thomasdonegan
Former amateur ornithologist
This paper may be of interest to this forum:
Digby et al. 2016. Pelagic surveys in the Colombian Caribbean reveal changes in marine bird distribution patterns during the migration period. Conservacion Colombiana 24: 37-39.
http://www.proaves.org/wp-content/uploads/2016/11/Seabirds-Cons-Col-24-37-39-Digby-et-al.pdf
Abstract: Records at sea in the Colombian Caribbean are presented for October and November 2015. This coincided with the migratory period. We observed five major "falls" of Nearctic migratory passerines, each one dominated by a single species: first Blackburnian Warblers Setophaga fusca, next Blackpoll Warblers Setophaga striata and finally American Redstarts Setophaga ruticilla. In comparison to surveys during non-migratory periods, large numbers of raptors, particularly Peregrine Falcon Falco peregrinus and Merlin Falco columbianus were observed at sea, which predated on the passerines. In contrast, highly marine species such as Storm-Petrels (Hydrobatidae) or Shearwaters (Procellariidae) were absent, perhaps vacating to more remote sea areas to escape these predators. We found the same pattern of abundance between Brown Boobies Sula leucogaster
and Masked Boobies Sula dactylatra, the former dominating south of 11°N and the latter dominating north of this latitude. Interesting records of rare species in Colombia such as Bridled Tern Onychoprion anaethetus, Pomarine Skua Stercorarius
pomarinus and Red-footed Booby Sula sula were also recorded.
Digby et al. 2016. Pelagic surveys in the Colombian Caribbean reveal changes in marine bird distribution patterns during the migration period. Conservacion Colombiana 24: 37-39.
http://www.proaves.org/wp-content/uploads/2016/11/Seabirds-Cons-Col-24-37-39-Digby-et-al.pdf
Abstract: Records at sea in the Colombian Caribbean are presented for October and November 2015. This coincided with the migratory period. We observed five major "falls" of Nearctic migratory passerines, each one dominated by a single species: first Blackburnian Warblers Setophaga fusca, next Blackpoll Warblers Setophaga striata and finally American Redstarts Setophaga ruticilla. In comparison to surveys during non-migratory periods, large numbers of raptors, particularly Peregrine Falcon Falco peregrinus and Merlin Falco columbianus were observed at sea, which predated on the passerines. In contrast, highly marine species such as Storm-Petrels (Hydrobatidae) or Shearwaters (Procellariidae) were absent, perhaps vacating to more remote sea areas to escape these predators. We found the same pattern of abundance between Brown Boobies Sula leucogaster
and Masked Boobies Sula dactylatra, the former dominating south of 11°N and the latter dominating north of this latitude. Interesting records of rare species in Colombia such as Bridled Tern Onychoprion anaethetus, Pomarine Skua Stercorarius
pomarinus and Red-footed Booby Sula sula were also recorded.
