John J. Ozoga

Mortality Rates of Marked and Unmarked Fawns

Sex ratio and birth date of captured and tagged newborn white-tailed deer (Odocoileus virginianus) did not differ from fawns not handled as newborn from 1977 to 1985 (for all years combined) in a 252-ha enclosure in Upper Michigan. Mean age of mothers was not different (P < 0.05) for the 2 groups of fawns in the study. Captured and tagged fawns suffered less mortality than the unhandled fawns (9 vs. 18%, respectively). J. WILDL. MANAGE. 52(3):549-551 Information concerning development and survival of newborn fawns is critical to proper management of deer. Investigators have captured and marked newborn fawns to calculate birth and conception dates (McGinnes and Downing 1977), determine fawn growth rates (Nelson and Woolf 1985), and assess the causes and rates of fawn mortality (Carroll and Brown 1977, Huegel et al. 1985a, Nelson and Woolf 1987). However, because of certain sex-related differences in newborn fawn behavior (e.g., males are more active) (Jackson et al. 1972), and age-specific variations in maternal care and fawn rearing success (Ozoga et al. 1982, Ozoga and Verme 1986) data based on captured animals could be biased. Our objective was to determine if data from captured newborn fawns accurately depicted that for a given population of known sex and age composition. We tested the null hypothesis that there was no difference in mothers age, and sex, birth date, and mortality rates for fawns captured and tagged when <14 days old versus the same data for fawns not captured as newborn. We thank C. S. Bienz, D. L. DeLisle, J. L. Ozoga, L. J. Perry, L. J. Verme, and other Department of Natural Resources personnel for assistance. This paper is a contribution from Michigan Federal Aid in Wildlife Restoration Project W-127-R and the Cusino Wildlife Research Station.

Characteristics and Management of Black Bears That Feed in Garbage Dumps, Campgrounds or Residential Areas

Many black bears, Ursus americanus, in northern Michigan habitually supplement their natural summer diets by feeding in garbage dumps, campgrounds or residential areas. In the past, many of these bears were destroyed as nuisances. To minimize such waste, the Michigan Department of Natural Resources began capturing nuisance bears and releasing them away from areas of human habitation. In conjunction with this program, we estimated the age and recorded the weight, sex and breeding condition of each captured bear in an attempt to learn the sex ratio, age structure, growth rate and fecundity of wild black bears that supplement their diets with garbage. This paper reports and discusses our findings.

Initial and subsequent maternal success of white-tailed deer

Maternally unsuccessful 2-year-old white-tailed deer (Odocoileus virginianus) bred later and conceived more male progeny compared to successful mothers of the same age. We hypothesize that social factors modified the reproductive traits of these unsuccessful does, and they exhibited breeding characteristics typical of yearlings. J. WILDL. MANAGE. 50(1):122-124 Earlier (Ozoga et al. 1982; Ozoga and Verme 1982a, 1984) we suggested that if a 2-year-old white-tailed deer failed to rear her fawn(s), she reverted back to yearling age status in terms of her reproductive traits the following breeding season. Here we document this phenomenon and hypothesize as to the evolutionary or adaptive value of such behavior. This paper is a contribution from Mich. Fed. Aid Wildl. Restoration Proj. W-127-R, and Cusino Wildl. Res. Stn. We thank C. S. Bienz, R. K. Clute, D. L. DeLisle, J. L. Ozoga, and L. J. Perry for assistance during the study. C. L. Bennett and G. E. Burgoyne provided helpful criticism of the manuscript.

Relationship of Photoperiod to Puberty in Doe Fawn White-Tailed Deer

Experiments on doe fawn white-tailed deer ( Odocoileus virginianus ) in Upper Michigan revealed that artificially long days (16L:8D) in autumn did not induce a greater fertility rate compared to short-day (natural daylight) controls. Eleven (61.1%) of 18 long-day doe fawns became pregnant and carried fawns to term, vs. 8 (72.7%) of 11 short-day controls. However, onset of puberty (i.e., estrus) tended to be delayed among long-day specimens compared to the controls. Data support the concept of a doe fawns critical fat/lean biomass ratio regulating the temporal onset of puberty. In northern climes, nutritional constraints rather than rapidly diminishing photoperiod probably serve to curtail folliculogenesis, resulting in a low fertility rate among doe fawn deer.

THE THYMUS GLAND AS A NUTRITIONAL STATUS INDICATOR IN DEER1

In this study we examined the thymus glands from Upper Michigan white-tailed deer (Odo- coileus virginianus) to determine cyclic growth pattern and possible deviations from the norm due to nutritional factors. Data from free-roaming animals revealed that in fawns this gland reached its maximum size during September and October, and was smallest in January and February. Among older deer, thymus weights peaked in June and July, with minimal levels from November through April. Experiments on penned fawns showed that inadequate nutrition in autumn resulted in much smaller glands by mid- December compared to animals on high diet. Moreover, the data indicated that regrowth of the involuted thymus in spring was appreciably delayed by nutritional deprivation. These findings suggest that the periodicity and amplitude of variations in thymus weight of fawns provide a means of evaluating differ- ences in their dietary plane on a seasonal and regional basis. A model is presented which illustrates the prospective relationships between thymic size and current nutritional state of deer from autumn through spring. J. WILDL. MANAGE. 42(4):791-798 The ability to assess correctly the gen- eral well-being of deer is a prime requi- site for proper herd management. Ap- praisal of relative physical condition

