Czyż B. (2011) Do female Penduline Tits Remiz pendulinus adjust parental decisions to their mates’ behaviour? ARDEA 99 (1): 27-32

In contrast to older models of parental care, recent theoretical models assume that parents do not make their decisions independently of one another, but respond to the behaviour of their mates. Studies involving mate removal have mostly been conducted in biparental species and such experiments in uniparental species are scarce. I studied the Penduline Tit Remiz pendulinus, a small passerine bird with uniparental care provided either by a female (45% in the studied population) or a male (17%). During the egg-laying period, one parent (or both; 38% in the studied population) deserts the clutch and starts a new breeding attempt. The aim of this study was to find out whether the parental care decision of female Penduline Tits is affected by their mate’s decision to desert or not. In the control group (nests where males were caught, ringed and released), almost 50% of the females deserted the nest. By contrast, most females from the manipulated group did not desert their nests after I had removed their mates. In the following days 12 experimental females (60%) mated with replacement males at their nests; this behaviour was not observed in the control group, and is very rare in the study population (3.7%). These results may suggest that female behaviour is affected by the male decision to desert or stay. However, after attracting a replacement male, some females deserted their nests. As a result, only 11 experimental females (55%) stayed and started incubation, which represents a proportion similar to that found in the control group. This study shows that Penduline Tit females respond in real time to the behaviour of their mates and that their reproductive tactics are flexible.