Harry A. Jacobson

Denning ecology of black bears in the White River National Wildlife Refuge, Arkansas

Lack of adequate den sites may adversely affect cub survival and reproductive success in black bears (Ursus americanus). Management of remnant bear populations in the lower Mississippi floodplain necessitates understanding denning ecology. We monitored 23 radiotagged black bears for 33 den years from 1993 to 1995 in White River National Wildlife Refuge, Arkansas to investigate denning chronology and den requirements. Bears entered dens between 1 January-20 February and emerged between 12 March-28 April. Mean (±SE) denning duration was 92.9 ± 6.6 days and varied between sex-age classes (P = 0.002). Pregnant females denned longer (117.8 ± 5.2 days, P = 0.029) than males and non-pregnant females (84.2 ± 7.7 days). More than 44% of the bears that denned (n = 27) used >1 den during a denning season, and one female used 4 dens. Most (90.2%, n = 51) dens were elevated tree cavities with a hollow opening on the top or middle of the main trunk. Three species of trees were used with 77.8% (n = 46) being overcup oak (Quercus lyrata). Basal area of trees ≥10 cm diameter at breast height (dbh; P < 0.001) and number of stems ≥84 cm dbh (P < 0.001; the min. dbh of den trees documented in this study) differed among vegetation plots with and without den trees. For seasonally flooded habitats, our results suggest the need for maintenance or augmentation of trees ≥84 cm dbh to increase the number of potential dens and to enhance the quality of den microhabitat in the lower Mississippi Alluvial Valley.

Forest Management and Female Black Bear Denning

Abstract: Most habitats available to black bear (Ur,~usamericanus) in the Mississippi Alluvial Valley (M.4V) consist of seasonally flooded commercial forests where lack of suitable dens may limit population growth. \Ve studied interactions between forest management and flooding relative to female black bear denning. Denning behavior differed between commercial and noncommercial forests. Females used tree dens exch~sivelyon nonco~nmercialforests, whereas on commercial forests, most (83%) were ground dens. L7ariationsin ground den elevation resulted in differing inundation probabilities, altering survival prol.)abilities for neonates. On commercial forests, ground dens with similar inundation probabilities as tree dens allowed successful repro-duction to occur. Management practices that enhance suitable cover in areas of nlirlimal inundation probability may mitigate for lack of den trees in flood-prone landscapes. JOURNAL OF WILDLIFE MANAGEMENT 65(1):34-40 Key words: batture, black bear, denning, elevation, flooding, forest management, Misissippi Allu~ialValley, reproduction, topography, Ursus arnericanus.

Variance component analysis and heritability of antler traits in white-tailed deer

Information on genetic and environmental sources of variation that control antler development in white-tailed deer (Odocoileus virginianus) is needed to develop harvest management programs. We estimated genetic and environmental components of variance for antler development traits collected from deer born from 1977 to 1993 in a captive population. Antler traits were incidence of spikes versus forks, number of points, maximum inside spread, total mass, main beam circumference, and main beam length. In 1.5-year-old males, the degree of additive genetic determination, or heritability (h 2 ), was low (range = 0.00-0.13) for incidence of spikes versus forks, number of points, maximum inside spread, total mass, and main beam length, and was moderate for main beam circumference (h 2 = 0.25). The relatively large carryover influence of the dam as a source of variation was more important than heritability. In 2.5-year-old males, antler-trait heritabilities were low to moderate (0.08-0.39), whereas heritability ranged from 0.03 to 0.43 in mature males (3.5-7.5 years old) with repeated antler-trait records. Permanent and residual effects caused by nonadditive genetic and environmental factors accounted for most of the variation in antler traits expressed by mature males. Our results do not support the use of yearling antler records as criteria for selective breeding management or harvest schemes to alter the genetic quality of a white-tailed deer population.

