I am currently seeking a Master's of Science degree from the University of Wyoming under the guidance of Dr. Carlos Martinez del Rio. I
am interested in the mechanics, physiology and ecological consequences of animal movement, and the evolutionary forces that have
shaped those qualities. My M. Sc. thesis project involves quantifying correlations between the morphological phenotypes of 13 species of
Cinclodes ovenbirds with the environments in which they occur. My work is novel in that I am pairing morphometrics, to characterize
phenotypes, with stable isotope analyses that identify and quantify environmental correlates to the divergence of these phenotypes
(deuterium and oxygen for elevation, carbon and nitrogen for marine/terrestrial resource use). I am using an established well-resolved
phylogeny to interpret these environment/phenotype correlation data in an evolutionary context.
I have collected a large data set of metrics along with a sample of contour feathers (for stable isotope analysis) from specimens in four
museum collections. My preliminary results suggest that the genus has diversified primarily in wing morphology. Migrant species tend to
have more pointed wings, which contrasts with the rounded wingtips of sedentary and high-elevation species. I have also demonstrated
that the robustness of Cinclodes bills is highly conserved across their range of body size, and I am currently working on a method to
describe the curvature of their bills. The results of the stable isotope analyses have revealed an interesting (and to my knowledge
completely novel) correlation between feather deuterium content and elevation. Carbon and nitrogen isotope rations in Cinclodes
feathers clearly differentiate between species with marine and terrestrial diets, and migrant species seem to occupy a broader isotopic
space between these two groups. I am currently developing methods that will allow me to correlate the environmental features revealed
by stable isotope analyses with the morphological features that I have measured. To my knowledge, my research will, for the first time,
track the evolution of “isotopic niches” along a well supported phylogeny, and establish correlations between environmental features as
revealed by stable isotope analyses and morphology.
My interests in biomechanics are diverse, but I am primarily interested in studying major evolutionary transitions in vertebrate
locomotion. Specifically, I am intrigued by the transition from lateral spinal flexion in proto-mammals to the dorso-ventral flexion
exhibited by crown-group Mammalia, and the evolutionary trajectory that led some theropod dinosaurs to take to the air. I feel that a
multidisciplinary program that includes study of the morphology, mechanics and ecology of both modern and fossil forms can be a
powerful way to address these questions. In my Ph. D., I would like to study the evolution of powered avian flight from a morphological,
energetic, and functional perspective. There is abundant evidence that many (if not all) maniraptoran theropod dinosaurs possessed fore-
limb feather fans. It seems fairly certain that many of these animals weren’t flying or gliding, which begs the question of what adaptive
value those feather fans served. Could they have been control surfaces that aided in terrestrial locomotion? To get at this, there are
several direct questions that need to be addressed: 1) Do modern birds utilize their wings for terrestrial locomotion? 2) Does evidence
exist that maniraptorans were utilizing their feather fans for aerodynamic purposes? 3) Were maniraptorans capable of running at the
speeds necessary to make the feather fans useful for maneuvering?
|All Images © 2009 Jonathan Rader and respective copyright holders. All Rights Reserved. Content may not be reproduced without permission.