Navigation Links
Age increases chance of success as two-timer

This release is available in German.

The coal tit appears to live a strictly monogamous life. Couples often stay together for their whole lives. That's only a facade. This indigenous songbird is among the top ten two-timers worldwide. That is what research by biologists at the University of Bonn shows. For this they have taken genetic fingerprints from more than 200 breeding couples and their young. In this way they were able to identify the biological father in 90 per cent of the nestlings. According to this research older coal tit males were particularly successful at cheating on their partner. They produced significantly more 'cuckoo kids' than younger males. The results have now been published in the journal 'Behavioral Ecology' (doi: 10.1093/beheco/arm082)..

Germany's most researched population of coal tits lives in a coniferous forest in Lower Saxony, in Emsland, very near the town of Lingen, to be more precise. Dr. Wolfgang Winkel from the Institute of Ornithological Research (Instut fur Vogelforschung) at the Heligoland Ornithological Station has for decades been studying the coal tits that live here. Many of the birds are ringed, so that their exact age is known. 'It really is an exceptionally good set of data which we were able to access,' the Bonn evolutionary biologist Dr. Tim Schmoll explains.

In conjunction with his colleague Professor Thomas Lubjuhn he investigated how often coal tits cheat upon their spouses and what role their age plays in this. 'For this we did paternity tests on more than 200 breeding couples and their offspring in 2000 and 2001,' he explains. With the aid of a 'genetic fingerprint' the researchers were able to match the biological father to the nestlings in nine out of ten cases.

For coal tits are only monogamous on the surface. The partners often stay together for the rest of their life and Mum and Dad take care of their joint offspring together. But are the young really always the offspring of the father who is taking care of the brood" The genetic data tell a completely different story: 'With the primary brood in May, every third nestling is from a two-timing spouse, with the second brood in June, it's even every second one,' Tim Schmoll says. 'With the second brood coal tits are among the top 10 world wide who have'extra-marital affairs'!"

'Greenhorns' father fewer 'cuckoo kids'

Older males succeed considerably more often in palming off a 'cuckoo kid' on their rivals than 'greenhorns' do. In their first year of breeding, male coal tits father only 0.3 'extra-marital offspring' on average. In the years after this, they manage to get almost two young per season into their rivals' nests. But in doing so, they do not neglect their own female. The success of their 'regular' procreation is not affected by trespassing on foreign territory. 'We carried out our study in two different years, in order to see whether our observations were reproducible,' Tim Schmoll explains. 'The effect of age is very significant and reliable. However, other factors such as singing, attract-tiveness of plumage or social status are probably also of significance for their success as Casanovas.

But why are the older coal tits more successful at cheating" Is this due to the fact that females tend to fall for the older seducers rather than the younger ones" The ones that survive long should have good genes, maybe these genes are therefore par- ticularly popular. A preference of the females for more mature males would be rewarded with offspring which are particularly fitted to survive and be favoured in the course of evolution.

The study, funded by the German Research Association (Deutsche Forschungs-gemeinschaft, the DFG), does not draw any final conclusions yet. 'We presume that the male's experience also plays a significant role.' In that case, older males may well know better than 'greenhorns' when they can flirt with their neighbour and leave their own female alone safely, without running the risk that a rival will exploit this oppor-tunity. More experienced coal tit males might also behave more rationally with the care of the brood. With their first offspring they've got their wings full, so to speak, so there's simply no time for a bit on the side.


Contact: Tim Schmoll
University of Bonn

Related biology news :

1. Sexual cooperation: Mating increases longevity in ant queens
2. Morphine for Chest Pain Increases Death Risk
3. Global warming increases oyster sensitivity to pollution
4. Prenatal exposure to famine increases risk of schizophrenia
5. Gene increases risk of tuberculosis
6. Male rivalry increases when females at most fertile, say researchers
7. Lack of a key enzyme dramatically increases resistance to sepsis
8. Variation in bitter-taste receptor gene increases risk for alcoholism
9. Gene variation increases SIDS risk in African Americans
10. Single cell amoeba increases MRSA numbers 1000- fold
11. Mosquito spray increases toxicity of pyrethroids in creek, study finds
Post Your Comments:
(Date:11/4/2015)... , November 4, 2015 ... new market report published by Transparency Market Research "Home Security ... Trends and Forecast 2015 - 2022", the global home security ... 30.3 bn by 2022. The market is estimated to ... period from 2015 to 2022. Rising security needs among ...
(Date:10/29/2015)... --  MedNet Solutions , an innovative SaaS-based eClinical technology ... is pleased to announce that it has been selected ... of only three finalists for a 2015 Tekne ... category. The Tekne Awards honor Minnesota ... and leadership. iMedNet™ eClinical  technology ...
(Date:10/29/2015)... , Oct. 29, 2015 Daon, a ... that it has released a new version of its ... in North America have already ... v4.0 also includes a FIDO UAF certified server ... already preparing to activate FIDO features. These customers include ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... 2 nouvelles études permettent d , ... les souches bactériennes retrouvées dans la plaque dentaire ... . Ces recherches  ouvrent une nouvelle voie ... de l,un des problèmes de santé les plus ... --> 2 nouvelles études permettent d , ...
(Date:11/25/2015)... Nov. 25, 2015 /PRNewswire/ - Aeterna Zentaris Inc. (NASDAQ: ... business and prospects remain fundamentally strong and highlights ... doxorubicin) recently received DSMB recommendation to continue the ... review of the final interim efficacy and safety ... Endpoint in men with heavily pretreated castration- and ...
(Date:11/25/2015)... ... November 25, 2015 , ... Jessica Richman and Zachary Apte, ... their initial angel funding process. Now, they are paying it forward to other ... stage investments in the microbiome space. In this, they join other successful ...
(Date:11/24/2015)... , Nov. 24, 2015 Halozyme Therapeutics, Inc. (NASDAQ: ... in New York on Wednesday, December 2 ... Torley , president and CEO, will provide a corporate overview. ... York at 1:00 p.m. ET/10:00 a.m. PT . ... relations, will provide a corporate overview. --> th ...
Breaking Biology Technology: