Energy and protein balance of free-ranging black-tailed deer in a natural forest environment

Authored by KL Parker, MP Gillingham, TA Hanley, CT Robbins

Date Published: 1999

Sponsors: No sponsors listed

Platforms: No platforms listed

Model Documentation: Other Narrative

Model Code URLs: Model code not found

Abstract

The purpose of this study was to quantitatively examine the validity of conclusions derived from reductionist studies of nutritional ecology of black-tailed deer. We measured protein and energy intake, activity budgets, and changes in body mass of free-ranging animals in a natural forest environment in relation to availability and nutritional quality of forage and environmental constraints (snow, temperature) over a 2-year period. We compared those observations of intake with modeled predictions of requirements. Daily protein intake remained above demands during all months of the year except February, whereas deer were unable to meet energy requirements for more than half the year. Compounded by increased demands associated with lactation during summer and with snow rather than temperature during winter, the availability of digestible energy is potentially the greatest nutritional limiting factor for black-tailed deer in Alaska. Changes in body mass were directly related to the ratio of energy intake to requirement. Body reserves accumulated during summer with abundant digestible energy were critical to winter survival. Reductionist studies of nutritional and physiological processes provided a strong mechanistic basis for understanding and predicting animal-habitat interactions in a natural environment.

Tags

Individual-based model Carrying-capacity Mule deer Odocoileus-hemionus-sitkensis Cervus-elaphus-nelsoni Labeled water method Southeast alaska Foraging efficiency Western hemlock Nutritional basis