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CRP Mountain Lion Study

CRP Mountain Lion Study

Coyotes, Bobcats and Deer, Oh my!

This morning we started off with a full crew of eight volunteers.  The sun rose through a smokey haze as we drove east to the first cameras.  We were mindful of the many wildfires impacting people and animals across California as we drove.

The sun rising through the smokey haze. Erin Hauge

In these times when so much wildlife is being displaced, it’s important to remember to drive with care as animals may be crossing roads to escape fires and in confusion and panic as they cope with intense heat and rapidly changing landscapes. If you live in a rural or country area near where fires have been burning, leaving buckets of water out in your yard can help exhausted wildlife rehydrate as they pass through and bringing all domestic pets in at night keeps pets safe and allows wildlife to pass through safely as well.

We have such a committed and dedicated camera crew that we’re looking at expanding to three teams of two folks each for our weekly camera checks.  This would allow us to expand our camera deployment and cover more area on the Preserve, increasing our chances of catching a passing mountain lion on camera. We’ll be having a team meeting and volunteer recruitment call soon so we’ll be talking about what’s working, what’s not, what can be improved and some new ideas as well.

A few of our awesome crew members, Diana, Mary and Tom, checking a camera! Erin Hauge

Mountain Lion Foundation biologist Diana had some great suggestions for improving our image data record sheet that will help us record more accurate and detailed data over the long term.  We’ll also be adding additional track and scat identification tools to the go packs so crew members will have more visual aids in addition to our trusty rulers for reading and identifying tracks and scat in the field.  Even the best trackers cite a less than 100% accuracy rate when making field calls for tracks and scat but the more ‘dirt time’ our crew gets in, the better we’re getting at observing and discerning field signs including track and scat.  Asking those important three questions is always paramount: 1. What am I seeing?  2. What does it mean?  3. What animals are involved?

We often come across ambiguous images from the trail cameras back at the office that require us to use best judgement, observation and reasoning skills. We call in the experts – the BLM biologists on the Preserve and other experienced trackers – to help us determine uncertain reads (especially, “is it a mountain lion?!”).  Last week we had an image that could have been a fox. The image caught the eagle eye of Richard, one of our crew members, who immediately questioned this possibility. If it’s a fox, that would be the first time our camera study has captured one on the trail cameras!  Both red and grey foxes are known to live on the Preserve.

A bobcat sits on the right for size comparison, and on the left, likely a gray fox is passing almost the same spot several days earlier. Courtesy of Bureau of Land Management

This week we had two instances where we caught very close up ‘selfies’ of critters that had us briefly thinking of a large feline carnivore with a tawny coat and long, dark-tipped tail!  Take a look and see what you think!

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Suspicious! Whiskers, rounded-looking ear. We did a double-take. Courtesy of Bureau of Land Management

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Different camera but here we had another breathtaking moment! Curious lion? Courtesy of Bureau of Land Management

As it turns out, the first image was a deer, though several images of the whiskers and rounded ears had us sitting on the edges of our seats until we put together the previous and following images, all taken within the same 60-second timeframe.

At first we see the whiskers and rounded-looking ear….the next frame shows several deer browsing next to the camera and a curious deer got a little up close and personal!  Both photos were taken on October 11, 2017 at 5:58am.  Courtesy of Bureau of Land Management

The second image is of a raccoon who reached up to sniff the camera!  The same capture of whiskers and rounded ears made us catch our breath especially since this camera is deployed where a lion was seen earlier this year. It’s set at about mountain lion height and a lion could easily walk by at night and take a sniff at the camera in passing.

The camera shows a raccoon moving toward the camera, and the next frame?  Raccoon selfie! Both photos were taken on October 15, 2017 at 10:53pm.  Courtesy of Bureau of Land Management

While these trail cameras don’t make a sound as they’re taking images, they do emit an infrared flash which often attracts the attention of passing animals at night. So this raccoon took a closer look at what was going on.  How do we know?  The previous and following images were of a raccoon group passing, again all taken within the same 60-second timeframe.

