spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online April 17, 2009
Journal of Experimental Biology 212, 1259-1269 (2009)
Published by The Company of Biologists 2009
doi: 10.1242/jeb.025411
This Article
Right arrow Summary Freely available
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplementary Material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Helm, B.
Right arrow Articles by Gwinner, E.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Helm, B.
Right arrow Articles by Gwinner, E.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

Circannual basis of geographically distinct bird schedules

Barbara Helm*, Ingrid Schwabl and Eberhard Gwinner

Max Planck Institute for Ornithology, 82346 Andechs, Germany


Figure 1
View larger version (6K):
[in this window]
[in a new window]

  		Fig. 1. Photoperiodic simulations used in the present study. Grey triangles and broken line gives daylength simulating the photoperiodic conditions experienced by Siberian stonechats during breeding, migration and wintering. Black closed circles and solid line show conditions of European stonechats, and open diamonds and dotted line indicate constant conditions used for circannual studies.

 

Figure 2
View larger version (27K):
[in this window]
[in a new window]

  		Fig. 2. Reproductive and moult cycles of stonechats under native photoperiodic conditions separated by age class. Age is indicated by black closed symbols and solid lines for yearlings, and white open symbols and broken lines for second-year birds. European stonechats (left column, circles) and Siberian stonechats (right column, triangles) were kept under their respective native photoperiods for two years. The curves show weekly daylength (top panel), monthly medians ±s.e.median of male testis size and plasma testosterone (middle panels) and follicular size of females (bottom panel). Horizontal bars connect the median ±s.e.median dates of onset and end of primary moult.

 

Figure 3
View larger version (18K):
[in this window]
[in a new window]

  		Fig. 3. Breeding and moult schedules of F1 hybrids and parental stonechat taxa under identical conditions. Birds were kept under the photoperiod of Siberian-type long-distance migration. Data as in Fig. 2. (A) Testicular cycle and moult (horizontal bars) in males; (B) male plasma testosterone; (C) follicular cycles and moult in females. Hybrids: solid dark lines and black closed squares; Siberian stonechats: broken grey lines and triangles; European stonechats: dotted lines and black closed circles. Inlays: gonadal cycles of F1 hybrid offspring of European (black closed circles) and Siberian (grey triangles) mothers.

 

Figure 4
View larger version (36K):
[in this window]
[in a new window]

  		Fig. 4. Circannual reproductive cycles of European and Siberian stonechats. Birds were kept under a constant 12.25 h photoperiod for at least two years. Upper graphs show circannual testicular cycles of individual European males (left) and Siberian (right) males. Lower graph shows median cycles of European (solid black line and black closed circles) and Siberian (grey line and grey triangles) males; years are shown by vertical dotted lines. Data for European stonechats are replotted based on published data (Gwinner, 1991Go).

 

Figure 5
View larger version (26K):
[in this window]
[in a new window]

  		Fig. 5. Schedules of European and Siberian stonechats under native and reciprocal photoperiods. Data as in Fig. 2. Top panel shows the simulation of daylength experienced by European (circles) and Siberian (triangles) stonechats. Middle panels show cycles of testis size, moult and plasma testosterone of males, bottom panel shows follicular and moult cycles of females for European stonechats (left column) and Siberian stonechats (right column); the two photoperiodic treatments to which both taxa were exposed are indicated by different shading; grey shading shows scheduling under Siberian-type conditions and black shading under European-type conditions.

 

Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?



© The Company of Biologists Ltd 2009