bluuebunny/crossref_metadata_2025 huggingface dataset:
Microtus Population Densities and Soil Nutrients in Southern Indiana Grasslands
Authors: Krebs Charles J. , Keller Barry L. , Myers Judith H.
Published: May 2006

The sodium hypothesis of Aumann and Emlen (1965) states that peak population densities of microtine rodents are strongly correlated with soil sodium levels. We tested this in southern Indiana with snap—trapping data from 21 grassland areas occupied by Microtus pennsylvanicus and M. ochrogaster. A total of 128,052 trap—nights were expended from 1965 to 1970, and soils from area were analyzed for seven soil parameters including sodium. Soil sodium levels did not correlate with either peak density or mean density levels of either Microtus species. In M. pennsylvanicus 38% of the variation in peak densities could be explained by differences in soil pH and potassium levels. Cover may be an important predictor of peak densities but this was not measured. Microtus pennsylvanicus is not confined to bottomland soils in the Bloomington, Indiana, area and both species of Microtus coexist over a broad range of soil types.
Natural Regulation of the Aphid Pterocomma Populifoliae on Bigtooth Aspen in Northern Lower Michigan
Authors: Sanders C. J. , Knight F. B.
Published: May 2006

The development of colonies of the aphid Pterocomma populifoliae (Fitch) was studied in sucker stands of Populus grandidentata Michx. Estimates of the losses from the colonies were made by substracting the actual numbers present at four day intervals from the potential number calculated from the reproductive rates of the individual females. Based on their development the colonies were divided into three groups. The disappearance of many colonies before the first nymphs had matured (Group 1) was attributed to predation by wandering predators such as spiders and adult coccinellids. In larger colonies which were destroyed before dispersal started (Group 2) Seymnus larvae acconted for up to 40% of the losses, and they and other predators resident in the aphid colonies such as syrphids and chamaemyids were largely responsible for suppressing these colonies. Losses from the remaining colonies (Group 3) were much higher than could be explaned by predation or by the dispersal of alatae. Such losses were attributed to the dispersal of mymphs and aptearae. This was verified by trapping the aphids leaving large, caged colonies. Parasitism was unimportant, never acconting for more than 8% of the losses. It was concluded that there were three levels in the development of a colony where numerical growth might be limited. At the lowest level suppression was by errant predators, at the next highest by resident predators and errant predators. When suppression by predators failed, numbers increased to where dispersal was triggered. The chance of success of a colony appeared to increase with an increasing number of founding females.
The Naturally Varying Energy Environment and Its Effects Upon Net Photosynthesis
Authors: Idso Sherwood B. , Baker Donald G.
Published: May 2006

Measurements of meteorological parameters were made at St. Paul, Minnesota, on four different types of days. The data obtained were analyzed by an energy—balance technique which yielded daily trends of light intensity and temperature for individual plant leaves. The computed leaf temperatures were verified experimentally. Together with the light—intensity data they were then used to construct typical net photosynthetic rate curves which would have been characteristic of maize and sorghum growing under these conditions. On a clear—acool day the net photosynthetic rates of maize and sorghum both rose gradually to a sharp peak near solar noon and then declined. On a clear, warm day, however, net photosynthesis in sorghum rose rapidly to establish an enduring high rate throughout the major portion of the day, while maize showed a midday slump with photosynthetic rates depressed almost to zero. On a cool, cloudy day both species had only a nominal net CO2 fixation and a day with broken cumulus clouds resulted in an oscillation of the net photosynthetic rates of both species between quite high and medium values.
Relationship of Availability of Phosphorus and Cations to Forest Succession and Bog Formation in Interior Alaska
Authors: Heilman Paul E.
Published: May 2006

Concentrations of P, K. Ca. Mg, Mn, and Zn in black spruce foliage were examined in relation to forest succession on north slopes in interior Alaska. decline in levels of P and K in the foliage appear to be deficient on sphagnum soils. Mg levels show a slight decrease, but do not fall below deficiency status even on deeper sphagnum soils. Ca, Mn, and Zn show no relationship to forest succession and are at adequate levels on all stages. Concentrations of available phosphorus and exchangeable cations in the soils show no differences between soils corresponding to those found in nutrient levels in the foliage. However, total quantities of P, K. and Mg in available and exchangeable forms are consistently lower in sphagnum soils. Also, the depth distribution of these nutrients on a volume basis differs among soils: in sphagnums they are located at deeper depths, while on mineral soils they are concentreted in surface layers. this distribution difference and the incrasing coldness of the soil as moss accumulates appear to be sufficient to reduce the availability of these nutrients. Radiocarbon dates showed that 18—28 inches (41—71 cm) of sphagnum peat, weighing 270,000—510,000 kg/ha, had accumulated in less than 185 years. The average annuual increase of 1,500—2,800 kg/ha indicates that, in spite of low growth of trees on sphagnum soils, total productivity in dry weight is appreciable.
The Adaptation of Heterotrophic Microcosms to Different Temperatures
Authors: Allen Stephen D. , Brock Thomas D.
Published: May 2006