Artificial insemination trials with white-tailed deer

We used frozen semen from 8 white-tailed deer (Odocoileus virginianus) in 53 artificial insemination trials. The resulting pregnancy rate was 75% and a mean of 1.48 fawns/pregnant female was produced. Semen was frozen in tris-yolk diluter of 0.2 M, 6.8 pH, and 7% glycerol solution at final dilution. Semen was collected by electroejaculation from 6 males and at 1 and 5 hours postmortem from 2 males. Pregnancies were obtained from semen from all males. Semen with post-thaw progressive motility >70% resulted in 100% conception (n = 15) compared to conception rates of 66% (n = 38) for semen with <60% progressive motility. High conception rates demonstrated artificial insemination can be a useful tool for introduction of new genetic material or preservation and long term storage of rare genetic material of wild ruminants. J. WILDL. MANAGE. 53(1):224-227 Genetic manipulation of wild and captive populations of wildlife will become important in the future. Genetic introduction has been recommended to reduce inbreeding depression of ungulates in reserves and in geographically isolated populations (Allendorf 1983, Chesser 1983). Artificial insemination eliminates high costs associated with animal transport and reduces risks of potential introduction of diseases or parasites. Preservation and propagation of endangered species are other reasons for developing procedures for artificial breeding of wild ungulates. Semen has been collected from cervids (Bierschwal et al. 1970, Dott and Utsi 1971, Lambiase et al. 1972, Jaczewski and Morstin 1973, Krzywinski 1976, Graham et al. 1978, Krzywinski and Jaczewski 1978, Seager et al. 1978, Bearden et al. 1980, Haigh et al. 1983), frozen (Graham et al.1978, Krzywinski and Jaczewski 1978, Seager et al. 1978, Krzywinski 1981, Haigh et al. 1983), and fawns have been produced from artificial insemination of cervids (Krzywinski and Jaczewski 1978, Haigh 1984). However, quantitative data are lacking on the effectiveness of artificial insemination for cervids. These data are needed before artificial insemination becomes a routine research and management tool. We document a procedure for artificial insemination of white-tailed deer and the success we have had producing fawns from the procedure. We thank R. E. Zaiglin and K. R. Herriman for their assistance in conducting insemination trials. This study was financed by the Mississippi Agricultural and Forestry Experiment Station and by E. L. Cox, Jr. and E. L. Cox, Sr., Athens,

Acoustics of White-Tailed Deer (Odocoileus virginianus)

Eight stereotypic sounds of white-tailed deer ( Odocoileus virginianus ) are distinguished: 1) bleat, 2) distress call, 3) nursing whine, 4) grunt, 5) alert-snort, 6) footstomp, 7) snort-wheeze, and 8) aggressive snort. Only the grunt was associated with both dominant-subordinate and cohesive behavior. The grunt, alert-snort, footstomp, snort-wheeze, and aggressive snort originated from yearling and older deer. The nursing whine was heard only from fawns, and the bleat was emitted only by fawns and juveniles. The distress call was made by both sexes of juveniles and adults. Twelve voice parameters, expressing unique phonetic qualities of distress calls from 10 neonatal fawns, allowed significant discrimination of individual fawns, sibling pairs, and between sex and weight.

Influence of Mississippi alluvial valley rivers on black bear movements and dispersal: implications for Louisiana black bear recovery

American black bear (Ursus americanus) populations were significantly reduced throughout their range, particularly in southeastern North America. Currently, populations in this region are very fragmented, resulting in concern over possible barrier effects of rivers to normal bear movements and dispersal. This is particularly true for Mississippi, where black bear dispersal into the state is critical if populations are to be recovered. Thus, we studied the relative effects of rivercourses on bear movements and dispersal patterns in southeastern Arkansas, 1992–1996. We captured, radiocollared, and uniquely tagged 40 bears and used radiotelemetry to determine their movements. The Mississippi River (width ≈1600 m) deflected bear movements, whereas the White River (width ≈200 m) was not a barrier to bear movements or dispersal patterns. Frequency of river crossing differed by gender (P=0.007) and season (P<0.001). Male bears crossed rivers more frequently than females. Rivers were crossed less from December to March compared to other seasons. Rivers acted as a semipermeable barrier to bear movements and dispersal patterns, which may have major implications for conservation of large mammal metapopulations. Males appear to be influenced less by rivers, so female translocations across rivers may be necessary to recover fragmented bear populations. We provide an example describing direct implications of this study to the recovery of the threatened Louisiana black bear (U. a. luteolus).

