Read Online Animals in Translation by Temple Grandin - Free Book Online
Authors: Temple Grandin
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are used to seeing on a ranch. Anti-backup gates hang down from overhead instead of being attached on one side, and basically look like a cow- or pig-sized dog door in a house. Plants install one-way gates in single-file alleys to keep the cattle from backing up into the long line of animals behind them. The pig or cow pushes through the gateâthe same way a dog pushes through a dog doorâand the gate falls down behind each pig or cow after it walks through. Itâs not flexible like a dog door, so you canât push it backward, only forward.
The animals hate having to push through the gate. Thatâs the problem, the going-through. The anti-backup gates bother the animals so much I donât like to use them. I work with the cattle gently enough that theyâre all happy to keep walking forward, and I can just tie the doors up out of the way, where the cattle donât see them and donât have to deal with them.
Â
You could make up the same kind of list for any animal, although it would be different for each one. Bats have sonar and dogs donât, so the list of common distractions for bats is going to have some sonar distracters on it, while the dogâs distracter list wonât. But any list of common distractions for an animal would be highly, highly detailed, exactly like this one.
T HE D IFFERENCE B ETWEEN A NIMAL V ISION AND H UMAN V ISION
Although I created this list for cattle and hogs, you can use this list to predict trouble spots for any other animal if you think about what these eighteen distracters have in common.
First of all, fourteen out of the eighteen distracters are visual, and I wouldnât be surprised to find a ratio like that for most animals. Butto predict what kind of visual object will distract or frighten an animal, you have to know more about what animal vision is like.
Itâs pretty different from ours. For instance, you always hear that dogs âdonât see well,â which is true as far as it goes. Dogs donât have very good visual acuity, which is the ability to see the tiny details of what youâre looking at clearly and crisply. People with 20/20 vision have excellent visual acuity, and a lot of animals donât. That means that most animals arenât going to be frightened by tiny objects, simply because they canât see them well.
A typical dog has a visual acuity of 20/75, which means that a dog has to stand twenty feet away to clearly see an object a person with normal vision sees well standing seventy-five feet away. The dog has to get much closer to the object than we do. This isnât due to nearsightedness but to the fact that dogs have fewer cones in their retinas than people do. Everyone probably remembers from biology class that cones handle color and daytime vision, and rods handle nighttime vision. Basically dogs have traded good visual acuity for good nighttime vision. A dog doesnât see any objects as sharply as a person does, including an object thatâs right under his nose. Thatâs why itâs so hard for dogs to see a piece of kibble youâve dropped on the floor for them to eat. If they didnât watch it fall, most dogs canât see it lying on a mottle-colored tile floor (though some can).
Thereâs also a lot of variation in visual acuity among the different breeds of dogs, as well as among individuals of a breed. One study found that 53 percent of German shepherds and 64 percent of Rottweilers were nearsighted. You might wonder whether being nearsighted matters to a dog since everything it sees is fuzzy to start out with, but tests show that it does. A nearsighted dog has much worse visual acuity than a normal-sighted dog. Interestingly, although German shepherds tend to be nearsighted, only 15 percent of the Shepherds in a demanding program for guide dogs were myopic. 2 Probably the nearsighted dogs were flunking out of the program without the trainersâ knowing
The animals hate having to push through the gate. Thatâs the problem, the going-through. The anti-backup gates bother the animals so much I donât like to use them. I work with the cattle gently enough that theyâre all happy to keep walking forward, and I can just tie the doors up out of the way, where the cattle donât see them and donât have to deal with them.
Â
You could make up the same kind of list for any animal, although it would be different for each one. Bats have sonar and dogs donât, so the list of common distractions for bats is going to have some sonar distracters on it, while the dogâs distracter list wonât. But any list of common distractions for an animal would be highly, highly detailed, exactly like this one.
T HE D IFFERENCE B ETWEEN A NIMAL V ISION AND H UMAN V ISION
Although I created this list for cattle and hogs, you can use this list to predict trouble spots for any other animal if you think about what these eighteen distracters have in common.
First of all, fourteen out of the eighteen distracters are visual, and I wouldnât be surprised to find a ratio like that for most animals. Butto predict what kind of visual object will distract or frighten an animal, you have to know more about what animal vision is like.
Itâs pretty different from ours. For instance, you always hear that dogs âdonât see well,â which is true as far as it goes. Dogs donât have very good visual acuity, which is the ability to see the tiny details of what youâre looking at clearly and crisply. People with 20/20 vision have excellent visual acuity, and a lot of animals donât. That means that most animals arenât going to be frightened by tiny objects, simply because they canât see them well.
A typical dog has a visual acuity of 20/75, which means that a dog has to stand twenty feet away to clearly see an object a person with normal vision sees well standing seventy-five feet away. The dog has to get much closer to the object than we do. This isnât due to nearsightedness but to the fact that dogs have fewer cones in their retinas than people do. Everyone probably remembers from biology class that cones handle color and daytime vision, and rods handle nighttime vision. Basically dogs have traded good visual acuity for good nighttime vision. A dog doesnât see any objects as sharply as a person does, including an object thatâs right under his nose. Thatâs why itâs so hard for dogs to see a piece of kibble youâve dropped on the floor for them to eat. If they didnât watch it fall, most dogs canât see it lying on a mottle-colored tile floor (though some can).
Thereâs also a lot of variation in visual acuity among the different breeds of dogs, as well as among individuals of a breed. One study found that 53 percent of German shepherds and 64 percent of Rottweilers were nearsighted. You might wonder whether being nearsighted matters to a dog since everything it sees is fuzzy to start out with, but tests show that it does. A nearsighted dog has much worse visual acuity than a normal-sighted dog. Interestingly, although German shepherds tend to be nearsighted, only 15 percent of the Shepherds in a demanding program for guide dogs were myopic. 2 Probably the nearsighted dogs were flunking out of the program without the trainersâ knowing
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