Learn More
Plasma metabolite profiling offers a potential means to assess stopover refueling performance of migratory birds from a single capture. However, this method has not previously been validated where site quality has been determined independently using analysis of capture data. We captured and blood sampled six passerine bird species refueling at known(More)
Unsuccessful attempts to identify the leptin gene in birds are well documented, despite the characterization of its receptor (LEPR). Since leptin and LEPR have poor sequence conservation among vertebrates, we speculated that a functional assay should represent the best way to detect leptin in birds. Using a leptin bioassay that is based on activation of the(More)
The hormone leptin is involved in the regulation of energy balance in mammals, mainly by reducing food intake and body adiposity and increasing energy expenditure. During energetically demanding periods, leptin's action is often altered to facilitate fat deposition and maintain high rates of food intake. Despite the present controversy over the existence of(More)
Seasonal adjustments to muscle size in migratory birds may result from preparatory physiological changes or responses to changed workloads. The mechanisms controlling these changes in size are poorly understood. We investigated some potential mediators of flight muscle size (myostatin and insulin-like growth factor, IGF1) in pectoralis muscles of wild(More)
Latitudinal variation in avian life histories can be summarized as a slow-fast continuum, termed the 'pace of life', that encompasses patterns in life span, reproduction, and rates of development among tropical and temperate species. Much of the variation in avian pace of life is tied to differences in rates of long-term metabolic energy expenditure. Given(More)
The migratory flights of birds are fuelled largely by fatty acids. Fatty acid transporters, including FAT/CD36, FABPpm and H-FABP, and enzymes involved in fatty acid oxidation (CPT, CS, HOAD) are seasonally up-regulated in flight muscle to meet the demands of this intense aerobic exercise. The mechanisms that control these biochemical changes in response to(More)
The Tachycineta genus of swallows is comprised of nine species that range from Alaska to southern Chile. We sequenced the entire mitochondrial genome of each member of Tachycineta and generated a completely resolved phylogenetic hypothesis for the corresponding mitochondrial gene tree. Our analyses confirm the presence of two sub-clades within Tachycineta(More)
Behavioural side-bias occurs in many vertebrates, including birds as a result of hemispheric specialization and can be advantageous by improving response times to sudden stimuli and efficiency in multi-tasking. However, behavioural side-bias can lead to morphological asymmetries resulting in reduced performance for specific activities. For flying animals,(More)
Plasma metabolites, including triglycerides, beta -hydroxybutyrate, and glycerol, can be used to estimate mass change in birds. Although dietary fatty acids can be ingested and absorbed as phospholipids, they have been largely overlooked as a potential indicator of mass change. The plasma ratio of triglyceride to phospholipid could also provide insight into(More)
  • 1