Heterotrophic microcosms were developed at a variety of temperatures from 2°C to 75°C, using as inocula a mixed microbial flora from a wide variety of sources. Even after extensive cross—seeding, each microcosm developed a characteristic flora and fauna, showing that temperature alone is able to control species conposition. Experiments using C14— clucose showed that the microcosms through the range 25°—75°C were optimally adapted to the temperature at which they were developed. Those developed at temperatures below 25°C were not optimally adapted.
Autotoxic Feedback in Relatin to Germination and Seedling Growth in Typha Latifolia
Authors: McNaughton S. J.
Published: May 2006

Seed germination of Typha latifolia was completely inhibited by an aqueous extract of cattail leaves but was only partially inhibited by extract treated with polyclar AT to remove phenolic compounds. Seedling growth was slightly inhibited by water from cattail marshes, was highly inhibited by water squeezed from soil in which cattails were growing, and was stimulated (as compared with the distilled water control) by water obtained from a Sphagnum bog. Cattail populations, once established, may this effectively preclude invasion by alien typha genotypes, and the autotoxic properties of the accumulated organic residues may accentuate the unidirectional orientation of marsh succession.
Senecio Sylvaticus in Relation to Douglas‐Fir Clear‐Cut Succession in the Oregon Coast Range
Authors: West Neil E. , Chilcote William W.
Published: May 2006

Senecio sylvaticus is a northern European adventive which has adapted well to a short term dominance at the beginning of secondary succession on slash—burned class—cuts in the Douglas—fir region. The species time—space niche is related to its copious production of small pappus—borne cypselas, low competitive ability, and apparent high soil—fertility requirements associated with the release of minerals directly following slash burning.
Dynamics of the Shrub Continuum Along the Gallatin River in Yellowstone National Park
Authors: Patten D. T.
Published: May 2006

Willows dominate the shrub vegetation along the Gallatin River and with the other shrubs allow different growth and mortality responses relative to their position from the river and other environmental factors. The shrub species from a continuum from the river to the dry grassland depending upon the varying moisture regime. The sequence of shrub species from wet to dry appears to be Salix farrae, S. lutea, S. drummondiana, S. exiqua, Artemisia cana, and A. tridentata. Individual species also vary in their ability to survive present environmental pressures, including periodic heavy browsing.
Utilization of Soil Temperature Data for Ecological Work
Authors: Chiang H. C. , Baker Donald G.
Published: May 2006

An examination of the climatological data published by the Environmental Science Services Administration, U. S. Department of Commerce, for all 50 states shows that soil temperatures are recorded at very few localities and at varying depths and hours. In order to make greater use of such data, relationships between (a) the temperature at a given depth and the average temperature conditions of the plow layer (which includes the major portion of the rhyzosphere) and between (b) the temperatures at a given hour and the average temperature for the day were examined. Procedures to approximate the daily rhyzosphere mean temperature from limited soil temperature measurements are suggested.
The Response of Tribolium Confusum to Variations in the Volume of Its Environment
Authors: McDonald Daniel J.
Published: May 2006

The size of the population formed by the flour beetle Tribolium confusum has been found to depend on the volume of the environment rather than the amount of nutrient provided. This was determined by mixing powdered polyethylene with the flour medium, to vary the volume while holding the amount of nutrient constant. The polyethylene is probably not injurious to the adults for it appears to have no major effect on death rate. However, polyethylene and flour mixtures do alter some individual and population characteristics, probably those involved in cannibalism and egg production.
Inhibition of Reproductive Maturation and Function in Laboratory Populations of Prairie Deermice: A Test of Pheromone Influence
Authors: Terman C. Richard
Published: May 2006

Ninety percent of the females born into and retained in freely growing laboratory populations of prairie deermice (Peromyscus maniculatus bairdii) fail to produce young. Further, the reproductive organs of males and females from these asymptotic populations are significantly lighter in weight than controls. As a means of testing the influence on reproductive maturation of possible pheromones produced in the populations, 20 bisexual pairs of mice were raised from weaning until 100 days of age on bedding (a) soiled by asymptotic populations, (b) soiled by bisexual pairs from a breeding colony, and (c) unsoiled by mice. Analysis of the reproductive performances of the mice and the weights of their ovaries, uteri, and testes gave no indication of inhibition of reproductive development or function of animals maintained on bedding soiled by asymptotic populations. Rather, the data indicated that both reproductive function and maturation were stimulated in these animals compared to the other two treatments.
Survival of Seedlings of An Alpine Clover (Trifolium Nanum Torr.)
Authors: Bonde Erik K.
Published: May 2006

