THE IMPORTANCE OF DIFFERENT PATERNITY GUARDS IN THE POLYGYNANDROUS PENDULINE TIT (REMIZ PENDULINUS)

It is well documented that extra-pair copulations are a strategy by wh ich males can increase their reproductive success and females may obta in genetic benefits. Whereas in monogamous species extra-pair copulati ons are the only way for both sexes to increase their reproductive suc cess, in polygamous systems both partners can benefit from mating with several individuals. Here we examine the intensity of sperm competiti on and the rate of extra-pair fertilizations in relation to male anti- cuckoldry tactics in a small passerine, the polygynandrous penduline t it (Remiz pendulinus), where both sexes have the opportunity to become polygamous. The results revealed rather low rates of extra-pair pater nity for this species: 6.9% (14 out of 201) of young being sired by an extra-pair male. Males build elaborate nests to attract females and b ecause of this high initial investment, one would expect males to evol ve anti-cuckoldry tactics to ensure paternity. However, male mate guar ding intensity as well as within-pair copulation frequency were rather low in comparison to other polygynandrous species, and hence both str ategies are unlikely to ensure paternity. In fact our results show tha t those males which deserted their females early in their fertile cycl e (already before the second egg is laid) did not lose paternity, wher eas those males which tended to guard their females throughout their w hole fertile period were more likely to be cuckolded. Thus, although n o obvious anti-cuckoldry tactics exist in this species, extra-pair pat ernity is very low. This indicates a tendency in females to cooperate with their pair-males rather than seek extra-pair copulations.