Some Longevity Records for Female White-Tailed Deer in Northern Michigan

Longevity records are presented for 14 ear-tagged wild female white-tailed deer (Odocoileus virginianus) known to be from 9 to nearly 1S years of age at the time of their final handling. Two were taken by hunters, 12 were recovered when they returned to the winter deeryard. Table 1. Longevity records for female white-tailed deer in northern Michigan. Age Date Age Date Method and Fate Juv. 3-10-55 14 yr. 9 mo. 3-12-69 Capture-gun and released Adult 2-22-35 14 yr. 7 mo. 1-15-48 Live-trapped and released Juv. 1-29-54 13 yr. 7 mo. 11-67 Highway kill Adult 36-56 12 yr. 11 mo. 56-67 Found dead Juv. 2-25-55 12 yr. 8 mo. 1-27-67 Snared and released Adult 25-52 12 yr. 8 mo. 21-63 Live-trapped and released Juv. 2-28-41 11 yr. 8 mo. 2-13-52 Live-trapped and released Adult 22-55 11 yr. 6 mo. 11-27-64 Hunting season kill Juv. 1-23-42 10 yr. 10 mo. 43-52 Live-trapped (died in captivity4-12-53) Juv. 28-51 10 yr. 9 mo. 3-10-61 Live-trapped and released Adult 1-27-54 10 yr. 8 mo. 2-20-63 Live-trapped and released Adult 3-16-60 9 yr. 9 mo. 37-68 Snared and released Juv. 2-17-52 9 yr. 8 mo. 2-21-61 Live-trapped and released Juv. 2-27-51 9 yr. 5 mo. 11-16-59 Hunting season kill 1027 Records of extreme longevity in whitetailed deer generally concern captive or semi-wild females that have received special care and/or feeding. Popov (1950), Palmer ( 1951), Severinghaus and Cheatum ( 1956 ), and Verme ( 1962 ) report instances of such animals living 12 to 20 years. However, longevity records for wild deer continually facing natural hazards are scarce. Since 1935, nearly 2,000 deer have been live-trapped, ear-tagged, and released at the Cusino Wildlife Research Station in Michigans Upper Peninsula. Subsequent recovery of some of these animals provides evidence of the maximum life span of wild females of the species. Data for all deer 1 A contribution from Federal Aid in Wildlife Restoration Project W-117-R, Michigan. known to be more than 9 years old when last examined are shown in Table 1. Animals judged to be adults at their initial handling were arbitrarily assigned the age of 1 year as of the previous spring. Their designated age at recovery is therefore minimal. Although juvenile males were livetrapped in about the same proportion as juvenile females, the oldest known-age male in our records is 8 years and 5 months old. Only 2 of 14 does listed were eventually taken by hunters, despite antlerless deer hunting seasons in this area for the past 12 years. All other does were recovered when they returned to the winter deeryard. Thus, it seems that the most important mortality factor for these aged animals is their survival during the critical winter period, rather than their escape from hunters. INITIAL CAPTURE RECOVERY This content downloaded from 157.55.39.243 on Wed, 05 Oct 2016 04:05:56 UTC All use subject to http://about.jstor.org/terms BROWSE QUALITY INFLUENCED BY TREE OVERSTORY IN THE SOUTH LOWELL K. HALLS, Wildlife Habitat and Silviculture Laboratory, Southern Forest Experiment Station, USDA Forest Service,

Red Fox Feeding Habits in Relation to Fawn Mortality

Feeding habits of the red fox (Vulpes vulpes) have been investigated throughout the United States (e.g., Errington 1935, Scott 1943, Scott and Klimstra 1955). Most studies revealed that foxes are omnivorous, with their diet being influenced by food availability. Although rarely identified in fox scats, newborn white-tailed deer (Odocoileus virginianus) represent a potential food source in many areas. A recent experiment enabled us to maintain extremely high deer populations in a fenced enclosure while their reproduction was closely monitored (Ozoga and Verme 1982). The objective of the present study was to determine if the diet of coexisting foxes was influenced by the number and mortality of fawns present.

Determining fetus age in live white-tailed does by X-ray

fects of age, sex, and weight on social rank in penned white-tailed deer. Am. Midl. Nat. 106: 92-101. VERME, L. J. 1965. Reproduction studies on penned white-tailed deer. J. Wildl. Manage. 29:74-79. 1969. Reproductive patterns of white-tailed deer related to nutritional plane. J. Wildl. Manage. 33:881-887. , L. D. FAY, AND U. V. MOSTOSKY. 1962. Use of x-ray in determining pregnancy in deer. J. Wildl. Manage. 26:409-411. , AND J. J. OZOGA. 1981. Sex ratio of whitetailed deer and the estrus cycle. J. Wildl. Manage. 45:710-715. WOODSON, D. L., E. T. REED, R. L. DOWNING, AND B. S. MCGINNES. 1980. Effect of fall orphaning on white-tailed deer fawns and yearlings. J. Wildl. Manage. 44:249-252.

A Mechanical Recorder for Measuring Deer Activity

An inexpensive device for recording the number of white-tailed deer (Odocoileus virginianus) moving in runways and the time of movement was developed for use in northern Michigan. The record is made by the movement of a trip line attached to a lever which marks a tape attached to a clock; the lever also turns a countershaft. Results of extensive field tests indicate that these recorders have functioned satisfactorily, and observations from blinds have revealed that they provide a reliable index to the intensity and time of deer activity. During a winter study in northern Michigan, it became necessary to develop, a method for measuring the amount and recording the time of the activity of whitetailed deer. Since deer generally concentrate in coniferous cover and travel wellworn trails during this period, it seemed logical that a recorder could be utilized to tally the number of deer passing on runways. Low cost and low maintenance were essential, since a number of recorders, widely separated in large areas, would have to, be in operation concurrently to give an adequate picture of the time and intensity of deer activity.