Movement patterns of Peruvian Boobies off Isla Lobos de Tierra 2006

Carlos Zavalaga

doi:10.15468/wp77qe

Movement patterns of Peruvian Boobies off Isla Lobos de Tierra 2006

Citation

Zavalaga C, OBIS-SEAMAP (2021). Movement patterns of Peruvian Boobies off Isla Lobos de Tierra 2006. OBIS-SEAMAP. Occurrence dataset https://doi.org/10.15468/wp77qe accessed via GBIF.org on 2024-12-15.

Description

Original provider: Carlos B. Zavalaga Dataset credits: Carlos B. Zavalaga Abstract: GPS loggers and time-depth recorders were used to haracterize the foraging behavior of the sexually dimorphic Peruvian booby Sula variegata on 2 islands in northern Peru. We evaluated whether (1) its foraging behavior differed from tropical boobies and temperate gannets (the Peruvian boobies feed in areas of enhanced productivity and high fish density), and (2) females and males exploited different foraging habitats as a consequence of size dimorphism. Birds foraged only during daylight hours, 1 to 3 times a day, in trips of short duration (median = 1.8 h). Overall, 92% of the total foraging time was spent flying. They fed exclusively on anchovetas Engraulis ringens, which were captured in shallow dives (median = 2.5 m, max = 8.8 m) with a dive median rate of 11 dives h–1 (max = 37 dives h–1). The median foraging range was 25 km (max = 68 km), whereas the median total distance traveled was 69 km (max = 179 km). Foraging site fidelity was high, and the orientation of foraging flights in any given day was similar among birds that departed at the same time. There were no sex-specific differences in 13 of 15 foraging variables; however, females dived slightly deeper and spent a larger proportion of time sitting on the water. We speculate that (1) the foraging behavior of Peruvian boobies contrasts with that of their tropical and temperate relatives as a result of the proximity and predictability of food sources, elevated energetic demands of the brood (up to 4 chicks) and high prey encounter rate in the Peruvian upwelling system, and (2) the lack of spatial segregation between sexes may be related to the attraction of birds to feeding aggregations that are formed in the vicinity of the colonies. Once the foraging patches are localized, females dive deeper because of passive mechanisms associated with a heavier mass.

Purpose

Not available

Sampling Description

Study Extent

NA

Sampling

NA

Method steps

NA

Additional info

marine, harvested by iOBIS

Taxonomic Coverages

Scientific names are based on the Integrated Taxonomic Information System (ITIS).

Sula variegata
common name: Peruvian Booby rank: species

Geographic Coverages

Southern Eastern Pacific

Bibliographic Citations

Contacts

Carlos Zavalaga
originator
position: Primary contact
Universidad Científica del Sur
email: czav_1999@yahoo.com
homepage: http://avesfragatasperu.com

OBIS-SEAMAP
metadata author
Marine Geospatial Ecology Lab, Duke University
A328 LSRC building
Durham
27708
NC
US
email: seamap-contact@duke.edu
homepage: http://seamap.env.duke.edu

OBIS-SEAMAP
distributor
Marine Geospatial Ecology Lab, Duke University
A328 LSRC building
Durham
27708
NC
US
email: seamap-contact@duke.edu
homepage: http://seamap.env.duke.edu

Carlos Zavalaga
owner
position: Primary contact
Universidad Científica del Sur
email: czav_1999@yahoo.com
homepage: http://avesfragatasperu.com

Carlos Zavalaga
administrative point of contact
position: Primary contact
Universidad Científica del Sur
email: czav_1999@yahoo.com
homepage: http://avesfragatasperu.com