Behavior Of White-tailed Deer Research Articles

Isotope values reveal “canopy effect” in deer territoriality and maize consumption for dogs from archaeological sites in Kentucky dating to the Middle Woodland through Late Fort Ancient time periods

This research analyzes stable carbon, nitrogen, and oxygen isotope values in tooth collagen and enamel to investigate foraging and territorial behavior in white-tailed deer (Odocoileus virginianus Zimmermann) and maize (Zea mays Linneaus) consumption in dogs (Canis familiaris Linneaus). The study analyzed 22 deer teeth from 13 archaeological sites in Kentucky covering a span of approximately 1,500 years of human occupation. The article presents evidence of foraging and territorial behavior in white-tailed deer, identified through the “canopy effect” observed in deer stable carbon isotope values in remains spanning from the Middle Woodland (200 BCE – CE 500) to Late Fort Ancient (CE 1400 – 1680) time periods in Kentucky. Additionally, teeth samples from nine dog and one wolf (Canis lupus Linneaus) were analyzed and indicate significant consumption of maize in seven of the dog samples. These specimens came from seven archaeological sites in Kentucky dating from the Early through Late Fort Ancient (CE 1400 – 1680) time periods. The study also contributes to the growing database of isotope studies in the Eastern Woodlands by presenting carbon and nitrogen isotope values on deer bone collagen from nine deer bone samples from three of the same archaeological sites dating to the Middle Woodland to Early Late Woodland.

Environmental drivers and fitness consequences of partial migration under climate change

Abstract Animals migrate to access seasonally variable resources or to escape unfavorable local conditions. Partial (flexible) migration strategies offer animals a fitness trade-off in which individuals may choose whether to incur the energetic costs of migration depending on the potential benefits associated with avoiding adverse conditions. Partial migration patterns may shift due to anthropogenic land use and climate change, possibly reducing the benefits of migration and resulting in unpredictable migration cues. We examined causes, consequences, and changes in individual-level partial migration of white-tailed deer Odocoileus virginianus by analyzing archival telemetry data (1986-2014) across four distinct populations in the Great Lakes region, North America. We hypothesized that if the costs of migration outweigh benefits, we would see migratory behavior decline. Migratory behavior declined from 75% in 1987 to 11% in 2014 independent of population identity. Annual mortality was higher for migratory white-tailed deer, while increasing minimum temperatures positively impacted survival but did not influence migration. Our results suggest that migratory behavior in white-tailed deer is declining over time and may be associated with declining winter severity. The loss of migratory behavior in large mammals may have ecosystem-level impacts and our study emphasizes the need to better understand and conserve these migratory traditions.

Chronic wasting disease effects on a breeding season behavior in White-tailed Deer (Odocoileus virginianus).

Wildlife disease outbreaks can lead to population declines, which are usually attributed to increased direct or indirect mortality. Alternatively, behavior associated with sickness can lead to social isolation, potentially decreasing fitness of affected individuals. A useful case study to examine this dynamic is chronic wasting disease (CWD), a neurological disease of cervids, known to affect behavior and movement. In this study, we monitored scraping, a White-tailed Deer (Odocoileus virginianus; WTD) breeding season behavior, in an area of high CWD prevalence to determine if this reproductive behavior is affected by CWD. At 107 scrape sites, we detected 3,063 scrape interactions and 218 unique bucks. Bucks engaged with scrapes most often, performing 73% of interactions-compared to 23% by does, and 4% by fawns. Twenty-one bucks captured on camera traps at scrape sites were harvested through recreational hunting, 13 testing CWD-positive and 8 CWD not-detected. We found no significant effect of CWD status on specific scraping behaviors. There may, however, have been population-level effects, with shifts toward greater proportions of scraping by yearling bucks and during daylight hours compared to findings from past studies.

