Nutrition underpins survival and reproduction in animal populations; reliable nutritional biomarkers are therefore requisites to understanding environmental drivers of population dynamics. Biomarkers vary in scope of inference and sensitivity, making it important to know what and when to measure to properly quantify biological responses. We evaluated the repeatability of three nutritional biomarkers in a large, iteroparous mammal to evaluate the level of intrinsic and extrinsic contributions to those traits. During a long-term, individual-based study in a highly variable environment, we measured body fat, body mass, and lean mass of mule deer (Odocoileus hemionus) each autumn and spring. Lean mass was the most repeatable biomarker (0.72 autumn; 0.61 spring), followed by body mass (0.64 autumn; 0.53 spring), and then body fat (0.22 autumn; 0.01 spring). High repeatability in body and lean mass likely reflects primary structural composition, which is conserved across seasons. Low repeatability of body fat supports that it is the primary labile source of energy that is largely a product of environmental contributions of the previous season. Based on the disparate levels in repeatability among nutritional biomarkers, we contend that body and lean mass are better indicators of nutritional legacies (e.g., maternal effects), whereas body fat is a direct and sensitive reflection of recent nutritional gains and losses.

Chemical immobilization is an important tool for the capture, study, and management of wildlife. Increased regulation of traditional opioids has necessitated a search for alternative drugs in wildlife capture. Butorphanol-azaperone-medetomidine (BAM) is one promising alternative that has been used in a range of taxa, though often on medium-size mammals using groundbased methods. We tested the efficacy of BAM via remote delivery from a helicopter in a wild population of moose (Alces alces shirasi) in northwestern Wyoming. In March 2020 and 2021, we immobilized male (n = 15) and female (n = 26) moose with butorphanol (0.20 mg/kg), azaperone (0.066 mg/kg), and medetomidine (0.079 mg/kg), with antagonists atipamezole (0.495-0.527 mg/kg) and naltrexone (0.124-0.151 mg/kg) to reverse immobilizations. Mean induction (x̄± SE; 9.2 ± 0.6 min) and mean recovery times (7.2 ± 0.5 min) were longer but still comparable to published instances of moose captured using traditional chemical immobilizers (carfentanil, etorphine, thiafentanil). All animals survived >60 days post-capture. Our findings add to a body of work demonstrating that BAM provides rapid inductions, reliable sedation, and quick reversals in a variety of taxa and by aerial remote delivery.