Takeoff flight performance and plumage wettability

Authors: Víctor Manuel OrtegaJiménez Saúl ÁlvarezBorrego Sarahí ArriagaRamírez Martin Renner Eli S Bridge

Publish Date: 2009/07/25

Volume: 151, Issue: 1, Pages: 169-

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Abstract

Due to their marine habitats and distinctive foraging modes seabirds face unique challenges with respect to flying that are negotiated differently by various species One such challenge is taking off from the water with wet plumage This study evaluated plumage wettability and takeoff performance in three seabird species two wingpropelled divers with high wing loading Cassin’s Auklet Ptychoramphus aleuticus and Xantus’s Murrelet Synthliboramphus hypoleucus and Leach’s Stormpetrel Oceanodroma leucorhoa a surface feeder with low wing loading The plumages of the diving birds held less water than that of O leucorhoa ~67 of body mass vs 95 This difference is explained by O leucorhoa’s surface to volume ratio being larger than that of the alcids Furthermore the alcids have afterfeathers larger than those of O leucorhoa which promotes a better insulation during diving Examination of takeoff performance both before and after experimentally submerging the birds indicated that wingbeat frequency speed and massspecific power peak and mean and energy per wingbeat decreased in all species when plumage was experimentally wetted whereas mean acceleration increased O leucorhoa was more strongly affected by wet plumage than the alcids with a 32 of reduction in massspecific energy per wingbeat compared to ≤25 in the alcids Takeoff angle was reduced in alcids but not significantly so in O leucorhoa Our results offer insights into the takeoff mechanics problems of wet seabirds given their differences in life history and morphologyWe would like to thank members of the fishing cooperative ‘Pescadores Nacionales de Abulón’ for providing logistic support and transportation to San Benito Island Wingbeat frequency was calculated using software developed by Dr Modesto OrtizFigueroa CICESE Dr Rogelio Vázquez CICESE kindly provided the field electricity generator V OrtegaJiménez had a graduate student scholarship from CONACYT All methods were approved by the Mexican Secretaría de Medio Ambiente y Recursos Naturales to grant the permit for the study Oficio Num/SGPA/DGVS/01081 We acknowledge two anonymous reviewers for their constructive criticism

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