Merriam's Turkey Nest Survival and Factors Affecting Nest Predation by Mammals

Abstract: Nest success is an important parameter affecting population fluctuations of wild turkeys (Meleagris gallopavo). Factors influencing mammalian predation on turkey nests are complicated and not well understood. Therefore, we assessed nest hazard risk by testing competing hypotheses of Merriam's turkey (M. g. merriami) nest survival in a ponderosa pine (Pinus ponderosa) ecosystem during 2001–2003. We collected nesting information on 83 female Merriam's turkeys; annual nest success averaged 50% for adult females (range = 45–59%) and 83% for yearling females (range = 75–100%). Proportional hazard modeling indicated that precipitation increased the hazard of nest mortality. However, estimated hazard of nest predation was lowered when incubating females had greater shrub cover and visual obstruction around nests. Coyotes (Canis latrans) were the primary predator on turkey nests. We hypothesize that precipitation is the best predictor of nest survival for first nests because coyotes use olfaction effectively to find nesting females during wet periods. Temporally, as the nesting season progressed, precipitation declined and vegetation cover increased and coyotes may have more difficulty detecting nests under these conditions later in the nesting period. The interaction of concealment cover with precipitation indicated that nest hazard risk from daily precipitation was reduced with greater shrub cover. Management activities that promote greater shrub cover may partially offset the negative effects of greater precipitation events.     

Factors Affecting Songbird Nest Survival in Northern Mixed-Grass Prairie

ABSTRACT Factors associated with the nest survival of mixed-grass prairie passerines are not well known, especially in the context of contemporary grassland management. We documented the nest survival of clay-colored sparrows (Spizella pallida), savannah sparrows (Passerculus sandwichensis), and bobolinks (Dolichonyx oryzivorus) in managed prairie in northwestern North Dakota, USA. We used logistic exposure models and an information-theoretic framework to estimate nest survival and evaluate support for mechanisms (grazing, temporal factors, nest parasitism, nest-site vegetation, and nest-patch factors) relevant to nest survival. Survival for the entire nesting interval (23–28 days) was low for clay-colored sparrow (18.2%), savannah sparrow (15.5%), and bobolink (3.5%). We found support for a cubic effect of nest age; survival of savannah and clay-colored sparrow nests was greatest during mid-incubation and least during the mid-nestling period. Parasitized clay-colored sparrow and bobolink nests had greater survival rates than nonparasitized nests. Nest survival of clay-colored sparrows increased with increasing vegetation height and density. For savannah sparrows, nest survival was lower when cattle were present than when cattle were absent. Characteristics of the nest patch did not have strong effects based on model coefficients and confidence intervals, though they appeared in many of the most supported models. Positive effects of vegetation height and density on nest survival of clay-colored sparrows and negative effects of cattle presence on nest survival of savannah sparrows suggest some detrimental effects of grazing. However, the need to restore and maintain intact prairies likely warrants the continuation of cattle grazing on conservation lands.     

Factors Affecting Nest Survival of Greater Sage-Grouse in Northcentral Montana

Abstract: We studied greater sage-grouse (Centrocercus urophasianus) in northcentral Montana, USA, to examine the relationship between nest success and habitat conditions, environmental variables, and female sage-grouse characteristics. During 2001-2003, we radiomarked 243 female greater sage-grouse, monitored 287 nests, and measured 426 vegetation plots at 4 sites in a 3,200-km² landscape. Nest survival varied with year, grass canopy cover, daily precipitation with a 1-day lag effect, and nesting attempt. In all years, daily survival rate increased on the day of a rain event and decreased the next day. There was temporal variation in nest success both within and among years: success of early (first 28 d of nesting season) nests ranged from 0.238 (SE = 0.080) in 2001 to 0.316 (SE = 0.055) in 2003, whereas survival of late (last 28 d of nesting season) nests ranged from 0.276 (SE = 0.090) in 2001 to 0.418 (SE = 0.055) in 2003. Renests experienced higher survival than first nests. Grass cover was the only important model term that could be managed, but direction and magnitude of the grass effect varied. Site, shrub and forb canopy cover, and Robel pole reading were less useful predictors of nest success; however, temporal and spatial variation in these habitat covariates was low during our study. We note a marked difference between both values and interpretations of apparent nest success, which have been used almost exclusively in the past, and maximum-likelihood estimates used in our study. Annual apparent nest success (0.46) was, on average, 53% higher than maximum-likelihood estimates that incorporate individual, environmental, and habitat covariates. The difference between estimates was variable (range = +8% to +91%). Management of habitats for nesting sage-grouse should focus on increasing grass cover to increase survival of first nests and contribute to favorable conditions for renesting, which should be less likely if survival of first nests increases.     

