Telomeres and telomerase in birds: Measuring health, environmental stress, and longevity

Aging is a complex suite of subcellular-, cellular-, and tissue-damaging events that culminate in the demise of the organism. One of the hallmarks of cellular aging is telomere shortening, a phenomenon observed in vertebrates including mammals and birds. Although the domestic chicken remains a premier avian model for the life sciences in this postgenomic era, researchers have expanded the array of bird species used in aging research. Recently, there has been an explosion in the use of telomere length measurements as a proxy for the cumulative impact of environmental stressors on welfare, longevity, aging, and reproductive success in wild and captive birds. This chapter provides a brief summary of the state of telomere research in birds and explores selected research studies that use telomere shortening as a surrogate to measure environmental stress in wild and captive bird populations.