4,084 research outputs found

    A STUDY OF THE DEFENSIVE BEHAVIORS OF FREE-RANGING DEKAY’S BROWNSNAKES, STORERIA DEKAYI (HOLBROOK, 1836)

    Get PDF
    The defensive behaviors of free-ranging Dekay’s Brownsnakes, Storeria dekayi, were studied at a site in Erie County, Pennsylvania, USA. Twenty-nine unique sequences of defensive behavior were documented. A total of 50 individual snakes (26 males and 24 females) provided 88 observations during the initial phase, of which 78% (n = 69) were of snakes that remained in place. Snakes were tapped with the investigator’s hand to elicit defensive behaviors during the contact phase. Snakes were more than twice as likely to attempt to flee during the contact phase (46%) than during the initial phase (22%). During the contact phase, mean surface body temperatures were significantly higher in snakes attempting to flee (22.3 ± 1.3 °C) than those that remained in place (16.1 ± 2.2 °C). The most frequently observed response during the contact phase was dorso-ventral flattening of the head and body (n = 42). During capture, most snakes (94%) smeared their cloacal contents on themselves and the investigator’s hand

    NATURAL HISTORY OF DEKAY’S BROWNSNAKE, STORERIA DEKAYI (HOLBROOK, 1836), AT A SITE IN NORTHWESTERN PENNSYLVANIA

    Get PDF
    A population of Dekay’s Brownsnake, Storeria dekayi was studied using mark-recapture techniques in Erie County, Pennsylvania, USA during the spring, summer and autumn of 2012. Morphometric data were similar to that reported for the species, with adult females averaging larger and more massive than adult males. However, sexual dimorphism in snout-vent length (SVL) and total length (TL) was not significantly different (P>0.05) in juveniles, although relative tail length (tl/TL) was dimorphic. Relative tail length in both juveniles and adults was greater in males (tl/TL = 0.22-0.27) than females (tl/TL = 0.18-0.23). Storeria dekayi were active from 21 March through 22 October, and displayed a bimodal activity pattern, with peaks in April and August. Using the Schnabel and the Schumacher-Eschmeyer methods, population size was estimated to be 122 ± 19 and 130 ± 35 individuals, respectively. Density was estimated to be 244 and 260 snakes/ha, and biomass 1.60 and 1.71 kg/ha. Additional data regarding population structure, mortality, diet, reproduction, body temperature, movements and site fidelity are also presented

    A Connection between Paired Data Analysis and Regression Analysis for Estimating Sales Adjustments

    Get PDF
    The two methods most often recommended for obtaining market-derived adjustments utilized in the sales comparison approach to appraisal are Paired Data Analysis and Multiple Regression Analysis. These approaches are viewed as competing alternatives, with advocates and detractors for each. The main purpose of this paper is to demonstrate that these two alternatives to estimating sales adjustments are equivalent under certain circumstances. This point of equivalence may prove to be a useful starting place for improving our understanding of the differences between and similarities of the two methods. After explaining the data requirements of each method, we provide a set of sufficient conditions under which the two methods produce identical adjustment estimates. We finish with a discussion ofrelative advantages and disadvantages of these two methods in estimating sale comparison adjustments.
    • …
    corecore