REFERENCE AND BASELINE HEMATOCRIT MEASURES FOR THE THREATENED NEW ENGLAND COTTONTAIL (SYLVILAGUS TRANSITIONALIS) AND COMPARISON WITH SYMPATRIC EASTERN COTTONTAIL (SYLVILAGUS FLORIDANUS) RABBITS.

From June 2014 to June 2015, capillary tube collections of blood were obtained concurrently with ear clips of trapped free-ranging, globally vulnerable New England cottontails (NEC; Sylvilagus transitionalis) and eastern cottontail rabbits (EC; Sylvilagus floridanus) in the Hudson Valley region of New York, United States. Species identification (NEC, EC) and sex (NEC) were determined genetically using a mitochondrial DNA assay and Y chromosome marker, respectively. Hematocrit values were obtained using a microhematocrit centrifuge. We provide the reference values 35.15-49.55 (2.5 and 97.5 percentiles) and 90% confidence intervals (CI) [lower: 33.00, 36.08; upper: 46.95, 51.00], for hematocrit of NEC. The mean hematocrit for NEC was 42.35% (SE = 0.58, n = 47) and a comparative contemporaneous mean in the same area for EC [39.96 (SE = 0.81, n = 26)], which was significantly different from NEC (P = 0.02). There was a significant sex difference for NEC [male: 43.99 (SE = 1.02, n = 28); female: 39.92 (SE = 0.78, n = 19), P < 0.0001], though not for EC.