Dogs’ Eyes Have Changed Since Humans Befriended Them
theatlantic.com
theatlantic.com
1. They can only see blue/yellow. Not like humans' RGB.
2. They are short sighted. For far away objects, their sight is like a T-Rex, they can see moving objects, not stationary objects. Remain still, and they can't see you. Then again, they can smell you, especially if it's downwind.
3. Their flicker fusion threshold is higher than humans. If you show them a cute mobile picture of a baby, they'll see a lot of flickering. As well, did you know lights have a flicker? If you think it's bad, it's even worse for dogs which can lead to stress.
More:
https://www.dogwalkersmelbourne.com.au/articles-dog-walking-...
And yet, he contantly amazes me by the range and precision of his vision. Downwards pointing with my left arm means come here at once, which he will reliably register at a distance more than a hundred meters. Other dogs he will recognize at distances further than that, and he will unerringly home in on thrown stick bobbing on the water, as long as it's on the right, where his good eye can see.
Clearly, there's more to it than just they are short sighted.
any suggestions on what energy efficient bulbs to replace them with?!
In our bedroom, I put in some LEDs, not realizing there could possibly be a difference between cheap and expensive ones. One night I filmed my cat doing something dumb in slow motion, and when I looked at the playback the whole room was strobing.
It was pretty wild. I might even still have the video, and could see about posting it somewhere.
As someone who notices and gets really tired from the stroboscopic effects of cheap LEDs, I can only imagine how terrible that must be for dogs
Technically speaking, a similar kind of solution that exists for LEDs also exist for fluorescent tubes: using high frequency ballasts that do not perceptibly flicker (not even (near)subconsciously - which is true for a lot of LED and fluorescent lights). Those are more expensive, hard to find and not the default though.
If you're going to go non-electrical, I think an oil lamp (e.g. paraffin) is your best bet. Very cheap, safer than candles in the right lantern, and clean-burning (assuming a quality oil that doesn't have a lot of sulfur and other pollutants).
Let's consider live music, first. A lot of instruments have significant harmonics well above 20 KHz. So let's say you are practicing your violin or trumpet, and your dog is in the room. The maker of your instrument took great care to get the sound right, which mainly consists of making sure that the various harmonics are at the right relative amplitudes.
Does the instrument maker take any care to get the harmonics above 20 KHz right? They don't affect how the instrument sounds to humans, so I'd expect not. That could mean that your beautiful violin has a horrible screech that only your dog hears.
How about recorded music? If my guess is right and our instruments sound bad above 20 KHz, recorded music may be an improvement from the dog's point of view, because we filter out those highs when recording.
But if live instruments do actually sound OK above 20 KHz, then to a dog our record are going to seem limited at best.
This is a thing I've wondered about too. Their frequency range is only part of it. There's also the frequency weighted sensitivity; it's why we humans perceive music the way we do. A dog might be able to hear a tone at 45kHz, but it might require significant amplitude, e.g. threshold of perception at 45kHz might be 80 dB SPL. The ISO 226:2003 equal loudness contours shows that human sensitivity for high frequencies falls off very sharply after about 16kHz[1]. Looking stuff up for dogs, I'm finding mixed results, so I'm less confident in my assertion here, but it seems to me that dog hearing still falls off sharply near the upper end of it's range. From the charts I find, a dog's sensitive band seems to be wider than humans and centered higher[2], but there's still that sharp upper cutoff.
> Let's consider live music, first. A lot of instruments have significant harmonics well above 20 kHz.
This is heavily dependent on the nature of the instrument. A bass instrument like a tuba or a bass guitar isn't going to have much frequency content once it gets into the mid-to-high hundreds of Hz. A guitar is going to be done between 10-15kHz, and most of it's frequency content that defines its character is going to be down in the mid-range (mid-hundreds to low thousands of Hz). Cymbals? Yeah, I'd be in no way surprised if those contain tons of content above 20kHz that's only detectable with lab equipment or a dog's ears.
> Does the instrument maker take any care to get the harmonics above 20 KHz right? They don't affect how the instrument sounds to humans, so I'd expect not. That could mean that your beautiful violin has a horrible screech that only your dog hears.
