It's in the bag: Corticosterone levels and behavioral responses of Eastern Bluebirds (Sialia sialis) vary with type of holding bag

2019 ◽  
Vol 131 (3) ◽  
pp. 701
Author(s):  
Reneé E. Carleton ◽  
Rachel M. Caldwell
Keyword(s):  
Behavioral Responses ◽  
Sialia Sialis ◽  
Eastern Bluebirds

Ectoparasitic blow flies (Protocalliphora sp.) and nestling Eastern Bluebirds (Sialia sialis): direct effects and compensatory strategies

2006 ◽  
Vol 84 (7) ◽  
pp. 921-930 ◽  
Author(s):  
Kristina Hannam
Keyword(s):  
Brood Reduction ◽  
Direct Effects ◽  
Negative Effects ◽  
Compensatory Strategies ◽  
Blow Flies ◽  
Sialia Sialis ◽  
Eastern Bluebird ◽  
Eastern Bluebirds ◽  
Nestling Period ◽  
Host Parasite

Variation in environmental factors such as parasitism can have direct effects on an organism’s fitness. Because parasites draw resources directly from their hosts, they are expected to have negative effects; however, several nestling host – parasite systems show no evidence of direct effects. Absence of direct effects may be explained by compensation strategies used by parents or nestlings themselves. In this study evidence for both direct effects and compensatory strategies in a blow fly (genus Protocalliphora Hough, 1899) – Eastern Bluebird (Sialia sialis (L., 1758)) system were examined. Nestlings showed no direct effects of blow flies on survival and on size at fledging; however, parasitized broods were significantly anemic. There was no evidence for compensation by parents in the form of brood reduction and there was no support for compensation by nestlings via a hierarchy of tissue preservation. Nestlings did compensate for parasitism by accelerating growth at the end of the nestling period and delaying fledging.

Annual Productivity and Its Measurement in a Multi-Brooded Passerine, the Eastern Bluebird

The Auk ◽  
1979 ◽  
Vol 96 (3) ◽  
pp. 562-572
Author(s):  
Benedict C. Pinkowski
Keyword(s):  
Success Rate ◽  
Age Groups ◽  
Nesting Success ◽  
Egg Laying ◽  
Success Rates ◽  
Sialia Sialis ◽  
Eastern Bluebird ◽  
Annual Productivity ◽  
Eastern Bluebirds ◽  
Breeding Seasons

Abstract Breeding and demographic parameters are examined for 434 Eastern Bluebirds (Sialia sialis) attempting 324 nests in southeastern Michigan during 1968-1977. Nesting birds spent an average of 10.4 weeks (63.9% of a 16.2-week season) in the study area. Only 154 (35.5%) of the nesting birds remained for entire breeding seasons; these season-long residents averaged 2.14 nests/season and had a higher success rate (68.4%) and presumably greater productivity (5.6 young · pair−1 · season −1) than other birds because site fidelity depends on nesting success. Although two seasonal peaks for egg-laying were observed, only 75 of 357 birds (21.0%) successfully raised two broods. Evidence is presented to suggest that birds observed for only part of a season initiated nests at the same rate while in and not in the study area, so that an average annual productivity value of 5.0 young · pair−1 · season −1 is calculated for all nesting birds from the observed success rate (57.1%) and mean length of stay in the area. Estimated average productivity of yearlings (4.3 young · pair−1 · season −1) was lower than that of adults (5.7 young · pair−1 · season −1) although nesting success rates were similar in the two age groups.

scholarly journals You Can't Judge a Pigment by its Color: Carotenoid and Melanin Content of Yellow and Brown Feathers in Swallows, Bluebirds, Penguins, and Domestic Chickens

The Condor ◽  
2004 ◽  
Vol 106 (2) ◽  
pp. 390-395 ◽  
Author(s):  
Kevin J. McGraw ◽  
Kazumasa Wakamatsu ◽  
Shosuke Ito ◽  
Paul M. Nolan ◽  
Pierre Jouventin ◽  
...  
Keyword(s):  
High Performance ◽  
Domestic Chick ◽  
Gallus Domesticus ◽  
Hirundo Rustica ◽  
Sialia Sialis ◽  
Aptenodytes Patagonicus ◽  
Eastern Bluebirds ◽  
Eudyptes Chrysolophus ◽  
Barn Swallows ◽  
High Concentrations

