by Judy Hoy, Stevensville
On the front page of the Missoulian on Thursday, November 17, there was a photo of a large male bison. The angle of the photo shows a complete lack of a scrotum on the bison. It was obviously born with ectopic testicles, a very severe birth defect on a male mammal. Many of the male bison in Yellowstone National Park and in other bison herds in North America have been born with ectopic testicles, as are the males of many other wild animals. On animals in the wild, a large male bison is the easiest animal to observe the lack of a scrotum and the consequent ectopic testicles. However, the most recent data collected by biologists on accident-killed adult male white-tailed deer in 2018-2019 was over 30% prevalence for males with ectopic testicles.
Why is there not more concern about what is causing this severe birth defect on male mammals?