Age-dependent breeding dispersal and adult survival within a metapopulation of Common Terns Sterna hirundo

作者：Breton Andre R^*; Ni**et Ian C T; Mostello Carolyn S; Hatch Jeremy J

来源：Ibis, 2014, 156(3): 534-547.

DOI：10.1111/ibi.12161

• actuarial senescence
• Buzzards Bay
• capture-mark-recapture
• immigration
• movement rates
• predation
• program MARK
• program U-CARE

Dispersal is increasingly recognized as a process of fundamental importance in population dynamics and other aspects of biology. Concurrently, interest in age-dependent effects on survival, including actuarial senescence, has increased, especially in studies of long-lived seabirds. Nevertheless, datasets necessary for studying dispersal and age-dependent effects are few, as these require simultaneous data collection at two or more sites over many years. We conducted a 22-year capture-mark-recapture study of Common Terns Sterna hirundo at three breeding colonies 10-26km apart in Buzzards Bay, Massachusetts, USA. All birds in the study were of known age (range 2-28years, median 7years, n=3290) and 77% were of known sex. Estimates of adult recapture, survival and breeding dispersal rates were obtained for all age-classes from 2 to 20years. The model that acquired 100% of the QAICc (Akaike%26apos;s Information Criterion adjusted for small sample size and overdispersion) weight in our analysis included age-specificity in all parameters but no relationship with sex. Our study may be the first to demonstrate age-specificity in recapture, survival and breeding dispersal rates simultaneously, using a single model. Annual rates of breeding dispersal ranged from %26lt;0.01 to 0.27, with a population-weighted mean of 0.065; they decreased with increasing distance between colony sites and, unexpectedly, increased with age. Breeding dispersal did not increase consistently after years with predation on adults or after an attempt to displace birds from an oiled site. Survival rates did not vary among sites or years. Annual adult survival increased from 0.80 in 2-year-old birds to a maximum of approximately 0.88 around age 8years and then declined to 0.76 at age 20years, yielding strong evidence for actuarial senescence. The peak annual survival rate of 0.88 is at the low end of other estimates for Common Tern and in the lower part of the range recorded for other terns, but total numbers in the three colonies increased seven-fold during the study. This was part of a slower increase in the regional population, with net immigration into the study colonies. Our results demonstrate the biological significance of breeding dispersal in local population dynamics and age-related effects on survival and dispersal from a metapopulation of a long-lived seabird.

• 出版日期2014-7