Corticosterone stress response and plasma metabolite levels during breeding and molt in a free-living migratory songbird, the wood thrush (Hylocichla mustelina)

2011 ◽  
Vol 171 (2) ◽  
pp. 176-182 ◽  
Author(s):  
Tyler Done ◽  
Elizabeth A. Gow ◽  
Bridget J.M. Stutchbury
The Auk ◽  
2006 ◽  
Vol 123 (2) ◽  
pp. 563-574 ◽  
Author(s):  
Dana A. Acevedo Seaman ◽  
Christopher G. Guglielmo ◽  
Robert W. Elner ◽  
Tony D. Williams

Abstract Variation in plasma metabolite profiles can provide information on physiological state and relative rates of mass change in free-living birds caught only once, and this technique could be used to compare rates of mass change (fattening) among populations or sites in relation to habitat quality. We compared plasma metabolite levels, as an index of relative refueling rates, in migratory Arctic-nesting Western Sandpipers (Calidris mauri), on a landscape scale at as many as nine sites over two years and during three different migratory stages within the Georgia Basin-Puget Sound region of British Columbia and Washington. There was significant intersite variation in plasma triglyceride levels in both years, but only for the northward migration. By contrast, there was little evidence of intrasite variability (i.e. metabolite profiles of birds using the same site were consistent between years and migratory stages), though we documented intrasite variation resulting from birds' use of different microhabitats at the same site. Plasma glycerol levels did not vary systematically among sites, though they varied among years; on average, birds had higher glycerol levels during northward migration than during southward migration. For the northward migration only, there was a positive relationship between plasma triglyceride levels and total macrofaunal prey abundance among sites. Birds using smaller sites with a lower index of mudflat exposure (mean number of kilometer-hours of mudflat exposed in a 24-h period, reflecting the opportunity to forage at each site) tended to have lower triglyceride levels. Fisiología a Escala de Paisaje: Diferencias entre Sitios en las Tasas de Reabastecimiento Indicadas por Análisis de Metabolitos del Plasma en Chorlos Migratorios Silvestres


The Condor ◽  
2002 ◽  
Vol 104 (1) ◽  
pp. 92-102 ◽  
Author(s):  
Todd J. Underwood ◽  
Roland R. Roth

Abstract We tested the ability of 29 indices of productivity to predict and track actual productivity of a Wood Thrush (Hylocichla mustelina) population for 21 years and to detect year-to-year changes in that productivity. Of 29 indices tested, only the productivity of nests initiated in May showed promise. This index reasonably predicted productivity, correctly tracked two out of three temporal trends in productivity, and detected a significant proportion of year-to-year changes in actual productivity. Although they were not useful for predicting annual productivity, other indices based on nest data tracked trends in productivity moderately well, and all, except percent nest success, detected a significant proportion of year-to-year changes in productivity. Productivity indices based on non-reproductive variables, such as abundance of males or females, return rates, and veteran:novice ratios, did not reflect productivity trends or changes. From these results, we recommend that only an intensive measure of actual productivity or a partial measure of it, such as May productivity, be used to make inferences about annual productivity of a population. Indices based on other nest data should be used only for tracking productivity trends. Non-reproductive indices are unreliable for making any inferences about productivity. Las Variables Demográficas son Malas Indicadoras de la Productividad de Hylocichla mustelina Resumen. Pusimos a prueba la capacidad de 29 índices de productividad para predecir y seguir las variaciones anuales en la productividad real de una población de Hylocichla mustelina por un período de 21 años. De los 29 índices probados, sólo el de la productividad de los nidos iniciados en mayo resultó promisorio. Este índice predijo la productividad razonablemente bien y detectó correctamente dos de tres tendencias temporales en la productividad y una proporción significativa de los cambios anuales en la productividad real. Aunque no fueron útiles para predecir la productividad anual, otros índices basados en datos de nidos siguieron las tendencias en la productividad aceptablemente bien. Con excepción del porcentaje de nidos exitosos, todos estos índices detectaron una proporción significativa de las variaciones anuales de la productividad. Por su parte, los índices de productividad basados en variables no reproductivas como la abundancia de machos y hembras, las tasas de regreso y el cociente de aves veteranas: novatas no reflejaron las tendencias o cambios en la productividad real. Con base en estos resultados recomendamos que para hacer inferencias sobre la productividad anual de una población sólo se utilice una medida intensiva de la productividad, o una medida parcial de ésta (i.e., la productividad en mayo). Los índices basados en otros datos de nidos deben ser utilizados únicamente para monitorear las tendencias en la productividad. Los índices no reproductivos son poco confiables para hacer inferencias sobre la productividad.


