We went to Yellowstone National Park in spring and fall 2017. In the 17 photos of adult male bison I took in the park, mostly from our moving vehicle as we passed them, only one (6%) had a normal length bilateral scrotum. All male bison used to have a long, very visible scrotum with the testes side by side (bilateral). Male bison with ectopic testes and no visible scrotum were in 35% of the photos, 7 times what is supposed to raise a red flag for a birth defect. No scrotum is a very serious birth defect on a male mammal! The scrotums on the rest of the photographed bison (59%) were formed with the left half of the scrotum directly forward of the right and many were abnormally short.
Oddly, the park biologists don’t seem to notice that many of the large adult male bison walking by them every day have no visible scrotum or have a scrotum that is totally weird looking. According to CDC records, genitourinary disorders on newborn male humans have increased significantly since 2001. I would think that health officials would be concerned enough to insist we find what is causing the epidemic of extremely serious reproductive birth defects on bison and other mammals. Wouldn’t you?
Judy Hoy
Stevensville