Northern Shrike - Lanius excubitor

Northern Shrike has a partial preformative molt, and absent to partial prealternate molts that are difficult to detect. Age can generally be determined readily by plumage. Although males are on average somewhat darker than females, sex can be reliably determined only through brood patch / cloacal protuberance during the breeding season.

Northern and Loggerhead Shrikes are fairly similar in appearance; Northern Shrike can be separated by a pale base to the lower mandible, a distinct white supercilium contrasting with the black eyeline, and extensive although sometimes faint barring on the underparts.

Quick tips

• Look for molt limits among median and greater coverts or between the greater and primary coverts - on FCF/FCU (HY/SY) birds there are retained juvenile feathers with buffy tips contrasting with replaced all-black feathers; on DCB/DCU (AHY/ASY) birds the median, greater, and primary coverts are uniformly black.
• Check the contrast between dark and pale on p6 - on FCF/FCU (HY/SY) birds there is a gradual transition, while on DCB/DCU (AHY/ASY) birds there is a sharp distinction.
• Consider the overall appearance - FCF/FCU (HY/SY) birds have a brownish tone initially, gradually becoming more grayish; DCB/DCU (AHY/ASY) birds are uniformly gray above and white below, aside from light barring on the breast.

Species account prepared by McGill Bird Observatory (2018). Last updated by Marcel Gahbauer (Mar 2022)