Recent Tail and Eye Injuries

13 Dec 2023 Leave a comment

by yipps:janetkessler in Blue eyes in coyotes, coyote eyes, coyote injuries, Injuries, urban coyote ailments

I want to make folks aware that injuries and ailments abound in the coyote world. Here are three youngster coyotes, all 8 months old, who have conditions to contend with which will impact them moving forwards.

Probable Glaucoma from an Injury:

I’ve recently posted about Lapis’ condition, above. Her right eye, from the time I first noticed it when she was about two months old, was blue. It remained this way for many months, but about a month ago that eye suddenly looked quite different: I don’t know if this is a developing condition, or if it is the result of trauma, so I contacted an animal veterinarian eye specialist who diagnosed her condition through photos as follows: “From what I can tell from the picture, the right eye likely has glaucoma (increased internal eye pressure.  The lens within the eye is probably shifted rearward (posterior lens luxation).  The right eye is probably blind, but appears to be comfortable as there is no squinting evident.  Could be from a traumatic injury.”

The eye indeed looks glassy and blind, and from her behavior, it doesn’t seem to be painful. Without a second eye, she would have no depth of field, so this definitely will impact her survival skills. However, coyotes are resilient survivalists, and I expect her to live as full a life as any of the other coyotes. At this point in time, she plays with her siblings and hunts, but she is not adventurous when it comes to exploring new places: she prefers the safety of her immediate area. Then again, a sister of hers from last year’s litter behaved in this exact same way without such an affliction, so the eye may be having no effect at all on her life, so far.

Probable Corneal Edema from a Virus:

This youngster visits a backyard about once a day, so a human was able to take these concerning photos. The cloudy eyes are alarming, so we sent these photos to the same eye specialist as before. His response:

“The clouding of the eyes could be due to corneal edema.  Since this is a youngster, I would suspect some sort of systemic infection caused inflammation of the cells lining the interior of the cornea (endothelial cells).  One possibly is canine adenovirus type 1, which causes a viral hepatitis.  This can cause corneal edema due to endothelial cell inflammation.  Vision is present, but it is going to be hazy.”

A friend and colleague of mine who knows coyotes well tells me that generalities are always broken by coyotes. I.E., there are exceptions always. My own take is that this fella is compromised which will affect the quality of his life, but then again, he might be the exception. I can’t imagine an easy life with hazy vision. However, he has a safe-haven in someone’s backyard which he can retreat to. He is welcome there whenever he wants. Nonetheless, he’s a male and males have strong drives: he’ll want to find a mate and claim his own territory at some point. But let’s see how his story develops. As long as he returns to his backyard safety zone, we’ll be able to get updates.

Caudectormy from an accident or injury:

And then this shocking injury occurred within the last month: a completely severed tail. We have no idea how this happened, but when it was first observed, the cartilage was exposed and the wound was furious red. However, as we all know, coyotes are resilient, and the little female seems to be recovering and is functional, and hopefully out of pain at this point. If you see her, please leave her alone: her tail cannot be restored, and she already is healing. Remember that what is most important to these coyotes is their families and relationships within those families. Allowing them to remain with their families until they are ready to disperse is crucial for their well being. Unless a wild animal is immobile, or has mange, we leave most alone, allowing nature to follow its course.

For more urban coyote injuries and ailments, see Injuries and Ailments: a coyote’s life is hard and short.

Eye Sore

18 Sep 2016 1 Comment

by yipps:janetkessler in coyote behavior, coyote eyes, coyote injuries, coyote vision, Injuries, urban coyote ailments Tags:

This young female coyote spent considerable time rubbing and scratching her sore eye with her wrist, possibly even with her dew claw. When her wrist was not up in her eye to relieve the itch or pain, or possibly to dislodge the irritant, you could see that the eye was red, swollen, teared-up and recessed a little. I don’t know what was going on, except that it bothered her. I’ve seen quite a number of eye-injuries or irritations in coyotes, so it must be a fairly common malady. They are close to the ground where sticks, brambles, grit and bugs could easily get caught in and become lodged in their eyes. Coyotes are particularly dependent on their binocular vision for hunting, so it was important for her to take care of her afflicted eye.

