Survival and longevity of the Puerto Rican Vireo

The Puerto Rican Vireo (Vir eo latimeri), a Puerto Rican endemic, is declin ing in at least one forest reserve as the result of pressures from introduc ed nest predators and an introduced brood parasite. We collected data on ad ult survival, adult longevity, and juvenile survival from a long-term mist netting study (1973-1999) and a demographic study of color-marked birds (19 90-1993) in Guanica Forest, Puerto Rico. Of the adult birds banded in the f irst three years of the demographic study, 24 of 32 males (75%) and 6 of 7 females (86%) were known to survive until June of the year following their banding. Model-based estimates of adult survival rare from capture/resighti ng of 65 color-marked birds was 0.74 (+/- 0.05 SE); for 51 adult males anal yzed separately, survival rate was 0.74 (+/-0.06; data were insufficient to estimate survival rate of females). We recorded a new longevity record for the Puerto Rican Vireo of 13 years, 2 months. Juvenile survival was estima ted by enumeration to be 0.40 (+/-0.15). Juveniles spent prolonged periods on their natal territory, which might increase their probability of survivi ng to first breeding. Puerto Rican Vireos have relatively high survival rat es despite the presence of numerous introduced predators in their habitat, a highly seasonal environment, and the stress of renesting as many as 6 tim es in a season.