shoulder length, and tail length (see Table 1 for measurement collection details). Body mass, body length, and chest girth were recorded in every area outside Mississippi, while eye to snout length was recorded only in Alabama, Hawaii, and South Texas. Body mass, body length, and eye to snout length were recorded as in Mississippi. Chest girth was recorded by measuring the widest length from the center of sternum behind the scapula to the spine and multiplying this value by 2. Although we expect our measured individuals to have mild body asymmetries, bilateral symmetry is a fundamental characteristic of vertebrate body plans, so we did not expect this chest girth measurement to affect our inference. Hindfoot length and tail length were not measured outside Mississippi. Because shoulder length was measured as the shorter distance between the spine to the bottom of the hoof outside Mississippi (i.e., vs. from the tip of the scapula to the hoof), we decided not to use this measure for individuals outside Mississippi.