Influence of Visual Input on Behavior of White-tailed Deer (Odocoileus virginianus) to an Auditory Alert Recording

Author(s): Gallagher, George R.; Holloway, Catherine H.; Williams, Kelly L.; Ellenburg, Robyn Y.; Saylors, Brianna M.; Van Der Heiden, Lara; Peters, Sunday O. | Abstract: The objective of this study was to determine the importance of visual verification in the behavioral response of white-tailed deer to an auditory alert recording. We utilized a portable, remote-controlled sound system to play recordings of the white-tailed deer alert “blow.” In Phase I, the sound treatment was administered from a single location in a 1.3-ha grass lawn surrounded by wooded areas and roads with limited visibility, to free-ranging white-tailed deer on the Berry College campus during day and night hours. In Phase II, sound treatments were administered from varying locations in open lawn and hay fields. Recordings of deer activity were obtained from a digital camcorder and a FLIR thermal imagery camera. Behavior of white-tailed deer in response to the audio recording was classified as Passive (no altered behavior), Alert (actively observing and/or listening toward the recorded sound), Active (slow to moderate intentional movement toward or away from the recorded sound), or Flight (running away from the recorded sound). Six 10-sec periods of activity were evaluated. The pretreatment period (Pre Treat) began one minute prior to activation of the alert sound. The next four time periods [Sound (T1-T3)] represent the four consecutive 10-sec time frames from initiation of the sound treatment. A post-treatment (Post Trt) period was approximately 60 sec following the T3 period. In both phases, deer exhibited decreased Passive Behavior and increased Alert Behavior and Active Behavior following administration of the sound treatment. In the more confined area (Phase I) at night, deer tended to exhibit Alert and Active Behaviors longer than during the day. In the more open areas (Phase II), the degree of Active Behavior was diminished, with deer in the day tending to seek out the location of the sound. The results indicate that the use of visual verification to the auditory alert influenced behavioral response of white-tailed deer, and may be more critical in the areas where that process is limited compared to more open landscapes.

Roadside Activity and Behavior of White-Tailed Deer and Other Wildlife near Unfenced Underpasses

More than 1.2 million deer–vehicle collisions (DVCs) occurred in the United States in 2014. U.S. highways have thousands of bridges and culverts large enough to facilitate safe passage of large animals beneath the road. Because these structures were built for drainage or other purposes unrelated to wildlife passage, they are typically spaced miles apart and have no fencing. This study was the first in the United States to evaluate deer activity and behavior at unfenced underpasses and adjoining sections of Interstate roadside. Although black bear activity and other wildlife activity were not a primary focus, they were also evaluated. Thirty-eight cameras were installed beneath a large bridge underpass and a box culvert and along the adjoining 0.5-mi roadside on both sides of the underpass and culvert. There was frequent use of the underpass and culvert by deer to cross the highway (1,187 per year) and high deer activity along the roadside (1,181 per year) despite deer access to the underpass and culvert. A statistically significant relationship was found between roadside deer activity and DVCs. Predominant behaviors were feeding and walking along the roadside, and roadside walking was significantly correlated with DVCs in October and November. Although highway crossing attempts were a low proportion of deer behaviors, crossing attempts resulted in 7.5 DVCs per year on 1-mi highway segments adjacent to the unfenced underpasses. The findings support the installation of fencing along the roadside adjacent to existing large underpasses and culverts used by deer, to mitigate DVCs.

Social and Environmental Influences on Female White-Tailed Deer Dispersal Behavior

Dispersal behavior is primarily a male-biased behavior in white-tailed deer (Odocoileus virginianus) throughout the species range. However, in the agriculture-dominated lower Midwest and Great Plains, female dispersal also occurs. We examined the effects of the social and physical environment experienced by female fawns marked in central and northern Illinois, where dispersal rates were high (31%–61%) and forest cover occupied <5% of the county landscape. Dispersal probability was high for females born to subordinate mothers (25 of 26) and for fawns paired with a sibling that also dispersed (25 of 31). Females that dispersed came from populations with similar densities as those of females that remained sedentary. The lower dispersal rate for females born to dominant mothers suggests that the higher resource availability present within the home ranges of dominant mothers affects dispersal behavior. Subordinate mothers generally inhabit smaller, less secure ranges with fewer resources available to offspring. Resource availability appears to be one of the proximate factors influencing female fawn movement behavior.