Instruments with significant frequency content in our most sensitive bands (e.g. human voice, eletric guitar, trumpet) are often considered 'lead' instruments, and they're are also the ones where getting the frequency balance right to sound good instead of harsh is the trickiest. So, my intuition is that a similar thing plays out with dogs. Those instruments that do contain significant frequency content in the high kHz to low 10s of kHz (e.g. cymbals) are more likely to sound harsh, IMO. Something like a tuba, a dog probably cares less.
> How about recorded music? If my guess is right and our instruments sound bad above 20 KHz, recorded music may be an improvement from the dog's point of view, because we filter out those highs when recording.
> But if live instruments do actually sound OK above 20 KHz, then to a dog our record are going to seem limited at best.
My guess here is that our recordings probably sound unnaturally muffled. In my own study of recording and mixing, it seems common to filter sharply above 20Khz, or maybe a little less, because their's no sense in frying the tweeters with content nobody can hear anyway. Additionally, the DACs in modern recording gear are going to have their filters set to filter sharply above 20kHz anyway, to keep digital aliasing noise from impairing an accurate reproduction of the original analog signal from the digital one. It might not sound bad to the dog, but I'm pretty sure a dog would be able to easily tell the difference between a recording of a cymbal, and a live cymbal.
I was kind of surprised at how little information I could find a while back when I searched online for information about animal hearing and animal vision. I was playing around with making a camera to automatically take a photo whenever an animal stopped by to eat the seeds and nuts I put out for them.
I've got a sensor that measures the distance to an object by bouncing an infrared laser off it. It's a class 1 laser, which basically means that it is not possible to exceed safe exposure by looking at it, even with a microscope or telescope. But that's for humans. What if a curious bird decided to get right up to it and take a look?
I couldn't find anything on laser safety for birds or squirrels or other animals likely to visit.
I've also got a distance sensor that uses a 40 KHz ultrasonic pulse. I couldn't find anything on the safety of that, either, for animals.
I did some tests with the IR laser and found that it didn't work very well for this application. It worked great at detecting when my hand was in front of it, but was very flaky with birds and squirrels. I guess features and fur just doesn't reflect IR light well enough.
Ultrasonic worked better, and so that's still in the running if I ever get time to finish this thing. I still don't know about safety of that for the animals, but figure that if the animal can hear it they will stay away if it is loud enough to harm them.
Alternatively, I may just go with having the camera take a photo every second, and try to figure out in software which ones have an animal in them. No risk of harming the animal that way, and also the camera could then be in my house looking out a window instead of outside, which would make power a lot easier and get rid of the need for weatherproofing it.
(A big reason that there's a growing movement questioning if we should have more dedicated DC wires/plugs/sockets in our homes and do AC to DC conversion once for entire circuits instead at the socket/in the plug "wall wart" for every single device. Also interesting that USB A sockets are probably the closest we have to a ubiquitous home standard actually moving in that direction.)
You can run the lights off of 12V batteries and charge those from a few solar panels, or just have one dedicated high-quality AC-DC transformer for the DC circuits.
Am I wrong in assuming incandescent bulbs would be better
Article has a couple of interesting points if people are wondering how we can actually know anything about T-Rex vision.
I wonder if is possible design glasses with the same goal.
Only if the dog is downwind. Contrary to repeated myths about bears, no animal can air-scent objects downwind of themselves.
Some weekend I hope to make enough time to add something to represent the short sightedness using image depth data as well as a few other features I would like to add.
I actually had not heard about the flicker fusion threshold being different, thanks for the links!
* https://itunes.apple.com/us/app/dog-optics/id1447069492?ls=1...
If I throw him a treat and he misses it, he will default to looking around with his eyes and missing it until I point it out. But give him the ready cue, and he can find a tiny piece of food or odour hidden in a drawer in a room in under a minute.
So my take on that is it takes a lot of processing power to run the nose, and after a search session it's definitely nap time.
