| Title: | Role of testosterone in stimulating seasonal changes in a potential avian chemosignal |
| Author(s): | Whittaker DJ; Soini HA; Gerlach NM; Posto AL; Novotny MV; Ketterson ED; |
| Address: | "BEACON Center for the Study of Evolution in Action, Michigan State University, 1441 Biomedical and Physical Sciences Building, East Lansing, MI 48824, USA. djwhitta@msu.edu" |
| DOI: | 10.1007/s10886-011-0050-1 |
| ISSN/ISBN: | 1573-1561 (Electronic) 0098-0331 (Linking) |
| Abstract: | "Songbird preen oil contains volatile and semivolatile compounds that may contain information about species, sex, individual identity, and season. We examined the relationship between testosterone (T) and the amounts of preen oil volatile and semivolatile compounds in wild and captive dark-eyed juncos (Junco hyemalis). In wild males and females, we observed an increase in volatile compound relative concentration early in the breeding season. This increase mirrored previously described seasonal elevation in T levels in wild males and females, suggesting a positive relationship between hormone levels and preen gland secretions, and a possible role for these secretions in signaling receptivity. In females, the greatest relative concentrations of most compounds were observed close to egg laying, a time when steroid hormones are high and also the only time that females respond to an injection of gonadotropin-releasing hormone with a short-term increase in T. In a study of captive juncos held on short days, we asked whether the seasonal increases observed in the wild could be induced with experimental elevation of T alone. We found that exogenous T stimulated the production of some volatile compounds in non-breeding individuals of both sexes. However, of the 15 compounds known to increase during the breeding season, only four showed an increase in relative concentration in birds that received T implants. Our results suggest that testosterone levels likely interact with other seasonally induced physiological changes to affect volatile compound amounts in preen oil" |
| Keywords: | Animals Female Gas Chromatography-Mass Spectrometry/veterinary Grooming Immunoenzyme Techniques/veterinary Male Photoperiod Reproduction Seasons Sebaceous Glands/chemistry/*metabolism Sex Attractants/analysis/*metabolism Songbirds/*physiology Testosterone; |
| Notes: | "MedlineWhittaker, Danielle J Soini, Helena A Gerlach, Nicole M Posto, Amanda L Novotny, Milos V Ketterson, Ellen D eng Research Support, Non-U.S. Gov't 2011/12/17 J Chem Ecol. 2011 Dec; 37(12):1349-57. doi: 10.1007/s10886-011-0050-1. Epub 2011 Dec 16" |