Population density influences dispersal in female white-tailed deer

Dispersal behavior in white-tailed deer (Odocoileus virginianus) predominantly occurs in 1-year-old males; however, females of the same age also disperse. The timing of female dispersal during fawning season and low dispersal rates suggest that competition for mates and reduced inbreeding are not ultimate causes of female dispersal, as suggested for males. We proposed that female dispersal is the result of competition for space when pregnant females seek to isolate themselves before and after parturition. To test this hypothesis, we conducted a meta-analysis of female dispersal rates from 12 populations of white-tailed deer and predicted dispersal rate and distance were positively related to deer density. We found a positive relationship between dispersal rate and deer per forested km 2 and between dispersal distance and deer per forested km 2 . These results are consistent with the hypothesis that female dispersal is density-dependent and caused by the exclusion of subordinate 1-year-olds as adult females seek isolation before and after parturition.

Influences of Hunting on the Behavior of White‐Tailed Deer: Implications for Conservation of the Florida Panther

The effects of deer hunting by humans on deer population dynamics and behavior may indirectly affect the population dynamics and behavior of deer predators. We present data on the effects of hunting on the behavior of white‐tailed deer (Odocoileus virginianus) on the Osceola National Forest, a potential reintroduction site for the endangered Florida panther ( Felis concolor coryi). We then use this information to formulate and recommend testable hypotheses to investigate whether these changes in deer behavior influence panther movements, mortality, and hunting success. We monitored 14 radio‐collared deer from June 1990 through July 1991 to compare movement, activity, and habitat‐use patterns between the hunting and nonhunting seasons. Mean distance of deer to the nearest road, mean distance of activity centers of diel home ranges to the nearest road, and mean nocturnal rate of activity were greater during the hunting than the nonhunting seasons. During the hunting season, deer avoided clearcuts, young pine plantations (4 –10 years old), and other open habitats and preferred swamp and mature pine forests, both of which provided cover. These results suggest that deer responded to hunter disturbance by moving away from roads and increasing nocturnal activity. Although recreational deer hunting may reduce the prey base for panthers, the changes we observed in deer behavior during the hunting season may benefit panthers in the following ways: (1) an increase in nocturnal activity and movement away from roads by deer into areas frequented by panthers may increase prey availability for panthers; (2) the movement of deer away from roads may in turn draw panthers away from roads, which may decrease the chance of panthers being killed by vehicular traffic or poachers.Influencias de la Cazería en la Conducta del Venado Cola Blanca: Implicaciones en la Conservación de la Pantera de FloridaLos efectos de la caza de venados por humanos en su dinámica poblacional y conducta podría afectar indirectamente las dinámicas poblacionales y conducta de los depredadores de venados. Presentamos datos de los efectos de la cacería en la conducta del venado cola blanca (Odocoileus virginianus) en el Bosque Nacional Osceola, un sitio potencial para la reintroducción de la pantera de Florida ( Felis concolor coryi) amenazada de extinción. Utilizamos esta información para formular y recomendar hipótesis probables para investigar si los cambios en la conducta de los venados influencían los patrones de movimiento, mortalidad y éxito de caza de la pantera. Monitoreamos 14 venados con radio‐collares de Junio 1990 hasta Julio 1991 para comparar movimientos, actividad y patrones de uso de hábitat entre las estaciones de caza y caza restringida. La distancia media entre un venado y la carretera más cercana, la distancia media de centros de actividad diurna y la media de la tasa de actividad nocturna fueron mayores durante la estación de caza que durante las estaciones de caza restringida. Durante la temporada de caza, los venados evitaron áreas taladas, plantaciones de pinos jóvenes (4 –10 años de edad) y otros tipos de hábitats abiertos, prefiriendo los pantanos y bosques maduros de pino, ambos proveedores de cobertura. Estos resultados sugieren que los venados respondieron a las perturbaciones ocasionadas por la caza alejándose de las carreteras e incrementando su activdad nocturna. Aunque la caza recreativa del venado puede reducir la abundancia de esta presa base de las panteras, los cambios observados en la conducta de los venados durante la temporada de caza podría beneficiar a las panteras de las siguientes maneras: (1) un incremento en la actividad nocturna y los movimientos de los venados alejándose de las carreteras hacia áreas frecuentadas por panteras podría incrementar la disponibilidad de presas para las panteras y (2) el movimiento de los venados alejándose de las carreteras podría alejar a las panteras de las carreteras y por lo tanto disminuir la posibilidad de que las panteras sean eliminadas por el tráfico vehicular o por cazadores.

