Wing Length and Mass at Fledging Predict Local Juvenile Survival and Age at First Return in Tufted Puffins

• Published in: The Condor
• Main Authors: Kyle W. Morrison, J. Mark Hipfner, Carina Gjerdrum, David J. Green
• Format: Text
• Language: English
• Published: American Ornithological Society 2009
• Subjects: Triangle Island; fratercula
• Online Access: https://doi.org/10.1525/cond.2009.080099

In long-lived species, juvenile survival and the age at which individuals begin the process of recruitment have important consequences for individual fitness and population growth. We investigated how characteristics of fledglings (mass, wing length, and date) influenced the local survival of juveniles and age at first return to the natal breeding colony of two annual cohorts of the Tufted Puffin (Fratercula cirrhata) at Triangle Island, British Columbia. Although both cohorts were produced in years when nestlings grew quickly and had high mass at fledging, only 8% of banded nestlings from the 1999 cohort, but 43% of nestlings from the 2000 cohort, were resighted up to 2008. Age at first return of the 2000 cohort averaged one year younger than that of the 1999 cohort. In addition to the cohort effect, we found that the local survival of juveniles increased strongly with wing length at fledging, providing an ultimate explanation for puffin nestlings' preferential allocation of energy and nutrients to wing growth over mass growth. Mass and date at fledging had detectable, but much weaker, effects on survival. Conversely, nestlings' age at first return decreased strongly with mass at fledging, weakly with wing length at fledging. Ours is the first study to report an effect of characteristics at fledging on juvenile survival and age at first return in an alcid whose offspring receive no parental care after they leave the nest site.