I find this to be a better explanation for the abnormally large population of cryptorchid black-tailed deer on the south end of Kodiak.
Based on lesions and the before mentioned abnormalities observed in the testes of affected deer, the most likely cause of the observed antler and testicular dysgenesis was determined to be an estrogenic environmental agent. This could include a number of chemicals including many endocrine disruptors. It was hypothosized that this might involve the consumption of contaminated seaweed because these deer frequent low lying areas and are known to eat seaweed, but this was not investigated further.
From a 2010 Environmental Assessment of The Kodiak National Wildlife Refuge Integrated Pest Management plan(2) we find that there are known endocrine disrupting agents used on Kodiak island. It is documented that deer have been observed and are known to consume these agents and use areas treated with them.
From this management plan: “Elk, goat, marten, red squirrel, muskrat, and beaver do not occur in any areas known to support invasive plants. On the other hand, field observations indicated that deer and hare have used areas that support invasive plants for foraging and, in some cases cover, including sites subjected to active management.” The “active management” referred to is the use of several herbicides, many of these are know endocrine disruptors.
Like with the prevalence of abnormal deer, the presence of weeds and use of herbicides has been mostly restricted to low land areas on the island. “Since the current distribution of non-native plants is restricted to lower altitudes (less than 1,000 ft. elevation), our summary of vegetation is restricted to that zone.”(2)
Two herbicides have been, and were being proposed to be used further on Kodiak Island, these are Aminopyralid and Glyphosate(2) Glyphosate has been shown to target sertoli cells in rats, and affect leydig cells.(3) In Kodiak black-tailed deer we see “hyperplastic Sertoli cells, often arranged in rosettes and sometimes with neoplastic changes, in several abdominal testes“.(1) It has also been shown that Glyphosate and its co-factors have a known and measurable endocrine disrupting ability beyond the targeting of sertoli cells(4)