Pattern of space use by female black bears in the White River National Wildlife Refuge, Arkansas, USA

Abstract The manner in which space is used by animals may influence several aspects of biology, including the pattern of resource use and intra-specific competition. We monitored 16 radio-collared female black bears (Ursus americanus) for 9,216 radio days during 1993–1995 in the White River National Wildlife Refuge (WRNWR), Arkansas, U.S.A. to investigate space use patterns. Annual home ranges (95% convex polygon) ranged from 2.10 to 11.34 km2 with a mean (± SD) size of 4.90 (± 2.09) km2 (n = 16). Largest home ranges were occupied by 2 females with yearlings during one year of study. Home ranges among neighbouring bears overlapped considerably. Although bears maintained larger home ranges during summer, the size of home range did not differ among seasons (P > 0.50). Our estimates of home range size for female black bears were smaller than those obtained in a study of the same population during 1979–1982. Because the size of the bear population at WRNWR was substantially smaller (about 130 bears) during 1979–1982 compared to the present population of ≥348 bears, these results suggested that population density and size of female black bear home ranges may be negatively correlated. Conservation implications of density-dependent space use pattern are also discussed.

Effects of season and area on ectoparasites of white-tailed deer (Odocoileus virginianus) in Mississippi.

Nine species of ectoparasites (4 Acari, 2 Mallophaga, 1 Anoplura, 1 Diptera, and 1 Siphonaptera) were recovered from 126 white-tailed deer collected in northern, central, and southern Mississippi. Intensity and prevalence of adults of Ixodes scapularis and larvae, nymphs, and adults of Amblyomma americanum varied significantly over collection periods, but not between host sexes. Lipoptena mazamae occurred on deer from only one study area. Although individual deer were heavily parasitized by Tricholipeurus parallelus and T. lipeuroides, their prevalence was limited. Hoplopsyllus sp., Solenopotes sp., Amblyomma maculatum, and Dermacentor albipictus had prevalences of <10% and were not tested for area, host sex, and seasonal effects. The potential pathogenicity of these ectoparasite species are related to white-tailed deer in Mississippi.

Dental eruption in bobcats.

We documented tooth eruption in 9 hand-raised bobcat (Felis rufus) kittens. Tooth lengths were measured to the nearest mm. Deciduous dentition began to erupt at 11-14 days of age and was completed by 9 weeks of age. Permanent dentition began to erupt at 16-19 weeks of age and was completed by 34 weeks of age. The sequence and timing of deciduous and permanent dentition will aid in estimating parturition and copulation dates from bobcat kittens in the wild. J. WILDL. MANAGE. 52(3):515-517 Information on the dental eruption patterns of known-age bobcats has not been published. Data on sex ratios, age structures, and age-specific reproductive rates have been collected and analyzed by states to assess the status of resident bobcat populations (Gluesing 1982). These data have been compared to data collected and analyzed in a similar manner from prior studies (Gluesing et al. 1986). Therefore, researchers have compared 1 unknown to another when estimating age structure and periods of reproductive activity. Estimates of breeding and parturition dates of the bobcat have been based on dentition-eruption schedules and growth rates of the domestic cat. Crowe (1975) developed a dentition eruption schedule for bobcats using the tooth eruption schedule of the domestic cat presented by McClure et al. (1973:211). Crowes (1975) schedule has been used to age wild bobcat kittens (Blankenship 1979). The purpose of our study was to determine eruption schedules for deciduous and permanent teeth from knownage bobcat kittens. An accurate knowledge of the tooth eruption schedules of bobcat kittens will aid in elucidating parturition and conception dates of wild bobcats. This manuscript is dedicated to E. A. Gluesing, who initiated the study and whose efforts and guidance made this study possible. We thank J. R. Jackson, V. M. Woshner, and others who helped raise the kittens. We also thank B. D. Leopold, E. P. Hill, and R. M. Kaminski for their help in editing this manuscript, and K. M. Vandevelde for typing it. Financial support was p ovided by Mississippi Federal Aid in Wildlife Restoration Project W-48-30 and the Mississippi Agricultural and Forestry Experiment Station.

