Although I have no cite on the deer population, it’s been growing over the past 50 years in areas that I’m familiar with. Also having grown during the same time frame: the automobile density.
More deer + more cars = more deer hit by cars.
On a slightly but similar note, the coyotes in my neighborhood learn to cross roads. They will stop on the verge and look both ways; if it is clear they will cross. However, younger coyotes haven’t got the potential speed of approaching cars, and I have to brake. Never had to for an older one. BTW it is rare to see dead coyotes here.
On the other hand, our deer haven’t a clue as to safe behavior. Javalina seem to be able to figure it all out but have lousy vision, so they are more of a hazard than coyotes. And lizards are totally clueless…the common response of Gila monsters is to stop, arch the tail and head up and hiss, which is not scary to a car.
shrug Intelligence is their dump stat. Evolution is working on boosting other things.
As to squirrels, I’ve seen several who were about to clear the car’s path of travel, who doubled back suddenly and got hit. Every once in awhile, I’ll think about it and speculate that they have an instinct or habit of jinking when a shadow touches them. Might work great for owls and hawks, but doesn’t do them any favors on the road.
(I’m not in a high-squirrel area. Anyone with more observation time is free to correct me or otherwise chip in.)
Some time ago, I was riding my bike down the street. A squirrel ran out into the road crossing my path. Sensing a threat, said squirrel decided to turn and run in the same direction I was traveling. In line with my bike’s front wheel.
Squirrels are as smart as they need to be. Food animals don’t need to be very smart.
Coyotes are very smart animals
Smarter deer can only have an evolutionary advantage if they exist in the first place. If the deer population doesn’t happen to have any alleles that correspond to better road-crossing behavior, then dumb deer will just keep dying and getting replaced by other dumb deer.
It’s a bit like asking why they haven’t evolved to be bulletproof (or at least more bullet-resistant), considering all of the deer that get shot by hunters. If there aren’t (or can’t be) alleles for bullet-resistance in a population, then shooting most of them each generation won’t make their descendants bullet-resistant (unless a bullet-resistance mutation happens to crop up, but that probably won’t happen before the population is wiped out).
An excellent point.
Thank you, Charles Darwin!
Not the one I’m familiar with. He’s a genius. In fact, a super-genius.
Do you watch cheap thriller movies often? When the good (stupid) guy is being chased by Godzilla/giant snake/giant gila monster/giant robot/giant-whatever, which direction does he run? Does he weave around buildings to lose something that big? Does he duck into a door or window or ditch? NO! He runs flat out into the open, making sure he’s in plain site and the way is big and flat enough for whatever is chasing him to appear big and looming from behind.
That’s how deer run away from cars too.
very wile.
The western corn rootworm liked to lay its eggs in corn fields in the fall. When they hatched in the spring, the larvae needed to eat corn roots in order to survive.
This annoyed farmers greatly. So they had an idea. Plant corn and soybeans in the fields in alternating years. That way, when the larvae emerge in a soybean field, they starve.
This worked for a while. But now we have strains of western corn rootworm that lay their eggs exclusively in soybean fields. When the larvae emerge in the spring, they have plenty of yummy corn roots to eat because the farmers have rotated their crops. (By the way, the northern corn rootworm dealt with the same problem by laying eggs that remained dormant in the soil for two years.)
I don’t know if avoiding corn fields is a behavior comparable to avoiding cars, but I think this is a cool story anyway.
That’s because, as noted up-thread, cars have only been around for a little over 100 years – not nearly long enough for them to have evolved Gila monster aversive responses.
As for deer, the role of learning has only been slightly touched upon. One of the clever tricks that higher-intelligent animals (meaning, pretty much most mammals, compared to, say, fish) have evolved is the ability to learn by observation. When a group of deer cross a road and one of them gets squished by a car that hasn’t learned deer-aversive behavior yet, that one deer may never have a chance to evolve further (nor the car either) – BUT, the other deer will see that, and they will tend to learn car-aversive behavior simply from having seen that.
This has been suggested as the evolutionary pressure that led mammals to have curiosity (to differing degrees in various species). When an animal meets an unfortunate end, his buddies will often stand by and watch in morbid shocked horror. This enables them to learn about hazards vicariously even without experiencing it themselves.
ETA: In other words, curiosity may actually save more cats than it kills.
Behavioral traits can be inherited genetically (instinct) or extragenetically (culture, i.e. learned behavior). Evolution can reinforce or squelch behavior that is transmitted by either mechanism, e.g. maybe you’ve got shitty instincts for predator avoidance, but your momma explained/demonstrated it all to you very carefully, and so now you avoid predators through conscious cognition. Culture allows organisms to adapt to new environmental pressures much more quickly than instincts. Culture has been observed in, for example, Japanese macaques.
The deer in FoieGrasIsEvil’s neighborhood are unlikely to have evolved instinctive car-avoidance behavior so rapidly; it’s much more likely that this is learned behavior.
It seems that the bucks know when hunting season starts. They parade around all year, until the deer season, then vanish. This is in WA state. In normal seasons, you can only kill bucks.
Stop yelling at deer for not getting cars. Start yelling at birds for not finally figuring out how to aviod cats. They have spent hundreds of years getting killed by cats because they don’t know to see them as a threat.
I used to have cypress trees and the quail (ground nesting birds) would build nests in the top of the tree. I’d find broken eggs or baby quail on the ground all the time.
If a bird the was made to nest on the ground can’t figure out that its a bad idea to build nests in trees, deer will will never figure it out.
I believe the squirrel’s natural reaction to an approaching car is to stop and scream (caution: link is to a video with sound of screaming woodland creatures).
One might almost say Wile E.
Perhaps some sort of mutant cerebro-deer breeding program is in order…
2a. Or they may not migrate to where the best eats are.
Predators don’t like the noisy vehicles, sounds like scary bigger predator, and makes it harder to track dinner in the natural way…deer evade predators and migrate where they aren’t…which is where the vehicles are, but since they cant smell vehicles like they do predators…we get splats.
Skunks “think” that stopping in front of, and then spraying, an oncoming vehicle will dissuade it. Umm, no. :dubious: Trucks and trains have a nose only in the metaphorical sense. 
I’ve been on commuter trains that have hit skunks, and once I actually heard the engineer tell one of the conductors by radio that the skunk had stopped in front of the oncoming train and sprayed. Last act of defiance and all that. :smack: