‘Butter Butt’ is the affectionate nickname given by birders to the songbird, Yellow-rumped warbler, Setophaga coronata.  I’ve been fortunate to host at least one Yellow-rumped warbler each winter for the past few years.  These attractive warblers, muted in color when I see them in winter, are widespread throughout North America.  My home in Central Texas is in the middle of their geographically wide migratory path; many  overwinter here.

“My” little Butter Butt–and I think it’s the only one this winter–is a female, a member of the “Myrtle” subspecies.  There are two subspecies of Yellow-rumps:  “Myrtle”  warblers, from the eastern half of North America and “Audubon’s” warbler, from western areas.  The primary distinguishing features between the two subspecies are that the male Myrtle has a white throat and black mask across the eyes, while the Audubon’s throat is yellow and has no black mask.  There are other differences too, mostly in amount of white between the males and females on the wings and faces.

I’ve identified my Yellow-rump as female.  She lacks the black mask across the eyes that a male Myrtle Yellow-rump warbler wears.  Even without the mask and the bold coloring, she’s still very cute.

When Butter Butts molt (in late spring) their coloring is quite dramatic. You can see  photos of these beauties in their finest feathered forms, here.   Even without the dramatic breeding colors, I think this little bird qualifies as a head-turner in the looks department.

I typically see her at the suet feeder, or bathing in the bog area of the pond.  Plus she frequently forages along the ground in the garden; I have no clue what she noshes under the plants.  Seeds?  Insects?  Probably both!  Yellow-rumped warblers enjoy the widest menu choices of any warbler species.  They eat a huge variety of insects, gleaning those with their pointed beaks from trees and snatching with expertise during flight.  These warblers stand alone–maybe I should say they digest alone–with their consumption of bayberry and wax myrtle berries; no other warblers digest those two berry species.  Ornithologists believe that Yellow-rumps ability to eat the two widely available berries allows them to overwinter farther north than most other warblers. 

I’ve observed scads of little songbirds flitting in my trees and always assumed they’re eating parts of leaves or spring flowers with pollen, and maybe, some insects. But in observing this Yellow-rump as she hops along the limbs and darts through the leaves, it’s clear that she’s focused on insects, rather than nibbling at vegetation for her meals.  Ms. Yellow-rump is a bundle of energy, constantly in movement:  up, down, and all around.   I haven’t witnessed any bug-munching, but most afternoons when I look for her, she’s there, in the trees, hunting for protein.

According to Cornell Lab of Ornithology, Yellow-rumps forage on the outside branches of trees and along those limbs in the bottom third of the tree.  That’s exactly where I’ve noticed my warbler and thank goodness for that!  She’d be even more difficult to observe if higher up in the trees.

In winter, Yellow-rumped warblers spend their time in mixed arboreal landscapes–those areas with plenty of trees and fruit-bearing shrubs, like parks and urban gardens, all good habitats brimming with the needed munchies.  In their breeding areas, far north from Central Texas, they concentrate on insect eating, but easily switch to fruits, if available.  Yellow-rumps nest in coniferous trees, the female building the chicks’ homes along branches.  Both parents feed the chicks, which fledge within two weeks.  They grow up so fast!

These hardy warblers are adaptable, which is why their populations are relatively stable.  That said, it’s always a good when gardeners plant for birds:  native plants are best to provide berries and seeds, to provide cover for protection, and to provide a rich, diverse garden habitat.   Also, habitats free of insecticides is a must, since many birds (not only warblers) require insects for themselves and their offspring.

And there it is–the famous, often talked about, but only briefly glimpsed–yellow rump!

The flash of that bodacious booty is easily visible–at the correct angle, with tail feathers up–as they bop around the ground or zoom through trees, but catching these busy birds to photograph their famous bums is a little trickier. It requires patience and some good luck.

For more great information on this charming songbird, check out the Cornell Lab of Ornithology or Audubon’s site on the Yellow-rumped Warbler.

What wild things are in your garden?  Please share and leave a link when you post a comment–and happy spring and wildlife gardening!