Rose-breasted Grosbeak - Pheucticus ludovicianus

Rose-breasted Grosbeak has a partial preformative molt, and a prealternate molt that is partial to incomplete in the first cycle (FCA/SY) but only absent-limited in subsequent cycles (DCU/ASY). Plumage can be used to distinguish sexes at all ages. Although males are generally easy to age based on plumage, females can be quite tricky, and even with a good view of the wing and tail, some may be reliably aged only by skull in fall, and should be considered M-FCA (AHY) in spring and summer.

Conseils clés

• Consider overall plumage - any individuals with black feathers are males, although those lacking black are not necessarily female, as males also lack black until they reach FCA (SY).
• Check the underwing coverts - they are pinkish on males, and yellowish-orange on females.
• Look for molt limits among the greater coverts or between the median and greater coverts - FCF/FCA (HY/SY) birds often show a contrast between darker median coverts (and sometimes also inner greater coverts) and paler juvenile greater coverts, while on DCB/DCU (AHY/ASY) birds the coverts are uniform, but beware this contrast is much more subtle on females.
• Examine the tail - the presence of any brown and narrow juvenile feathers indicates an FCF/FCA (HY/SY) bird, but uniformly broad rectrices can occur on both FCF/FCA (HY/SY) and DCB/DCU (AHY/ASY) birds.

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