We all tend to forget that wildlife has its share of ailments and injuries, not dissimilar to our own, and that even if these don’t incapacitate an animal, they make it that much more difficult to perform their daily living routines, and can serve to shorten their lives.

By the time I saw her on the next day she was no longer tending the eye — the affliction had passed.

 

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Coyote Night Vision and What Coyotes Know About Human Vision

23 Sep 2014 6 Comments

by yipps:janetkessler in coyote behavior, coyote eyes, coyote night vision, coyote vision Tags: , , ,

coyote eyes

coyote eyes

Coyotes may be seen at any time of the day — they are diurnal animals, however for convenience in urban areas they have arranged their daily schedules to avoid human activity, so in cities they are active mostly at night when we are not. They can do this because their eyes have many more rod receptors than the human eye has, so they can see in the dark: they have night-vision.

Coyotes, like dogs and cats, have retinas that are almost entirely composed of rods. They have a superabundance of rods with only few cones.  Rods require less light to activate than cones, but they only allow you to see black and white; having lots of rods means great night vision. Humans, on the other hand, have predominantly cones and fewer rods. Cones require a lot of light to be fired up, but they allow color vision in bright daylight and they produce a very sharp vision. Cones do not respond to low light: under low light, humans rely on their lower number of rods. Note that for us, at dawn, dusk and nighttime, everything looks black and white, and not very clear or sharp, and we can’t see far.

Rods have a photosensitive pigment called rhodopsin which is particularly sensitive to low light. This pigment actually breaks down in strong light rendering it ineffective during the day, but at night, and when there is a superabundance of the rods as is the case with coyotes, the pigment is created faster than it breaks down. So these animals, out at night, can see pretty well even though you can’t, but they cannot see as sharply as those of us who use cones in daylight.

In addition to more rods, there is another factor which aids coyotes and other critters in their night vision. Have you ever noticed that if you take a photo of animals at night, their eyes shine? This is because they have a sort of “mirror”, called a tapetum lucidum, beneath their retina. This collects and re-emits light back into the retina, giving the rods a second chance to absorb visual information, enhancing their ability to see clearly in low light conditions.

Other  adaptions allow a number of animals to function at night and during the daytime, such as slit-eye pupils which cats and foxes have. Their pupils can open completely during the night, yet the slit protects their eyes from bright daytime light. One of the adaptations of owl eyes — owls only function at night — is the huge size of their eyes: their eyes often take up a full half of the room in their skulls. The increased retinal surface of large eyes permits even more rods which can collect even more ambient light. Since owl eyes are so large and must fit tightly into their sockets, owls cannot swivel their eyes in their sockets like we can. Instead, they rotate their heads at the neck to focus on different things. They can rotate their necks a full 270º!

So, coyotes are diurnal and can see well at any time, whereas humans see best when there is plenty of light.

The interesting thing is that coyotes seem to know where human perception lies, that we can’t see well at night — I saw an example of this just a few days ago. As I watched this older coyote in the photo below, he became aware that I was watching, and he curled up in a ball to watch back. Coyotes do this often — they’ll watch back and be just as entertained as you are! It got darker and darker and pretty soon I could no longer make out any details about this fella lying in the grass — in my eyes, he became a barely perceptible colorless bump in the grass.

As he lay there, a group of five young women began approaching. They were not quiet and sedate, but animated and active. It was a Friday night and they were headed-out excitedly together. You would have thought the coyote would move — he was only 8 or so feet off the path. But as I watched, fascinated, the coyote remained exactly where he was, and the girls walked by without even seeing the coyote right next to them. The coyote didn’t move because he knew from experience that he would not be detected at all. I’m not sure whether the girls thought he was just a pile of dirt or a rock, or if they even noticed that. I approached them afterwards, and asked, and they said they had had no idea.