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Native Californian, biologist, wildlife conservation consultant, retired Smithsonian scientist, father of two daughters, grandfather of 4 small primates. INTJ. Believes nature is infinitely more interesting than shopping malls. Born 100 years too late.

Wednesday, September 9, 2009

An old bold coyote




I've been revisiting the cow carcass in Photoshop -- cropping coyote images to figure out how many animals were in that family.

This coyote -- look carefully at the left side of the picture -- was bold enough to walk up to the camera and check it out. 

The camera took two photos of it 3 seconds apart.

Here it is a minute later having a snack of marinated beef jerky.  


 
Its body proportions tell me it's an adult, and if you look at that hind foot at the top of the page you'll see that it has a few battle scars. 

This is the first time I've had a coyote check a camera up close. 

It happens all the time with bears, which are naturally curious, but the legendary coyote usually doesn't take chances like this. 

But all coyotes aren't alike.

Eveline Sequin Larrucea and her co-workers studied the reaction of marked and radio-collared coyotes to camera traps, and found interesting differences between breeding territorial coyotes (alphas), nonbreeding resident adults (betas), and dispersing transients.

Her photos revealed leery coyotes making haste, but the fast Trailmaster film cameras and active infra-red sensors captured full body images good enough for individual identification. 

First finding of note: coyotes didn't rush in as soon as the cameras were set. 

On average the first coyote photo was taken 14 days into the 6-week trapping sessions.

Camera trap success (total # of coyotes divided by # of active camera traps) was highest for adult coyotes during March and April, and for juveniles during July and August.

Photo-captures of adults peaked at midnight, while juveniles showed more or less equal peaks   at dusk, dawn, and midnight. 

Photos of adults peaked 2-weeks after the cameras were deployed, while photos of juveniles peaked during weeks three and four.  

Social status also had its effect. 

Only three territory-holding coyotes, the resident breeders, were photographed and all between midnight and 2:30AM. 

Resident nonbreeding adults (the betas) were photographed throughout the night, while the transients were photographed most often at dawn and dusk.   

There were other differences too, but what it all boils down to is this: population estimates based on photo-capture and recapture of identifiable animals can vary two-fold depending on the time of year.

Spring estimates overestimate coyote density because transient coyotes, the ones just passing through, are vulnerable to photo-ops. 
 

Reference

Larrucea, E.S., P.F. Brussard, M.M. Jaeger, and R.H. Barrett. 2007. Cameras, coyotes, and the assumption of equal detectability. Journal of Wildlife Management 71(5):1682-1689. 


3 comments:

cfiehler said...

I wonder if boldness could be related to exposure to humans. It's open season on coyotes in California. A coyote can be shot on sight and there is not bag limit as long as the shooter has a valid hunting license. These are smart animals. I wonder if they are bolder in areas where they haven't been shot at.

Camera Trap Codger said...

That family of coyotes sees Cowboy Ross on a daily basis, and I have heard that they do become habituated to people. The other factor was all that marinating beef jerky. It was a powerful draw to the yotes and the camera trappers.

Wow Gold said...

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