The potential for bamboos to become naturalized rises as their popularity grows for ornamental horticulture and biofuel pursuits. Bamboos spread rapidly through prolific rhizomatous production, but their infrequent semelparous flowering cycles may present more ominous consequences – short-term increases in the likelihood of Peromyscus maniculatus (deermouse), a voracious seed predator and a carrier of the Sin Nombre Virus (hantavirus) coming into contact with humans. Increases in zoonotic diseases (e.g. Plague and HPS) and bamboo masting events are linked in eastern Asia and South America where rodents and bamboos often occur sympatrically. Rodents feed upon the temporarily abundant bamboo fruits, then spread to crop fields and dwellings as they exhaust the supply of bamboo fruits. We evaluated the effects of an introduced bamboo seed diet on the weight maintenance and fitness of P. maniculatus in feeding trials. P. maniculatus were fed either native grass seed (Agropyron spicatum), seeds of native Pinus ponderosa, commercial rodent chow and fruits from Bambusa distegia, a temperate bamboo from Sechaun, China. Weight of the mice was monitored for six weeks; other groups of females were mated, gestated and supported pups to weaning while feeding exclusively on one of the four diets.
Results/Conclusions
P. maniculatus, regardless of diet, maintained weight. Bamboo seeds, however, had a significant positive effect on reproduction. Adult females fed a bamboo diet produced significantly more offspring than females in other treatments. Pups borne from females fed a bamboo diet had no significant difference in their weight or post-lactation survival compared with pups borne to females on other diets. Increased fitness in bamboo-fed females cannot be attributed to differences in calories or nutrient content between treatments. In the event that any bamboo species proliferates within the range of P. maniculatus, e.g. the coniferous forests of the Pacific Northwest, the subsequent risk to human health could be substantial if rodent populations rapidly increased and then spread into nearby settlements. This human health dimension may need to be included in decisions to introduce and market bamboos in regions where P. maniculatus with high hantavirus infection is common.