Survival percentages of Trifolium nanum seedlings in Colorado at 3,932 m altitude were 82.1, 55.8, and 27.5, respectively, at the end of the first, second, and third summers. Data on seedling substrates and growth are also presented.
Ecology of Vervet Monkeys (Cercopithecus Aethiops) in The Masai‐Amboseli Game Reserve, Kenya
Authors: Struhsaker Thomas T.
Published: May 2006

Aspects of the ecology of vervet monkeys (Ceropithecus aethiops) are described on the basis of a 21 month field study in East Africa. Analysis of home range utilization demonstrated differences between 4 groups. The smallest group distributed its time over a greater area than did the other groups. For 3 of the groups there appeared to be a strong relationship between group size and the amount of optimal habitat defended. The smallest group defended more optimal habitat than expected. However, this same group spent only 60% of its time in this habitat, whereas the other groups all spent more than 95% of their time in it. The smallest group may have avoided the optimal habitat of its territory as an area of frequent intergroup aggression, and as a result utilized a larger and less productive area. Sleeping—tree preferences of groups and individuals are described and discussed. The minimal distance traveled each day by vervet groups varied from 148 to 2,797 yd. In comparing the mean daily distance covered by 2 groups of equal size it was found that one moved significantly further than the other. More trips were made to permanent water holes between 1300 and 1500 hr and during the dry season than at other times. The frequency of group progressions was greatest at 0700 to 1000 and 1600 to 1900 hr. Study of food habits shows that they were opportunistic omnivores. Elephants were the greatest food competitors of the vervets. The monkeys had at least 16 potential predators. Outside of parks and reserves the greatest predator was the European commercial trapper. Ecological characteristics of vervets and their niche separation from baboons are discussed.
Periphyton Growth on Artificial Substrates in a Radioactively Contaminated Lake
Authors: Neal Ernest C. , Patten Bernard C. , DePoe Charles E.
Published: May 2006

Periphyton colonization, biomass development and radionuclide accumulation were studied by suspending polyethylene tape vertically for up to 9 weeks in a radioactively contaminated lake. After 2 weeks biomass growth was nearly complete on the upper tape sections, but full development on the deeper sections took longer. Maximum biomass occurred at 25.4—50.8 cm (6—20 in.) depth. Bacterial colonization and slime formation went unobserved. Blue—greens were the initial algal dominants, succeeded by diatoms and filamentous greens. Species succession continued beyond biomass equilibrium, with blue—greens tending to maintain importance in the deeper zones and greens developing best in the upper, lighted regions. Animals were minor constituents. Radioisotope concentrations equilibrated rapidly in both the artificial substrates and the periphyton biomass. Zinc—65 was concentrated highly by the polyethylene tape, Cs137 moderately, and Co60 and Ru106 only slightly or not at all. Ambient concentrations of Zn65 in water and periphyton were below detection. The other isotopes contributed about equally (ca. 10—20 dpm/mg) to biomass radioactivity. Biomass activity—densities of Ru106 and Cs137 increased slightly with depth; this pattern was pronounced for Co60. Factors considered to account for observed vertical distributions include: different radioisotope concentrations in surface and deep water; a hyperbolic rather than linear relationship between activity—density and biomass; and, in the case of Co60, concentration by blue—green algae as an essential element, or by microbiota for use in cobalamin synthesis.
Home Range Tendency of the Largemouth Bass (Micropterus Salmoides)
Authors: Lewis William M. , Flickinger Stephen
Published: May 2006

By repeated sampling of a population of largemouth bass, including individually marked fish, and by use of reference markers along the shoreline, the observance of a home range by the bass was demonstrated. Of 96 recaptures considered, 59% were recaptured within 100 ft, 83% within 200 ft, and 96% within 300 ft of the original point of capture. The extent of movement away from the initial point of capture did not increase with time. After being offshore over winter the bass again demonstrated a marked tendency to resume the use of the same segment of shoreline they had frequented the previous summer. Straying from the home range followed by return to it was also observed. Observations on the dispersion of bass along the shoreline are given.
The Algal Flora of Two Washington Soils
Authors: Fairchild Eugene D. , Willson Dan L.
Published: May 2006

The algal flora of a neutral loamy sand and an alkaline sandy loam soil in Grant County near Beverly, Washington, was determined. The 60 soil samples contained 21 genera and 34 species of algae. In the loamy sand soil there were 22 species including 11 blue—greens, 8 greens, and 3 diatoms. In the sandy loam soil there were 19 species comprising 13 blue—greens, 4 greens, and 2 diatoms. Seven genera were common to both soil types, but a greater dissimilarity than similarity existed: nine genera were unique to the loamy sand and four genera were peculiar to the sandy loam. Algal populations associated with macrovegetation appear to differ from those in open soil.
Altitudinal Zonation of Chipmunks (Eutamias): Interspecific Aggression
Authors: Heller H. Craig
Published: May 2006

