Blood cortisol and fecal cortisol metabolite concentrations following an ACTH challenge in unanesthetized brown bears (Ursus arctos)

Fecal cortisol metabolites (FCMs) are increasingly used to index physiological stress in wildlife. Cortisol and other stress hormones act to mobilize glucose, providing energy for the organism to respond to environmental perturbations. Cortisol, the predominant glucocorticoid (GC) in most mammals, is metabolized by the liver and excreted as FCMs. For FCMs to serve as a meaningful physiological index of stress in brown bears (Ursus arctos), we sought to quantify the relationship between blood cortisol and FCM concentrations. Consequently, we conducted an adrenocorticotropic hormone (ACTH) challenge on nine unanesthetized captive brown bears at the Washington State University Bear Research, Education, and Conservation Center. We collected 10mL of blood at 0, 3, 6, 24, 48, and 72 hours post-injection to measure changes in blood cortisol concentrations. Fecal samples were collected between 7:00 am to 8:00 pm from 24 hours prior to injection through 72 hours post-ACTH challenge. We found tha..., We conducted this study in June 2021 using nine captive brown bears (five females, four males) ranging in age from six to 20 years. Bears were housed at the Washington State University Bear Research, Education, and Conservation Center. For the duration of the experiment, bears were housed individually with indoor (3m x 3m x 2.5m) and outdoor (3m x 5m x 5m) access. The study bears had been trained previously to enter a holding crate and present a rear leg through the bars for blood collection. All bears were trained via positive reinforcement using dilute honey (in water), a method shown to not influence plasma cortisol levels (Joyce-Zuniga et al., 2016). Bears were fed a commercial bear diet in the form of kibble from Mazuri (Wild Carnivore Bear Plus), apples, and a small amount of meat (e.g., chicken, beef, or wild game) at 7:20 am and 3:00 pm during the active season (Mid-March through November 1st).
We challenged bears with 5μg/kg Cortrosyn (Sandoz Pharmaceuticals and Amphastar Pharm..., , # Blood cortisol and fecal cortisol metabolite concentrations following an ACTH challenge in unanesthetized brown bears (*Ursus arctos*)

We collected 54 blood cortisol concentration samples across six sampling times (pre-injection, 3 hours post-injection, 6 hours post-injection, 24 hours post-injection, 48 hours post-injection, 72 hours post-injection) among nine bears. We also collected 205 fecal cortisol metabolites (FCMs) samples from 24 hours prior to injection through 72 hours post-injection. We conducted ANOVAs and TukeyHSD to determine when/if baseline (average of cortisol or FCMs concentrations prior to injection) concentrations differed at each time point and when concentrations returned back to baseline.

## Description of File Structure

#### FecalCortisolMetabolites.csv refers to fecal cortisol metabolite data.

Column A: \"Bear\" in column refers to an individual. In our study, each bear was given a name ID and that's how we refer to them.

Column B: \"Day\" refers to whether ...