Sandpipers (Scolopacidae) switch from monoester to diester preen waxes during courtship and incubation, but why?
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.
Reneerkens
Jeroen
J
Royal Netherlands Institute for Sea Research (NIOZ), PO Box 59, 1790 AB Den Burg, Texel, The Netherlands. reneer@nioz.nl
Piersma
Theunis
T
Sinninghe Damsté
Jaap S
JS
D000818:Animals; D001717:Birds / Q000502:physiology*; D001947:Breeding; D004952:Esters / Q000737:chemistry; D005088:Exocrine Glands / Q000378:metabolism; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods / Q000662:veterinary; D008297:Male; D013058:Mass Spectrometry / Q000379:methods / Q000662:veterinary; D008970:Molecular Weight; D012726:Sexual Behavior, Animal / Q000502:physiology*; D014885:Waxes / Q000737:chemistry*
D004952:Esters; D014885:Waxes