Influences of Hunting on the Behavior of White-Tailed Deer: Implications for Conservation of the Florida Panther

Influences of Hunting on the Behavior of White-Tailed Deer: Implications for Conservation of the Florida Panther

Is Social Learning an Important Influence on Foraging Behavior in White-Tailed Deer?

The use of hand-reared deer in foraging experiments is a common practice, but its validity as a technique for estimating wild deer behavior has often been questioned. We conducted 2 experiments to determine the influence of learning and experience on forage selection and foraging efficiency in white-tailed deer (Odocoileus virginianus). In the first experiment, we compared food selection (diet composition) and foraging efficiency (biting rate, bite size, and intake rate) among a group of adult hand-reared deer that had been used in previous field experiments (experienced adults), and 2 groups of fawns, one of which was weaned to a diet of 13 browses, a pelleted ration, and alfalfa hay (experienced fawns), the other weaned to pellets and hay alone (naive fawns). Each animal was offered an identical array of 6 browses varying in palatability in a series of 5 feeding trials. The naive fawns selected a diet similar to that of the experienced fawns and adults. The ordering of preferences of the 6 browses was not statistically different among the 3 groups of animals. Biting rates, bite sizes, and intake rates were not statistically different between naive and experienced fawns, although bite size and intake rates were generally greater for the adult animals. In a second experiment, we compared food selection and foraging efficiency of wild and hand-reared adult deer using a procedure similar to experiment 1. Food selection by tame and wild deer was similar except for a difference between groups for one of the lesser-preferred species of browse. Preference rankings of the 6 browses were not statistically different when preferences were ranked according to mass consumed or number of bites taken. We suggest that food selection by white-tailed deer is largely an innate behavior and that hand-reared deer are essentially the foraging equivalents of maternal-reared or wild animals.

Tail-flagging and other antipredator signals in white-tailed deer: new data and synthesis

We present a series of predictions concerning the costs and benefits of antipredator behavior in ungulates and then test them with data on white-tailed deer reacting to a human on foot. Costs of tail-flagging were apparently low and no data supported the idea that flagging serves as a warning signal to conspecifics, in either this or in other studies. Flagging deer fled at greater speeds than nonflaggers, indicating that flagging could possibly signal prey's ability to escape. Dropping the tail at the end of the flight may additionally have made deer inconspicuous. Snorting did not appear directed at conspecifics, and comparative data suggest that it signals that the predator has been detected. In contrast, foot-stamping was effective in alerting other deer to the observer's presence. Deer may have bounded to clear obstacles along their flight path. These preliminary data indicate that several aspects of antipredator behavior in white-tailed deer may be pursuit-deterrent signals, and they therefore highlight the necessity of observing natural predators' reactions to signals given by deer in future studies.

