Hematologic, biochemical, and endocrine characteristics of bobcats during a prey decline in southeastern Idaho

Abstract

We studied the hematology and blood chemistry of 33 adult bobcats (Felis rufus) captured from 1982 through 1985 in southeastern Idaho during a decline in lagomorphs, their major prey. Our objectives were to relate blood physiology of bobcats to sex, season, and a decline in abundance of black-tailed jackrabbits (Lepus californicus) and Nuttall's cottontail rabbits (Sylvilagus nuttallii). Males had higher (P < 0.10) erythrocyte counts (RBC) and hemoglobin levels (Hb) and lower (P < 0.10) insulin concentrations than females. Bobcats sampled during spring had higher (P < 0.10) mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and'insulin levels, and lower (P < 0.10) Hb, packed cell volume (PCV), RBC, and cholesterol levels than bobcats captured in autumn. The decline in lagomorph prey abundance from 1982 to 1983 was reflected in bobcat blood by lower (P < 0.10) phosphorus and insulin levels and higher (P < 0.10) Hb, RBC, and PCV. Progesterone levels in females reflected field results indicating that reproduction was curtailed when prey was scarce.