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Sunday, September 27, 2015

Big Red Is Down

Hello, hello, are you dead yet?
The driveway and the front gate have a good view across the Dipper Ranch, so I always scan the property when I come and go. On May 18th, 2015, I left the Dipper Ranch to run an errand and all seemed right with the Dipper world.

When I returned four hours later and opened the front gate, I noticed the big red cow lying on her side in a far sunny corner of Pasture 2. With her head on the ground in the middle of the day, it didn't look right.


Hastily repaired barbwire around the corral.   
Cattle do lie down at night, and during the day especially in the shade to chew their cud. We typically see a resting cow like this: partially reclined with its belly on the ground, front legs tucked under its brisket, hind legs stretched out to one side and head up. The last time I witnessed a live cow completely prostrate on the ground was so late at night I wasn't actually there. It was the end of the 2014 grazing season and Cowboy V had gathered his cattle in the corral where he gradually trucked them off the property in trailer loads of six. With 80-some cattle, it was going to take two days. That night, the remaining cattle crashed through seven strands of barbwire around the corral and scattered across Pasture 2. Something scared them.

Jostling in the corral before bedtime.   
Cowboy V had to restring the barbwire and round the cattle back up which took most of the next day. He hauled cattle until dark, and between trailer loading, I mounted two wildlife cameras on corral posts. Whatever spooked the cattle, I was hoping the cameras would capture its return a second night.

By 10pm, most of the herd settles down for the night but many are still awake with heads up.   
The next day the cattle were still in the corral and while Cowboy V spent the day hauling, I sorted through over 2000 photos of sleepy cows. With darkness, the cattle settled down directly in front of the older camera, jostled each other, got up, sat down, and were frequently changing positions like a class of kindergarteners. By 10 pm most of the herd was down, but there were always a few heads up and eyes open - just enough activity to trigger the motion-sensitive camera every few minutes for nearly the entire night. Finally around 4 am, most of the bovine bodies were flat on the ground. No predators visited the corral that second night at roundup time in 2014.

How cows get up - first they lean forward on their front knees.   
All down by 4 am.   
So there you go, cattle do sometimes rest those entire huge bodies flat on the ground. But from far above at the front gate in May 2015, the red cow didn't look so peaceful.

I drove down to the house, grabbed my pack and tools, and hiked down to a water trough on a slope about 250 feet above the red cow. I climbed on top of the trough for a better view. It was quiet. Carefully scanning with binoculars, I couldn't detect any movement from the red cow, the surrounding grassy pasture or the forests on the other side of the fence. I loudly banged the metal side of the trough with a shovel and shouted, "Hey cow, get up!" Not even an ear flick. This really didn't look good. Because predators have occasionally killed cattle on the Dipper Ranch, I wasn't going to solo approach the cow and instead radioed the rangers for help.

When the ranger arrived, he was clearly nervous. Checking suspicious livestock on a ranch inhabited by coyotes and mountain lions was not one of his regular duties. We banged on the trough, again with no response, then slowly hiked downhill. We talked loudly on the way down. Clutching my shovel I was alert for any motion on the other side of the fence.

Big Red is dead with no signs of wounds.   
The red cow was not breathing. Her eyes were clouded but otherwise her coat looked clean and unbroken. All four of her limbs were sticking straight out and slightly flexible. Even her tongue was still visible in her open mouth which meant that the vultures had not arrived yet. She had not been dead long. We looked all over her topside and legs for signs of wounds and even pried up her heavy neck with the shovel as best we could to check for a fatal bite along the vertebrae. But there were no cuts, bite marks, or blood. The ground was bare in a narrow circle as if she had paced around the pasture corner but there were no large clods of dirt thrown up or drag marks indicating some type of struggle.

I mounted a wildlife camera on the corner fence post, and left to call Cowboy V with the bad news.