Ontogeny and Adaptiveness of Tail-Flagging Behavior in White-Tailed Deer

I observed white-tailed deer use two tactics to avoid predation: freeze behavior to avoid detection, and flight, during which deer frequently flagged their tails. Remaining motionless increased in use with increasing vegetative cover and occurred less often among larger groups. Tail flagging was observed in all age and sex groups, even neonates within hours after birth. The tendency to tail flag was greatest among fawns. As fawns became older, tail flagging decreased so that by 7 mo of age they tail flagged at a rate similar to that of yearlings and adults. Does tail flagged more often than bucks. For all deer, tail flagging increased as distance from escape cover increased. If deer fled while in cover, their tendency to tail flag increased with amount of vegetative cover. Single deer tail flagged more often than deer in groups. My observations suggest that white-tailed deer evaluate each encounter with a predator according to the nature of their immediate environment. My data do not support the hypothesis that tail flagging is directed at the predator. Instead, tail flagging appears to be an innate, conspecific signal that reduces predation through group cohesion. I suggest that the behavior evolved as part of continued and intense doe-fawn interactions. Fawns decrease the risk of predation by becoming a part of a group in flight; they benefit further by accompanying adults, who are more experienced deer. Tail-flagging behavior may have a secondary adaptive value as a general risk-free alarm signal.

White-tailed deer roadside behavior, wildlife warning reflectors, and highway mortality

The behavior of white-tailed deer ( Odocoileus virginianus) and the effect of Swareflex Wildlife Highway Warning Reflectors were studied along a busy two-lane highway in Crab Orchard National Wildlife Refuge, Illinois, U.S.A. Focal-animal observational sampling was conducted through all seasons and for 24 h day −1. Deer roadside activity was primarily between 17:00 and 07:00 h and appeared unaffected by weather conditions or traffic volume. During the baseline studies of Area I (bordered on one side by a corn field and on the other by hardwood forest), 70% of the observed deer crossed or attempted to cross the highway; feeding on the grassy right-of-way was observed in 32% of the sightings, mostly after corn was depleted. In Area II (bordered on both sides by hardwood forest), 36% of the observed deer crossed or attempted to cross the highway; 68% fed on the grassy right-of-way. In the presence of traffic, deer commonly looked up from feeding and stared at the approaching vehicle. Crossing behavior was similar in both areas; deer generally walked to the highway and stopped at the edge of the pavement before moving across. Adult females usually crossed in a relaxed, cautious manner. Fawns appeared less cautious and followed adult females. Adult and yearling males (rarely observed along the roadway) crossed with more excitement than adult females and fawns. After baseline data had been obtained, Swareflex reflectors were installed for 14 months in Area I while observational sampling continued. Deer roadkills occurring between dusk and dawn were the same with reflectors deployed as during the 2 years prior to testing, even though the deer population had decreased. Behavior of deer crossing the road did not appear to be altered by the reflectors.

