Date of Graduation


Document Type


Degree Type



Davis College of Agriculture, Natural Resources and Design


Animal and Nutritional Sciences

Committee Chair

H. Klandorf.


Birds have few reliable indicators of aging. Pentosidine (Ps), a biomarker of aging, is a product of non-enzymatic glycation, which accumulates in the tissues of an animal over its lifespan. The intent of this study was to determine if comparable change in Ps concentrations could be established in the skin of wild birds of known ages. Skin samples were obtained from the breast of 44 birds of various species. Foot webbing samples were obtained from 24 California Gulls. Collagen was measured by a hydroxyproline spectrophotometric method and Ps was quantified using reverse phase HPLC. Ps concentration in the skin and foot webbing increased linearly with age (p < 0.001). Measurement of Ps in birds of unknown ages provided age estimates within the established life-span of these species. Hydroxyproline concentrations from the foot webbing were comparable to that measured in the skin, however Ps concentrations were approximately one-fourth of that in skin. Knowledge regarding the longevity of birds could provide information for species survival programs (SSPs) and insight into variations in longevity of an entire population.