Abstract The two main pigment types in bird feathers are the red, orange, and yellow carotenoids and the black, gray, and brown melanins. Reports conflict, however, regarding the potential for melanins to produce yellow colors or for carotenoids to produce brown plumages. We used high-performance liquid chromatography to analyze carotenoids and melanins present in the yellow and brown feathers of five avian species: Eastern Bluebirds (Sialia sialis), Barn Swallows (Hirundo rustica), King Penguins (Aptenodytes patagonicus), Macaroni Penguins (Eudyptes chrysolophus), and neonatal chickens (Gallus domesticus). In none of these species did we detect carotenoid pigments in feathers. Although carotenoids are reportedly contained in the ventral plumage of European Barn Swallows (Hirundo rustica rustica), we instead found high concentrations of both eumelanins and phaeomelanins in North American Barn Swallows (H. r. erythrogaster). We believe we have detected a new form of plumage pigment that gives penguin and domestic- chick feathers their yellow appearance. No Puedes Juzgar un Pigmento por su Color: Contenido de Carotenoide y Melanina de Plumas Amarillas y Marrones en Golondrinas, Azulejos, Pingüinos y Gallinas Domésticas Resumen. Los dos tipos principales de pigmentos que las aves incorporan en sus plumas son carotenoides, para desarrollar plumajes rojo, naranja o amarillo, y melaninas, para adquirir coloración negra, marrón, gris o tonalidades color tierra. Sin embargo, existe información conflictiva sobre la potencial coloración de plumas amarillas basadas en melanina y la presencia de caroteniodes en el plumaje marrón de ciertas especies. En este estudio, usamos cromatografía líquida de alto rendimiento para analizar los tipos y cantidades de carotenoides y melaninas presentes en las plumas amarillas y marrones de cinco especies de aves: el azulejo Sialia sialis y la golondrina Hirundo rustica, los pingüinos Aptenodytes patagonicus y Eudyptes chrysolophus y el plumón natal amarillo de la gallina doméstica Gallus domesticus. En ninguna de estas especies detectamos pigmentos carotenoides en las plumas. A pesar de que los carotenoides han sido encontrados en el plumaje ventral de la golondrina Hirundo rustica rustica, nosotros en cambio encontramos altas concentraciones de eumelaninas y feomelaninas en H. r. erythrogaster y en azulejos que variaron entre individuos y regiones de plumaje. Creemos que hemos detectado una nueva forma de pigmento de plumaje que le da a las plumas de pingüinos y pollos domésticos su apariencia amarilla.

scholarly journals Eastern Bluebirds Eject Brown-Headed Cowbird Eggs

The Condor ◽  
2006 ◽  
Vol 108 (3) ◽  
pp. 741-745 ◽  
Author(s):  
Brian D. Peer ◽  
Lyndon R. Hawkins ◽  
Edwin P. Steinke ◽  
Patricia Blair Bollinger ◽  
Eric K. Bollinger
Keyword(s):  
Selective Pressure ◽  
Molothrus Ater ◽  
Conspecific Brood Parasitism ◽  
Sialia Sialis ◽  
Eastern Bluebird ◽  
Egg Ejection ◽  
Cavity Nesting ◽  
Eastern Bluebirds ◽  
Cowbird Parasitism ◽  
The Relationship

Abstract The relationship between the Brown-headed Cowbird (Molothrus ater) and its cavity-nesting hosts has received little attention because of the assumption that cowbirds rarely parasitize these hosts. We tested the Eastern Bluebird (Sialia sialis), a host that is sometimes heavily parasitized by cowbirds, for egg ejection behavior. Bluebirds ejected 65% of experimentally added cowbird eggs (n  =  20), but ejected no experimentally added conspecific eggs (n  =  66). This suggests that cowbird parasitism, not conspecific brood parasitism, is the selective pressure responsible for egg ejection in this species. This level of rejection may be conservative because bluebirds nest in dark cavities, which may make cowbird eggs difficult to detect by bluebirds.

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