Survival and Longevity of Adult Male Florida Grasshopper Sparrows

Survival and longevity were estimated for the endangered Florida grasshopper sparrow (Ammodramus savannarum floridanus) from resightings of 48 colorbanded adult males during 1989-1992. Annual survival rate was 0.598 and mean life expectancy was 2.95 years (1.95 years for sparrows >1 year old). The high survival rate and longevity of the subspecies may facilitate the recovery of populations remaining in good breeding habitat. Annual recruitment of 5.4 young per pair is needed to maintain a stable population of grasshopper sparrows on the study area. Information on population dynamics may help evaluate recovery efforts. Additional information is needed on the fecundity of the Florida subspecies.