Mate-Guarding, Territorial Intrusions and Paternity Defence in the Polygynous Corn Bunting Miliaria calandra

Abstract

Mate-guarding behaviour and territorial intrusions were examined in a population of polygynous Corn Buntings Miliaria calandra. All males showed only a weak tendency to mate-guard by close following of the female. Monogamous and polygynous males did not differ in their extent of mate-guarding, and there was no difference in the extent to which polygynous males guarded primary and secondary females. Territorial intrusions and attempted extra-pair copulations were infrequent and not timed to coincide with the fertile period of females. All intrusions were by territory-holding males, the majority of which were immediate neighbours. Unmated males did not intrude more than paired males and were not observed to attempt any extra-pair copulations. Polygynous males did not suffer significantly more intrusions than monogamous males. We suggest that either the high detectability of intrusions in an open habitat or female control over access to fertilizations made close mate-guarding unnecessary. Males may benefit more from maintaining their own territory in the hope of one or more females settling to breed, rather than seeking extra-pair copulations.