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 12 of 12 for “"Hummingbirds"”.
-
Radiation in the genus Amazilia: A comparative approach to understanding the diversification of hummingbirds.
… of morphology and behavior are documented in hummingbirds. I perform a phylogenetic analysis of Amazilia, the largest genus in Trochilidae, and putative sister taxa to test whether the unusual divergence of this genus is an artifact (Chapter 1). Phylogenetic analyses resolve several clusters …
-
Hummingbird Hovering Energetics and Flight Capacities Across Elevational Gradients
… associated with life at high elevations. Using hummingbirds, a group of animals with high hovering metabolic rates and wide elevational distributions, I examine the flight capacities and aerobic scopes across an 1800-m elevational gradient, as well as any morphological adaptations that permit …
-
Levy flight as a robotic search pattern
… For example, robots based on the features of hummingbirds and bees have already been developed though they are not yet autonomous. Incorporating Levy flight searching strategies into these miniaturized robots could yield more efficient and effective searching machines.
-
Plant-flower visitor interactions in the Sacred Valley of Peru
… highest altitudes. Using ordination analysis, hummingbirds, honeybees, flies and beetles were identified as major functional groups of flower visitors with significantly different visitation profiles. Nestedness analysis revealed that the plant-flower visitor networks had a similar structure to …
-
Junkballer
… heat-stroke, and mosquitos the size of hummingbirds.</p>
-
Fight and flight: Behavioural drivers and evolutionary consequences of resource competition in birds
… related to high-performance flight in hummingbirds through the lens of species foraging competition. I show that variation in mass-adjusted keel and humerus morphologies is not explained by species differences in foraging strategies, but instead explained by sex differences presumably …
-
The evolutionary roots of vocal learning: Exploring vocal learning abilities in vocal non-learners in birds
… of birds are vocal learners in birds: parrots, hummingbirds, and songbirds (oscines). In birds, there is also compelling evidence that suboscines that share a common ancestor with parrots and oscines have rudimentary vocal learning abilities. To better understand how vocal learning evolved, I …
-
Pollination ecology of the simultaneously flowering Impatiens capensis and I. pallida
… attract bumblebees while I. capensis depends on hummingbirds and small bees for pollination. Thus competition for pollinators between these Impatiens represents an important plant-plant and plant·pollinator interaction with potential consequences. When I. capensis is less frequented by bumblebees …
-
An Analytical Investigation of Flapping Wing Structures for Micro Air Vehicles
… air vehicles (MAVs) are based on insects and hummingbirds. These animals have lightweight, flexible wings that undergo large deformations while flapping. Engineering studies have confirmed that deformations can increase the lift of flapping wings. Wing flexibility has been studied through …
-
A Comparative Study of the Reproductive Biology of Sympatric Morning Glories (<em>Ipomoea</em>-convolvulaceae)
… and <em>I</em>. <em>trichocnrpa</em>), and hummingbirds and butterflies visited their respective flowers (/. <em>hederifolia</em> and /. <em>quamoclit</em>). Nectar, as predicted by the pollination syndrome concept, was of smaller volume and more concentrated in the bee flowers compared to …
-
Pollination Biology of Gentianales in a Southern Ecuadorian Montane Forest
… flower observation showed that nine different hummingbirds (Trochilidae) were frequent visitors. At night, only a few sphingid individuals were observed. Pollination experiments showed that flowers exclusively presented to nocturnal pollinators had a low fruit set (14%) but a high seed set …
-
Early patterns of Andean diversification, genomic and color patterns variation across the Metallura tyrianthina complex of the Northern Andes
La topografía altamente variable, la historia climática y la gran variedad de nichos de la cordillera de los andes ha contribuido a la formación y mantenimiento de la asombrosa diversidad genética y morfológica de las aves tropicales, promoviendo dos mecanismos de especiación. El primero consiste …