Last year Mike wrote a superb and typically lyrical post asking “What is a Waxwing?“. I’m not going to even attempt to better his phrasing by covering the same ground he went over so eloquently - if you haven’t read his post yet click the link you’ve just hurried past immediately - but I do want to post a few photos highlighting the differences between the Bohemian Waxwing Bombycilla garrulus (which is distributed across the northern hemisphere’s boreal zone from Alaska to Siberia) and its more range-restricted American cousin the Cedar Waxwing Bombycilla cedrorum (which breeds from Canada south to California with wanderers
making it into Central America).
Before I’d had a chance to see both species well I’d always thought that apart from some obvious plumage differences - most notably a Bohemian’s chestnut undertail coverts vs. a Cedar’s white - they were essentially pretty much very similar species. In fact, as many birders will concur, while they both share red “waxy” blobs on the secondaries (as adults), a yellow-tipped tail, brownish plumage, shaggy crests and dark “bandit” masks they can be quickly separated on structure alone. Bohemian always appears to be a chunky, Starling-like bird with a distinctively ’solid’ silhouette, whilst the Cedar is much slimmer with a longer tail giving it a surprisingly finch-like profile (I used to regularly overlook Cedars at the tops of trees on my first encounters with them as I was looking for a much heavier bird).
http://10000birds.com/cedar-waxwing-vs-bohemian-waxwing.htm