Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 27 for “"insect abundance"”.
-
Indirect effects of agricultural intensification on tree swallow (Tachycineta bicolor) foraging behaviour, body condition, and physiology
Throughout North America, many species of aerial insectivorous birds – birds that capture flying insects – have exhibited sharp declines, with tree swallows (Tachycineta bicolor) experiencing a 2.8% annual decline in Canada since 1989. The timing of these declines coincides with major changes in …
-
Factors affecting the activity patterns of Myotis tricolor (Chiroptera: Vespertilionidae)
… cloud cover, wind speed, rainfall and insect abundance. These data were used to calculate emergence time, number of foraging bouts and foraging duration for each reproductive period, which were then correlated with the environmental variables.
-
Availabilty of Potential Invertebrate Foods for Anatini Ducklings Above and Below the Water Surface of Eastern South Dakota Wetlands
… sorted and identified to family. Total and taxa abundance and volume displacement were measured. Additional habitat characteristics were also measured at each sampling site. Simple correlation revealed no similar trends in invertebrate abundance and volume during 1998 or 1999. In 1998, there was …
-
Non-target effects of extended-release LongRange eprinomectin on coprophilous insects
… Extended-release LongRange (LR) on dung breeding insects. Field and lab studies over two years showed that residues are excreted for at least 25 weeks post-treatment at levels sufficient to reduce survival of some taxa with detectable effects on total insect abundance, taxa richness, and …
-
Ecological interactions of biological control agent, Mecinus Janthinus Germar, and its target host, Linaria Dalmatica (L.) Mill.
… weed biological control. Field evaluation of an insect's establishment, spread and early host impact within its new environment must be performed before agent success can either be doucmented or predicted. Population attributes of the ednophagous biological control agent, Mecinus janthinus Germar …
-
Examining the Impacts of Valley Fills in Stream Ecosystems on Amphibian and Aquatic Insect Communities in Southeastern Kentucky
… in ecology. Because of their relatively high abundance and complex life cycles, stream salamanders and aquatic insects are important trophic links and serve a critical role in transferring energy. Despite this importance little research has examined their community structure simultaneously in …
-
Detection, habitat use, and occupancy dynamics of Black-billed Cuckoos and Yellow-billed Cuckoos in Illinois
… covariates, these species’ reliance on ephemeral insect abundance may ultimately be driving these wide-ranging movements. These findings will improve monitoring and management efforts, but also imply the need for creating and protecting areas within a broader spatial context to allow these species …
-
Recovery of community structure and leaf processing in a headwater stream following use of a wetland passive treatment system to abate copper pollution
… 7.7 μg/L at the reference site. In kick samples, insect abundance (n) and the number of taxa (#) were reduced at the impacted sites (n = 31, 22, 33, 24 and # = 190, 246, 266, 345, at sites 2 - 5, respectively) relative to the reference site (n = 52, # = 973). Red maple (Acer rubrum) leaves broke …
-
From soil to air: exploring two novel approaches to studying cryptic aspects of insect ecology
Insects play critical roles in forest ecosystems; however, their overwintering ecology and spatial behavior remain poorly understood due to methodological challenges in observing their cryptic life stages and movements. This thesis integrates two complementary approaches to address these gaps in …
-
Mycotoxins Risk in Maize Fields in Relation to Insect and Edaphic Factors in South Dakota
… and Bt maize hybrids. The relationship of insect abundance, insect kernel damage and edaphic factors with mycotoxin concentrations in conventional and Bt maize were investigated in eastern South Dakota during 2008 through 2010. Caterpillar abundance and kernel damage were positively related …
-
Bat activity over wetlands: temporal and spatial variation
… temporally as well as spatially. For temperate insectivorous bats, wetlands are important forage habitats because they provide water and high abundances of insects. My overall objective was to identify abiotic and biotic factors that influence bat foraging activity over wetlands in the channeled …
-
Grazing and Climate Effects on High Elevation Meadow Resources
… and vegetative type. Arthropod taxa abundance responded differently to grazing management and environmental variables in these meadow communities. Coleoptera abundance during peak sage-grouse usage periods had an increase of roughly 40% in some meadows with increased grazing …
-
Native Forb Establishment in Tall Fescue-dominated Cattle Pastures
… contributing to the global decline in insect abundance due to habitat loss and a lack of floral resources. This has prompted conservation organizations to support pollinator conservation on working landscapes by increasing floral resources, but gaps remain in the consistent …
-
The influence of an umbelliferous understory on the parasites of organic apple orchards in Canterbury
… other potential regulating factors on parasite abundance and activity were also examined. This involved measurement of meteorological factors, behavioural observation and records of orchard management activities. The amount of damage to fruit from the major apple pests was assessed at different …
-
Urbanization's Effects on Avian Morphology, Hormones, and Behavior Across Ontogeny
… evidence that limited food, i.e. , reduced insect abundance, in urban environments is likely the urban ecological pressure driving these differences in morphology, maternal hormone transfer, and physiological responses in an insectivorous urban bird. This dissertation advances our …
-
Addressing Insect Declines Via Biodiversity Monitoring, Ecological Restoration, and Population Genetics
Insects are influential in all terrestrial and freshwater ecosystems and are the most diverse and abundant animal group. Yet there are major knowledge gaps concerning ecology, population genetics, and responses to management practices. Recently reported global declines in insect abundance, biomass, …
-
Assessing the Effects of Chronic Neonicotinoid Insecticide Exposure on Aquatic Insects using Multiple Experimental Approaches
Neonicotinoid insecticides are among the most widely used plant protection products in industrialized agriculture, and are hypothesized to be contributing to losses in non-target insect biodiversity. The lack of toxicological data evaluating the effects of neonicotinoids restricts the ability of …
-
Effects of Local Plant Neighborhood on Plant Herbivory in Perennial Polyculture Cropping Systems
… and row spacings) that could confer specialist insect pest resistance via reduced host plant apparency, changes in herbivore attraction, and host plant tissue quality. The three chapters in this dissertation examine these themes of perennial polyculture and effects of spatial heterogeneity on …
-
Feeding Ecology and Aspects of Life History in <i>Microcebus Rufus</i> (Family Cheirogaleidae, Order Primates)
… are expected to include a high proportion of insects in their diet to meet protein and other nutritional requirements.</p> <p>I monitored body fat and activity levels of known live-trapped individuals. Feeding behavior was determined primarily through analysis of fecal samples. Feeding data …
-
Spring Phenology and Trophic Ecology of Trees, Caterpillars, and Migrating Neotropical -Nearctic Songbirds
… tree preferences relate to tree phenology and insect abundance. Among all three years, tree and caterpillar phenology varied in accordance with spring temperature. The timing of bird migration through the stopover did not vary. As an indirect result of trophic asynchrony in two years, the …
Page 1 of 2