Scientists working in Yellowstone National Park have shown how pregnant and new mother moose use humans to help ward off potential predators.
Why did the moose cross the road?
The scientists tracked a number of moose starting in the year 1995 to study their movements over time. They found, to their surprise, that mother moose in around Yellowstone and Grand Teton National Parks move an average of 400 feet closer to roads around the time they give birth.
In this article on BBC.com, Dr. Joel Berger calls the behavior, "using human infrastructure as a shield." He adds, "The study's results indicate that moose and other prey species find humans more benign and hence move to humans for safety, whereas predators do not because we humans tend to be less kind to predators."
The article also claims that monkeys, elephants and deer have also been witnessed using humans as shields.
Safety might not be the only thing the moose mothers are seeking...
Brown bears are known for rarely going anywhere near roads. The study has obvious ramifications on our image of National Parks as displaying "untouched" wilderness. Turns out the parks' animal behaviors may be more affected by us than we thought.
There is a herd of mule deer from the foothills above Jet Propulsion Laboratory which have taken up residence on the Lab where the presence of humans keeps cougars and coyotes at bay. There is abundant lush grass in the lawns, water available from sprinklers, and, in season, yummy jacaranda blossoms.
About four years ago a cougar ambushed a deer from among a number of deer resting on the south porch of Building 144 (it's on the JPL map) which is a good place for cud-chewing because the deer have their backs to a building and a clear view of the rest of their perimeter, with plenty of open ground and no cover for attackers. Yet somehow the cougar managed to catch a deer. The animal used the concrete walks and stairs to drag the carcass away.
Some individual deer have learned how to operate the turnstile man-gates so they can get through high fences and not have to go the long way around.
Several deer have been seen crossing at crosswalks, copying the humans they see.
I'm just guessing here, but suppose moose were approaching roads during the hunting close season?
I'm British, and I'm not familiar with when hunting is and isn't allowed, but I'm assuming close season coincides with pregnancy and infancy. If hunting season has existed for decades, you'd expect it to be having a selection effect on the behaviour of hunted animals. When humans were hunting, proximity to them would be dangerous, but when they weren't, it would offer a safety blanket.
In the US, I believe you can only hunt male moose. Females who could figure out it was safer to give birth near roads might also notice those hunters were not often a threat to them. It makes sense also when you consider there are other gender specific behaviors in these animals which they themselves are aware of.
Hunting season is also in the fall. Birthing season I would expect to be in the spring for these animals.
It's also important to note that these studies were conducted in National Parks where very little, if any, hunting is allowed...another significant variable thrust upon the whole situation.