Yellow-rumped Warbler

The Yellow-rumped Warbler is a medium-sized warbler, notable for its yellow patches on the rump, sides, and crown. The bird has distinctive grey plumage with black streaks on its back and wings, along with white wing bars and tail spots.

Males are more vibrantly colored than females, particularly in breeding season when they display black cheeks and breast patches. During winter, both sexes become more subdued, with brownish-grey upperparts and less prominent yellow markings.

There are two main varieties: the Myrtle Warbler (found in eastern/northern North America) with a white throat, and the Audubon's Warbler (in western North America) with a yellow throat.

The Yellow-rumped Warbler's song is a series of sweet, whistled trills that rise and fall in pitch. Their call is a distinctive, sharp 'chip' or 'check,' often repeated.

During foraging or in flight, they may give a soft 'tsip' note. In winter, flocks communicate with quiet 'contact' calls to maintain group cohesion.

• Look for flashes of yellow on the rump as the bird flies or hops between branches
• Listen for their distinctive 'chip' call, which is often repeated
• Check berry-producing shrubs in fall and winter, where these warblers often feed
• In the US and Canada, watch for them in mixed flocks during migration

Yellow-rumped Warblers have a varied diet, including insects, spiders, and berries. They are unique among warblers in their ability to digest the waxes found in bayberries and wax myrtles, allowing them to winter farther north than other warbler species.

In summer, they primarily consume insects caught on the wing or gleaned from vegetation.

Yellow-rumped Warblers typically form monogamous pairs each breeding season, which begins in late spring. Males perform aerial displays and sing to attract mates.

Nests are usually built in coniferous trees, constructed primarily by the female using twigs, grass, and moss, lined with feathers and hair. The female lays 3-5 pale blue-white eggs with brown spots.

Incubation lasts about 12-13 days, carried out mainly by the female. Both parents feed the nestlings, which fledge after 10-14 days. Pairs often raise two broods per season in the southern parts of their range.

Yellow-rumped Warblers are agile foragers, often seen flycatching from perches or gleaning insects from foliage. They form loose flocks outside of breeding season, frequently mixing with other small bird species.

These warblers are known for their ability to switch between insect and fruit diets, adapting to seasonal food availability.

Yellow-rumped Warblers are currently of least concern due to their large range and stable population. However, they face threats from habitat loss and climate change.

Conservation efforts focus on protecting breeding and wintering habitats, including boreal forests and coastal areas.