In the Field:  Once again, we noticed a healthy Black-tailed deer presence as we moved from camera to camera. This is good news for mountain lions.  Any lion in the area is certainly eating well whether or not he or she decides to become a Preserve resident.  Deer tracks and scat were present at just about all cameras.  And as we were checking cameras today we saw at least four deer on the road ahead of us as we drove and a coyote also crossed the road ahead of us, just seconds before we saw the deer further on! Another great example of how wildlife shares the same landscape.

Black-tailed deer on the road out to a camera check. Where there’s deer, there’s likely to be mountain lions!  Erin Hauge

The deer and the coyote were both passing through, both foraging, but obviously for different resources.  While family packs of coyotes are known to bring down deer, this coyote was likely looking for voles, mice and gophers and the deer were browsing late summer/early fall vegetation.  Deer are ‘browsers,’ meaning they eat a wide range of vegetation and often move as they eat, taking a bite here and a bite there of different trees and plants.  It’s thought this may be why they aren’t always affected by poisonous plants they may eat in the ecosystem, because they’re only eating a small amount and mixing it with a lot of other harmless plants that may even counteract the poisonous plants they ingest.

We saw lots of great tracks and scat.  There were many good coyote tracks in the sandy substrate at several of the cameras and we found a great set of raccoon tracks, showing both the front and hind paw.

A clear set of raccoon tracks, showing the front paw on the top and the hind paw on the bottom.  Erin Hauge

Several bobcat scats show the great variability in scats of all animals as it depends on the age, health and diet of each individual of a species.  Bobcats are known to eat plantain, perhaps when they have digestive upset and in one of the photos below there appears to be a wad of plantain in the scat of a bobcat who may have been feeling a bit off.

Two bobcat scats.  The one on the left is dark and well-segmented.  Because of the dark color, this bobcat likely just dined on a fresh kill.  The scat on the right may be older and looks to contain some plantain on the upper right, eaten by bobcats possibly for digestive upset.  Erin Hauge

Bobcats have been known to populate the Cosumnes River Preserve in the last twenty years.  It’s thought they may have migrated from Stone Lakes National Wildlife Refuge several miles to the north.  The first bobcat pioneers would have had to navigate county highways, human persecution and probably Interstate 5 as they went in search of territory and mates. It’s likely that Stone Lakes NWR had a healthy population of bobcats and it became necessary for them to expand their range. The Cosumnes River Preserve would be a safe place for them to settle once they reached it.

Bobcats are very elusive and are mainly nocturnal hunters but can be active at any time of night or day.  Their main diet is rabbits although they are opportunistic ambush hunters and will also eat mice, voles, gophers, birds, insects and bats.  They’ll also eat adult deer!  Being ambush hunters, bobcats will wait until deer are bedded down and more vulnerable before attacking.  Bobcats can also prey on young domestic animals and chickens when hunting near agricultural operations.

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A lone bobcat out and about on the Preserve at night, probably hunting for rabbits and mice.  Courtesy of Bureau of Land Management

Bobcats are usually solitary and quite territorial and can range in size from 11 to 40 pounds. Females don’t share territory with each other and male territories can overlap.  This is opposite to mountain lion behavior, in which the females will share territories and the males definitely do not.  But the territory of one male mountain lion may overlap several females, allowing him to sire multiple litters of kittens throughout his territory.

Bobcats rely on scent marking – urine, feces and scent glands – to claim territory and territory size can vary.  Typically, males will acquire 25-30 square miles while females only need about 5 square miles.

Within the last few years there have been kittens seen on the Preserve cameras so we know Preserve bobcats are resident and may even be doing well.  Bobcat moms can have more than one den for raising kittens, a main den (or natal den) and more remote dens that can be used for shelter as needed.

The Bobcat Protection Act passed in 2013 made it illegal to trap bobcats in California, but they are still hunted in the state. Bobcats on the Preserve are protected.  Habitat loss is one of the biggest threats to remaining bobcats in California.

Next week, the search for a mountain lion continues!

Possible location for another lion camera on the Preserve.  Erin Hauge

Blog by Erin Hauge

 

 Bobcat natural history information from Defenders of Wildlife and the Peterson Field Guide to Mammals of North America by Fiona A. Reid

The following photos are courtesy of Bureau of Land Management:

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Raccoon family. BLM

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Two does. BLM

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Coyote on the move. BLM

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Tom turkeys squaring off. BLM

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Bobcat sitting, at night. BLM