Great Reed Warblers: Wintertime Song Practice for Springtime Success
Winter Singing: A Surprising Practice
While many birds migrate south for the winter to escape the harsh conditions, some species, like the great reed warbler, have a unique wintertime practice: singing.
Why Winter Singing?
Scientists have long wondered why birds sing during the winter, when they are not breeding. One theory is that singing helps males guard their territory. However, research has shown that great reed warblers sing a different type of song during the winter than they do during the breeding season.
Testosterone and Song Behavior
Testosterone is a hormone that is linked to singing behavior in birds. During the breeding season, males with higher testosterone levels sing more complex songs. However, researchers found that great reed warblers that sang during the winter did not have higher testosterone levels than those that remained silent.
Practice for Springtime
Another theory is that winter singing is a form of practice for the breeding season. Great reed warblers are known to change their songs from year to year, adding new syllables each time. Researchers believe that winter singing may help males develop more complex and appealing songs for the spring.
Song Complexity and Plumage Color
Researchers also found that the species that spend the most time singing in winter are those in which males produce the most complex breeding songs but have the most drab plumage. This suggests that practice may be more important for species that rely on their songs to attract mates rather than their appearance.
Other Possible Functions
While practice is a plausible explanation for winter singing, it is also possible that there are other functions for the tunes. For example, singing may help males establish social bonds or defend their resources.
Remaining Questions
Despite the research that has been done, there are still many unanswered questions about winter singing in birds. For example, it is not clear how frequently and intensely birds sing during the winter, or whether winter singing is an essential function for all migratory songbirds.
Different Perspectives
Scientists have different perspectives on the importance of winter singing. Some believe that it is an essential practice for successful breeding, while others believe that it may serve other functions or may not be essential at all.
Future Research
More research is needed to fully understand the role of winter singing in birds. Future studies could investigate the frequency and intensity of singing, the effects of winter singing on breeding success, and the potential for other functions of winter tunes.