The day broke clear and cold and the sunrise foretold another dry day. The lack of precipitation this season is concerning. With last year’s historic flooding, resources on the Preserve have abounded, causing all the wildlife to thrive and produce more babies because there’s been more food and favorable conditions for raising young. But the bounceback of another possible drought this year would mean that there will be larger populations of wildlife competing for smaller pools of resources. So wildlife could have a more challenging time this year if we move into a hot, dry summer.
If more mountain lion kittens were born this last year because of the good conditions, it’s possible that there could be a higher number of surviving individuals. However, habitat loss and human development may even that playing field as challenges to survival increase even with more bountiful prey availability.
Moms have one to three kittens generally and there’s a high mortality rate among kittens younger than one year old due to sickness, predation, orphaning and accidents, among other things. The average survival rate for kittens is about 50% (Audubon Canyon Ranch). If it’s been a good year, it’s possible we could be more likely to see a young, dispersing mountain lion down on the lower Preserve, looking for deer and a quiet place to hang.
The dry season that appears to be on it’s way could also make it more challenging for mountain lions who are dispersing from the Sierra. They may find themselves getting into more trouble with local agricultural operators as they descend the Cosumnes River watershed to the Valley floor. It’s so important to practice good livestock protection and predator deterrent methods to keep lion-livestock conflict to a minimum. We don’t know what we’ll see, but we’ll find out as the season warms up and progresses into summer. Paws crossed for rain and a good year for mountain lions and all wildlife.
In the Field
We like to take group shots of the crew du jour and today’s crew was alert and ready for the task that lay ahead – effective camera checks!
Of course, we had to get into character before we hit the dirt and we had quite an assortment of critters today. Mostly mountain lions here but there’s a crane and a deer in there, too if you look closely!
We had two teams in the field today and it was gorgeous. The sun warmed things up while the air stayed chilly, and our Outer route was quiet and full of colors on the landscape. The cranes are still here and we could hear them calling as they flew across the early morning sky, looking for good loafing and foraging opportunities on this day.
Our crew got right to work changing SD cards and checking camera operations. This camera was off by several months on the image data strip, so we adjusted that to reflect the correct information. At the beginning of each month we try to do an all points camera operations check to be sure we’re managing for important time/date information, temperature and moon phase. Then we make sure the cameras are recording 3-shot rapid fire images with a 5-second delay. We have a dedicated and capable crew who focuses on getting data as accurate as we can get it. Sometimes we find that a setting is off and that’s why we do the monthly camera operations check – to make sure we’re on track and adjusting as needed.
We also got an interesting look at the gait of a walking raccoon in the muddy pond edge at this camera. Notice the tracks are paired with a front paw and what would be the opposite side’s hind paw placed directly behind the front paw track. Any animal’s gait and track pattern will vary based on the speed at which he or she is traveling. Animal gaits are difficult to learn and require a lot of practice! They can be better understood with that age-old ‘dirt time!’ Gaits can give information about age, size, physiology, activity and possible intention of the animal and more. The four basic gaits of a 4-leg mammal are: walk, trot, lope, gallop. Hopping, bounding, ambling and pronking are other common gaits found in our wildlife. A great book to study up on gaits and tracks is: Mammal Tracks & Sign: A Guide to North American Species by Mark Elbroch (Stackpole Books).
At our low flow dam stop, we observed that the water in the Cosumnes River is dramatically receding. In fact, animals can now pass back and forth just under the huge log that’s resting on the low flow, so wildlife traffic there has resumed.
The sandy bank formations on the south side of the river change and shift during the season as the water level rises and recedes and today we found a beautiful, layered sandy shore that has formed on top of a clay shelf there. Rising waters will change and can even remove the sandy deposits depending on how fast the water is coming down the channel.
The picture below gives a sense of just how big this tree trunk is. And the weight of the water-logged trunk must be extremely immense! It’ll take a lot of water to move that thing on downstream so we may be looking at that trunk well into the next big rainy season!
We saw bobcats on a number of the cameras today and it even appears that one or more of the cameras are capturing several different individuals! This could be the mom and one of her kittens we saw back in November last year or it could be a mating pair of bobcats. Breeding usually peaks in February or March but can go year round in milder climates like the Central Valley. Breeding times are also linked to prey availability and resource abundance. When a female bobcat comes in to estrus she looks for a mate, and when she pairs with a male, he’ll stick around for a number of days while they mate repeatedly. But then he moves on and will look for other females to mate with. Male bobcats don’t take any part in raising the kittens.
Tune in next week for more wild fun….oh, and maybe a mountain lion! And hoping for rain.
Creature Feature – Nutria Alert!
Do you remember the ROUS’s from the movie ‘Princess Bride’? (Rodents of Unusual Size!) Well they’re as good as here in California. In an unfortunate turn of events, Nutria (Myocastor coypus) have been discovered again in the San Joaquin Valley. Nutria are a highly destructive non-native rodent that weighs about 20 pounds and is a prolific breeder. Native to South America, Nutria were introduced to California at the end of the 1800s for their marketable fur pelts. And while it was thought they were eradicated from California by 1980, it appears that a colony or two slipped under the radar because Nutria are now being found in the San Joaquin Valley and may be moving north. Nutria can be told apart from beavers because Nutria have about a 12-inch long tail that is round and hairless, not flat, like a beaver’s.
Nutrias have not been spotted on the Preserve yet but we should all stay alert for the possibility that they may make an appearance here. Be sure to let the Preserve staff know if you think you’ve seen a Nutria on the Preserve.
Find out more at CDFW’s invasive species website.
If you think you’ve seen a Nutria, try to get a photograph and immediately contact CDFW Invasive Species Program either online or by phone at 866-440-9530.
Critter Camera Captures