Telomeres, conserved DNA sequences at chromosome ends, naturally shorten with age, exacerbated by external factors like environmental challenges and reproduction. Birds, particularly psittacine, are gaining prominence as new aging models over the years because of their unique characteristics. This study explores erythrocyte telomere length (TL) and oxidative stress markers in plasma of long- and short-lived captive birds of the order Psittaciformes over four years. Long-lived birds consistently exhibited longer TL than short-lived ones (p = 0.012) but experienced a more pronounced TL shortening rate (p <
0.002) than short-lived ones. Breeding individuals experienced increased TL shortening compared to non-reproductive counterparts in long-lived birds (p = 0.008). Interestingly, long-lived birds showed a higher total antioxidant capacity than short-lived ones (p <
0.002), which was also increased during breeding (p = 0.026). A significant correlation was found between the telomere length shortening rate within the 4 years of study and the accumulated oxidative stress (r = 0.426, p = 0.069) in short-lived birds. These findings shed light on TL and oxidative stress dynamics over time, revealing distinct patterns influenced by life-traits among longevity groups.