Egg recognition and interspecific brood parasitism rates in red bishops (Aves: Ploceidae)

摘要: Abstract The observed rates of interspecific brood parasitism by diederik cuckoos, Chrysococcyx caprius , on red bishops, Euplectes orix are reported for four colonies. Experimental manipulations were used to examine how tolerant bishops towards foreign eggs. Red did not discriminate mimetic cuckoo-sized models the basis egg size, an increase in clutch size or stage at which parasite appeared nest. Only eggs that heavily maculated had a darker ground colour and quite unlike host's light-blue eggs, significantly rejected. Low rejection (11.1%) cuckoo-egg may be consequence evolutionary lag coevolutionary arms race between host parasite. Since cuckoo is good mimic cost bishop making mistake closed nest rejecting ‘own’ constrain rejection. unable exploit this constraint because corporate vigilance defence large colonies probably prevents any significant from taking place population; negatively correlated with colony size. potential exists equilibrium can breeders only small, low density poorly defended