Tuesday, May 22, 2012

Advanced Ecology Lab Week 6: Testing Response of Wildlife To Canine Urine

I'm taking you all back in time a bit.  The subject of this post is based around a long-term exercise that started in Week 6 of our lab this semester.  Although we started this assessment back in February....student analyses of the results were not due until near the end of the semester.  The semester has since ended, and the early results are in.

To give you a bit more background...I wrote this lab exercise in mid-January.  It sounded fun and was something I had been wanting to do myself for a while, just had never had the time.  In general, the whole exercise seemed reasonable when I wrote it....but because I came up with it from scratch right before the beginning of the semester, it had never been tested and I had no idea if it would even work!

The goal of lab was to set up an experiment involving camera traps to test the responses of certain species to various urines, and perhaps getting an idea of how territorial they are.

The focus was our local canines: the Coyote (Canis latrans) and the Red Fox (Vulpes vulpes).

First, finding a location for each set-up is key.  The strongest smelling urine in the world wont work, if you (a) don't have critters on-site to respond and (b) don't pick a good location.  Despite what manufacturers of commercial trapper lures promote, a scent lure will rarely draw critters in from miles away.  It can, however, be used to coax a critter that's already in the vacinity into standing in front of your camera.

So...as with many things involving camera traps....it's location, location, location.

A maintained trail between a woodland edge and an agricultural field seemed to be a promising spot....

But even then....setting up the experiment takes alittle bit of explanation.......
Photo by J. Scherer

...once the students got a feel for it, they sallied-forth to find their own locations and set up their own experimental camera sets.
All cameras were programed to record video clips.  Much easier to see response of individuals in video clips than in still photos.

Eventually, it came to application of the experimental treatments. 

First, a cotton ball soaked in Red Fox urine was placed within a commercially purchased wooden scent egg.

...next a cotton ball was soaked in Coyote urine and placed in another scent egg....

The urine scent eggs were placed 4 ft apart in front of the camera, with a control (cotton ball soaked with de-ionized water) placed in a scent egg exactly between them.  See what I mean in the two pictures below.

The set-up during lab went relatively well, and I was feeling good about our possibilities......which is always dangerous.

But, my good feelings were soon to be dashed because two days after we set the project up, it looked like this outside.


The best-laid plans..... 

Then....it rained the night after we "freshened" the scent during the second week of the experiment.


The third week, though.....no rain afterwards....but from that point on for the rest of the semester, it seemed like rain always followed our "freshening" of the urine.

Whether that made a difference or not, I can't say....but for six weeks the results rolled in. 

Below are some of the highlights.

When viewing these video clips, please note...
  • the scent egg on the left contains a cottonball soaked in Coyote Urine,
  • the egg in the center contains a cottonball soaked in Deionized Water (Control)
  • the egg on the right contains a cottonball soaked in Fox Urine.
Also, remember that the wooden "scent eggs" holding the urine are not always visible (covered in grass, etc.) but they are within the camera's field-of-view.

We started data collection on this project in late February.

Basically, what we found was that some individuals were obviously interested......
March 2nd
March 2nd (same deer)
March 15
March 17
March 24
March 28th
March 29
April 3rd
Some individuals were wary.....
March 2nd
April 5th (love the moon in the background)

Some individuals completely ignored our efforts.....
March 9
March 12
March 17
March 25
March 25
March 30
April 9

EVEN obvious prey of Coyotes and Red Fox seemed oblivious sometimes (also....I hate to be the bearer of bad news for you who put Coyote/Fox urine around your garden to scare away bunnies...but.....)

...and SOME individuals were absolutely no help in determining which scent was preferred at all!

But the canids were the target...... 
Interestingly, we ended up getting almost no response from Coyotes and Red Fox.  One might assume this was because they were not on-site.  Our other camera traps (the ones without scent) proved this was not true (particularly for red fox).

Here are our best videos of canines responding.  We assumed the coyote in the second video was over the 'yote urine.  We got two others clips of canines, but neither were showing an obvious response to the scents.
April 2nd
April 8
Despite their lack of response on our urine cams.....we nabbed many pictures of red fox in other locations on-site.  Below are the dates where Red Fox were photographed by other cameras (non-urine cameras) on-site during our scent experiments:
  • Feb. 29
  • March 6
  • March 17
  • March 18
  • March 20
  • March 21
  • March 22
  • March 24
  • March 25
  • March 26
  • March 27
  • April 2
During the experiment, Coyotes were photographed by one of our non-scent cameas only once: March 19.

This would suggest, perhaps, avoidance of the urine cameras, but I want more data. 

I did have the students conduct statistical analyses on the data.  However, we had almost no response from Canines, so I had them combine the response of all wildlife to each urine and compare their combined response to fox vs. 'yote urine.  Basically, there was no difference detected.  However, this could be due to short survey period (only 6 weeks) and small camera sample size (n=4).  By just watching the critters in the videos, it really seems as if they were more often lingering on the fox urine.....but the stats don't back this up.

I have become interested enough in our findings so far that I'm continuing these experiments indefinately and rotating camera locations periodically.

...stay tuned!


  1. My god, I love camera trapping. I think this entry is fascinating, and I can't wait to REALLY look at it. It's been a busy couple of weeks...but I've got a long day of travel tomorrow that will give me time to catch up! Thanks for sharing.

  2. Which cameras were you using and are they 840nm or 940nm IR

    1. Hi Ron...

      One of these cams was a ltl. Acorn. It was the 940.

      The other three were Bushnell Trophy Cams (2010).

      Had to mix and match based on the cameras I had available to me!