Grouse trapping and winter tracking
From September through November, we trapped ruffed grouse using mirror traps and walk-in funnel traps attached to a wire drift fence (Gullion 1965). We covered traps with vegetation to provide camouflage from predators and checked traps twice daily. We fitted grouse with VHF radio-collars (12 g, necklace-style, 4h or 6h mortality signal, Advanced Telemetry Systems Inc, Isanti MN) and uniquely numbered aluminum leg band (National Tag and Band Company, Newport KY). We measured body mass, tarsus length, bill length and assigned color morph variant, red or gray, by examining central tail feather coloration. We aged (juvenile or after-hatch-year adult) and sexed each individual according to standard criteria (Hale et al. 1954). We immediately released grouse after processing. We trapped grouse in the fall over 5 seasons: 2015 - 17 (Shipley et al. 2020) and 2020 - 2021.
Through winter (December through March), we obtained radiolocations of collared individuals 1-2 times a week between the hours of 0900 and 1700 using a handheld receiver and a three-element Yagi antenna (Advanced Telemetry Systems Inc, Isanti MN). When a mortality signal was detected, we determined cause of death by assessing for evidence of predation within 1-2 days of the signal (Bumann and Stauffer 2002).