Nest-Site Selection and Productivity of American Dippers in the Oregon Coast Range

Loegering, John P.; Anthony, Robert G.

doi:10.1676/04-100.1

Cited by 9 publications

(7 citation statements)

References 23 publications

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“…Furthermore, these characteristics coincide with the shape, substrate and material for nests described for other species of dippers (Cinclus sp.) (Smiddy et al 1995;Loegering and Anthony 2006). Nests found in this study had two defined structural zones: a dome and a cup.…”

Section: Discussionmentioning

confidence: 63%

“…Nests located at higher heights might suggest the need for greater protection from natural (e.g., river floods, predators) or anthropogenic (e.g., tourism) disturbances. However, we did not test this hypothesis, and other explanations also might be plausible and need to be tested (e.g., availability of nesting sites at greater heights above water) (Del Guasta 2003;Loegering and Anthony 2006). Nests in Caspala occur at a distance of 600 m (Fig.…”

Section: Discussionmentioning

confidence: 89%

“…Nests were found in plots with a narrower watercourse width than those in non-nest plots. Narrow watercourses can correspond with river sectors that also have vertical rock formations, providing substrate for building nests that are protected from predators (Loegering and Anthony 2006). Nests were found in nesting plots with a higher percentage of emergent rocks, slope and number of rapids and pools than non-nest plots.…”

Section: Discussionmentioning

confidence: 99%

“…Habitat variables at each nest found were measured in plots of 2 by 2 m (Loegering and Anthony 2006). Within each plot, the following habitat variables were recorded: 1) elevation (meters above sea level) and geographic coordinates (recorded with a GPS unit); 2) emergent rocks (%) (visually estimated as the percentage of the plot covered with rocks); 3) river slope (%) (measured with a clinometer); 4) number of rapids (i.e., section with higher water velocity and less depth; characterized by the formation of white water) and pools (i.e., section with lower water velocity and depth of more than 40 cm; characterized by the formation of backwater); 5) watercourse width (m) (determined by visually estimating the distance between cliffs or river banks); 6) river width (m) (determined by measuring the distance between shores with a metric tape); 7) water depth (m) (measured at five points using a graduated stick with a height of 1.80 m); and 8) water velocity (m sec -1 ) (determined by the number of seconds it took a Styrofoam sphere to travel 10 m in the river).…”

Section: Nest and Non-nest Plot Characteristicsmentioning

confidence: 99%

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Nests and Nest Site Characteristics of Rufous-Throated Dipper (Cinclus schulzi) in Mountain Rivers of Northwestern Argentina

2015

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Section: Discussionmentioning

confidence: 63%

Section: Discussionmentioning

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Section: Nest and Non-nest Plot Characteristicsmentioning

confidence: 99%

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Nests and Nest Site Characteristics of Rufous-Throated Dipper (Cinclus schulzi) in Mountain Rivers of Northwestern Argentina

2015

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“…In contrast, altitudinal migration in American Dippers has been argued to be an outcome of intraspecific competition for limited nesting sites at low elevations that forces the majority of individuals to either move to higher elevations to breed or forgo reproduction (Gillis et al 2008). (Loegering and Anthony 2006), residents have consistently higher annual productivity than migrants, and are predicted to have higher lifetime reproductive success (Gillis et al 2008). 2.…”

Section: Discussionmentioning

confidence: 99%

Altitudinal migration in American Dippers (Cinclus mexicanus): Do migrants produce higher quality offspring?

et al. 2010

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Breeding at high elevations can favour life-history strategies in which parents shift to investing in higher quality rather than higher numbers of offspring. In American Dippers (Cinclus mexicanus Swainson, 1827), altitudinal migrants produce fewer fledglings than sedentary individuals (residents) that breed at lower elevations. We examined whether migrants compensate for their lower fecundity by providing their offspring with a higher quality diet and (or) more food, and producing higher quality offspring. Nestling diet was assessed using observations and stable isotope analysis of feathers grown during the nestling period. Nestling quality was assessed using a condition index (residuals from a mass-tarsus regression) and postfledging survival. We found that migrants fed their offspring less fish, and despite having higher feeding rates, had lower energetic provisioning rates than residents. Migrants also produced offspring that were in worse condition and had lower postfledging survival. This study found no evidence that altitudinal migration is associated with a trade-off favouring the production of smaller numbers of higher quality young. Instead our data provide support for the hypothesis that altitudinal migration in American Dippers is an outcome of competition for limited nest sites at lower elevations that forces some individuals to move to higher elevations to breed.Résumé : La reproduction aux hautes altitudes peut favoriser des stratégies démographiques dans lesquelles les parents investissent dans des rejetons de plus grande qualité plutôt que dans un nombre plus élevé de rejetons. Chez le cincle d'Amérique (Cinclus mexicanus Swainson, 1827), les individus qui migrent en altitude produisent moins de petits à l'envol que les individus sédentaires (résidants) des altitudes plus basses. Nous vérifions si les migrateurs compensent leur fécondité réduite en procurant à leurs rejetons un meilleur régime alimentaire ou un régime plus abondant et en produisant ainsi des petits de meilleure qualité. Le régime alimentaire des petits au nid a pu être déterminé par observation directe et par analyse des isotopes stables dans les plumes élaborées durant la période au nid. La qualité des petits au nid a été mesurée par un indice de condition (résidus de la régression de la masse sur le tarse) et par la survie après l'envol. Les migrateurs apportent moins de poissons à leurs rejetons et, malgré des taux d'alimentation plus élevés, ils ont des taux d'approvisionnement en énergie inférieurs à ceux des résidants. Les migrateurs produisent aussi des petits en moins bonne condition dont la survie après l'envol est inférieure. Notre étude n'offre aucune indication que la migration en altitude comporte un compromis favorisant la production de petits moins nombreux mais de meilleure qualité. Au contraire, nos données appuient l'hypothèse selon laquelle la migration en altitude chez les cincles d'Amérique résulte de la compétition pour un nombre limité de sites de nidification aux altitudes inférieures, ce qui oblige certai...

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An assessment of run-of-river hydroelectric dams on mountain stream ecosystems using the American dipper as an avian indicator

Silverthorn

Bishop

Elliott

et al. 2018

Ecological Indicators

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Nest-Site Selection and Productivity of American Dippers in the Oregon Coast Range

Cited by 9 publications

References 23 publications

Nests and Nest Site Characteristics of Rufous-Throated Dipper (Cinclus schulzi) in Mountain Rivers of Northwestern Argentina

Nests and Nest Site Characteristics of Rufous-Throated Dipper (Cinclus schulzi) in Mountain Rivers of Northwestern Argentina

Altitudinal migration in American Dippers (Cinclus mexicanus): Do migrants produce higher quality offspring?

An assessment of run-of-river hydroelectric dams on mountain stream ecosystems using the American dipper as an avian indicator

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