What allows hardy coastal populations of the Yellow-rumped Warbler to feed on winter berries when insects are scarce?
Answer
Specialized high levels of bile salts
Yellow-rumped Warblers in coastal areas can process waxy coatings on winter berries, such as bayberry and juniper, due to specialized high levels of bile salts in their digestive systems.

#Videos
Fun & Interesting Facts About Warblers - YouTube
Related Questions
What does the Old French word *werbler*, which warblers are named after, signify?What key anatomical feature often distinguishes many New World warblers from other typical songbirds?Which warbler species is documented as undertaking migratory round trips up to 12,400 miles annually?What allows hardy coastal populations of the Yellow-rumped Warbler to feed on winter berries when insects are scarce?What foraging technique involves snatching insects mid-air, often associated with the tweezerlike beaks of warblers?Which warbler concentrates its hunt almost exclusively in the upper third of mature Ponderosa and Pinyon pine trees?What is the defense mechanism documented in the Yellow Warbler when a Brown-headed Cowbird lays an egg in its nest?What physical trait found at the base of the bill helps many warblers trap insects caught in flight?What is the primary difference in typical plumage coloration between New World and Old World warblers?What challenge severely complicates the identification of many warbler species during late summer and fall migration?