Defense of winter-dormant Alaska paper birch against snowshoe hares

Paul B Reichardt; John P Bryant; Thomas P Clausen; Gregory D Wieland

doi:10.1007/BF00384463

Defense of winter-dormant Alaska paper birch against snowshoe hares

Oecologia. 1984 Dec;65(1):58-69. doi: 10.1007/BF00384463.

Authors

Paul B Reichardt¹, John P Bryant², Thomas P Clausen¹, Gregory D Wieland²

Affiliations

¹ Department of Chemistry, University of Alaska, 99701, Fairbanks, AK, USA.
² Institute of Arctic Biology, University of Alaska, 99701, Fairbanks, AK, USA.

PMID: 28312110
DOI: 10.1007/BF00384463

Abstract

Mature growth-phase internodes of Alaska paper birch (Betula resinifera) are preferred by the snowshoe hare (Lepus americanus) over juvenile growth-phase internodes due to the low food value of the latter. While the mature over juvenile preferencec cannot be explained by the levels of inorganic nutrients or gross chemical fractions (resins or phenols), it can be explained by the striking differences in secondary metabolites of the two growth phases. The principle compound which renders the juvenile phase internodes unpalatable is papyriferic acid, a triterpene which is a demonstrated feeding deterrent to snowshoe hares and which is present in juvenile internodes at concentrations 25 times greater than those in mature internodes.