LACK OF MATE-GUARDING IN A TERRITORIAL PASSERINE BIRD WITH A LOW-INTENSITY OF SPERM COMPETITION, THE PIED FLYCATCHER (FICEDULA-HYPOLEUCA)

We examined a Norwegian population of pied flycatchers (Ficedula bypol euca) for behaviour associated with the paternity-protection tactic of mate-guarding and found that this tactic was absent The absence of ma te-guarding and the fact that pied flycatchers do not have a high rate of copulation make this population unusual to the extent that the cur rent literature implies that, in birds, one or other paternity guard s hould be present. Comparison of our population with a Swedish populati on that does exhibit mate-guarding lends some support to the notion th at differences in nesting density may drive the relative risk of extra -pair copulation, leading to the need for paternity guards such as mac e-guarding. However, we conclude that, whilst the results of both our study and the Swedish study are consistent with the nesting-density hy pothesis, there is at least one other plausible hypothesis that tits t he available data. Specifically, we direct attention to the role of th e female in determining overall patterns of pair behaviour and, potent ially, the rate of extra-pair paternity, challenging the primacy of ma le-male competition as the driving force behind the sperm-competition dynamics of this species.