Evaluating Condition of Alaskan Black Bears with Blood Profiles

Abstract

Blood samples were collected from 220 adult and 78 subadult black bears (Ursus americanus) from fall 1977 through summer 1985 on the Kenai Peninsula, Alaska. The samples were analyzed for 24 biochemical and 2 hematological parameters. Discriminant analysis was used to select useful blood parameters for assessing the condition of black bears based upon the dynamic spring to fall physical condition change. Parameters found to be most useful for females were hemoglobin (Hb), alpha 1 globulin (A1G), and calcium (Ca). The parameters most useful for males were globulin (G), packed cell volume (PCV), albumin/globulin ratio (A/G), sodium (Na), calcium/phosphorus ratio (Ca/P), and Hb. We recommend using Hb and PCV to determine the condition of black bears in the field. Blood profile changes in denning bears were detected for nearly all parameters. The urea/creatinine (U/C) mean was 8.9 for denning bears (n = 48). J. WILDL. MANAGE. 52(1):63-70 Blood chemistry and hematology values have been used to apply the indicator animal concept (Franzmann 1970) to assess the nutritional status of herbivores (Franzmann 1985). LeResche et al. (1974) outlined the procedure for establishing nutrition-blood parameter relationships: (1) determine those characteristics that may potentially influence blood values (boundary conditions); (2) establish normal values within the boundary conditions; and (3) determine the nature and magnitude of changes in blood values resulting from known changes in food intake, nutrition, or related parameters. Hanks (1981) suggested adding a fourth criterion; assess the resilience of an animal population, or some measurement of its ability to withstand further perturbations. Most black bear blood studies have provided data for the identification of boundary condit ons (Eubanks et al. 1976, Bush et al. 1980, Beeman 1981). Sex, age, hibernation, and seasonal changes are sources of variation in blood values for black bears (Matula et al. 1980, Palumbo et al. 1983). This content downloaded from 207.46.13.112 on Mon, 03 Oct 2016 05:30:12 UTC All use subject to http://about.jstor.org/terms 64 BLOOD PROFILES OF BEARS * Franzmann and Schwartz J. Wildl. Manage. 52(1):1988 Table 1. Blood values that differed (P < 0.05) among seasons from subadult (536 months old) black bears on the Kenai Peninsula, Alaska, 1977-85. Blood parameter Unit Seasona f SD n Hemoglobin g/dL Summer A 16.7 2.3 27 Fall 19.7 2.1 7 Den 19.1 2.2 33 Packed cell volume % Summer A 41.5 6.7 26 Fall AB 45.7 3.1 7 Den B 48.9 5.5 33 Cholesterol mg/dL Summer 276.0 55.0 28 Fall 275.0 40.0 9 Den A 396.0 111.0 35 Lactic dehydrogenase IU/L Summer A 774.0 141.0 26 Fall 625.0 159.0 9