Animal & Avian Sciences Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/2741
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Item Variations in Vocalizations of Fin Whales, Balaenoptera physalus, in the St. Lawrence River(1980) Edds, Peggy Louise; Buchler, Edward; Animal & Avian Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, MD)Recordings were made of vocalizations from fin whales, Balaenoptera physalus from a fixed hydrophone in the St. Lawrence River between 28 June and 27 September 1979. Land-based observers monitored activity from a hillside hut while recordings were being made from a shoreline site. Photographs of dorsal fin variations were used to identify distinctive individuals. The 1522 sounds recorded were classified into 11 categories based on frequency and temporal characteristics. The predominant call was a descending sweep of frequencies. Parameters measured for this downsweep exhibited a dichotomy of characteristics which indicates calls with initial frequencies below 40 Hz have less variability than calls with initial frequencies above 40 Hz. In general, solitary animals produced primarily the lower frequency downsweeps. Higher frequency downsweeps were recorded from pairs or trios of fin whales. Solitary individuals did not exhibit unique variations in downsweep parameters. No clusters of values which might indicate uniquely individual ranges were consistently present in multiple animal recordings. The data suggest that the variability of fin whale vocalizations is primarily contextual rather than individual.Item Infant and Juvenile-Directed Care Behaviors in Adult Toque Macaques, Macaca Sinica(1985) Baker-Dittus, Anne; Animal & Avian Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, MD)The identity of care-givers, and the distribution of care to young are examined in a free-ranging polygynous primate, Macaca sinica. Care behavior is used as one measure of investment in young. There is no evidence that dominance rank influences offspring sex, but high-ranking mothers provide more care to newborn infants than do low-ranking mothers. Mothers provide more care to infant and first year sons than to daughters. This supports Dittus's suggestion (1979, 1980) that mothers should schedule care to sons and daughters differently, providing high levels of care to sons before they emigrate from the natal group. Care to daughters is low per unit time, but continues over a long period because daughters remain in the natal group. Adult females, other than the mother, tolerate, groom and support young. These behaviors are low cost, relative to the high cost behaviors of nursing and carrying, which only mothers provide. Young tend to associate with adult female relatives. Unlike male-biased maternal care, adult female care is biased towards female young; and female young return care more than do male young . Adult female rank is positively correlated with the amount of support adult females provide to female young, and the amount of grooming they receive from female young. Adult female rank has no effect on any measure of association between adult females and male young. Taken together these findings suggest that reciprocal altruism has been important in shaping adult female interactions with young. Adult and subadult M. sinica males direct the low cost, affiliative behaviors of hugging, carrying and grooming towards male infants; and direct aggressive behaviors towards female infants. I suggest that the distribution of behaviors reflects their value to male and female young. Affiliative behaviors to male infants, and aggressive behaviors to female infants serve to channel infants into association with adults from whom they can learn appropriate sex-typical behaviors, and as such benefit both male and female infants. High cost care behaviors of support in agonistic interactions, and protection are provided only by the adult male, and are provided to male and female young equally.Item The Life Cycles, Ecology, and Evolution of the Witch-hazel Leaf Gall Aphid, Hormaphis hamamelidis (Fitch) (Homoptera: Aphidida)(1987) von Dohlen, Carol Dean; Gill, Doulgas E.; Zoology; Digital Repository at the University of Maryland; University of Maryland (College Park, MD)Two divergent life cycles based on geographic location have been documented for the witch-hazel leaf gall aphid, Hormaphis hamamelidis (Fitch, 1851). At low elevations in northern Virginia, the aphid was found to have seven distinct generations alternating between the primary host, Witch-hazel (Hamamelis virginiana L.), and a secondary host, river birch (Betula nigra L.). These findings confirm the original published life cycle description from the same locality. A second, abbreviated life cycle consisting of only three generations restricted to witch-hazel was discovered at high (1000 m) elevations in north central and northwestern Virginia. Aphids with each life cycle were sympatric at an intermediate elevation site. Based on available life cycle and geographic data, a preliminary Phylogeny of the tribe Hormaphidini is proposed that suggests an unusual polarity in the evolution of aphid life cycles. Several features of intraspecific interactions and host-plant relations were examined in both lowland and highland populations of Hormaphis. In contrast to previous publications documenting severe competition, density effects, and habitat heterogeneity for another galling, host-alternating aphid, Pemphigus betae on Populus angustifolia, the effects of density and host-plant qualities on Hormaphis hamamelidis were fewer and more benign. Aphids did not compete for gall sites, and gall Position and final leaf area did not influence reproduction. High gall densities negatively affected gall growth and aphid fecundity. Factors accounting for the differences in Population dynamics between Hormaphis and Pemphigus are hypothesized and discussed.Item Vertical Resource Partitioning and Sexuality of Three Sympatric Species of Red Sea Sandfishes (Xyrichtys melanopus, Labridae; Trichonotus nikii, Trichonotidae; Gorgasia sp., Congridae)(1988) Krall, Marianne Martha; Clark, Eugenie; Zoology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md)Three species of marine sandfishes were studied from 1984 to 