Factors Affecting Golden-Cheeked Warbler Nest Survival in Urban and Rural Landscapes

ABSTRACT We evaluated hypotheses concerning temporal, landscape, and habitat effects on nest survival of golden-cheeked warblers (Dendroica chrysoparia) in an urban and a rural landscape during the breeding seasons of 2005 and 2006 in central Texas, USA. We found support for temporal effects of year and cubic effect of date and included them in candidate models that evaluated habitat and landscape effects. Nest survival was lower in 2006 than in 2005 and decreased nonlinearly as the breeding season progressed. We found support for edge effects with decreased nest survival nearer edges and in areas with increased open edge density (wooded habitat abutting open habitat) or decreased trail density. However, confidence intervals for the model-averaged odds ratios overlapped 1.0 for all edge variables. Overall daily survival rate was 0.964 (95% CI = 0.949-0.975), resulting in a 25-day period survival of 0.398 (95% CI = 0.269-0.524). Period survival in Austin's urban landscape (0.399, 95% CI = 0.270-0.526) was similar to survival in Fort Hood's rural landscape (0.396, 95% CI = 0.261-0.528). Both landscapes likely support self-sustaining populations based on reasonable assumptions for adult survival and number of nesting attempts. We suggest that some large urban preserves can provide breeding habitat of comparable quality to rural locations and recommend protecting large parcels (>100 ha) of breeding habitat with limited fragmentation and reducing the amount of wooded edge abutting open habitat to ensure nest survival regardless of their landscape context.     

Some Factors Affecting Undergraduate Academic Achievement

A related series of studies, most of which have been published previously, is described. These studies form a coherent whole and demonstrate the development of a theme, namely, the identification of factors in the student and the medical school which, in their interaction, influenced undergraduate academic performance at one medical school. In the population concerned no reliable positive or negative correlation could be demonstrated between cognitive ability and academic performance, when the former was measured by the Wechsler Adult Intelligence Scale and the Medical College Admission Test, and the latter by the current assessment methods of the medical school. Other factors, including socioeconomic and individual personality variables, are at present under investigation as to their effect on academic achievement. It is emphasized that the results of these studies cannot be regarded as valid for all medical schools, but the methods employed can be generalized.     

北京高校喜鹊巢址选择的主要生态因素

根据从2003～2005年每年一次关于北京近20所高校校园喜鹊（Pica pica sericea）巢址的分布情况的调查,对影响高校校园喜鹊巢址选择的因素进行了分析,结果表明营巢树因素（营巢树的高度、胸径、巢位高度、巢上方的植被盖度）和环境因素（嘈杂度和食物的丰富程度）都会影响喜鹊对巢址的选择。研究结果对如何进行校园绿地的规划以及鸟类保护具有一定的指导作用。     

Some Factors Affecting the Hill Reaction Activity in Cotton Chloroplasts

A method of plant culture was developed for growing large leaves of glandless cotton on single stems. Chloroplasts isolated from these leaves actively reduced ferricyanide when assayed for the Hill reaction. Hill reaction activity increased 133% when the 0.5 m sucrose isolation medium was replaced with 10% (w/v) polyethylene glycol, both buffered at pH 7.6. The presence of 2 or 5% (w/v) bovine serum albumin in the sucrose buffer did not increase Hill activity. Ferricyanide reduction in the dark occurred in all assays, and the possibility of gossypol as the reductant is discussed. Half-life of the chloroplasts stored in 10% glycerol at -23 C was 23 days. The ammonium ion at 0.01 m enhanced Hill reaction activity up to 171%. Leaves containing chloroplasts with the highest Hill reaction activity were found near the 8th node below the apex. Leaf water potentials less than -28 bars reduced the activity about 50%. Daylight conditions during the winter months in the greenhouse reduced the activity about 30%.     

Factors Affecting Daily Nest Survival of Burrowing Owls Within Black-Tailed Prairie Dog Colonies

ABSTRACT Identifying environmental parameters that influence probability of nest predation is important for developing and implementing effective management strategies for species of conservation concern. We estimated daily nest survival for a migratory population of burrowing owls (Athene cunicularia) breeding in black-tailed prairie dog (Cynomys ludovicianus) colonies in Wyoming, USA. We compared estimates based on 3 common approaches: apparent nesting success, Mayfield estimates, and a model-based logistic-exposure approach. We also examined whether 8 intrinsic and extrinsic factors affected daily nest survival in burrowing owls. Positive biases in apparent nest survival were low (3–6%), probably because prior knowledge of nest locations and colonial behavior among nesting pairs facilitated discovery of most nests early in the nesting cycle. Daily nest survival increased as the breeding season progressed, was negatively correlated with ambient temperature, was positively correlated with nest-burrow tunnel length, and decreased as the nesting cycle progressed. Environmental features were similar between failed and successful nests based on 95% confidence intervals, but the seasonal midpoint was earlier for failed nests (31 May) compared to successful nests (15 Jun). The large annual variation in nest survival (a 15.3% increase between 2003 and 2004) accentuates the importance of multiyear studies when estimating reproductive parameters and when examining the factors that affect those parameters. Failure to locate and monitor nests throughout the breeding season may yield biased estimates of nesting success in burrowing owls (and possibly other species), and some of the variation in nesting success among years and across study sites may be explained by annual and spatial variation in ambient temperature. Any management actions that result in fewer prairie dogs, shorter burrow lengths, or earlier nesting may adversely affect reproductive success of burrowing owls.     

