Deer activity levels and patterns vary along gradients of food availability and anthropogenic development.

Animal activity reflects behavioral decisions that depend upon environmental context. Prior studies typically estimated activity distributions within few areas, which has limited quantitative assessment of activity changes across environmental gradients. We examined relationships between two response variables, activity level (fraction of each day spent active) and pattern (distribution of activity across a diel cycle) of white-tailed deer (Odocoileus virginianus), with four predictors-deer density, anthropogenic development, and food availability from woody twigs and agriculture. We estimated activity levels and patterns with cameras in 48 different 10.36-km2 landscapes across three larger regions. Activity levels increased with greater building density, likely due to heightened anthropogenic disturbance, but did not vary with food availability. In contrast, activity patterns responded to an interaction between twigs and agriculture, consistent with a functional response in habitat use. When agricultural land was limited, greater woody twig density was associated with reduced activity during night and evening. When agricultural land was plentiful, greater woody twig density was associated with more pronounced activity during night and evening. The region with the highest activity level also experienced the most deer-vehicle collisions. We highlight how studies of spatial variation in activity expand ecological insights on context-dependent constraints that affect wildlife behavior.

 prediction of wound healing outcome using skin perfusion pressure and transcutaneous oximetry: a single-center experience in 100 patients.

Chronic lower extremity wounds are challenging and typically occur in patients with complicating conditions such as diabetes and peripheral vascular disease. Noninvasive modalities developed to assess wound healing potential, such as transcutaneous oximetry (TcPO2), present problems including lengthy test time, variable results, and anatomical limitations. Skin perfusion pressure (SPP) testing appears to be a timely, objective, and reliable alternative. This prospective, single center, comparative study evaluated TcPO2 and SPP test results in 100 patients with chronic extremity wounds to determine their accuracy and usefulness in predicting wound healing potential. Concomitant baseline SPP and TcPO2 were measured and used as predictors of successful wound healing. A threshold of < 30 mmHg was selected as the cutoff below which the test was considered significantly abnormal and indicative of a wound that was unlikely to heal. Follow-up evaluations were conducted for 12 months or until healing, whichever occurred first. The study was evenly balanced for gender distribution and the mean age of the population was 63.4 years (range 19-94). Wounds were secondary to underlying diabetic, arterial, or venous conditions. SPP alone successfully predicted wound outcome in 87% of the cohort compared to TcPO2 at a rate of 64% (P < 0.0002). Furthermore, skin perfusion pressure was more sensitive in its ability to predict wound healing relative to TcPO2 (90% versus 66%; P <0.0001). SPP with values ≥ 30 mmHg is a useful positive independent predictor of wound healing potential. The continued use and investigation of SPP as a reliable and objective measurement tool in wound assessment protocols and other microperfusion assessments are recommended.