House Finch - Haemorhous mexicanus

House Finch has a variable preformative molt that can range from partial to complete, but is most frequently incomplete, including all greater coverts, some to all tertials, sometimes additional secondaries, usually at least some rectrices, and occasionally also some outer primaries and primary coverts. Prealternate molts are believed to be generally absent. Post-juvenile House Finches can usually be sexed easily by presence (male) or absence (female) of red plumage.

Because of the potential for a complete preformative molt, House Finches with uniform plumage are most reliably aged by skull until late September, and in areas where complete preformative molts occur, such individuals should subsequently be considered M-FCF (U/AHY).

Quick tips

• Look at the head and upper breast - any red plumage indicates a male, while lack of red generally suggests a female, although note that FCJ (juvenile) males also lack red until their preformative molt.
• Compare the greater coverts and primary coverts - there is usually a molt limit between darker grayish-brown greater coverts and paler brown primary coverts on FCF (HY/SY) birds, while they appear largely uniform in colour and wear on DCB (AHY/ASY) birds.
• Examine the primaries - some FCF (HY/SY) individuals show an eccentric molt, with darker/fresher outer primaries and inner secondaries; uniform primaries are less informative as they can occur at any age.
• Check the rectrices - if some or all are narrow and tapered they indicate a FCF (HY/SY) bird, but if they are all uniformly broad and rounded the bird may be either FCF (HY/SY) or DCB (AHY/ASY).

Species account prepared by McGill Bird Observatory (2016). Last updated by Marcel Gahbauer (Mar 2022)