Simulated effects of harvest strategy on reproduction in white-tailed deer

A deterministic simulation model was used to examine the possible effects of harvest strategy on the temporal aspects of white-tailed deer (Odocoileus virginianus) reproduction in Mississippi. The timing of bucks-only and antlerless deer harvests affected reproductive parameters. Delaying the start of buck hunting from mid-November to mid-December increased the proportion of does serviced on their initial estrus of the season from 0.77 to 0.91 and resulted in a mean fawning date that was 4 days earlier. Harvesting antlerless deer prior to peak rut allowed the maximum number of does to be serviced on their first estrus of the season. Decreasing the harvest rate of bucks from 0.81 to -<0.61 increased the proportion of does serviced on their first estrus from 0.76 to 0.91 and increased the fecundity rate from 1.56 to 1.61. The model was sensitive to the timing of the rut and the number of does serviced per buck. J. WILDL. MANAGE. 48(2):535-541 The variation in breeding dates of adult ( 1/r years) white-tailed deer in Mississippi is extensive. Jacobson et al. (1979) reported that the rut ranged from 20 November to 15 March, with over 80% of breeding occurring between 21 December and 21 January. Additionally, mean breeding dates in north-central Mississippi shifted from 22 December during 196063 to 19 January during 1976-79 (Jacobson et al. 1979). Age and nutrition are known to affect the onset of estrus in white-tailed deer. Yearling does (11/? years old) tend to breed a few days later than the average for older animals, and doe fawns breed substantially later (Haugen 1975, Butts et al. 1978, McCullough 1979: 49-50). Verme (1965) reported that does on a high level of nutrition began breeding 15 days earlier than poorly fed animals. Teer et al. (1965), McGinnes and Downing (1977), and McCullough (1979: 50-51) also indicated that time of estrus must be controlled to some extent by nutrition. Other factors that may influence breeding periodicity are photoperiod (Severinghaus and Cheatum 1956, McDowell 1970), temperature (Cheatum and Morton 1946, Severinghaus and Cheatum 1956), and fawn survival rates the previous year (McGinnes and Downing 1977). None of these factors appear to account for the 4-week shift in mean breeding date observed in north-central Mississippi by Jacobson et al. (1979). They suggested that harvest of adult bucks prior to the peak period of estrus may have contributed to the delayed rut noted after 1963. Prior to the 1971 season, 20 days of bucks-only hunting with firearms were allowed between 20 November and 4 January with a limit of two antlered bucks/hunter. In 1971, gun hunting was increased to 32 days, a primitive weapons season of 16 days was initiated, and the limit increased to four antlered bucks/hunter. Length of the hunting season and bag limit remained essentially unchanged from 1971 to 1976. During the 1977 season, the regulations allowed one antlered buck to be taken per hunter daily. Traditionally, hunting pressure has been heavy and the IPresent address: Department of Range and Wildlife Management, Texas Tech University, Lubbock, TX 79409. 2 Present address: Department of Forestry, Clemson University, Clemson, SC 29631. J. Wildl. Manage. 48(2):1984 535 This content downloaded from 157.55.39.206 on Sat, 17 Dec 2016 05:25:22 UTC All use subject to http://about.jstor.org/terms 536 HARVEST STRATEGY AND DEER REPRODUCTION * Gruver et al. INPUT INITIAL CONDITIONS