Coyote Study Highlights (Boddicker and Graves, 1987)

In the previous article I gave an overview of the study done by George E. Graves and Major L. Boddicker about their experiment with coyote scents and what worked best.

My head hurts after reading this, but I couldn’t stop.  Every paragraph is packed with useful information to the trapper.  But most people can’t get past the title “Field Evaluation of Olfactory Attractants and Strategies Used To Capture Depredating Coyotes” because it is already over their heads (as it was mine).  I plowed through it, and I will attempt to dissect it and put it so an average Joe can understand it.

Purpose Of The Study

The purpose of their study was to observe how coyotes reacted to certain scents.  This experiment took place in areas known to contain coyotes and these coyotes were preying on livestock.  They had a number of chemicals and also a number of commercial baits/lures that they tested.  They conducted the tests by actually trapping coyotes with foothold traps, snares, and M-44’s.  The experiment ran year round, and the test results were different depending on the time of year.  They broke it up into 2 main parts of the year, Spring/Summer and Fall/Winter. To make things even more difficult, the attractants were used alone as well as in combinations with each other.

Commercial Lures Used In The Test

Some of these I know and use, some of them I have never heard of, and some are no longer produced:

• Carman’s Canine Call
• Carman’s Final Touch
• Carman’s Pro’s Choice
• Olmstead Coyote Lure
• Olmstead Bait
• Stokers Bounty
• Mast #6 (Coyote #6)
• O’Gorman Government Call
• O’Gorman Long Distance Call
• O’Gorman Wolfer Scent
• O’Gorman Powder River Paste Bait
• Johnson’s Bait
• Kents Coyote Butter
• Fish Oil (Commercial)

Experimental Lures And Scents Used In The Test

• Trimethyl ammonium Decanoate (….no idea what this is…some kind of acid?)
• Rotten Meat Odor
• Synthetic Calf Crap (yes, you read that correctly)
• Synthetic Porcupine Hair
• Sheep Liver Extract
• Estrous Urine Fractions
• WU   (its not clear what this is in the paper)
• WU Acid (again, not sure what this is)

How Sets Were Constructed

Foothold sets were constructed with a trap buried, and lured usually with a q-tip.  M-44 sets were placed on the ground.  Snares were hung and a vial containing the lure was placed slightly higher than a coyote’s head so it would walk through the snare while investigating the scent.  During the summer and spring, the same kinds of sets were constructed, except breakaway snares were used, “trap rings” were used instead of foothold traps, and M-44 heads only were used instead of live M-44’s.

Data Recorded

A mind boggling amount of data was recorded such as temperature, date, time, barometric pressures, lunar cycles, and lure age (how long it was at the set).

Performance Of Devices

* a “trapnight” consists of a trap set each night.  If you have one trap, and leave it set 7 nights, that is 7 trapnights.
** for clarity I left off decimal places, which is why the percents do not always add up to 100.

Fall/Winter:  25,478 trapnights.  48% of the time an M44 was used, 44% a leghold used, and 7% a snare.
Total of 609 coyotes captured.  372 in M44s, 185 in leghold, and 52 in snares.  That is 61%, 30%, and 8% respectively.

Spring/Summer:  20,686 trapnights.  51% of the time an M44 was used, 51% a trap-ring used, and 7% a snare.
Total of 731 coyote visits recorded.  245 in M44s, 472 in leghold, and 14 in snares.  That is 34%, 65%, and 2% respectively.

Lure and Combinations Results – Fall/Winter

With all the lures listed, it can make quite a large combination of attractants.  The following table only shows lures/combos that caught 5 or more coyotes:

Leghold Traps, Fall/Winter

M44’s, Fall/Winter

Cable Snares, Fall/Winter

Leghold Traps (simulated trap rings), Spring/Summer

M44’s, Spring/Summer

Cable Snares, Spring/Summer

The study is called “Field Evaluation of Olfactory Attractants and Strategies Used To Capture Depredating Coyotes” by George E. Graves and Major L. Boddicker, and can be viewed here in it’s entirety.