Survival of white-tailed deer in intensively farmed areas of Illinois

Abstract

Survival of 265 female and 224 male [Formula: see text]1-year-old white-tailed deer (Odocoileus virginianus) marked on 3 study areas in central and northern Illinois was examined. Females lived, on average, 5.5 years and males 2.5 years from birth. Twenty-four of the 265 females lived for at least 10 years from birth, but only 14 males for at least 5 years. The oldest female was 18 years of age and the oldest male 9 years old when killed. For both sexes, deaths were concentrated in the fall, with males more likely to die than females. Males were more likely to die from hunting and females from other causes. Known wounding deaths were 1 for every 3 retrieved deer for archers and 1 for every 8 for firearms hunters. Dispersing male and female yearlings and 2-year-olds suffered greater mortality than did sedentary deer. Annual survival rates of yearling and older females ranged from 0.56 (dispersing 2-year-olds) to 0.92 (8-year-olds). Survival was significantly reduced for 5-year-old females compared with those both older and younger. Annual survival of rates males ranged from 0.35 (dispersing 2-year-olds) to 0.76 (sedentary yearlings).

Female Philopatry and Extreme Spatial Genetic Heterogeneity in White-Tailed Deer

“…Dispersal is usually biased toward males, although females also disperse (Nelson and Mech 1992;Nelson 1993;Rosenberry et al 1999;Purdue et al 2000;DeYoung 2011). In Illinois, radiotelemetry and tagging studies suggested a relatively large proportion of female fawns disperse with estimates ranging from 21% to 50% compared to male estimates of 56-78% (Nixon et al 1991(Nixon et al , 1993(Nixon et al , 1994(Nixon et al , 2007. Our results agree with the dispersal pattern seen among fawns, which is thought to be the largest dispersing cohort.…”

“…Deer typically disperse distances of 4-10 km (DeYoung 2011), but distances can vary considerably (Sparrowe and Springer 1970). Illinois deer disperse 41-49 km on average (Nixon et al 1991), similar to the average distances we found based on genetic assignment tests. The proportion of deer that disperse commonly varies with sex (Sparrowe and Springer 1970).…”

“…Although deer exhibit a variety of movement types, our reported distances between genetic source and sampling locations fell within the expected dispersal range of Illinois deer (Nixon et al 1991). Deer typically disperse distances of 4-10 km (DeYoung 2011), but distances can vary considerably (Sparrowe and Springer 1970).…”

“…Several additional long-distance dispersal events have been reported in white-tailed deer. Nixon et al (1991) (Nelson and Mech 1992;Nelson 1993;Brinkman et al 2005). Similarly, in South Dakota female deer moved distances of 163 and 225 km, and males moved 204 and 213 km (Sparrowe and Springer 1970;Kernohan et al 1994).…”

“…Genetic assignment tests are unable to determine whether individuals stayed in one location for their entire life, or if they made any migratory, transient (movement among 2 or more home ranges independent of seasonal cues), or exploratory movements (occasional, temporary movements outside of the home range; movement definitions from Skuldt et al [2008]). Exploratory movements were common among adult deer, whereas transient and migratory movements were less frequent but still documented in the population (Nixon et al 1991;Skuldt et al 2008). The previously mentioned Wisconsin deer that traveled a straight-line distance of 98 km out of the CWD area actually undertook a series of dispersal, exploratory, and transient movements resulting in a cumulative distance of 462 km traveled in just over a year (Oyer et al 2007 By using reported distances between source and sample locations to categorize our results as dispersal, examination of our data suggests that many deer disperse longer than the average distance reported by tagging or radiotelemetry observations (Nixon et al 1991), which is consistent with the genetic findings of Kelly et al (2010).…”