Some Factors Affecting the Activity of Diethylpyrocarbonate as a Sterilant

Quantitative data indicated logarithmic death in 5 degrees Brix Concord grape juice when concentrations of cells under 10(7)/ml were exposed to diethylpyrocarbonate (DEPC). Species differed considerably in their resistance; e.g., 50 ppm reduced the viable count of Saccharomyces cerevisiae over nine log(10) cycles, whereas 200 ppm reduced the count of Byssochlamys fulva ascospores by only about 1 log. DEPC lethality was enhanced by higher temperatures; destruction at 40 C was 10- to 100-fold greater than at 20 C. Studies on death rates showed that most yeasts and fungal spores were killed during the first hour of exposure, whereas 24 h or longer was needed for maximal destruction of several lactic acid bacteria. Repair of DEPC-induced damage was believed responsible for the slower death rates of the lactics.     

Some Factors Affecting the Lisboa Surface Film Test for Detergent-Sterilizers

S ummary : In experiments with a surface film test it was found that variation of certain test conditions affected the relative activity of two detergent-sterilizer formulations. It was also found that to achieve a high degree of reproducibility in the residual count on a treated surface from one occasion to another, it is necessary to control closely the numbers of bacteria present in the dried milk film.     

果实香气形成及其影响因素

综述了苹果(Malus domestica Borkh.)、草莓(Fragaria ananassa Duch.)、香蕉(Musa paradisiaca)、甜瓜(Cucumis melon L.)和番茄(Lycopersicon esculentum L.)等果实香气的化学成分、主要合成途径及其影响因素.果实的香气物质主要包括酯类、醇类、酮类、醛类、萜类和挥发性酚类物质等,这些物质主要由脂肪酸、氨基酸和次生代谢产生.品种、成熟度、乙烯、环境和栽培措施(光照、砧木、套袋和灌溉等)以及采后贮藏条件均影响果实香气的形成.     

果实香气形成及其影响因素

综述了苹果(Malus domestica Borkh.)、草莓(Fragaria ananassa Duch.)、香蕉(Musa paradisiaca)、甜瓜(Cucumis melon L.)和番茄(Lycopersicon esculentum L.)等果实香气的化学成分、主要合成途径及其影响因素。果实的香气物质主要包括酯类、醇类、酮类、醛类、萜类和挥发性酚类物质等,这些物质主要由脂肪酸、氨基酸和次生代谢产生。品种、成熟度、乙烯、环境和栽培措施(光照、砧木、套袋和灌溉等)以及采后贮藏条件均影响果实香气的形成。     

Some Factors Affecting the Anthocyanin Formation by Populus Cells in Suspension Culture

In order to elucidate the mechanism of anthocyanin formation by Populus cells in suspension culture, the favourable conditions for anthocyanin formation were investigated. The influence of some factors affecting the anthocyanin formation, i.e. light, sucrose and riboflavin etc. were also examined. Light irradiation and high sucrose concentrations brought about a marked increase of PAL activity, which increased rapidly at the lag phase preceding the anthocyanin formation. The effect of blue light on anthocyanin formation was markedly superior to other kinds of monochromatic light (green and red) or white light. Riboflavin was effective only under light exposure. It was inferred that light, sucrose, riboflavin and PAL activity etc. were closely related with the anthocyanin formation. Especially, light and sucrose cooperated in the increase of PAL activity which was a key enzyme in the biosynthesis of anthocyanin.     

Nest Building in Captive Gorilla gorilla gorilla

Although various aspects of gorilla nest building have been described in wild populations, nest-building behavior of captive gorillas has not been subject to much scientific review. We observed nest building in 17 gorillas during three periods: summer baseline, winter baseline, and winter treatment, in which the amount of available nesting material was doubled. We conducted observations exclusively in the indoor holding area in the hour following evening departure of animal care staff. During baseline, gorillas engaged in nest-building on 3.1% of scans and were on a constructed nest on 27.9% of scans. Overall, gorillas spent significantly more time on elevated nests than on floor nests. There were no statistically significant sex, age class, or rearing history differences in nest building, time spent on a nest, or nest location preference. Nest building consisted of both gathering and manipulating materials. The gorillas spent significantly more time building nests in winter than in summer. Additionally, they were more often on elevated nests during winter than summer. Doubling the amount of nesting material did not increase nest building, but it increased the number of floor nests. Our results suggest that providing adequate materials to captive gorillas for nest building may facilitate performance of species-typical nest-building, minimize competition among individuals for nesting sites and materials, and permit individual thermoregulation.