El Niño in the Warm Tropics: local sea temperature predicts breeding parameters and growth of blue-footed boobies

• Published in: The Journal of animal ecology Vol. 80; no. 4; pp. 799 - 808
• Main Authors: Ancona, Sergio, Sánchez-Colón, Salvador, Rodríguez, Cristina, Drummond, Hugh
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing 01.07.2011; Blackwell Publishing Ltd; Blackwell
• Subjects: Animal and plant ecology; Animal ecology; Animal, plant and microbial ecology; Animals; Biological and medical sciences; Birds - growth & development; Birds - physiology; Breeding; breeding effort; Breeding seasons; breeding success; chick growth; Chicks; Climate ecology; Eggs; El Nino; El Nino-Southern Oscillation; Fundamental and applied biological sciences. Psychology; General aspects; Hurricanes; Marine ecology; Mexico; ocean productivity; Ocean temperature; Oceans; Pacific Ocean; Parameter estimation; Rainforests; Reproduction; Reproductive success; Sea birds; sea surface temperature; Sea water ecosystems; Seasons; Southern Oscillation; Synecology; Temperature; Tropical Climate; tropical Pacific; Equatorial Pacific; Pacific Ocean; Mexico; Productivity; Sea surface; ocean productivity; tropical Pacific; Growth; Tropical zone; Surface temperature; Young animal; chick growth; Marine environment; breeding effort; Vertebrata; Reproduction; El Niño; Southern oscillation; Breeding success; Aves; sea surface temperature
• ISSN: 0021-8790; 1365-2656
• DOI: 10.1111/j.1365-2656.2011.01821.x

1. There is increasing interest in the impacts of El Niño Southern Oscillation (ENSO) on reproduction of apical predators such as seabirds and marine mammals. Long-term studies documenting ENSO effects on reproduction of seabirds in the warm tropics are scarce, and differential sensitivity of breeding parameters to ENSO has rarely been explored. 2. Analysis of 18 years of breeding data from a colony of the blue-footed booby Sula nebouxii (Milne-Edwards) showed a delay in onset of breeding when the global Southern Oscillation Index was negative; each unit of the atmospheric pressure differential (hPa) across the Pacific Ocean meant a delay of 7 days. 3. ENSO conditions also produced declines in breeding participation, clutch size, brood size, hatching success and fledging success, especially when surface waters surrounding the colony were warmer during winter and spring. Each additional degree (°C) of water temperature produced a reduction of 0·45 fledglings per nest. Different breeding parameters were sensitive to ENSO indices in different blocks of months. 4. Warming of local waters during the winter was associated with decline in ocean productivity in the current year and the following year, consistent with ENSO impacts on breeding parameters being mediated by effects on local productivity and prey availability. However, there was no evidence of lagged effects of ENSO on any breeding parameter. 5. Comparison of 5 years revealed that when local surface waters were warm, chicks grew more slowly, but no effects of ENSO on weight and size of eggs were evident in data of 9 and 7 years, respectively. 6. Our findings extend evidence of impacts of ENSO on seabird reproduction to the eastern tropical Pacific and indicate that several breeding parameters of blue-footed boobies (but not egg size) are affected in the short term by ENSO conditions, particularly by local anomalies in sea surface temperature associated with decline in ocean productivity.