Dg. Hewitt et Rl. Kirkpatrick, RUFFED GROUSE CONSUMPTION AND DETOXIFICATION OF EVERGREEN LEAVES, The Journal of wildlife management, 61(1), 1997, pp. 129-139
Puffed grouse (Bonasa umbellus) in the southeastern United States comm
only eat evergreen leaves during winter. Despite their abundance, thes
e leaves rarely make up >50% of the diet. We fed diets containing 20 a
nd 40% mountain laurel (ML) (Kalmia latifolia) and Christmas hollyfern
(CHF) (Polystichum acrostichoides) to captive ruffed grouse to determ
ine the bird's ability to exist on these forages and to investigate de
toxification of secondary plant compounds. Grouse consuming diets with
20% of test forages performed similar to grouse eating a control diet
. Diets with 40% of the test forages caused reduced intake and birds c
onsuming the CHF diet were unable to maintain body mass. Conjugate-bas
ed detoxification systems were stimulated by both test forages, althou
gh detoxification strategies varied between forages and levels of fora
ge in the diet. Although grouse appear unable to exist solely on everg
reen leaves, these forages probably contribute to ruffed grouse winter
survival by remaining available during snow accumulation and by decre
asing foraging times due to high intake rates.