1986. Their inter- and intraspecific behavior was monitored during the daylight hours to examine interactions that could result in the vertical stratification of the species over the sandy bottom within the fringing and patch reefs in the north Red Sea. Horizontal plankton tows were taken at three heights and three times a day. These samples were compared to stomach contents of the fishes to determine the trophic relationships in the community and their affects on spatial relations between the species . Prey specificities of the fishes were determined by using an electivity measure. Using paraffin histology, Xyrichtys melanopus was determined to be a monandric protogynous hermaphrodite and Trichonotus nikii, a gonochorist. Previous work on the mating systems and territoriality of all three sandfish species helped in part to explain the vertical spatial arrangement of the sandfish species within the community. Effects of pollution on the b iota of the Northern Gulf of Aqaba are noted.Item Periparturient Behavior of Beef Cows and Calves(1987) Ramli, Abdullah Sani; Stricklin, W.R.; Animal & Avian Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md)Crossbred and purebred gestating Angus and Hereford cows were monitored during the 1985 and 1986 spring calving seasons (number of calvings = 375). Cows were assigned randomly to one of two treatment groups that were balanced by breed-class, age and expected date of calving. The control group was fed corn silage at 0900 hours, and hay was available free choice. The treated group was fed the same diet but at 2100 hours, and time of access to the hay was restricted to between 2100 and 0900 hours. Each group was kept in a 3.2 ha paddock and observed continuously during the 1985 calving season. During 1986 similar treatments were used, but observations were not continuous. Data recorded were behavioral signs of parturition, times and locations of parturition and behaviors of cow-calf pairs observed continuously until 8 hours post-partum. Group diurnal activity patterns were recorded over 61 consecutive days in 1985. Post-partum behavior variables of the dam were time to first standing and grooming and total time spent standing, lying, grooming, browsing and eating. Calf variables were initial standing, teat seeking, mobility, suckling, total time spent on these activities and body weight at weaning. A significant (P <.05) shift in the diurnal activity patterns of the cows occurred when the feeding schedule was altered, but treatment did not affect (P>.10) the time of day when parturition occurred. The percentage of cows calving between 0600 and 1800 hours were 55 and 60 for the control and the treated groups, respectively. During the first 8 hours post-partum, differences in the time of onset and total time spent on some behaviors were determined to be related to breed of sire and dam, parity and sex of calf. Multiple regression of weaning weight on periparturient behavioral traits resulted in R2 values of 54 and 24% for heifer and bull calves, respectively. It was concluded that night-time feeding does not result in a significant increase in day-time calvings, and there is at least a moderate relationship between cow-calf behavior in the first 8 hours after birth and the calf's weaning weight.Item Habitat, home range, and population study of the eastern box turtle (Terrapene carolina)(1986) Hallgren-Scaffidi, Lynette; Flyger, Vagn; Animal Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md)This study covers the home range, population size, habitat type and components of habitat of the eastern box turtle, Terrapene carolina. The study area was within the floodplains of the Patuxent River on the grounds of Patuxent Wildlife Research Center, Laurel, Maryland. A home range and population study was conducted by Lucille Stickel in 1945 within the same study-area and provided a basis for comparative analysis including information on population trends. Mark-recapture data and a tread-trailer device were used to estimate populations, trace the daily route of eleven individual turtles, and home range size. The range length and convex polygon methods were used to calculate home range size. The average box turtles home range as calculated by the range length method was .733 hectares. In addition the average area calculated by the convex polygon method is .955 hectares for the thread-trailer technique. These home range estimates depict a small reduction in range size from Stickels original estimates Forest maturation is proposed as one of the primary factors influencing this reduction of range size. The population size of the box turtle within the study-area was ascertained by mark-recapture techniques. Using the Schnabel Method of estimating population size, an average of 8.62 (8.30 for 1984; 8.92 for 1985) turtles per hectare was determined. The total number of turtles found during the 1985 study season (58) in comparison to the total number found during the 1945 study season (284) demonstrates the declining population of the Patuxent box turtles over the las t four decades. The largest population of box turtles were found in forest habitat s or forest-field ecotones. Determination of box turtles preference for habitat types and components of habitat was emphasized in this study. Two habitat types, 'dried streambeds' and 'woods opening', encompassed the smallest areas of the study site while providing habitat for the greatest number of turtles. In addition many turtles showed preference for two components of habitats (out in the open and under a log). However, because it is easier to locate turtles out in the open, it is proposed here that the large number of turtles found in this Component of Habitat is due to bias surveying technique s and not a preference for turtles. The results also provide information for improving box turtle habitat within parklands. Changes to the study-area and surrounding ecosystems have occurred over the pa s t four decades. The fore s t has matured, upstream waters have been impounded by dams, filtration plants built and increased pollution of the Patuxent River have occurred. The decline in box turtle abundance is probably due to the frequent floods that inundate turtle eggs when upstream dams are opened.