Eutamias alpinus, E. speciosus, E. amoenus, and E. minimus are contiguously allopatric on the eastern slope of the Sierra Nevada, California. This paper is part of a study of the factors determining the lines of contact between these contiguously allopatric populations. Overlapping fundamental niches and overlapping realized niches indicate that competitive exclusion has occurred. Patterns of intra— and interspecific aggression are described for these four species. The aggressive dominance of alpinus and amoenus explain the limited realized niches of speciosus and minimus. Hypotheses regarding the evolution of the patterns of aggressive behavior observed in these species are suggested. Aggression has been selected for in alpinus and amoenus because of a seasonal, potentially limited food supply which is economically defendable. Aggression has not been selected for in minimus because it is not metabolically feasible to engage in aggressive interactions in the hot sagebrush desert. Aggressive behavior has not been selected for in speciosus probably because of predator pressure and the seasonal abundance of food in its habitat.
A Colorimetric Method for Determining Oxygen Concentration in Terrestrial Situations
Authors: Beyers Robert J. , Smith Michael H.
Published: May 2006

A method for the determination of gaseous oxygen is described. The technique is based on the manganous hydroxide‐potassium iodide method of Winkler. The use of the method in measuring the oxygen content of the burrows of the old‐field mouse Peromyscus polionotus is demonstrated.
Estimation of Photosynthetically Active Radiation Under a Forest Canopy With Chlorophyll Extracts and From Basal Area Measurements
Authors: Perry Thomas O. , Sellers Harold E. , Blanchard Charles O.
Published: May 2006

A chemical light meter that uses chlorophyll is described. The quantity of radiant energy that is utilizable for photosynthesis can be estimated through use of crude chlorophyll extracts in conjuction with a thermopile and recorder. Two hundred or more determinations can be made per day at a negligible cost relative to the cost of using a comparable number of thermopiles and recorders. Preliminary tests with this apparatus revealed that about 75% of the forest floor under a dense hardwood stand received enough radiation to compensate for the respiration losses by the plants. The light in a 28—year—old, 6— by 8—ft Pinus virginiana Mill. plantation was considerably brighter than that under a dense hardwood stand. All of the sample points under the pine plantation received sufficient radiation to permit photosynthesis to compensate for respiration. The experimental results and theoretical analysis of several research workers are combined to develop the generalization that radiant energy is transmitted through a canopy of leaves in the same manner as radiant energy is transmitted through a solution–i.e. in accord with Beer's law: Optical density @8 —log (fraction of radiant energy transmitted) ° KF K is a constant of proportionality and F is the concentration of leaves per acre. Because of the exponential relationship between basal area per acre and quantity of leaves, basal area may be substituted for quantity of leaves in the equation.
Pollen Size Variation in Selected Grass Taxa
Authors: Bragg Louis H.
Published: May 2006

Variation in pollen size in transplanted clones of four widespread prairie grasses was correlated geographically. Pubescent, non—glaucous clones of Andropogon gerardi Vitman, Andropogon scoparius Michx., and Sorghastrum nutans (L.) Nash, as well as non—glaucous clones of Panicum virgatum L. from eastern Texas, had larger pollen grains than non—pubescent, glaucous clones of these species from central Texas and non—pubescent, glaucous P. virgatum from north—central Texas under garden conditions.
A Corer for Sampling Soil and Litter Arthropods
Authors: Tanton M. T.
Published: May 2006

A corer with plastic sample rings enclosed in a split inner lining for efficient sampling of soil and litter arthropods is described.
Seed Germination in Cedar Glade Talinum
Authors: Ware Stewart A. , Quarterman Elsie
Published: May 2006

Talinum calcaricum Ware is a succulent perennial herb endemic to the cedar glades of middle Tennessee and northern Alabama. Its seeds which germinate in the spring, require moist cold treatment, light, and alternating temperatures for good germination. At constant temperatures some germination occurs at 25°C, but not at 20° or 30°C. Laboratory dry storage does not eliminate requirements for cold storage and light, but does increase germination reached after cold treatment. Germination requirements of T. calcaricum are advantageous in its cedar glade habitat. Seeds of T. mengesii Wolf, a species of sandstone and other outcrops of the southeastern United States, also require cold treatment and light, but not alternating temperatures, for good germination.
Plant Diversity in a Chronosequence at Glacier Bay, Alaska
Authors: Reiners William A. , Worley Ian A. , Lawrence Donald B.
Published: May 2006

Eight sites of known age were sampled in Glacier Bay National Monument, Alaska, to examine the changes in plant diversity during primary succession in that region. Four strata–trees, tall shrubs, low shrubs—herbs, and bryoid—thalloids–were sampled independently. Data suggested a sequence of wave—like invasions on sites by strata, largely in order of increasing size. Bryoid—thalloids were exceptional in demonstrating a late peak in cover values. In general, diversity of a particular stratum declined during the period in which the stratum dominated the community in terms of foliar cover. Richness (species number) of communities increased rapidly in the first 100 years, then more gradually to reach a maximum in the muskeg steady state. Equitability (evenness of distribution of foliar cover among species) was erratic, but tended to increase with age. After initial rises, three diversity indices showed nearly flat curves with two exceptions: marked decreases in the 30— to 50—year period; and a rise to maximum levels in the final steady state. Total information per unit area calculated from diversity and foliar cover increased in a sigmoid manner with peak information in the final muskeg stage.
Field Populations of Deermice with Supplemental Food
Authors: Fordham R. A.
Published: May 2006

