Physiological and behavioral effects of coniferyl benzoate on avian reproduction

Abstract

Various plant secondary metabolites related to cinnamic acid are of interest because of their repellency to birds and their occurrence in ecologically important food items. Coniferyl benzoate (CB), a phenylpropanoid ester that occurs in quaking aspen (Populus tremuloides) is of particular ecological interest because of its effect on ruffed grouse (Bonasa umbellus) feeding behavior and its possible influence on the population dynamics of this bird. During detoxification processes, CB and other analogous compounds are metabolized into by-products, such as ferulic acid (FA), that can cause anti-reproductive effects. We tested whether consumption of CB produces antire-productive effects similar to FA using male and female Japanese quail (Coturnix coturnix) as avian models for ruffed grouse. The parameters we investigated included: the production, morphology, and development of eggs; reproductive characteristics influenced by estrogen; serum prolactin levels; and male reproductive behavior. Dietary CB did not produce antireproductive effects similar to FA at intake levels that Japanese quail and ruffed grouse would freely consume. Consumption of CB by Japanese quail significantly reduced egg production and body mass but did not affect male reproductive performance. Coniferyl benzoate's effect on egg production may be explained by lower energy acquisition and retention rather than endocrine changes per se. Contrary to previous reports, it is unlikely that FA, or similar compounds act directly as estrogen mimics or antagonists. Although, CB did reduce egg production in quail, it is unlikely that it would affect egg production in wild ruffed grouse. Detoxification costs and the effects of CB on nutrient utilization may explain why ruffed grouse avoid high dietary levels of CB.

Plant Secondary Metabolites Compromise the Energy Budgets of Specialist and Generalist Mammalian Herbivores

“…We identified the proportion of energy loss derived from PSMs and fiber. Energy from PSMs and fiber dilutes the total amount of energy that can be harvested from the diet and therefore inflates true excretory costs of processing PSMs (Jakubas et al 1993, Foley and McArthur 1994, ). We also identified the proportion of energy lost in the urine and feces that could be attributed to endogenous energy sources and/or metabolizable energy from the diet that was not absorbed.…”

Deadly combination of genes and drought: increased mortality of herbivore‐resistant trees in a foundation species

“…Genetic variation in resistance and susceptibility to herbivory could have a particularly strong influence on the responses of a plant species to climate change. Plant genes are known to interact with the environment to produce phenotypes that affect the performance and preferences of insect and vertebrate herbivores (Jakubas et al, 1993;Hemming & Lindroth, 1995;Orians & Fritz, 1996;Lawler et al, 1998;Underwood & Rausher, 2000;O'Reilly-Wapstra et al, 2002. In addition, insect herbivory has been predicted to increase with some climate changes, such as increased drought frequency and severity (White, 1969(White, , 1993Logan et al, 2003;Breshears et al, 2005), potentially resulting in insect outbreaks that reduce plant performance (Ferrell et al, 1994;Raffa et al, 2008).…”