And side note, I'd like to see AI efforts aiming at the level of a dog before we go for humans. It's amazing what they can do but it takes so long to train them and you have to start from scratch each time.
Is it not fairer to suggest that this is not evolution/natural selection at work here, but rather just selective breeding? I can't think of another species of animal that has been so widely twisted and manipulated in appearance by human's selective breeding than dogs.
Seems odd to suggest that this part of a dogs' body was due to evolution, but that rest of the crazy variety in dogs' body is not? A trait like this that humans like seems like is an obvious thing to get selected surely?
Or is there some strong evidence to suggest that this was really was nothing to do with selective breeding?
I would guess that for most of our co-existence breeding was up to the dog to figure out, which might explain the oldest breeds being of a particular region. Task breeds came very much later.
Edit: Also, how do you selectively breed for muscles that didn't previously exist?
I think that breeding before 17th century was focused on the dogs job such as hunting wolves (Wolfhounds), sheep herding (Border Collies), watch dogs.
When you don't breed for apperance and only have a low number of different kinds of jobs for dogs, then you only need very few breeds.
The Irish Wolfhounds were out of jobs in 1786 (no more wolves in Ireland) and the breed practically died out.
In the end, we are using words to describe genetic processes. The genetics of dogs have changed remarkably both over the last 200k years and over the last 500 years. In my view, it's a combination of natural selection, unconscious selection, and conscious selection of breeding individuals.
Both are social animals. Dogs have the speed and the teeth. Humans have the brain power, stone throwing and cooking. Dogs can mind the human young to a large extent and humans can feed the baby dogs cooked food. It's win win and a fearsome combination.
One of the most common feature across domesticated species was tighter jaws.
Ive a one year old pup, border collie/labrador mix. I can take a quick glance at his face and know exactly how he's feeling. Probably 80% of the time, its pure joy. Happy to run around, chew on toys, jump on the furniture and try and play (unrequitedly) with our cats. About another 10%, he's scared of other animals he can see out of the Windows of our townhouse and barks incessantly. The other 10%, I have no idea.
Eyes on a dog don't tell the whole story. Need to look at eyes, ears, back position, tail and legs to tell.
As I write this, my dog is laying against me, calm amd near sleep. Depending on perspective, I could see his face as seeming sad, but I know he's just sleepy. He's only awake because I am and I've not put him to bed yet. But his face says to me he's calm and content. His breathing is also slowing. His favorite chew toy is inches from his mouth and against my arm and he's content to let it stay there; that's how I know he's tired. If you were to just look at a photo of my dogs face right now, he might appear sad, but I know hes just calm and sleepy.
I spent about the first week sleeping on the floor next to him to make sure he was comfortable and to take him out if he started whining.
We were also told to expect him to top out around 35 lbs. We had him neutered on Black Friday last year. Figured he was born about May 1st last year. When he got fixed he was already 45 lean pounds. A year after bringing home, he seems to have peaked at 60 pounds, nearly twice what we told to expect. He definitely has tons of energy and is very athletic (he can easily jump entirely over our couch). He could easily clear the baby gates we have to keep him in the living room/kitchen in our townhouse. He did it once without thinking, chasing one our cats upstairs.
First 3 months or so, there were a lot of accidents with urinating and defecating in the house. And he had worms when we first brought him home. I had to carry him up and down the stairs for that period, as well. At firat because he just couldn't get up and down the stairs on his own, and then later to prevent him having an accident before getting outside (never had an accident while I was carrying him).
A year in, he's fairly well trained, but we still have some problem areas like barking and jumping on people. He's crate trained. He sleeps in his crate overnight and when we're away from home for a bit. My wife works from home and sleeps in a bit and he's gotten used to me taking him out early in the morning to do his business and goes right back into his crate on his own after having a bit of food and water until my wife wakes up an hour or so later.
Glad to hear things are working out for you :)
Want to go out after work? Gotta go home and tend to the dogs first
Weekend getaway? The cost just increased by however much it's going to cost you to board the dogs or hire a sitter.
Surprise! One of your dogs has developed a thyroid condition and will require daily medication for the rest of its life.