A description is given of a field experiment from winter through fall in which excess artificial food was provided in some areas with Peromyscus maniculatus, but not in others. Population size and production of young increases, and adult but not juvenile survival improves slightly with additional food; hence the hypothesis that no differences in breeding and survival would exist between experimental and control areas is rejected in part. The numbers of adult males in experimental and control situations are similar, suggesting that the male portion of the breeding population may, as hypothesized by Sadleir (1965) and Healey (1967), be held relatively constant during breeding by behavioral mechanisms. Attention is drawn to the different numerical responses of males and females, and the possibility of different regulating mechanisms for the sexes.
Dispersal of Scandium‐46‐Labeled Pantorhytes Weevils in Papuan Cacao Plantations
Authors: Lamb K. P. , Hassan E. , Scotter D. R.
Published: May 2006

The movement of adult apterous cacao weevils, Pantorhytes szentivanyi Mshl. (Coleoptera: Brachyderinae) marked with scandium—46 was studied in cacao plantations with open or closed canopies. A diffusion model of dispersal was used to calculate diffusivities (D). These were higher in a closed canopy (D = 0.75 m2/day) than in open canopy (D = 0.16 m2/day). This reflects the more rapid dispersal occurring when the branches of adjacent trees are touching. In a closed canopy plantation, the calculated probable distance moved by any individual in a month was 14—25 m (P = 0.1 — 0.001).
Dispersal of Snakes from a Hibernaculum in Northerwestern Utah
Authors: Hirth Harold F. , Pendleton Robert C. , King Arthur C. , Downard Thomas R.
Published: May 2006

A total of 196 snakes (64 Mormon racers, Coluber constrictor mormon; 51 Great Basin rattlesnakes, Crotalus viridis lutosus; 81 striped whipsnakes, Masticophis t. taeniatus) were tagged with Ta182 after emergence from a communal hibernaculum in the spring. Using gamma scintillometers, 73% of the Mormon racers, 56% of the rattlesnakes, and 61% of the whipsnakes were recovered at least once during the summer. Recaptures provided information on the dispersal patterns of the three populations as well as the extent of individual movements. Mormon racers not only remained closer to the den than rattlesnakes and whipsnakes, but over a period of several months they moved about less than the two larger species. Whipsnakes dispersed the greatest distance. Recaptures of this species were made at distances of 1.5, 3.2, and 3.6 km from the den. The majority of each species recaptured in the summer were found in one or in two quadrants around the den. Except during periods of ecydsis most individual movements on the summer range were unpredictable. Daily movements and behavior of a male and female rattlesnake are described in detail. Mormon racers were found underground as often as on the surface. Almost equal numbers of whipsnakes were sighted or captured in shrubs as on the surface. Most rattlesnakes occupied epigean niches in the summer. Cloacal temperatures of between 8° and 13.6°C were close to the ecological minima; rattlesnakes were the most cold—hardy, whipsnakes the least. The concept of "total range" most accurately describes movements of the three species. Whipsnakes have the largest "total range" and Mormon racers the smallest.
Reproductive Variation Between Turtle Populations in a Single Geographic Area
Authors: Gibbons J. Whitfield , Tinkle Donald W.
Published: May 2006

Statistically significant differences were found in body length, body weight and clutch size between three southern Michigan populations of the painted turtle (Chrysemys picta) occupying differing habitats. The clutch size differences were as great as those reported from different parts of the range of this and other species. Diet, rather than body weight or shell length, is suggested as being the factor responsible for observed differences in reproductive potential.
Ecology of Cladophora in Farm Ponds
Authors: Mason Charles P.
Published: May 2006

The ecology of Cladophora glomerata (L.) Kutzing was studied in five farm ponds near Ithaca, New York, in comparison with a control pond in which the alga was absent. Periodic samples and observations were taken over a 14—month period for temperature, pH, light penetration, water level (including ice and snow cover), nitrate, phosphate, BOD, plankton (counts and identity), and condition of Cladophora glomerata. C. glomerata was found to live throughout the year in the vegetative condition. In the pond which contained the most C. glomerata, ankinetes occurred in abundance throughout the year except in May when a large percentage of them germinated. Approximately 5% of the overwintering vegetative cells in that pond also released zoospores during May and the first half of June. Filaments which overwintered on the bottom began rising to the surface in mid—May, and their vegetative growth during late June and early July caused the greatest increase of the alga. Increase in mass of the alga from germinating akinetes and zoospores was minor compared with vegetative increase from overwintered filaments. Temperature, pH, and phosphate concentration were not directly related to C. glomerata productivity. Amount of light did not limit the abundance of the alga, but decrease in amount of light may initiate akinete and zoospore formation. Plankton counts in the six ponds indicate that each has approximately the same total productivity. High productivity of C. glomerata was directly associated with high nitrate and high biochemical oxygen demand.
Studies on Water Metabolism of the Hill Kangaroo, Macropus Robustus (Gould), in Northwest Australia
Authors: Ealey E. H. M. , Bentley P. J. , Main A. R.
Published: May 2006

