Conifer-seed preferences of small mammals

Abstract

The preferences of the deer mouse ( Peromyscus maniculatus (Wagner, 1845)), southern red-backed vole ( Myodes gapperi (Vigors, 1830)), heather vole ( Phenacomys intermedius Merriam, 1889), long-tailed vole ( Microtus longicaudus (Merriam, 1888)), and meadow vole ( Microtus pennsylvanicus (Ord, 1851)) for lodgepole pine ( Pinus contorta Dougl. ex Loud.), white spruce ( Picea glauca (Moench.) Voss), and subalpine fir ( Abies lasiocarpa (Hook.) Nutt.) seeds were investigated using cafeteria-style feeding experiments. Seed selection by P. maniculatus and M. gapperi in the field was also studied. Peromyscus maniculatus, M. gapperi, M. longicaudus, and M. pennsylvanicus showed a distinct preference for lodgepole pine seeds and avoidance of subalpine fir seeds, and consumed the different species of seeds in similar relative proportions. Phenacomys intermedius behaved very differently from the other rodent species in that it did not show a preference among seed species, and consumed very few seeds in total. Findings from the field seed selection trials were consistent with laboratory results. We suggest that postdispersal seed predation by small mammals could limit the recruitment success of lodgepole pine and white spruce, but would not be a major problem in the regeneration of subalpine fir stands. This could provide an advantage for subalpine fir over neighbouring competitive species.

The efficacy of conifer seeds as major food resources to deer mice (Peromyscus maniculatus) and southern red-backed voles (Myodes gapperi)

“…Dietary protein limits growth, maturation, and reproduction in mice and voles (Cole and Batzli, 1979;Lindroth and Batzli, 1984;McAdam and Millar, 1999). Therefore, increased protein content could be a major contributor to the preference for lodgepole pine seeds over white spruce seeds observed in many rodent species (Lobo et al, 2009), and a key reason why both mice and voles fed lodgepole pine seeds were able to maintain body mass.…”

“…Rodents are also known to prefer some species of conifer seeds over others (Abbott, 1961;Martell, 1979;Duchesne et al, 2000;Lobo et al, 2009). Internal seed chemistry greatly influences seed selection, largely through the presence of plant secondary metabolites (PSMs) that act as a deterrent (Freeland and Janzen, 1974;Saitoh, 2003).…”

“…Nutrition plays an important role in food preference as well (Schlesinger, 1975), and rodents appear to select foods that have high energy and intermediate protein content (Vickery et al, 1994;Lewis et al, 2001). Lobo et al (2009) found that deer mice (Peromyscus maniculatus), southern red-backed voles (Myodes gapperi), long-tailed voles (Microtus longicaudus) and meadow voles (Microtus pennsylvanicus) all showed a distinct preference for lodgepole pine (Pinus contorta) seeds and an intermediate consumption of white spruce (Picea glauca) seeds, while almost completely avoiding subalpine fir (Abies lasiocarpa) seeds. Since seed availability and abundance were kept constant, foraging theories dictate that the mice and voles were selecting "higher quality" foods (lodgepole pine and white spruce seeds) over "lower quality" (subalpine fir seeds) foods (Ellis et al, 1976;Belovsky, 1984;Vickery, 1984;Bozinovic et al, 1997).…”

“…The effects of lodgepole pine and white spruce seed-diets on rodents were also examined for purposes of comparison, since rodents prefer these over subalpine fir seeds (Lobo et al, 2009), and all three tree species are common associates (Alexander et al, 1990). Deer mice and southern redbacked voles were used in this study, since they are the dominant rodent species in the study area and are very common across North America.…”

Pine seed removal in fragments of three temperate plant communities

“…The removal is motivated by seed traits such as the nutritional quality, size and the presence of secondary compounds that vary among a large number of plants (Shimada & Saitoh 2003, Hulme & Kollmann 2005, Wang et al 2012, including pines (Lobo et al 2009), and intervene in their evolution process (Hulme & Benkman 2002). In temperate forests, rodents exert a significant impact on the establishment and permanence of different pine species (Briggs et al 2009).…”