Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Physiological Condition in Magellanic Penguins: Does It Matter If You Have to Walk a Long Way to Your Nest?

Brian G. Walker, P. Dee Boersma and John C. Wingfield
The Condor
Vol. 106, No. 3 (Aug., 2004), pp. 696-701
Stable URL: http://www.jstor.org/stable/4151066
Page Count: 6
  • Read Online (Free)
  • Download ($12.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Physiological Condition in Magellanic Penguins: Does It Matter If You Have to Walk a Long Way to Your Nest?
Preview not available

Abstract

Colony edges, as opposed to interiors, are often considered less advantageous nesting places in colonial species. For temperate-breeding penguins, inland colony edges should be less desirable than other edges, as there are added costs of walking farther inland, and ambient temperatures are higher. During settlement and incubation, we compared body condition and baseline and stress-induced levels of the hormone corticosterone in male Magellanic Penguins (Spheniscus magellanicus) nesting on the sea edge of a colony with those nesting on the inland edge, >800 m from shore. Body condition in both groups was significantly lower during settlement than during incubation, but was similar in both groups within breeding stages. Corticosterone levels were similar between breeding stages and for groups within each breeding stage. While body condition can vary over time, penguins appear to be well buffered to physiological extremes, as they do not show modification of corticosterone levels with variations in nesting conditions. /// En especies coloniales, los bordes de la colonia son generalmente considerados como lugares menos ventajosos para el establecimiento de nidos. Para los pingüinos que crían en climas templados, los bordes de las colonias orientados tierra adentro deben ser menos deseables que otros bordes, ya que se suman los costos adicionales de caminar una distancia mayor desde la orilla y debido a que las temperaturas ambientes allí son más elevadas. Durante el establecimiento y la incubación, comparamos las condiciones corporales y los niveles de referencia e inducidos por estrés de la hormona corticosterona en los machos de Spheniscus magellanicus que anidaban en el borde de la colonia adyacente al mar con los que anidaban sobre el borde que mira hacia el interior, a más de 800 m desde la orilla. La condición corporal en los dos grupos fue significantemente menor durante el establecimiento que durante la incubación, pero fue similar en los dos grupos durante las etapas de crianza. Los niveles de corticosterona fueron similares para ambas etapas de crianza y para los dos grupos durante cada etapa de crianza. Aunque la condición corporal puede variar en el tiempo, los pingülinos parecen amortiguar bien los extremos fisiológicos, ya que no muestran modificación de los niveles de corticosterona con las variaciones en las condiciones de nidificación.

Page Thumbnails

  • Thumbnail: Page 
696
    696
  • Thumbnail: Page 
697
    697
  • Thumbnail: Page 
698
    698
  • Thumbnail: Page 
699
    699
  • Thumbnail: Page 
700
    700
  • Thumbnail: Page 
701
    701