Wildlife studies don't "prove" anything. They may show a high correlation between variables within the study area. However if you read on page 6 of the published study "although our results show that coyotes benefit ducks by reducing nest depredation by foxes, coyotes can also prey extensively on duck nests, especially where coyotes are considered abundant (Glup and McDanial 1988). Our study was conducted in a region where coyote populations were relatively low."
I also remember from my wildlife management classes at OSU.. something to the effect that coyote populations can be sustained at up to 80% kill rate each year.
"Mike Bodenchuk, Texas state director for the USDA’s Wildlife Services, said coyotes have a 60 percent annual mortality rate in some cases, whether they are hunted or not. In order to have an impact, it’s vital to remove either 70 to 80 percent of the entire population, or to remove the right coyotes at the right time."http://www.grandviewoutdoors.com/deer-h ... population
My point... Killing coyotes in Ohio, will have a negligible effect on increasing/decreasing the duck populations. To decrease the population of coyotes, over 60% will have to be killed every year. Kill away boys.
Also, be careful saying "wildlife studies prove," and then cite one wildlife study. One study does not equate to "wildlife studies." Good wildlife study though. I enjoyed reading it.