November 28, 2023

First Phase of Predator Prey Study Reveals Interesting Data But Nothing Conclusive

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From an article posted recently on, deer hunters and others are rushing to conclude that coyotes are killing all the deer in the Upper Peninsula of Michigan. At the same time, wolf lovers are declaring a victory in that grey wolves didn’t top the list of predators killing the deer.

What was written about in the article was information on data collected from the first phase of a three-phase study intended to determine what is killing too many deer in the UP of Michigan. The first phase took 3 years to complete.

If you read the article and examine the information provided with an open and understanding mind, you see what on the surface appears to be interesting so-called conclusions from the data. However, it is my opinion that no such definitive conclusions can nor should be made at this time.

The first basic thing to understand is that the study involved deer fawns. Only deer fawns were collared and the study was used to determine what was killing the deer fawns. It is my understanding also, from reading this report, that any of this data used to estimate total deer mortality was based on modeling and not hard data. Where the data is being collected on fawns, are researchers then inclined to believe that wolves, coyotes and bobcats do not kill adult deer?

Phase one took place deliberately in what researchers called a “low snow zone”. Phases two and three will take place in “medium snow zones” (depths of snow) and “high snow zones”, respectively. Phase one also was done where there were low densities of wolves and high densities of coyotes.

The data from Phase I showed that coyotes accounted for more fawn deaths than any other predator. This was followed by bobcats second and wolves fourth. No official numbers for comparison were published in this article.

While it appears that Phase I presents some interesting tidbits of information, for anyone to conclude that wolves don’t kill all the deer or that coyotes do kill all the deer, is simply premature.