I think it comes down to the winter range where the two collide. Elk eat more than deer and more elk means less food in hard times for the deer. I feel in Utah where I live we focus to much on the elk and not enough on the mule deer. I am a builder and I feel bad how easy it is to get a subdivision approved in deer winter range and habitat. DWR needs to do something for the winter ranges and focus more on deer now.
My beef is how the majority of conservation efforts go towards increasing elk numbers. (Or so it seems.) It seems that w/ the extremely healthy elk heards we have, that sometimes they are grazing food that would go towards the Mule Deer. I don't have any solid facts or numbers, this is just the way it appears.
Michael~All Gods creatures welcome... right next to the mashed potatoes and gravy.
I share the same opinion that elk may negatively impact deer.
I agree that elk compete with deer for winter feed. I drier climates like AZ and NM they will also compete for water. The larger elk who are more herd type animals have first dibs at waterholes.
I think the impacts are relatively small. Deer are PRIMARILY "browsers", meaning they eat mostly twigs, leaves, buds, etc. Elk are PRIMARILY "grazers", meaning they eat mostly grasses. Of course, there is some cross-over. The biggest impact on the deer would come in the winter when both animals will eat just about anything.
I'm old enough to have seen with my own eyes the effect the elk have on deer populations. When I started hunting in the 60's there were no elk in my favorite unit. During the late 70's the elk were transplanted or just moved in. Only a few at first but as time past the elk grew more numerous and right before our eyes the deer numbers began to decline.
If you look at the Kiabab (12-A west AZ) today you will see few elk because the G&F have and are working to keep them out. In 12-A west elk tags are given out even though populations are very very small. The deer just can't compete with such a large and prolific animal like elk. Many AZ units are deer units and many are elk units. They all were deer units at one time. The elk, if left to do what they want will win every time.