The hill kangaroo, Macrophus robutus, is able to survive in hot and arid conditions not because of its ability to concentrate urine, but because it avoids high air temperatures by sheltering in caves where it can withstand considerable dehydration. Urine concentrations were high throughout the year studied. The sodium concentration relative to the potassium concentration was greater in the hot dry periods. Plasma sodium concentrations were similar in field animals at all times of the year and not significantly different from animals kept in yards with unlimited water. Severe dehydration in the yards resulted in an elevation of the plasma sodium concentration. Comparison of the urine area concentrations of animals from areas of high and low protein pasture suggests that this was directly dependent on protein value of the food grasses in the area where the animals lived. When kept on a dry diet and no water the animals survived a water loss corresponding to 20 to 30% of their body weight during five days. The average volume of water consumed at each drink by field animals during the hot dry time of the year corresponded to 12% of their body weight, although it is known that few drink as frequently as once in five days.
Small Mammal Populations on Islands
Authors: Webb William L.
Published: May 2006

Small mammal populations on three islands in Adirondack lakes were studied by trap removal, and results compared with trap removal data from three similar mainland areas. Number of species present on islands was less than on the mainland, but island size did not affect faunal diversity. Microtus were much more prevalent on islands and occurred in forested habitats. Total population density of small mammals on the islands was determined by extended removal trapping. Total density and density by species are given. Short periods of removal trapping do not indicate species composition of the community because some abundant species are seldom captured in the early part of the trapping period. Species differences in initial attraction to the traps or changes in behavior following extensive removal of "social dominants" may be involved. Probability of capture is variable, and not consistently related to population density. Several census methods are evaluated and shown to provide an inaccurate estimate of population. Comparison of capture rates on mainland areas with that on islands suggests that invasion may not be a major factor until after 10 to 15 days of trapping. Long—continued trapping on mainland areas produces periods of high catch which may exceed capture rates of the initial period. The reasons for these periods of high catch are not known.
A Three‐Year Study of Mating Behavior in a Freeranging Band of Rhesus Monkeys
Authors: Kaufmann John H.
Published: May 2006

The mating behavior of a freeranging band of rhesus monkeys in an island colony near Puerto Rico was studied for three consecutive years. From approximately July through December females had repeated cycles of estrous behavior in which they associated closely with males, groomed with them, and engaged in copulation. About one—half of the females which conceived had postconception estrous periods, including copulation. The average number of estrous periods per female was two, each period lasted an average of 11 days, and most estrous cycles lasted about 28 days. An average of three males associated with a female during one period. Most females began breeding when they were three years old and there was no significant difference between the mating activity of females three, four, and five years old. Six—year—old females showed a definite increase in mating activity, and females seven years old showed a still greater increase. No significant increase was apparent after the females reached seven. The females' rank in the dominance hierarchy apparently had no effect on their mating activity. The quantity of the males' sexual activity was generally correlated with their dominance rank. The highest male was the most active by far, the first to become active, and the only male to form many exclusive consort relationships with individual females. Progressively lower ranking males were usually less active, but low—ranking males were active early and late in the mating season. The findings concerning average period and cycle length, number of males associating with females, and the relation between the males' rank and mating activity agree closely with those of C. R. Carpenter (1942) on Cayo Santiago in 1940. Though several promising lines of inquiry have been opened, much work remains to be done before we can explain the relation between rhesus mating behavior and its physiologic basis, or explain variations in reproductive periodicity.
Insects and Pollinia
Authors: Frost S. W.
Published: May 2006

A large number of individuals of many insect species visited the flowers of milk—weed (Asclepias spp.). Most of these insects revealed pollinia attached to various appendages. Some were captured and held prisoners; others were able to free themselves. A relatively small number were able to avoid these traps. The largest number of pollinia adhered to the hairs of the tarsi, pulvilli, and mouth parts. This might be expected as these are the appendages most closely associated with flower visitation.
Ecological Distribution in Anoline Lizards of Puerto Rico
Authors: Rand A. Stanley
Published: May 2006