Mother-Young Behavior in White-Tailed Deer, Odocoileus virginianus

-Mother-young behavior was studied in a population of free-ranging white-tailed deer (Odocoileus virginianus) in southern Texas. Fawns remained hidden and inactive for the first three or four weeks of their lives except when visited by their mothers, and siblings were maintained separately during this period. After four weeks of age, fawns remained active with their mothers for longer periods and began to appear in larger multi-family groups. The amount of nursing, both in frequency and duration, dropped sharply three to four weeks postpartum. Nursing infrequently was observed after fawns were ten weeks old. The behavior of white-tailed deer (Odocoileus virginianus) has attracted considerable attention in recent years (Hawkins and Klimstra, 1970; Moore and Marchinton, 1974; Hirth, 1977; Nelson and Mech, 1981), as biologists have tried to link the behavior of this species with a variety of ecological factors in different parts of its range. However, the mother-young relationship seldom was reported on in free-ranging animals (Michael, 1966; Jackson et al., 1972; Ozoga et al., 1982) because of the cryptic behavior of fawns and the dense cover in which they often are located. This paper describes the doe-fawn relationship in its first six months, during which fawns undergo a transition from the isolation of a strictly hiding phase, to a following phase, to gradual integration into the adult social structure. Types of doe-fawn interactions and their rates are detailed throughout this critical developmental period. Field work was conducted on the Welder Wildlife Refuge near Sinton, Texas. The refuge is in southern Texas, approximately 80 km northeast of Corpus Christi and 5 km from the Gulf of Mexico. Deer on this refuge were free-ranging; the population was not hunted. The density of deer was estimated at 0.5 per ha (Evans, 1975). Habitat at the Welder Refuge was a mixture of open grasslands and large areas of dense brush, known as chaparral. A more complete description of the soils and vegetation is provided by Box and Chamrad (1966). METHODS.-Observations using 7x binoculars and a 20x telescope were made from platforms atop 10 m high utility poles. The study area was flat, and the observation platforms made excellent vantage points enabling me to see great distances in open areas and down into the chaparral in brushy areas. My presence in these towers was seldom detected by deer. The study period lasted from May 1971 to mid-January 1972, by which time fawns were integrated into larger social units. Fawns in this study were not marked, and their ages were estimated. No fawns were seen being born or in the neonatal period immediately following birth, but observations began when some were clearly only one or two days old. Interaction rates, calculated for all doe-fawn pairs (maternal and nonmaternal) within a social group (Table 1), were expressed as interactions per pair-hour to correct for groups with different numbers of does and fawns (Hirth, 1977). Pair-hours are the numbers of different doe-fawn pair combinations in a group multiplied by the number of hours the group was under observation. The nonparametric Kruskal-Wallis test was used to evaluate differences in interaction rates over time, and the Dunn method, also nonparametric, was used to test pairwise comparisons between individual months (Hollander and Wolfe, 1973). This content downloaded from 207.46.13.112 on Mon, 03 Oct 2016 05:01:13 UTC All use subject to http://about.jstor.org/terms The Southwestern Naturalist TABLE 1.-Rates of interaction between adult does and fawns (interactions/ hr). Observation time was calculated as doe-fawn pairs multiplied by time under observation. Common superscripts within rows indicate no significant difference between rates (P>0.05).

White-Tailed Deer Visibility and Behavior along Forest Roads

The visiblity and behavior of white-tailed deer (Odocoileus virginianus) in a forested area was studied from 1962 through 1977 in northern New York based on 4,727 observations involving 6,237 deer. Deer observation rates were correlated with fluctuations in regional population levels and effectively predicted trends in regional fall buck harvests. Several factors influenced deer viewing opportunities including population density, summer range location, individual deer behavior, sex, age, seasonal range, flight behavior, forest type, timber harvesting, and hunting. Summer range location determined from radio-collared deer and observations of deer marked with collars and ear streamers indicated that some animals were highly visible and contributed a majority of deer observations along particular sections of road. Observation rates were significantly correlated with cover types, basal area density of roadside forests, presence of small clearings, and hunting. Hunting negatively influenced observation rates because of reduced deer density and loss of highly visible deer. Bucks only hunting may be compatible with deer viewing by controlling illegal harvest of females. Deer viewing opportunities were equal throughout daylight hours.

Parturition Behavior and Territoriality in White-Tailed Deer: Impact on Neonatal Mortality