We wondered if the big red cow had died during calf birth. As soon as Cowboy V arrived a few hours later, he checked, and I mean he checked where it counts. He confirmed that she was not pregnant nor did she show any signs of recently giving birth. The cow was 8 years old and about 1800 lbs. Cowboy V speculated that maybe the cow had eaten a poisonous plant and that might explain her sudden, wound-free death. Rattlesnake bite, gunshot wound, sudden seizure - possibilities that we could not detect on the heavy fallen carcass.

Mounting newly cleaned wildlife camera with branches to discourage vultures from perching and excreting on it.   
Down a steep slope away from roads, we could not get any equipment in place to bury her. As a cam-trapper, however, I knew that carcasses provide opportunities. There was a slight possibility the wildlife camera I mounted on the corner post might provide some clues to the cow's death or at least to the wildlife population on the ranch. Often, a predator will return to a carcass that it has killed or to an animal that it has harassed, but many other animals are opportunists and scavenge on a carcass which they did not kill. On other cow carcasses on the Dipper Ranch, I have seen or gotten photos on a wildlife camera of vultures, ravens, coyotes, mountain lions, bobcats, gray foxes, skunks, opossums, a juvenile golden eagle, and once even a rattlesnake.

Two weeks later, vultures are still wheeling around the hillsides waiting for their chance at the carcass.    
Two weeks post mortem, I packed up disposable latex gloves, handy wipes, and fresh camera batteries, and hiked down to the carcass. As I rounded the buckeye drainage, turkey vultures lifted from the corner of the pasture and landed in a nearby snag. They knew I was headed their way.

Even knocked down, the camera catches vultures slipping under the fence.   
The carcass was largely intact and sprinkled with a white splash. It smelt bad. The maggots and vultures had attacked the eyes, teat, and the soft skin around the mouth and anus, but they seemed to be waiting for a heavier-toothed or -clawed animal to cut into the thick skin to gain access to the large reserves of flesh. I was disappointed to see the wildlife camera was likewise splattered white and had been pushed loose from its mounting to face downwards. That camera wasn't going to give me much information on who had visited the carcass over the past two weeks. Sneaky vultures.

Vulture pellet - as with other birds, vultures often cough up balls of feathers and hair they cannot digest.  
I pulled on the latex gloves, wiped down the splashed camera and remounted it. As I tied branches to the post and barbwire strands to keep the vultures from landing on the camera, I noticed a hairy oval-shaped scat stuck on the side of the fence post. Strange shape and strange location.

Turkey vultures squabbling for position on the carcass at sunset and waiting to get in.   
Later, I found out it was actually a turkey vulture pellet. Although we mostly hear about owl pellets, vultures and many other types of birds also cough up dry masses of indigestable hair, feathers and bones from their last meal (Elbroch). I would continue to find these vulture pellets around the carcass throughout the summer and noticed that none had any garbage in them indicating the Dipper vultures were consuming a natural diet. I've found some indirect references that vulture droppings are sanitized by their highly acidic digestive juices but I was glad I still used latex gloves while cleaning and remounting the camera.

Common ravens join the turkey vultures in the waiting game at the carcass.  
I checked the carcass cam every month or less throughout the summer although I would scan from the front gate almost every day. From 800 feet away with binoculars, the carcass gradually deflated but otherwise didn't seem to change. Most of the photos were of turkey vultures and common ravens sitting on the carcass, waiting and arguing. So much bird squabbling that the camera battery was running out every few days. And I didn't find the time or stomach to go down to the carcass that often although at one point I did switch the camera to night-time only mode.

A gray fox inspects the carcass on May 30th.  
On May 30th, a gray fox visited at night but still the carcass seemed largely intact.

By June 18, the carcass had started to shrink and some large bones were pulled out.    
When  I checked again in mid-June, a few large chewed bones were scattered around and dirt was piled up next to the carcass but the exposed skin was an unperforated sheet of dry and stiff leather draped over the underlying bones. The camera showed that the fox was burrowing under the carcass to get to chewable parts.