Time for that annual teeth cleaning ($$$$$)
That said, next to fatherhood, it's one of the more rewarding things in my life.
Seriously, dogs are a shitload of work and especially, no matter how fucked the weather outside is, you gotta take the dog to walks so that the dog can take a dump. In addition, many of the larger breeds are working dogs which means that they require massive amounts of attention and daily exercise so they don't literally go mad. Please do proper research upon the characteristics of your desired breed, and don't take in a rescue dog as your first dog either. Rescue dogs can and will have psychological issues.
You are absolutely right about understanding the breed and the work a dog requires. It makes my wife and I sad whenever we see someone get a 'cute' working dog puppy that requires proper exercise, and then barely letting it outside 2x/day.
Any dog can have psychological issues, so all dogs should be trained. I highly recommend taking a training class with any new dog. The basics are easy, and generally work.
EDIT I wanted to also add that insurance is a good thing to have with a dog. I never want to be in the vet and have to make a medical decision based on cost. My 2 year old dog had to have back surgery and the vet explained that many people just put the dog down when this injury happens even though it's completely fixable and recoverable otherwise.
WRT cats, I'd argue that perhaps you just haven't met the right cat. :P I've come to think there's an expectation incongruity at play in that people who are used to dogs are thrown off when a cat wants his/her alone time, whereas a dog is pretty much always "on" socially. Becoming the target of a cat's affection is imo emotionally rewarding in a special way partially because they don't give it away to just anyone.
No argument here. It's saved me a few times now where sudden very large bills would have been hard to stomach.
> WRT cats, I'd argue that perhaps you just haven't met the right cat.
My original comment was too far on one side. I debated how to say it for a few minutes while writing. I had one cat for almost 17 years and he was awesome. My connection with him was just different than with my dogs. But you're right that it is more different than better or worse.
We got them really young (rescues) and she just bonded to me from the start :).
Every time I look at my amazing rescue dog (my first dog ever) and think about how he was almost put to death in a kill shelter it brings me to tears and I'm so happy that I have him.
It's not purebred vs rescued mutt. It's the age of the dog and whether or not it was mistreated and developed problems that new owners are unlikely to know how to fix.
Young rescues are usually fine.
As you noted, a good rescue agency will do their homework before placing dogs. Not all rescues are good.
And of course, all dogs should be put through a puppy skills course of some sort, even if they're not puppies. Most pet stores and many boarding facilities run classes. They're as much for the owner as the animal.
I've owned three dogs as an adult, the first two from breeders, the 3rd from a rescue. The rescue has had more behavioral issues than the two I raised as puppies. All the behavioral issues are directly linkable to his previous owner (a puppy mill, where he was kept crated most of the day). It's been a TON of work to get him to a point where he's mostly well-adjusted (and I knew going in this would be true). If he had been my first dog, he likely would have been my last as well.
Yes. Any one can call themselves a rescue. And rescues can have a wide variety of beliefs and procedures.
Rescue dogs are usually surrendered because the owner didn't train them. So even excluding any emotional issues, the dog has to be broken of bad habits. A new puppy won't soil where it sleeps, so house training is easy. But a dog that's been locked up most of it's life will, and extra effort in training is needed... not the best for a new dog owner.
This goes double when it comes to larger or more powerful breeds like ASTs, Dobermans, boxers, etc. A Pomeranian that's bitey is regrettable, a Rottweiler that's bitey is dangerous. Getting a shelter pet is a lot like buying a used car in that you're signing up for a lot of unknowns.
Also, unless you live in a metro area, you're probably limited in your choice of shelters. There is nothing, absolutely nothing, wrong with a reputable pet store (read: one not supplied by puppy mills) or breeder if you're the slightest bit uncomfortable with the shelter or their selection. This also means you're more likely to get a breed that fits your lifestyle and living situation.
they told me as much as they could about her from the 10 days they’d had her (for spaying, vaccines, and microchipping) after rescuing her from the county shelter (who found her wandering the streets).
her main behavioral issue was anxiety, probably partially due to prior abuse (she’s cautious around bigger men), which manifested mainly as nervous diarrhea for the first two months, along with panting and self-scratching/gnawing. it took some work to get her to trust me so she could self-regulate her anxiety and calm down at home.
but she’s a bundle of joy, eager to please, very playful & friendly (with dogs & people), and so attuned to me, that i feel immensely lucky to have found her. i wouldn’t trade her for the world!
