While hiking in my local park, I came across a carcass of a deer. I know the area well, but I haven’t hiked this trail in a while. On the central coast of California black-tailed deer (Odocoileus hemionus) are a primary prey of mountain lions, so naturally I got excited about this being a possible mountain lion kill. The carcass looked pretty old. I continued on the trail, which now led through a narrow canyon with oak, buckeye, and sycamore trees gently arching above a seasonal creek. But just a few hundred yards further I noticed another deer carcass in the creek bed. This one seemed even older, nonetheless I started to wonder if the culprit was still active in this area. I continued up the creek bed, and as I came out from behind a bend, I was startled by a turkey vulture (Cathartes aura) who flapped its wings heavily to fly to safety. Bits of flesh and blood dripped from its beak. I could have guessed what was for dinner; a fresh deer carcass.
It was a young doe. Her rear quarters were gone, and the rib cage was open with the stomach and intestines out, but the rest of the body was intact. Mountain lions will often consume the heart, lungs, and liver first. The doe’s neck and head were twisted backwards, and upon closer inspection, had the indisputable set of four teeth marks on the back of her neck. This was a lion kill without a doubt. I looked around the creek for tracks or any other signs of how the cougar ambushed its pray. There was a sycamore tree with a horizontal limb stretching right above the trail. A big chunk of moss was hanging down from it where the lion must have climbed, and there were three markings in the moss on the opposite side, likely from the lion climbing up in the undulating motion. The doe must have unsuspectingly walked under the tree when the lion dropped down on her and delivered the deadly bite that severed its neck vertebrate.*
Mountain lions often come back to feed on their kills for several days, so I ran back to get a trail camera with a plan to get a photo of it.
A fresh deer kill is like an open buffet for all other carnivores and scavengers in the area, so on my way back up I slowed down to a stalk right before the kill site. There, right behind a fallen log, was a bobcat (Lynx rufus) feeding on the carcass. I became very still but it must have heard the sound of my camera because it became alert and run up the trail.
I looked for an inconspicuous spot to place the camera. Since it was right along the trail, I didn’t want it to be easily visible to potential passersby, but I wanted to photograph the lion at a good angle if it came back to feed on the carcass. I decided to place it near the head of the deer, right along the bank of the creek. I camouflaged the camera with some dead leaves, and continued on the trail.
I returned two days later, in the evening. As I got closer I heard a repetitive call of a cooper’s hawk (Accipiter cooperii). I followed the sound slowly up the trail, and noticed a hawk dive bombing a juvenile great horned owl (Bubo virginianus). It twisted its head almost 360 degrees as it looked up at the harassing hawk. The owl did not seem very alarmed at the hawk, nor at me as I slowly passed it by.
I wanted to stay and continue to observe the interaction, but it was getting late and I wanted to get the camera before it got dark. An uneasy feeling came over me the moment that thought registered in my mind. It was getting late, I was alone in a steep canyon with no cell reception, and it was unlikely that anyone else would walk on this trail on a Monday night. I hiked more cautiously now, paying close attention to all overhanging trees and straining my ears for the slightest of sounds. It was me now, not the owl, who was twisting my head left and right to scan the sides of the canyon. I tried to assure myself that if a lion tried to stalk me it would have a hard time doing so completely silently with all the dry leaves on the ground. Right? When I got to the spot, I noticed the deer had been moved to the opposite side of the trail, and the front part of its chest and neck were eaten away. Something big was here since my initial discovery. I grabbed the camera, and started heading back down.
My senses were on full alert now. I slowed down before every bend in the trail and froze every time I heard a sound I did not recognize. Suddenly, I heard a bunch of ruffling on the other side of the creek. Something was moving in my direction. Fortunately, it was only a striped skunk (Mephitis mephitis) half loping, half sliding down toward the bottom of the canyon. I observed it for a while and then realized that our paths were going to intercept if I didn’t fasten my pace. The skunk got into its defensive pose as I passed it by, but it let me get by without an incident.
When I walked out of the canyon, I was greeted with a beautiful sky painted in pastel colors of red, orange and blue. The experience had already been full of exciting discoveries and I could barely wait to take a look at the pictures from the trail camera and find out what had happened over the course of the last two days when I was not around.
As I looked through the pictures on the remote camera, another story started to unfold itself. Twenty five minutes after I installed the camera, the bobcat came back to continue its meal. I wonder if it just hunkered down someplace up the bank of the creek and waited for me to leave. It investigated the deer carcass, and then it started to feed at the front part of the deer. It fed for a couple of minutes and then stopped and looked around and twitched its ears. The bobcat too, must have been aware of the potential risk of running into a mountain lion. Once it was satiated, or because it was getting dark, it covered the carcass with a few leaves and left the area.
Short time after sunset the mountain lion (Puma concolor) came down the trail. Judging by the muscular body but a small head, it looked like a young male.
He spent a few minutes sniffing around the carcass, likely getting information on who had visited before his arrival. Could he tell a bobcat got a free dinner just a short while ago?
He re-positioned the carcass and laid down to feast on the front shoulders of the deer, mooning the camera in the process and confirming my suspicion that this was a male lion.
After he fed for about 10 minutes, he dragged the carcass a little way up the creek bed to the location where I found it when I retrieved the camera. Mountain lions will often cache their prey and cover them with sticks, leaves, and other debris. This likely serves a dual purpose of keeping other animals from feeding on the kill, and to help keep the carcass cool. At another location I’ve visited recently, a mountain lion cut shrubbery vegetation with its teeth to cover up its kill, but this one did not bother scraping even a little bit of leaves over it, leaving it right out in the open.
The young lion left the site short time afterwards. Over the next 24 hrs, the bobcat and the lion had both re-visited the carcass, but with the most nutritious parts of the deer consumed, they did not bother with the leftovers. The bobcat visited only during the daylight hours though, quite possibly to stay out of the way of the lion who moved at night time. Each time they smelled the area, likely picking up information about each other and additional visitors.
The deer had given up its life to support animals higher up on the food chain. While this may seem sad and even gory, this is how apex predators such as mountain lions survive. They play a crucial role in their ecosystems by regulating populations of their prey and competitors.
With a good acorn crop we are having following last winter’s rains, the abundance of deer, small mammals, and even some birds may increase. The mountain lions, bobcats, great horned owls, coopers hawks and other predators will continue to play an important role in controlling the populations of their prey. Learning to read the sings of their activity can shed a light on otherwise hidden world of predator and prey dynamics. What signs of predators have you recently seen in your neck of the woods?
After discussing this adventure with a couple of advanced trackers with a lot of experience looking at mountain lion kill sites I learned that lions generally don’t ambush their pray by jumping down on it from a tree. My initial assessment was based on the obvious sing of moss disturbance on the tree, lack of (or my inability to find) other clear sign on the ground, and common lore that is not always accurate. I decided not to edit the original post as a record of my own learning and growth as a tracker.