PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of procbhomepageaboutsubmitalertseditorial board
 
Proc Biol Sci. Jan 7, 2002; 269(1486): 21–27.
PMCID: PMC1690866
Pheasant sexual ornaments reflect nutritional conditions during early growth.
Thomas Ohlsson, Henrik G Smith, Lars Råberg, and Dennis Hasselquist
Department of Animal Ecology, Lund University, Ecology Building, S-223 62 Lund, Sweden.
Thomas Ohlsson: thomas.ohlsson/at/zooekol.lu.se
Abstract
Differences in growth conditions during early life have been suggested to cause long-lasting effects on morphology and quality of adult birds. We experimentally investigated the effect of early growth conditions on the expression of sexual ornaments later in life in male ring-necked pheasants (Phasianus colchicus). We also investigated the effects on immune function, as it could be a functional link between early nutrition and ornament expression. We manipulated the dietary protein intake during the first eight weeks post hatching. Males receiving fodder with 27% protein during the first three weeks of life grew larger and more colourful wattles when sexually mature than males receiving a low-protein diet (20.5% protein). Spur length was unaffected by diet treatment. Manipulation of food protein levels during weeks 4-8 after hatching had no effect on the development of ornaments. The different protein treatments had no long-term effect on either humoral or cell-mediated immune responses. There was, however, a positive relationship between spur length and cell-mediated immune responsiveness. Our study shows that expression of a sexual ornament in adult pheasants reflects nutritional conditions early in life. Because the expression of secondary sexual ornaments is affected by conditions during early growth, by selecting more ornamented males, females would choose mates that are superior at handling early nutritional stress. If the susceptibility to early nutritional stress also has a hereditary basis, females may benefit by obtaining 'good genes'.
Full Text
The Full Text of this article is available as a PDF (119K).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
  • Westneat DF, Birkhead TR. Alternative hypotheses linking the immune system and mate choice for good genes. Proc Biol Sci. 1998 Jun 22;265(1401):1065–1073. [PMC free article]
Articles from Proceedings of the Royal Society B: Biological Sciences are provided here courtesy of
The Royal Society