Mother-infant behavior in a supplementally-fed captive herd of white-tailed deer (Odocoileus virginianus) was investigated to determine if crowding influenced fawn-rearing success. All does studied isolated themselves at parturition and demonstrated territorial characteristics lasting about 4 weeks if their progeny lived. Matriarch does defended the same fawning area annually; primiparous (2-year-old) daughters occupied adjacent exclusive sites, whereas 3-year-olds established new grounds away from the family group. Unsuccessful mothers failed to exhibit any prolonged solitary or aggressive behavior. Triplet siblings shared a common home range after 2 weeks, but bedded separately until 1 month old. Although fawns traveled more as they grew older, their movement distance during the first 2 months did not change. Doe-fawn spacing decreased after 2 weeks postpartum in the case of a singleton, but not until a month later for the triplet litter. A mother and her fawn(s) did not continuously associate with other deer before the 3rd month. Because whitetails forcefully defend a fawning ground, and complete isolation is essential for proper mother-infant bond formation, we conclude that crowding at peak herd density limited fawn rearing space, disrupted maternal behavior, and thus caused excessive neonatal mortality among fawns of 2and 3-year-old does. J. WILDL. MANAGE. 46(1):1-11 Neonatal behavior in white-tailed deer has been intensively investigated (Cook et al. 1967, Jackson et al. 1972, White et al. 1972, Jacobsen 1979), and features of maternal care have been reported for penned animals (Townsend and Bailey 1975, Langenau and Lerg 1976). Relatively little is known about mother-infant relationships at parturition. Moreover, the newborn fawn is a hider (Lent 1974), remaining inactive and virtually undetectable until the mother returns to groom and nurse it once or twice daily. Does tend to be hostile toward other deer at parturition, but such interactions are commonly regarded as defense of the fawn rather than being truly territorial in nature (McCullough 1979). In monitoring the reproductive performance of a supplementally-fed captive deer herd, we noted a drastic rise in neonatal mortality as the population increased to a high level (Ozoga and Verme 1982). Most of this loss was fawns of 2-year-old (primiparous) does; indirect evidence indicated that most fawns died shortly after birth (Ozoga et al. 1982). The purpose of the present study was to document mother-infant behavior and spacing during the parturition season in an effort to assess whether extreme crowding and attendant social tension were responsible for low fawn survival under these circumstances. This paper is a contribution from Michigan Federal Aid in Wildlife Restoration Project W-117-R and the Cusino Wildlife Research Station. The senior author wishes to acknowledge the assistance of his wife Janice, son John Jr., and J. H. Fitch in gathering behavioral data. We thank various DNR personnel for aiding in this endeavor, especially D. L. DeLisle and L. J. Perry; C. L. Bennett was instrumental in initiating the study; and E. E. Langenau provided helpful criticism of the manuscript. We are particularly indebted to U. S. Seal for providing certain telemetry equipment.

Aggressive Behavior of White-Tailed Deer at Winter Cuttings

Aggressive Behavior of White-Tailed Deer at Winter Cuttings

Aggressive Behavior of White-Tailed Deer

Aggressive Behavior of White-Tailed Deer

Surface Temperatures and Radiant Heat Loss from White-Tailed Deer

Measurements of surface temperatures and radiant heat loss from the trunks of two penned white-tailed deer (Odocoileus virginianus) fawns were made remotely with a portable radiometer during the winter. Surface temperatures were 6-8 degrees C higher than air temperatures. No difference was observed between the two deer in the surface temperature: air temperature relationships. The difference between air temperature and the surface temperature of the deer increased as air temperature decreased. Measurements of thermal radiation under clear skies at night showed a greater quantity of heat energy emanating from cedar cover than from upland hardwood cover or the clear sky in an open field. The radiant heat from the animal can be integrated with that from the different cover types if the radiation profile of the animal is known. The profile for white-tailed deer has not been determined, but may be estimated. Physiological evidence is cited which indicates the importance of radiant heat when the energy balance of an organism is being considered. The behavior of white-tailed deer with respect to observed weather conditions has been considered by several investigators. Observed responses of the animals have been assumed by some to be causally related to existing weather conditions, or perhaps to the microclimate surrounding the animal. An elucidation of these relationships is, indeed, a worthy goal for the animal ecologist. I suggest, however, that without a quantitative application of appropriate heat transfer parameters, it may be difficult to separate behavioral responses caused by weather conditions from those which may be related to social or psychological phenomena. The basic concept of energy, the means by which energy is transferred, and the energy environment of plants are discussed by Idso et al. (1966). Analyses of the energy exchange of sheep (Priestley 1957 and Blaxter et al. 1959), cattle (Kelly and Ittner 1948, Thompson et al. 1952, and Blaxter and Wainman 1964), swine (Bond et al. 1952) and chickens (Clayton and Boyd 1964) have been presented. The radiant 1 Study supported by the Graduate School, University of Minnesota. 2 Present address: Department of Conservation, Cornell University, Ithaca, New York. 338 energy exchange of the human with its environment has been studied by Hardy and DuBois (1938) and Suggs (1965). The energy relationships of wild species, including ruffed grouse (Brander 1965), whitetailed deer (Moen 1966), and Canada geese (LeFebvre and Raveling 1967) have been considered. Kelly et al. (1954) discuss the importance of thermal radiation in a consideration of animal-environment relationships. An important characteristic of the papers cited above is the explicit consideration of rates of heat transfer between the animal and its environment by different processes, as opposed to the simple comparison of animal behavior and weather data. This paper describes the radiant energy loss in relation to air temperature from the trunks of two well-fed white-tail fawns measured remotely in an outdoor pen during winter months. Measurements of radiation flux under clear skies at night in a nearby open field, upland hardwood stand, and cedar (Thuja occidentalis) habitats are also presented. The radiation data can be applied to the whole animal and integrated with other sources of heat loss (conduction, convection, and evaporation) if the radiaTEMPERATURES AND RADIANT HEAT LOSS FROM DEER * Moen 339 tion profile of the animal is known or assumed. Research was completed at the Cedar Creek Natural History Area (T34N, R23W), operated by the University of Minnesota, and about 35 miles north of the campus. The cooperation of Dr. W. H. Marshall, Director, Field Biology Program, is acknowledged. He also offered suggestions during preparation of the manuscript. The Minnesota Department of Conservation provided the test animals. Alvar Peterson, Resident Manager, and Bruce Kohn, Student Assistant, assisted in handling the deer.

