Movement patterns of Peruvian Boobies off Isla Lobos de Afuera 2007
Carlos B. Zavalaga
Zavalaga, C. 2014. Movement patterns of Peruvian Boobies off Isla Lobos de Afuera 2007. Data downloaded from OBIS-SEAMAP (http://seamap.env.duke.edu/dataset/1102) on yyyy-mm-dd.
Halpin, P.N., A.J. Read, E. Fujioka, B.D. Best, B. Donnelly, L.J. Hazen, C. Kot, K. Urian, E. LaBrecque, A. Dimatteo, J. Cleary, C. Good, L.B. Crowder, and K.D. Hyrenbach. 2009. OBIS-SEAMAP: The world data center for marine mammal, sea bird, and sea turtle distributions. Oceanography. 22(2):104-115.
GPS loggers and time-depth recorders were used to characterize 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.
Due to incorrect date/time or coordinates, the following records in the original data sheets were removed:
Bird ID 507
11:15:46, 3/8/2000, -80.821548, -7.104937
11:15:49, 13/08/2019, -80.8215, -7.105124
11:15:50, 13/08/2019, -80.821498, -7.105203
11:18:07, 13/08/2019, -80.815599, -7.10751
11:18:08, 13/08/2019, -80.815574, -7.107587
16:00:11, 5/1/2018, -80.779896, -7.11839
16:58:54, 5/4/2025, -80.760566, -167.071
16:09:57, 5/4/2025, -80.75794, -7.110085
Bird ID: 509
10:18:25, 13/08/2019, -80.693316, -7.032193
10:18:26, 13/08/2019, -80.693354, -7.032029
Bird ID: 530
12:25:10, 15/08/2019, -80.844323, -7.027227
12:25:11, 15/08/2019, -80.844369, -7.027112
Attributes described below represent those in the original dataset provided by the provider.
This section explains attributes included in the original dataset. OBIS-SEAMAP restricts the attributes available to the public to date/time, lat/lon and species names/counts only. Should you need other attributes described here, you are encouraged to contact the data provider.
Attributes in dataset provided
|Rays and sharks||0|
|Latitude||-7.53 - -6.81|
|Longitude||-81.10 - -80.37|
|Coord. prec.||5 decimal digits|
|Data type||Telemetry location|
|Tracklines||YES (ID: 1103)|
|Sharing policy||CC-BY (Minimum)|
|Also available from||iOBIS|
|See metadata in static HTML|
|See metadata in FGDC XML|
|See download history / statistics|