Navigation Links
Testosterone regulates solo song of tropical birds

This press release is available in German.

In male songbirds of the temperate zone, the concentration of sex hormones is rising in spring, which leads to an increase in song activity during the breeding season. In the tropics, there has been little evidence so far about such a clear relationship between hormonal action and behaviour, which is partly due to a lower degree of seasonal changes of the environment. Researchers of the Max Planck Institute for Ornithology in Seewiesen have now discovered that in duetting African white-browed sparrow weavers, the solo song of dominant males is linked to elevated levels of testosterone. What is more, the male-typical solo song could be activated via testosterone treatment in female birds. The study thus shows a complex relationship between song behaviour and hormone concentration also in a tropical bird species.

In species of the temperate zone, circannual rhythms are triggered by seasonal fluctuations in day length. The longer days in spring are accompanied by an increase of steroid hormone levels that lead to the onset of breeding activities. Consequently, there are changes in behaviour and at least in male songbirds, there is a relationship between the incidence and complexity of songs and circulating testosterone concentrations. In the tropics, however, the situation is different. Birds often vocalise year-round, and there are suitable conditions for breeding during a more extended period compared to the temperate zone. In addition, in many species testosterone concentrations are at a low level throughout the year. The underlying mechanism responsible for the song changes of tropical birds therefore remains elusive.

Cornelia Voigt and Stefan Leitner from the Max Planck Institute for Ornithology now showed that testosterone plays a crucial role in the regulation of song behaviour in African white-browed sparrow weavers (Plocepasser mahali). These birds live in groups of two to ten individuals and are characterized by a status-dependent song, where only the dominant male sings a so-called "solo song", whereas females and subordinate males sing an alternating duet song. In a long-term study of sparrow weaver colonies in Southwestern Zimbabwe, the researchers found a relationship between hormone levels and solo song in males. Dominant males had higher testosterone values than subordinate birds, both in the early breeding season from October until December and in the late breeding season from January until March.

However, these hormone concentrations were much lower compared to those responsible for song changes in temperate zone species. It could well be that the slightly higher values of dominant males only reflect the hierarchical status itself and are not responsible for the activation of solo song. That testosterone indeed plays a role in solo singing could be proved in an experiment in females that were kept in aviaries next to their natural habitat. These females received a testosterone implant. Within a week they started to sing the male-typical solo song that was fully developed after one month and differed only in a few features from male song. "With this study, we could show that a special type of song, the solo song, can be activated by testosterone in both sexes. Moreover, females remain receptive for the male hormone testosterone", says Cornelia Voigt.


Contact: Stefan Leitner

Related biology news :

1. Testosterone-fuelled infantile males might be a product of Moms behaviour
2. Zebrafish research shows how dietary fat regulates cholesterol absorption
3. Gut microbiota regulates bile acid metabolism
4. Law that regulates shark fishery is too liberal: UBC study
5. Prestigious Royal Society of Tropical Medicine and Hygiene journals join Oxford University Press
6. Tropical arks reach tipping point
7. Tropical plankton invade Arctic waters
8. Thieving rodents: Did they save tropical trees?
9. Have thieving rodents saved tropical trees?
10. Rodent robbers good for tropical trees
11. Native plant restoration not enough to maintain tropical dry forests in Hawaii
Post Your Comments:
Related Image:
Testosterone regulates solo song of tropical birds
(Date:11/16/2015)... Calif. , Nov 16, 2015  Synaptics ... of human interface solutions, today announced expansion of ... TouchView ™ touch controller and display driver ... revolution of smartphones. These new TDDI products add ... TD4100 (HD resolution), TD4302 (WQHD resolution), and TD4322 ...
(Date:11/11/2015)... --  MedNet Solutions , an innovative SaaS-based eClinical technology company ... to announce that it will be a Sponsor of the ... be held November 17-19 in Hamburg , ... iMedNet , MedNet,s easy-to-use, proven and affordable ... been able to deliver time and cost savings of up ...
(Date:11/9/2015)... Nov. 9, 2015  Synaptics Inc. (NASDAQ: SYNA ... announced broader entry into the automotive market with a ... the pace of consumer electronics human interface innovation. Synaptics, ... ideal for the automotive industry and will be implemented ... Europe , Japan , ...
Breaking Biology News(10 mins):
(Date:11/30/2015)... , Dec. 1, 2015 /PRNewswire/ - BioAmber Inc. (NYSE: BIOA ... has joined the American Business Act on Climate Pledge, alongside ... are standing with the Obama Administration to demonstrate an ongoing ... strong outcome to the COP21 Paris ... --> Sarnia, Canada . --> ...
(Date:11/30/2015)... , Nov. 30, 2015 Harvard Apparatus ... a biotechnology company developing bioengineered organ implants for ... notification from The NASDAQ Stock Market that it ... requirements. The letter noted that as a result ... stock having exceeded $1.00 per share for more ...
(Date:11/30/2015)... ... 30, 2015 , ... Imagine Exhibitions and Universal Partnerships & ... in March 2016 at Melbourne Museum in Melbourne, Australia. Immediately following the Australia ... tour dates. The Exhibition is based on Universal Pictures’ Jurassic World, one of ...
(Date:11/30/2015)... JACKSONVILLE, Florida , November 30, 2015 ... company specializing in the development of innovative peptide and ... & metastatic disease, today announced it will be presenting ... Event on December 1, 2015 at 2.30 PM PT. ... member and Strategic Advisor will be giving the presentation ...
Breaking Biology Technology: