Yellow-rumped Warbler
Setophaga coronata
Parulidae
The 'butter-butt' — small streaky warbler with a bright yellow rump patch that flashes as it flies. Yellow-rumped Warblers are the only warblers in North America that can digest wax-coated berries, which is exactly why they can overwinter in NJ when every other warbler has left for the tropics. They fuel their entire winter on bayberries and Eastern Red Cedar.
Present in NJ from October through April — the only warbler that regularly overwinters here.
How to spot one.
4.5–5.5 inches, small and active
Winter plumage: gray-brown with streaky sides, distinct yellow rump and yellow patch on flanks
Breeding male: slate-blue back, black cheek patch, yellow crown/sides/rump
Bright white throat and belly with dark streaking
White wing bars
What it sounds like.
Sweet warble in breeding season; winter call is a sharp 'chek!' — often heard before the bird is seen.
How it lives.
Fly-catches from perches, gleans insects from foliage, and — critically — hangs from bayberry and cedar berries in winter to strip them. Forms loose winter flocks. Migration in NJ is heavy in October and again in April.
The spec sheet.
- Status
- Migrant
- Size
- 4.7–5.5 inches
- Present in NJ
- January – December
- Native to NJ
- Yes
- Conservation status
- abundant
- Family
- Parulidae
What it eats.
Diet often shifts dramatically between breeding season and the rest of the year — especially for insectivorous birds that pivot to native berries in fall and winter.
Summer / breeding season
Caterpillars, beetles, wasps, gnats
Some spiders
Migrates to breed in northern conifer forests
Fall / winter
Northern Bayberry (Morella pensylvanica) — the signature winter food
Wax Myrtle (Morella cerifera)
Eastern Red Cedar berries
Poison ivy berries
Occasional insects on warm winter days
What it needs.
Native plants that feed this bird or provide shelter. Names in hydrangea link to the plant’s Field Guide entry.
Northern Bayberry
Fruit / berry source
Eastern Red Cedar
Fruit / berry source
Wax Myrtle
Fruit / berry source
Poison ivy (yes)
Fruit / berry source
Summersweet NJ · All About Birds (Cornell) · Audubon