Winter Diet and Nutritional Condition of White-Tailed Deer in the Northern Black Hills, South Dakota

<p>Habitat deterioration in the northern Black Hills (NBH) of South Dakota may be responsible for declining white-tailed deer (Odocoileus virginianus) population levels (Griffin et al. 1992). Because of the relationship between habitat and nutrition, a two-year research project was initiated in January 1992 to evaluate the physical and nutritional condition of white-tailed deer inhabiting five NBH winter subranges. Habitat variables were measured at 100 random locations on each study area. Pellet groups were collected throughout each study area at two-week intervals during January, February, and March 1992 and 1993. Five female white-tailed deer were collected from each study area in February 1992 and 1993. Diet quality was monitored using fecal nitrogen and phosphorus levels. Diet composition was evaluated using microhistological analysis of fecal samples. Eight blood and 10 morphological/physiological indices were used to evaluate deer condition. Using principal component analysis, winter subranges were separated into two categories: 1) ponderosa pine dominated, forested areas and 2) agricultural areas. In the mild winter of 1992, fecal nitrogen and phosphorus levels indicated that deer were consuming a spring diet by late March. In 1993, diet quality did not differ intraseasonally but fluctuated with snow levels. Intraseasonal trends in dietary composition paralleled changes in diet quality. Diet composition gradually changed from a winter diet to a spring diet in 1992 and fluctuated with snow depth in 1993. Despite higher animal densities, fecal nitrogen and phosphorus levels indicated supplementally fed deer consumed higher quality diets than non-supplemented animals in 1992 and 1993. Higher quality diets among supplemented animals may be related to higher corn consumption during both years and lower consumption of ponderosa pine (Pinus ponderosa), juniper (Juniperus spp.), and shrubs in 1993. Across all but one non-supplemented subrange, consumption of Oregon grape (Berberis repens), a low growing nondiciduous shrub, declined in the more severe winter of 1993, while consumption of other shrubs increased in 1993. Deeper, more persistent snow resulted in poorer deer condition in 1993. Total serum protein and fat indices declined from 1992 to 1993, indicating lower protein and energy availability in 1993. Although nonsupplemented winter subranges were able to meet deer nutritional requirements during a mild winter, deer relied more heavily on body reserves in 1993. Supplemental feeding improved diet quality and deer condition. Alternatives to improve deer condition include population reduction and winter range improvement.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - Open Access

Discipline thesis:degree_discipline

Wildlife and Fisheries Science

Year

1994

Author dc:creator

• Osborn, Robert G.

Contributors dc:contributor

• Jonathan A. Jenks

• Natural Resources and Conservation

Statement dc:rights

• Copyright © 1994 Robert G. Osborn. All rights reserved.

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/565

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-1565