Pair Formation in California Condors

SYNOPSIS. Pair formation is a prerequisite for reproductionin California condors and exploring the process has been centralto the captive breeding program for this endangered species.Observations show that once birds reach sexual maturity theycan form pairs within a matter of months; even birds who havelost or been separated from their mates will successfully bondwith others. However, some adults who are housed together showlittle indication of pairing. When such birds are placed withother potential mates they frequently successfully pair andproduce young, suggesting that individual differences play arole in pair formation. We recommend that adults who have notbonded within two years be housed with different potential mates. Condors raised together may or may not form pair bonds uponreaching sexual maturity; unfamiliar condors introduced at fouryears of age or older will form pair bonds. In the four caseswhere pairings have been successful the male initiates moreintrapair interactions with aggressive behavior than does thefemale. Unpaired condors housed in groups do show courtshipand the most dominant birds, usually males, are the most activein giving wings-out/head-down displays. Displays may be directedto males or females and may signal dominance and/or interest.Displays may be followed by mounts and one female may crowdin front of the bird to whom a male is displaying, increasingthe chances that she will receive the display and be mounted.Displaying and the response to displaying birds may be mechanismswhich influence mate selection.