Dirt piled up on the left side of the carcass.
Fox inspects carcass from left side.   
Fox burrows under left side of carcass.   
Fox emerges from under carcass 8 minutes later . . .    
. . .  and enjoys a snack.   
Although the camera was not always working thanks to interfering vultures, it was peculiar that no large scavengers came by to work the carcass which is how the smaller scavengers get into the flesh. A fox continued to burrow under the carcass, and a coyote took a quick peek under Big Red's skirt too. No mountain lions or bobcats showed and the coyote's visit was a single quick daytime inspection.

A coyote inspects the carcass the day after the fox visit.   
Coyote finds some beef jerky.   
Coyote also burrows under left side of carcass . . .    
. . . and likewise retrieves a snack from under the carcass.   
Other cattle carcasses that I've tracked on the Dipper Ranch (Beefeaters of the Santa Cruz Mountains) have been opened up and stripped of flesh by coyotes and/or mountain lions, then a parade of footed and feathered scavengers, and within a month, the skin and flesh were largely gone and bones widely scattered. In two to three months, evidence of death had largely vanished. Without the claws and jaws of big scavengers to rip open the cowhide, Big Red is going to take a long time to return to the earth.

With time, vultures also dive under the carcass.   
By the end of August, Big Red was a wrinkled table of red and white leather with a few bones scattered around, so I took the camera down. Maybe I will put it back up once it starts raining to see if something new visits a sodden carcass.

By August 30th, the pasture grass is dry and the carcass is hollowed out from underneath.   
I am not sure why the large scavengers never came to the carcass and I was surprised that the camera only showed one fox scavenger at a time, probably the same one. Last year, if I saw one fox, there was always another long-tailed companion with it. I'm concerned this might be another sign that the predators are not doing well in this ongoing drought. I still habitually scan for the carcass every time I go through the gate. Big Red is still there, still dead.


Each carcass feeds organisms large and small,
and disassembles on its own time according to its environment. 
One day this summer, I was sitting on the fence by the front gate with binoculars grumpily trying to decide if I needed to hike down to the stink zone again to change the batteries of the carcass camera and fix any vulture adjustments. A pair of bicyclists pulled into the drive behind me. I tried to ignore them. Cyclists and motorists often pull out at the front gate for the view and a rest which is fine with me as long as they don't smoke or litter. One of the cyclists said hello and as I turned on my perch, he asked if I wrote the Dipper Ranch Blog. That was a surprise. We had a short conversation but I decided not to ruin his idyllic view of ranch living by pointing out the decaying carcass of Big Red below us.

--------------------
Elbroch, Mark and Eleanor Marks. Bird Tracks and Sign: A Guide to North American Species. Stackpole Books. 2001.

Turkey vulture, Carthartes aura
Common raven, Corvus corax
Gray fox, Urocyon cinereoargenteus
Coyote, Canis latrans

4 comments:

  1. This is fascinating. Thanks for documenting Big Red.
    Just wondering -- does Cowboy V have no interest in the cow once it's dead?

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    1. The ranchers generally expect to lose 1-2% of their herd in any one year whether to sickness, accident, predators or unknown. It's a monetary loss so they certainly want to know the cause of death, if possible, so they can adjust their ranch practices or even breeding program to prevent additional loses in the future. Cowboy V and I compare notes about what shows up on the wildlife camera and what we otherwise observe on the Dipper Ranch regarding the cattle's behavior or wildlife and he's sometimes adjusted the rotation of his cattle from pasture to pasture accordingly. But once a cow is dead and you check the clues, there's not much else left to do from a rancher's perspective. It takes a nerdy biologist to wonder what happens week by week to a carcass.

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  2. Thanks for sharing this view of nature that first elicits a reaction of "Gross!" but is so captivating that the final reaction is, "That is really fascinating!".

    ReplyDelete
    Replies
    1. Yep, I often find that once I get past the initial yuck phase, lots of things in nature are really interesting. And when things fit together, like discovering that a fox will burrow under a large carcass to get to the soft tissues, that gives me a calm sense of awe about the orderliness of the world.

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