Carotenoid-based skin ornaments reflect foraging propensity in a seabird, Sula leucogaster

Biology Letters
By: , and 

Links

Abstract

Carotenoid-based ornaments are common signalling features in animals. It has long been proposed that such ornaments communicate information about foraging abilities to potential mates. However, evidence linking foraging with ornamentation is largely missing from unmanipulated, free-ranging populations. To investigate this relationship, we studied a coastal population of brown booby (Sula leucogaster brewsteri), a seabird with a carotenoid-based gular skin ornament. δ13C values from both feathers and blood plasma were negatively correlated with male gular colour, indicating birds that consumed more pelagic prey in offshore locations had more ornamented skin than those that fed on nearshore, benthic prey. This relationship was supported by our GPS tracking results, which revealed longer, more offshore foraging trips among highly ornamented males. Our data show that brown booby ornaments are honest indicators of foraging propensity; a link consistent with the rarity hypothesis and potentially driven by the concentration of carotenoids found in phytoplankton versus benthic algae. Carotenoid-based ornaments may reflect foraging tendencies in animals such as coastal predators that use food webs with distinct carotenoid profiles.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Carotenoid-based skin ornaments reflect foraging propensity in a seabird, Sula leucogaster
Series title Biology Letters
DOI 10.1098/rsbl.2018.0398
Volume 14
Issue 9
Year Published 2018
Language English
Publisher The Royal Society
Contributing office(s) Western Ecological Research Center
Description Article 20180398; 4 p.
First page 1
Last page 4