. The Canadian field-naturalist. 1987 Nagorsen: Winter Food Caches of the Heather Vole 83. X Figure 1. Winter cache of cut maple (Acer rubrum and A. spicatum) twigs. Note that most twigs have been stripped of bark. Lens cap is 50 mm in diameter. in the summer diet. Evidently there is strong selection for heather plants (Ericaceae) by P. intermedius during summer. Although Blueberry and Bearberry were common ground plants in the forests where I found Heather Vole caches, these habitats also supported a rich diversity of forbs that were not exploited by P. intermedius. Summer food piles of the H
. The Canadian field-naturalist. 1987 Nagorsen: Winter Food Caches of the Heather Vole 83. X Figure 1. Winter cache of cut maple (Acer rubrum and A. spicatum) twigs. Note that most twigs have been stripped of bark. Lens cap is 50 mm in diameter. in the summer diet. Evidently there is strong selection for heather plants (Ericaceae) by P. intermedius during summer. Although Blueberry and Bearberry were common ground plants in the forests where I found Heather Vole caches, these habitats also supported a rich diversity of forbs that were not exploited by P. intermedius. Summer food piles of the Heather Vole that 1 collected contained small quantities of plant material that would be consumed within a day or two. Because of the abundance of food resources, it is unnecessary for P. intermedius to store large food reserves in summer. Caching small amounts of food at burrows is probably a strategy for avoiding predators while feeding. Winter Caches A total of 65 separate winter caches was collected. They consisted of cut twigs piled on the forest floor (Figure 1). Size of tooth marks indicated that twigs were cut by a small cricetid or microtine rodent. Although four species of small rodents (Deer Mouse, Peromyscus maniculatus. Southern Red-backed Vole, Clethrionomys gapperi. Rock Vole, Microtus chrotorrhinus, and P. intermedius) were trapped in forests with twig caches, I attribute these caches to P. intermedius. There are no reports in the literature that P. maniculatus, C. gapperi, or M. chrotorrhinus cache twigs in winter. But several studies (Shaw 1924; Foster 1961) demonstrated that P. intermedius feeds on bark and caches twigs during winter. Moreover, Foster (1961) observed that this vole made piles of willow twigs in captivity. Twig piles were found at the base of shrubs and tree saplings, near old burrows, under rocks and logs (Figure 1), and under the branches of fallen trees. Branches and stems of woody plants near twig piles were usually girdled and the tips of
Size: 1933px × 1293px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorottawafieldnaturalistsclub, bookcentury1900, bookcolle
