The Influence of Willow Salix sp. Rose Insect Galls on Moose Alces alces Winter Browsing

Feeding trials were conducted with Moose (Alces alces) habituated to people to determine whether Moose prefer winter shoots of Scouler’s Willow (Salix scouleriana) with or without leafy willow rose insect galls created by rosette willow gall midges (Rabdophaga spp.). After sampling one or two shoots with galls, each Moose in the feeding trial showed a clear aversion to the galls and dropped or spit out parts of the willow shoot containing these structures in subsequent feeding bouts. Despite the reported importance of leafy materials in the fall and winter diets of Moose, these results suggest that morphological attributes of or chemical deterrents within galls may lead Moose to reject these structures in favour of gall-free shoots. Why galls are rejected is speculated upon, but remains untested.

Flower Visitors as Cheats and the Plants’ Responses

This chapter describes some of the kinds of cheating committed by flower visitors and what plants can do to avoid the costs of being cheated. While both plants and visitors have many ways of cheating, the diversity and deviousness of cheating by the plants seem to be substantially greater than the surreptitious stealing and ambushing that goes on in the animals. This is not surprising when considered in terms of the so-called life-dinner principle, and what each participant has at stake. The chapter begins with a discussion of how animals cheat by means of floral theft and thus get rewards without effecting pollination, including nectar theft, pollen theft, and florivory. It then examines three main options for defending plants against theft: physical barriers, chemical deterrents, and bribes. It also explains the overall effects of theft on flowers and concludes with an analysis of floral exploitation by hitchhikers and ambush predators.

New Oxidized 4-Oxo Fatty Acids from Hygrophorus Discoxanthus

The results are reported from the first investigation of the secondary metabolites of the basidiomycete Hygrophorus discoxanthus (Fr.) Rea. Five new oxidized 4-oxo fatty acids (C16, C18) were isolated from the fruiting bodies and their structures established on the basis of their spectroscopic data and an ozonolysis experiment. Preliminary data indicate a moderate fungicidal activity, suggesting a possible function of these acids as chemical deterrents against mushroom parasites and predators.

Foraging behaviour and food habits of Stone's sheep

Foraging behaviour of Stone's sheep (Ovis dalli stonei) was compared between different times of the year and between burned and unburned ranges. Seasonal habitat selection resulted in the sheep feeding on the ranges which provided the highest quality available forage. In winter, snow severely restricted the area that provided available forage. Sheep fed primarily on grasses, although forbs and browse were also important foods in the spring and summer. Plant species selected by the sheep in summer were not higher in protein or lower in acid detergent fiber than avoided species, but rather lacked the physical and chemical deterrents present in avoided plants. Intake rate (estimated from biting rate of ewes and foraging time) appeared to be independent of herbage quantity on spring ranges.