The eight species of lizards of the genus Anolis in Puerto Rico can be divided into four morphological similarities. One, Anolis curvieri, is very different from the rest and has not been discussed here. The other seven species fall into three groups. Each of these groups occupies a different structural habitat which can be defined in terms of perch height and perch diameter. Within each of these three groups the species have very similar but not indential structural habitats but differ very widely in climatic habitat defined in terms of shade. Shade preferences seem to result from the temperature preferences of the species involved. In each group there is one species with high shade preference which is essentially restricted to the mountains. Each group also has a species with a lower shade preference which occurs in the lowlands and extends up into the mountains in exposed or sunny situations. One of the three groups has an additional species which is restricted to the hot and southwest corner of Puerto Rico. When one compares the temperature preferences or eccritic temperatures of the various species, one finds in each group that the highland species has a lower eccritic temperature than does the lowland species. There is little temperature difference between the lowland species and arid southwest species in the group where this additional third species is present. The species within each structural habitat show many morphological similarities which may be the result of their being closely related or may be the result of adaptation to similar environments. The differences in microhabitat between the Puerto Rican anoles separate them spatially though not completely. In species occupying different structural habitats in the same area the overlap may involve part of the home range of most of the individuals in the area. In species occupying the same structural but different climatic habitats the overlap may involve all of the home range of some individuals but of only a small fraction of the individuals in the total population. The spatial separation among Puerto Rican Anolis can be suggested to be of ecological significance because it reduces interspecific competition and because it allows the various species to adapt more precisely to different parts of the available habitat. Thus members of a genus may exploit the habitat more efficiently.
Ecologic Aspects of Lipid Deposition in Some Postbreeding Arctic Birds
Authors: Johnston David W.
Published: May 2006

A series of 112 arctic birds representing five species (golden plover, western sandpiper, arctic tern, redpoll, and Lapland Longspur) was taken near Cape Thompson, Alaska, for lipid studies. The birds were collected in 1960 during the postbreeding and autumnal premigratory period of late summer. Relevant data on life history, distribution, migration, and molt are presented. Extractions of body lipids revealed that there was no significant increase in lipid deposits in any of the species except a few adult western sandpipers. Possible correlations among lipid levels, timing of migration, and migratory paths are discussed.
Inverse Relationship Between Temperature and Shyness in the Lizard Anolis Lineatopus
Authors: Rand A. Stanley
Published: May 2006

An increase in flight distance with a decrease in body temperature in 32 male Anolis lineatopus at Mona, Jamaica, supports more casual field observations that these lizards are shier when they are cold than when they are warm. It is suggested that this increased shyness compensates for the slowing effects of lower temperatures on biological processes and so helps protect these arboreal lizards from warm—blooded predators.
Ecology of a Northeastern Outlying Stand of Pinus Flexilis
Authors: Potter Loren D. , Green Duane L.
Published: May 2006

A small stand (208 acres) of limber pine (Pinus flexilis) occurs in association with Juniperus scopulorum in southwestern North Dakota, about 12 miles north of Marmarth, and at an average elevation of 2,850 feet in typical "Badlands" terrain. Both P. flexilis and J. scopulorum are reproducing well, although the pine shows greater relative density and a higher frequency index in the larger size classes, indicating site dominance. The total foliage cover of the shrub stratum was only 7.6% however, the dominance of one shrub, Rhus trilobata is of particular importance. From increment borings of 50 Pinus flexilis trees the oldest tree was 238 years old at breast height. The greatest diameter was 17.2 in. at breast height, and the greatest height was 26 ft. The average diameter growth was .11 in. per year. The trees growing on the knolls showed the greatest growth rate. Sectioned trunks showed a definite pattern of radial eccentricity, with growth the least on the south side and increasing toward the northeast side. This small stand of Pinus fexilis may have been seeded, either accidentally or purposely, by Indians camping in the area before settlement by the white man.
Transpiration of the Aleppo Pine (Pinus Halepensis Mill) as a Function of Environment
Authors: Gindel I.
Published: May 2006

Transpiration of Aleppo pine was studied in three hilly regions of Israel (Hills of Judea, Mt. Carmel, and Mt. Cana'an). In spite of differences in the ecological factors of the localities tested, fluctuations and pattern of transpiration rate were similar in all of them. During the dry period of July—December no significant changes were noted in transpiration and soil—moisture percentage. The first rains, however, accompanied by favorable temperatures raised the transpiration rate. During the driest and hottest months, when all climatic factors (sun energy, temperature, etc.), including intensity of evaporation, reached their highest values, transpiration are dropped considerably. This phenomenon was particularly noticeable during "hamsin" (hot and dry desert winds) days, when evaporation rate increases two— to threefold, temperature reaches its highest values, and relative air humidity drops to its lowest value.
Dormancy and Germination in Alpine Carex from the Colorado Front Range
Authors: Amen Ralph D. , Bonde Erik K.
Published: May 2006