I said nothing against rescue dogs, just that it is very, very unwise to adopt one as your first dog with no dog experience prior to it.
> Good adoption agencies will foster the dogs for a while and let you know if the dog actually has behavioral issues.
That's the first thing, how does one find out about the quality of the adoption agency? Plus fostering seems to be a US thing, haven't heard of this in Germany.
> and think about how he was almost put to death in a kill shelter
That's the second problem. Kill shelters are a horrible concept, in Germany this is prohibited by animal welfare laws.
"Dogs’ Eyes Have Changed Since Humans Befriended Them"
I was actually expecting a dire clickbait sort of article, when it actually turns out to be substantive and interesting.
it's always confusing when the title gets silently changed, and then there's comments complaining about a title that's no longer the title.
At the other extreme there's the odd dry-as-dust titled technical article that really needs some editorialising or at least posting on sub-head to have any chance of interest.
> With dogs, Horowitz points out, we’re so driven to connect that we often search for “smiles” in the shapes of dogs’ mouths.
I think a lot of the "smile" facial expression you see on dogs is produced, not by the mouth, but by the RAOL muscle pulling the corners of the eyes out slightly to mimic the way humans' eyes squint slightly when we smile.
In any case, it'd be surprising if dogs didn't have some behavioural / communicative adaptations, given that their role in our lives has historically been a collaborative one. Look at all of the dramatic cosmetic changes we've made in selecting different breeds of dog. Surely selecting for increased utility as a hunting or farming animal would exert even more pressure?
2 facial muscles? What about Chihuahuas to Great Danes, is that not a more impressive evolution than 2 facial muscles?
It’s reasonably likely the muscles that are universal among dogs existed among wolves at very low frequency and just exploded in frequency once they started hanging around humans. These kinds of hard sweeps happen when there’s either a very useful de novo mutation or a new environment makes a previously irrelevant or disadvantageous allele or trait beneficial. In humans think lactase persistence which was pretty much nonexistent 5,000 years ago or the Tibetan altitude adaptations which derive from the Denisovans who were living on the Tibetan plateau over a million years ago.
There is something impressive that a Chihuahua can instantly somehow recognise the Great Dane or Pekingese as of type dog, even at great distance upwind. Yet can react differently to cat, sheep, fox or squirrel at similar range.
While there are many differences between breeds and individual dogs, there are also common factors that link them together. For example, all breeds have an excellent sense of smell and hearing and have the same number of bones which are tied together by the same number of muscles, tendons and ligaments.
https://breedingbetterdogs.com/article/structure-and-movemen...
http://mentalfloss.com/article/91022/5-muscles-you-might-be-...
This seems wrong. What about breeds with significantly different tail lengths?
That being said, dogs will have between 6 and 23 bones in their tails depending on length.
Selective breeding works incredibly fast on evolutionary timescales. You can get a selected population to no overlap with the parent population on your variable of interest in seven generations quite easily.
Spinning a saga about dog evolution from examining 4 dead wolves is stretching...
I find that to be rather astounding actually. Given the wide variety of expressions Schnauzers at least are capable of emoting, it's pretty amazing how easy it is for two unrelated species to communicate on such a level. They speak a lot with their eyes. Look closely, you'll be amazed.
It could be the other way around: when that kind of ability appeared humans have very selectively decided to prefer dogs that had that trait. Dogs are pretty much a human creation (through centuries of selective breeding) so it's not really evolution rather selection when it comes to this particular example.
https://www.reddit.com/r/aww/comments/c1qt1x/doggos_polite_a...
Maybe we haven't consciously bred the trait into dogs, but we might have selected such dogs for breeding, over litter mates that never made eye contact.
(But it's typical and common human hubris to not call nature nature when it includes us.)
For sure.