The Reproductive Cycle of Male White-Tailed Deer in Central Texas

A study of 50 male Texas white-tailed deer (Odocoileus virginianus) showed the reproductive cycle occurred in three phases: primary development, full production, and rest. This three-phase cycle had not been described previously. Initiation of antler growth was accompanied by partial stimulation of testicular development during the primary development phase. In the full production phase, the seminiferous tubules were stimulated further by some factor, presumably testosterone, which enabled spermatogenesis to proceed to maturity. These changes coincided with the shedding of the velvet from the antlers. Involution of the seminiferous tubules and abscision of the antlers were followed by a short period of testicular rest and were characteristic of the rest, the third phase. Peak spermatic production occurred in the latter half of November and early December. Fifty male specimens of Texas whitetailed deer from the Edwards Plateau of Texas in Mason, McCulloch, and Sutton counties, were collected to determine the normal reproductive cycle. A description of the reproductive behavior in white-tailed deer of the nearby Llano Basin has been published, but was primarily concerned with herd reproduction as determined by examination of female reproductive tracts and census data (Teer 1964). This study was designed to extend separate observations of the reproductive cycle of male deer in New York (Cheatum and Morton 1946), Massachusetts (Wislocki 1943), and southern Texas (Illige 1951). Our gratitude is expressed for the help and encouragement of Dr. C. H. Bridges, Mrs. Lucille Schultz, and R. Gardner. Additional thanks are expressed to Mrs. Dorthea Robinson for her typing skill and editorial efforts. METHODS Two male deer were collected at biweekly intervals throughout the year from September 1, 1962, to August 31, 1963, in Mason, McCulloch, and Sutton counties in the Edwards Plateau of central Texas. Immediately after collection, the deer were weighed and their ages estimated using the technique described by Severinghaus (1949). A necropsy was performed to observe the gross appearance of all organs and antler development of the deer. The testes were incised and preserved in 10 percent buffered formalin along with representative tissues of other organs. After fixation, the testes and accessory sex glands were dissected free from extraneous material and weighed. Tissue sections were cut from the testes approximately 4 mm from the incised surface, imbedded in paraffin, and sectioned at 6 microns. In the preparation of the sections for microscopic study, hematoxylin and eosin stains were routinely employed. Detailed observations of the sections were recorded and correlated with the gross appearance, testicular weights, and antler development. 1 This is a contribution of a cooperative project between the Texas Parks and Wildlife Department and the Department of Veterinary Pathology, College of Veterinary Medicine, through the Agricultural Experiment Station, Texas A & M University, supported by Pittman-Robertson Project W-90-R.