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Identifying factors that influence growth throughout development is important for understanding the consequences of variation in resource quality on recruitment. Marbled Murrelets (Brachyramphus marmoratus (J.F. Gmelin, 1789)) are threatened seabirds that are extremely cryptic in their nesting behaviour, which makes it challenging to understand how juveniles allocate resources during development. From a single capture at sea, we analyzed stable carbon isotopes in feathers and blood of juvenile murrelets to infer diet composition during both the pre- and the post-fledging periods. Consistent with the challenges juveniles face during their first year of life, we found that wing and bill growth were prioritized in the nest, whereas development of energy stores was delayed until after nest departure. We also found that diet quality after nest departure influenced bill size and body condition, two body components that continue to grow after independence. Our results provide evidence that murrelets strategically allocate resources according to their stage of development and that the availability of high-quality prey is likely to be important to juvenile development. These results identify a potential mechanism through which feeding conditions may influence reproduction of murrelets and demonstrate the utility of stable isotopes to examine the influence of diet quality on growth over multiple stages of development. Il est important d'identifier les facteurs qui influencent la croissance au cours du developpement afin de comprendre les consequences de la variation de la qualite des ressources sur le recrutement. Les guillemots marbres (Brachyramphus marmoratus (J.F. Gmelin, 1789)) sont des oiseaux marins menaces dont le comportement de nidification se deroule tout a fait furtivement, ce qui fait que la determination de l'allocation des ressources pendant le developpement par les jeunes pose un serieux probleme. A partir d'une seule recolte en mer, nous avons analyse les isotopes stables de carbone dans les plumes et le sang de jeunes guillemots pour en deduire la composition du regime alimentaire durant la periode avant ainsi qu' apres le depart du nid. En accord avec les defis auxquels les jeunes sont confrontes durant leur premiere annee de vie, il y a une priorite pour la croissance des ailes et du bec, alors que l'accumulation des reserves energetiques est reporte apres le depart du nid. La qualite du regime alimentaire apres le depart du nid affecte la taille du bec et la condition corporelle, deux composantes du corps qui continuent a croitre apres l'independance hors du nid. Nos resultats fournissent des indications que les guillemots allouent leurs ressources de maniere strategique en fonction de leur stade de developpement et que la disponibilite de proies de haute qualite est vraisemblablement importante pour le developpement des jeunes. Ces resultats identifient un mecanisme possible par lequel les conditions alimentaires peuvent influencer la reproduction des guillemots et ils demontrent l'utilite des isotopes stables dans l'examen de l'influence de la qualite du regime alimentaire sur la croissance au cours des divers stades du developpement. [Traduit par la Redaction], Introduction Periods of food restriction during early development can have important consequences for growth of juvenile animals (e.g., Boag 1987; Toft and Wise 1999). The effect of food restriction on [...]

We review the role of biogeochemical signatures, such as stable isotopes and trace elements, in the cornified claw tissue as a means of studying movement and foraging behaviour of vertebrates because this approach is noninvasive and can capture contemporary and historic signatures. Because biogeochemical techniques are still relatively new in studies of animal movement, we are only beginning to understand how the growth patterns of the cornified claw sheath may affect our ability to interpret the biogeochemical signals in these tissues. To move towards resolving this, we review the morphology of the epidermal cornified claw sheath in several taxa that illustrate substantial variation in growth patterns both between taxa and between individual distinct claw regions. For instance, in mammalian claws, deposition of keratinizing cells from the epidermis is nonlinear because the claw tip is composed of old and new cornified epidermal cells, whereas the cornified blade horn covering the claw's lateral walls is deposited continuously and without assortment, providing unbroken time-series data. We also consider patterns of growth in mammalian hooves, as well as reptilian, avian, and amphibian cornified claw sheaths, and address the need for expanded research in this field. We conclude this synthesis by describing a noninvasive technique for monitoring growth rates in a model mammal, the American badger {Taxidea taxus (Schreber, 1777)), and provide guidelines for future sampling of claw keratin, which will improve our ability to back-calculate the time of biogeochemical integration into this tissue. Nous faisons une revue du role des signatures biogeochimiques, telles que les isotopes stables et les elements en traces, dans le tissu corne des griffes comme moyens d'etudier les deplacements et le comportement alimentaire chez les vertebres, puisqu'il s'agit d'une methodologie non invasive qui peut retenir des signatures actuelles et passees. Puisque les techniques biogeochimiques sont d'usage relativement recent dans les etudes des deplacements animaux, nous commencons tout juste a comprendre comment les patrons de croissance de l'etui corne des griffes peuvent affecter notre capacite a interpreter les signaux biogeochimiques dans ces tissus. Pour faire du progres dans ce domaine, nous passons en revue la morphologie de l'etui corne epidermique de la griffe chez divers taxons, ce qui revele une importante variation dans les patrons de croissance, tant entre les taxons qu'entre les differentes regions distinctes de la griffe. Par exemple, dans les griffes de mammiferes, la deposition des cellules keratinisantes par l'epiderme ne se fait pas de facon lineaire parce que la pointe de la griffe est composee de cellules epidermiques cornees anciennes et recentes, alors que la lame cornee qui couvre les parois laterales de la griffe est deposee de maniere continue et sans assortiment, ce qui fournit une serie chronologique continue. Nous examinons aussi les patrons de croissance des sabots de mammiferes et des etuis cornes des griffes de reptiles, d'oiseaux et d'amphibiens. Nous terminons notre synthese en decrivant une technique non invasive pour suivre les taux de croissance chez un mammifere modele, le blaireau d'Amerique (Taxhka taxus (Schreber, 1777)), et fournissant des regles pour l'echantillonnage futur de la keratine des griffes, qui permettront d'ameliorer notre capacite de retrocalculer le moment de l'integration biogeochimique dans ce tissu. [Traduit par la Redaction], Introduction Understanding movement and foraging behaviour of animals on a daily, seasonal, or annual basis is fundamental to ecological, evolutionary, and conservation studies. Until recently, studying animal movement required trapping [...]

Economic and subeconomic concentrations of Sn, In, rare earth elements (REE), Ta, and Nb are known in Central Brazil, in the Goias Tin Province. The Sn-P enriched albitites studied in this paper occur in sharp contact with peraluminous granites of the Aurumina Suite (2.0-2.17 Ga) and schists of the Archean to Paleoproterozoic Ticunzal Formation, as dikes or lenses from late-stage magma of the peraluminous magmatism, probably in granite cupolas. Geological, petrological, and isotopic studies were conducted. The albitites consist of albite, quartz, cassiterite, apatite, K-feldspar, and muscovite, and have magmatic texture, such as alignment of albite laths, and snowball texture in quartz, apatite, and cassiterite. They are enriched in Na2O, P2O5, Sn, Ta, and Nb (Ta > Nb), and depleted in CaO, K2O, TiO2, MgO, Sr, Ba, Th, and REE. 40Ar/39 Ar in muscovite gave a plateau age of 1996.55 ± 13 Ma, interpreted as approaching the crystallization age. Oxygen isotope data in albite-cassiterite pairs resulted in an equilibrium temperature of 653-1016 °C and isotopic fluid composition of 8.66-9.7^oo. They were formed by crystallization of a highly evolved and sodic granitic magma. This study has implications for Central Brazil's economic potential and offers better understanding of tin behavior in rare, evolved peraluminous granitic magmas. [ABSTRACT FROM AUTHOR]