Partners for life? For some birds, better the devil you know

Common terns stay with the same partner for life even though they have poor breeding 
success 
Date: January 5, 2017
Source: University of Southern Denmark

Many birds choose partners for life -- it offers many advantages and often improves a couple's breeding output. New research reveals that for the common tern lifelong monogamy does not always lead to breeding success. Nevertheless, they don't split up.

Many bird species are monogamous. Especially long-lived species where both parents take part in caring for the chicks form lifelong partnerships. According to life-history theories there should be reproductive advantages of remaining with the same partner.

"Life-history theories predict that the choice of mating partner should improve an individual's chances to reproduce successfully," says Fernando Colchero, Associate Professor, Department of Mathematics and Computer Science and Max Planck Odense Center on the Biodemography of Aging, University of Southern Denmark.

Together with colleagues Maren Rebke from Avitec Research and the Max Planck Institute for Demographic Research in Rostock, Germany and Peter H. Becker from the Institute of Avian Research "Vogelwarte Helgoland" in Wilhelmshaven, Germany, they have developed a statistical model to analyze the long-term study on common terns in Lake Bant in Wilhelmshaven led by Prof. Becker.

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