Sandpipers (Scolopacidae) switch from monoester to diester preen waxes during courtship and incubation, but why?

• Published in: Proceedings of the Royal Society of London. Series B: Biological Sciences
• Main Authors: Reneerkens, J., Piersma, T., Sinninghe Damsté, Jaap S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2002
• Subjects: uropygial gland; sandpipers; mate choice; mating system; chemical ecology; CALIDRIS-CANUTUS; GLAND WAXES; Calidris canutus; Philomachus pugnax; Red Knot; Tundra
• Online Access: https://hdl.handle.net/11370/18583b61-7d0b-4730-93ca-ee3a570f0f32; https://research.rug.nl/en/publications/18583b61-7d0b-4730-93ca-ee3a570f0f32; https://doi.org/10.1098/rspb.2002.2132; https://pure.rug.nl/ws/files/6667661/2002ProcRSocLondBReneerkens.pdf

Recently, a shift in preen wax composition, from lower molecular weight monoesters to higher molecular weight diesters, was described for individuals of a sandpiper species (red knot, Calidris canutus) that were about to leave for the tundra breeding grounds. The timing of the shift indicated that diester waxes served as a quality signal during mate choice. Here, this hypothesis is evaluated on the basis of a survey of preen wax composition in 19 sandpiper species. All of these species showed the same shift observed in the high-Arctic breeding red knots. As the shift also occurred in temperate breeding species, it is not specific to tundra-breeding sandpipers. Both sexes produced the diester waxes during the incubation period until hatching, in addition to the short period of courtship, indicating that diesters' functions extend beyond that of a sexually selected 'make-up'. The few non-incubating birds examined (males of curlew sandpipers (C. ferruginea) and ruffs (Philomachus pugnax)) had the lowest likelihood of secreting diesters, indicating a functional role for diester preen waxes during incubation. We propose that diester preen waxes enhance olfactory crypticism at the nest.