The Auk ◽  
2006 ◽  
Vol 123 (2) ◽  
pp. 563 ◽  
Author(s):  
Dana A. Acevedo Seaman ◽  
Christopher G. Guglielmo ◽  
Robert W. Elner ◽  
Tony D. Williams

The Condor ◽  
2007 ◽  
Vol 109 (1) ◽  
pp. 48 ◽  
Author(s):  
SUSAN B SMITH ◽  
SCOTT R McWILLIAMS ◽  
CHRISTOPHER G GUGLIELMO

The Auk ◽  
2002 ◽  
Vol 119 (1) ◽  
pp. 109-124 ◽  
Author(s):  
Jason D. Lang ◽  
Larkin A. Powell ◽  
David G. Krementz ◽  
Michael J. Conroy

Abstract We monitored adult and juvenile breeding-season movements and habitat use of radio-tagged Wood Thrushes (Hylocichla mustelina) at the Piedmont National Wildlife Refuge, central Georgia, USA. We investigated the effects that management for Red-cockaded Woodpeckers (Picoides borealis), thinning and burning >30 year old loblolly pine (Pinus taeda) habitat, had on Wood Thrushes, a ground-foraging and midstory-nesting species. Adult Wood Thrush pairs regularly moved long distances between nesting attempts (range 1 to 17,388 m). The only experimental effect we found on adult movements was a decrease in weekly emigration rates (Ψ) from thinned and burned compartments after silvicultural management. Adult males preferred riparian hardwoods with sparse to moderate cover and those preferences increased following management. Juveniles remained near their nest site (x̄ = 177 m, SE = 113) for an average 24 days (SE = 6.3), and then dispersed a mean 2,189 m (SE = 342). Before dispersal, juveniles preferred upland hardwood–pine mixed habitat (P < 0.05) with moderate overstory cover (P < 0.05). We found no management effects on dispersal distances or predispersal habitat use. However, juveniles from thinned and burned compartments dispersed to hardwood habitats with dense cover, whereas birds from control compartments dispersed to pine-dominated habitats with sparse cover. All juveniles dispersed to areas with habitat similar to what they used before dispersal. Small-scale thinning and burning for Red-cockaded Woodpeckers may have had little effect on Wood Thrush habitat use and movements because typical movements were often larger than the scale (stand or compartment) targeted for management.


2010 ◽  
Vol 192 (10) ◽  
pp. 2473-2481 ◽  
Author(s):  
Svetlana N. Yurgel ◽  
Jennifer Rice ◽  
Monika Mulder ◽  
Michael L. Kahn

ABSTRACT The Sinorhizobium meliloti Rm1021ΔglnD-sm2 mutant, which is predicted to make a GlnD nitrogen sensor protein truncated at its amino terminus, fixes nitrogen in symbiosis with alfalfa, but the plants cannot use this nitrogen for growth (S. N. Yurgel and M. L. Kahn, Proc. Natl. Acad. Sci. U. S. A. 105:18958-18963, 2008). The mutant also has a generalized nitrogen stress response (NSR) defect. These results suggest a connection between GlnD, symbiotic metabolism, and the NSR, but the nature of this connection is unknown. In many bacteria, GlnD modifies the PII proteins, GlnB and GlnK, as it transduces a measurement of bacterial nitrogen status to a cellular response. We have now constructed and analyzed Rm1021 mutants missing GlnB, GlnK, or both proteins. Rm1021ΔglnKΔglnB was much more defective in its NSR than either single mutant, suggesting that GlnB and GlnK overlap in regulating the NSR in free-living Rm1021. The single mutants and the double mutant all formed an effective symbiosis, indicating that symbiotic nitrogen exchange could occur without the need for either GlnB or GlnK. N-terminal truncation of the GlnD protein interfered with PII protein modification in vitro, suggesting either that unmodified PII proteins were responsible for the glnD mutant's ineffective phenotype or that connecting GlnD and appropriate symbiotic behavior does not require the PII proteins.


The Auk ◽  
2008 ◽  
Vol 125 (1) ◽  
pp. 67-75 ◽  
Author(s):  
MELISSA L. EVANS ◽  
BRIDGET J. M. STUTCHBURY ◽  
BONNIE E. WOOLFENDEN

1987 ◽  
Vol 65 (4) ◽  
pp. 1038-1042 ◽  
Author(s):  
Carl L. Whitney ◽  
Joan Miller

A typical wood thrush (Hylocichla mustelina) song has three phrases. The first (A) is a series of low pitched sounds, the second (B) consists of loud flutelike notes, and the third (C) is usually a trill. Males have repertoires of two to eight different B phrases, which they use in different songs. In a previous study, males reared in isolation of adult song developed songs that were normal except for the structure of the B phrases. We tutored young males (at age 20–80 days) with recorded B phrases. The phrases were of four previously defined structural types, with four variants of each type, giving a total of 16 phrases. The variants of each type differed only in frequency (Hz). The objectives of the experiment were to determine (i) if wood thrushes copy the structure of B phrases that they hear as juveniles, and (ii) if they copy selectively in such a way as to develop repertoires of highly contrasting phrases. Results were obtained for five males. The B phrase repertoires developed by four subjects consisted entirely of phrases (N = 17) copied from the tutor tape. The repertoire of the fifth subject was of phrases (N = 4) that appeared not to be copied. The males that copied from the tutor tape showed no tendency to develop repertoires of highly contrasting B phrases. Three of the four males developed multiple versions of one or more phrase types, while ignoring other types, and in some cases these versions were very similar in frequency and other details of structure.


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