The nature of achene dormancy was studied in two species of alpine sedges, Carex albonigra and C. ebenea, from the Rollins Pass area of the Colorado Front Range. Germination response of achenes was determined under various treatments, including stratification, scarification, leaching, extraction, exposure to light, and application of various plant growth regulators. Two distinctly different requirements for seed germination are exhibited by the two species. In C. albonigra, only scarficiation at the basal end of the achenes resulted in germination. Only fluorescent and red light were effective in promoting germination in C. ebenea achenes, suggesting a reversible photoreaction as the mechanism responsible for dormancy in this species. The light effect was apparently cumulative, with a minimum of about 15 days of continuous light being required for the initiation of germination.
Role of the Coastal and Upper Estuarine Waters Contributing Phytoplankton to the Shoals of the Niantic Estuary
Authors: Marshall Nelson , Wheeler Bernice M.
Published: May 2006

Niantic Bay and the estuarine basin of the Niantic River were studied as source areas of phytoplankton transported across the shoals which separate the upper estuarine basin from the coastal waters and which support dense populations of bay scallops and other benthic filter feeders. Surface and bottom stations in the bay and estuarine basin and two stations over the shoals, where tidal excursions alternately transport water from offshore and from the estuary, were sampled at 5—week intervals for 1 year. Dinoflagellates predominated in the basin of the estuary and, to a lesser extent, were significant seaward into the Bay. The diatoms were most abundant in the Bay where they followed population trends characteristic of Long Island Sound and coastal waters. Two species of chrysophyceans were abundant, chiefly restricted to these near—shore waters but showing no indications that either the Bay or the more confined estuarine waters were more favorable. When the Bay was the predominant phytoplankton source area, as judged by the counts and population trends, the plankton of the mixed waters over the shoals was similar to that of the Bay in kind and in numbers. When the basin was the predominant source area, the plankton over the shoals, though similar in kind, commonly dropped to one—tenth the abundance found up—estuary. This drop may relate to the vertical migration of the flagellates into deeper waters which do not flow freely across the shoals. The lower plankton counts over the shoals may also result from the mixing of the waters ebbing from the basin with the relatively large volume of water over the shoals following the high tide. In the basin of the estuary the phytoplankton volume fluctuated around a mean of 6.90 mm3/liter. The average for the Bay was 0.23 mm3/liter. Over the shoals the average was 0.63 toward the upper estuary and 0.45 toward the Bay. These averages and other data constitute evidence that the upper estuarine area contributes more phytoplankton to the shoals than do the offshore waters.
Edaphic Controls of Tree Species in Presettlement Indiana
Authors: Crankshaw William B. , Qadir Syed A. , Lindsey Alton A.
Published: May 2006

A quantitative analysis of the soil relations of the tree species of Indiana was made using the General Land Office original survey records and the Indiana soil survey reports. The bearing trees recorded on the GLO records were located on modern county soil maps to identify the soil upon which each bearing tree was situated. Eleven soil characteristics of probable influence on trees were studied: thickness of the A and B horizons and solum, amount of nitrogen, pH, textural proportions, depth of leaching, available water capacity, and water intake rate. These factors were determined for the sites of 70,240 bearing trees. The random pairs and closest individual methods were applied to determine species and stand attributes. A separate multiple regression was run by computer for three dependent variables (importance value, basal area per acre, and mean basal area) for each of 45 tree species using the 11 soil characteristics as independent variables. The results of the regressions were interpreted by using a Deletion—probability Index, the average of the step at which a variable was deleted in the regression and the probability level at deletion. The indices were plotted on circular graphs which showed the relative influence of each soil factor on each species. For tree species in general, the most influential soil attributes proved to be depth of the soil horizons, percentage of nitrogen, and percentage of clay, in that order.
Bottomland Forests of North‐Central Oklahoma
Authors: Rice Elroy L.
Published: May 2006

The vegetation and selected edaphic factors of 47 stands of floodplain forest communities were examined in 10 north—central Oklahoma counties. Soil factors analyzed were pH; total nitrogen; total phosphorus; organic carbon; and percentage of sand, silt, and clay at the 0— to 6—inch and 18— to 24—inch levels. Normal precipitation in the study area varied from 28.0 to 37.5 inches. Ten types of communities were present, with Ulmus americana a dominant in six types and a dominant in 38 of the 47 stands sampled. Celtis occidentalis was dominant in only six stands. Other species which were dominant in at least one stand were Sapindus drummondii, Carya illinoensis, Fraxinus pennsylvanica, Celtis laevigata, and Juglans nigra. Ulmus americana occurred as a dominant throughout the entire area, whereas Sapindus drummondii occurred as a dominant in only the more xeric western countries and all other species occurred as dominants only in the central or eastern countries. The number of tree species increased markedly (11 to 23) and density increased slightly from west to east. No such trend was noted in basal area. The pH of the soil varied from above 8.0 in the west to 6.8 in the east. No consistent trends from west to east were evident in other soil factors analyzed. The best overall correlation appeared to occur between basal area and a combination of total nitrogen at the 18— to 24—inch level and normal precipitation. There were no apparent correlations between the type of plant community or the distribution of individual species and the soil factors analyzed.