We investigated whether trace elements in tail feathers of an insectivorous and long‐distance migratory bird species could be used to identify moulting areas and hence migratory pathways. We analysed tail feathers from birds of different age and sex collected from a range of different breeding sites across Europe. The site of moult had a large effect on elemental composition of feathers of birds, both at the European and African moulting sites. Analysis of feathers of nestlings with known origin suggested that the elemental composition of feathers depended largely upon the micro‐geographical location of the colony. The distance between moulting areas could not explain the level of differences in trace elements. Analysis of feathers grown by the same individuals on the African wintering grounds and in the following breeding season in Europe showed a large difference in composition indicating that moulting site affects elemental composition. Tail feathers moulted in winter in Africa by adults breeding in different European regions differed markedly in elemental composition, indicating that they used different moulting areas. Analysis of tail feathers of the same adult individuals in two consecutive years showed that sand martins in their first and second wintering season grew feathers with largely similar elemental composition, although the amounts of several elements in tail feathers of the older birds was lower. There was no difference between the sexes in the elemental composition of their feathers grown in Africa. Investigation of the trace element composition of feathers could be a useful method for studying similarity among groups of individuals in their use of moulting areas.

Analyses of stable isotopes and trace elements in feathers may provide important information about location and habitat use during molt, thereby enabling the investigation of migratory connectivity and its ecological consequences in bird species that breed and winter in different areas. We have compared the conclusions arrived at based on the use of these two methods on the same samples of feathers from two migratory birds, the Sand Martin Riparia riparia and the Barn Swallow Hirundo rustica. We investigated the effects of location, age and sex on stable isotope (d 13 C, d 15 N, dD) and trace element profiles (As, Cd, Mg, Mn, Mo, Se, Sr, Co, Fe, Zn, Li, P, Ti, V, Ag, Cr, Ba, Hg, Pb, S, Ni and Cu). The feathers of adults at the breeding grounds were removed, forcing in birds to grow new feathers at the breeding grounds; this enabled a comparison of composition of feathers grown in Europe and Africa by the same individual. Stable isotope and trace element profiles varied geographically, even at microgeographic scales, and also among age classes. The results of both methods suggest that food composition and/or source differs between adults and nestlings in the breeding area and that food and/or molting location changes with the age of individuals in Africa. In an attempt to determine the usefulness of data obtained from composition of feathers, we performed discriminant function analyses on information obtained on stable isotopes and trace elements in order to assess the correctness of the classification of group membership. When feathers molted in Africa were compared to those molted in Europe, trace element profiles of the 22 elements generally had a much greater resolution than the stable isotope profiles based on three stable isotopes. The proportion of correctly classified samples was also greater for analyses based on trace elements than for those based on stable isotopes.

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We studied phosphopeptidomannans (PPMs) of two Saccharomyces cerevisiae NCYC 625 strains (S. diastaticus): a wild type strain grown aerobically, anaerobically, and in the presence of antimycin and a [rho 0] mutant grown aerobically and anaerobically. The aerobic wild-type cultures were highly flocculent, but all others were weakly flocculent. Ligands implicated in flocculation of mutants or antimycin-treated cells were not aggregated as much by concanavalin A as were those of the wild type. The [rho 0] mutants and antimycin-treated cells differ from the wild type in PPM composition and invertase, acid phosphatase, and glucoamylase activities. PPMs extracted from different cells differ in the protein but not in the glycosidic moiety. The PPMs were less stable in mitochondrion-deficient cells than in wild-type cells grown aerobically, and this difference may be attributable to defective mitochondrial function during cell wall synthesis. The reduced flocculation of cells grown in the presence of antimycin, under anaerobiosis, or carrying a [rho 0] mutation may be the consequence of alterations of PPM structures which are the ligands of lectins, both involved in this cell-cell recognition phenomenon. These respiratory chain alterations also affect peripheral, biologically active glycoproteins such as extracellular enzymes and peripheral PPMs.

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