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).