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Comment by ams6110 | Hacker News Reader

Had no idea that dogs' visual acuity was so poor. My dog seems to be able to spot squirrels at 100 yards...

From what I understand, both dogs and cats have poor "static" vision but can spot minute changes very, very well. A squirrel has a very specific gait and movement style which they can spot very well. If your dog saw a photo of a squirrel from 100yrds away, I doubt it would heed much attention to it.

My dog can also spot food on the cement sidewalk from far away, too far to be just the smell.

Recent research[1] has found a fovea like structure on the canine retina. Fovea is a small patch of the retina with increased density of visual receptors. The finding suggests that the dogs has better visual acuity than previously suspected.

Quite likely this visualization were programed before this new development.

[1]: http://www.sciencedaily.com/releases/2014/03/140305191513.ht...

Dogs are hunters, not foragers. They spot movement very well indeed, and a squirrel's hop -- pause -- hop -- pause　movement style is very easy to recognise.

Perhaps smell is in there too, and perceiving movement better?

Spotting movement is a different receptor.

Maybe smell?

Is Smell directional in dogs?

Perhaps if the dog is also aware of the direction of the wind during the time of the smell.

With whiskers, it might actually work in that way...

Yeah, I honestly suspect they might be able to do that. Human hunters often pay attention to wind direction when stalking prey so that they don't give away their position. This would be fairly similar to that.

I think the nostrils are too close together for 3d smell detection beyond very short odor wavelengths.

yes, it's one of the reasons they articulate and constantly wet their nostrils.

http://chemse.oxfordjournals.org/content/30/4/291.full

It's not so poor. https://news.ycombinator.com/item?id=7441530

Reply on news.ycombinator.com