Characteristics of mule deer day-bed and forage sites in current-condition and restoration-treated ponderosa pine forest

Abstract

We characterized microhabitat (structure and microclimate) at 236 mule deer (Odocoileus hemionus) day‐beds, 152 diurnal forage sites, and 439 random locations during summers of 1998–2000. Our objectives were to 1) identify important microhabitat characteristics of day‐beds and forage sites in untreated forest, 2) compare relative availability of bed and forage sites having these characteristics between forest types, 3) determine whether mule deer selected either forest type disproportionately for these activities, and 4) compare characteristics of day‐bed and forage sites between forest types. Mule deer selected bed and forage sites with specific characteristics in untreated forest each year. Site temperature and canopy closure were the most influential attributes in bed‐site selection, while forage availability best described forage sites. Availability of characteristic day‐bed microhabitat was reduced 50–100%, while forage characteristics increased 31–66% each year in treated forest. Foraging mule deer selected treated forest in 1 year but demonstrated no preference in 2 years. Mule deer continued to use day‐beds in both forest types each year as expected based on proportional area of each forest type, but did so in treated forest in 1999 by utilizing a novel suite of microhabitat features. Bed sites in each forest type had similar levels of midstory canopy closure, but treated forest bed sites were warmer in one year, exclusively located under oaks (Quercus gambelii) rather than conifers, and less concealed than untreated forest beds. Small oak stands were the only dense patches retained in the restoration prescription we examined and provided marginal thermal and hiding cover for day‐bed use by female mule deer. These differences may increase thermoregulatory stress and the potential for increased disturbance and predation of female mule deer and fawns during summer. We recommend retaining >0.04‐ha patches of dense bedding and hiding cover in areas where both forest restoration and mule deer are management concerns.

Summer Habitat Use of Female Mule Deer in Oregon

“…Canopy cover was a strong predictor of mule deer habitat use during summer with the highest probability of use predicted at intermediate (~40%) amounts of cover. This finding is consistent with previous studies of mule deer (Kufeld et al , Ager et al , Germaine et al ). Higher values of canopy cover provide a buffer against climatic extremes (i.e., temperature, solar radiation, and wind speed) and protection from predation, whereas lower values are often correlated with higher quantities of forage (Mysterud and Østbye ).…”

Daytime bedsite selection by the texan white-tailed deer in xerophyllous brushland, North-eastern Mexico

“…Protection from predators is especially important for females trying to ensure the successful development of their offspring (Bowyer et al, 1998;Fox and Krausman, 1994;Gerlach and Vaughan, 1991;Germaine et al, 2004;Huegel et al, 1986;Kroll, 1992;). They search for bedsites with dense cover that is mostly located between the soil and one meter above the ground (Fox and Krausman, 1994;Germaine et al, 2004). Dams are very important sites for the deer given that, in addition to providing water, the riparian vegetation offers dense cover (thermal and concealment), and these are the only places where tree species such as A. farnesiana are found (Bello et al, 2001a).…”

“…Dense bedsite cover was found to be critical to fawn survival in Montana (Riley and Dood, 1984), Arizona (Smith and LeCount, 1979) and Iowa (Huegel et al, 1986). Germaine et al (2004) found that site temperature and canopy closure were the most influential attributes in bedsite selection by deer.…”

“…These places need to offer protection from predators (Gerlach and Vaughan, 1991;Germaine et al, 2004;Huegel et al, 1986), as well as thermal cover that allows the deer to minimize both the absorption of heat from exposure to the sun and the loss of water from evaporate cooling (Lang and Gates, 1985;Ockenfels and Brooks, 1994;Olson, 1992;Tull et al, 2001). Cover is of greater importance in arid and semiarid zones where it is important to prevent the loss of water in the high temperatures (more than 40 C) and limited availability of water that prevail for at least five months of the year (February-June).…”

Role of Thermal Environment in Habitat Selection by Male White‐Tailed Deer during Summer in Texas, USA

“…Effects of temperature, particularly cold temperatures, on whitetailed deer Odocoileus virginianus have been documented in temperate environments (Beier and McCullough 1990), but the effects of heat on habitat selection in subtropical environments are unclear. To reduce heat stress, cervids commonly become inactive and bed in areas with dense vegetation canopy cover (Sargeant et al 1994, Mysterud and Østbye 1999, Germaine et al 2004, Bowyer and Kie 2009). In southern Texas where maximum daily temperatures during summer may exceed 38 C, the need for thermal cover to reduce heat stress should be a major factor influencing selection of plant communities by white-tailed deer during midday.…”