Allegheny woodrat hard mast preference and response to food supplementation

Abstract

ABSTRACTRange‐wide declines of the Allegheny woodrat (Neotoma magister) have been attributed, in part, to reductions in mast associated with extirpation of American chestnut (Castanea dentata) and transition to oak (Quercus)‐dominated forests prone to periodic mast failure. Chestnuts produce mast more consistently than oaks; hence, efforts to restore a blight‐resistant hybrid chestnut may facilitate woodrat recovery. Our goal was to describe the implications of chestnut restoration for imperiled Allegheny woodrat populations. Our objectives were to evaluate woodrat preferences for American chestnuts, blight‐resistant hybrid chestnuts, and other hard mast items and to describe the response of woodrats to artificial increases in mast availability. From 2011 to 2013, we conducted a series of cafeteria‐style experiments among woodrat populations in southern Indiana in which we used remote cameras to quantify woodrat preferences for various mast items. Additionally, we introduced an abundance of mast into occupied den sites and evaluated differences in apparent survival, apparent recruitment, population growth rate, and body mass between mast‐supplemented and control populations. Discrete choice modeling revealed that woodrats preferentially removed northern red oak (Q. rubra) and black oak (Q. velutina) acorns over chestnuts and other seed types (i.e., hickories [Genus spp.], walnuts [Genus spp.]). Further, woodrats preferred American over hybrid chestnuts, suggesting that these seeds were not perceived as equivalent food resources. Apparent survival, apparent recruitment, population growth rate, and body mass did not differ between supplemented and control populations. Although chestnuts, as annually consistent mast producers, may benefit woodrat populations by reducing the risk of complete mast failure, our results suggest that the restoration of chestnut mast is unlikely to benefit woodrat populations during years of abundant acorn production. Accordingly, managers should foster a diverse and abundant oak community to ensure sufficient acorn resources are available to sustain woodrat populations as chestnut restoration efforts progress. © 2015 The Wildlife Society.