Carman's Silent Partner is a very solid and reliable lure for both red and grey fox.  It works best in areas where the reds outnumber the greys.  It does have some attraction to coyotes and bobcat, but is not rated as a top-notch lure for either.  This is a heavy "oily" lure that holds up well in both wet and very dry climates.  A very popular lure in both the east and midwest.  Can be used with or without bait.  This lure hardens into a paste at moderately cold temperatures but this does not effect the attraction of the lure.  For use from early October until Christmas in the north.  Good anytime in the south.