Yellow-rumped Warbler (Setophaga coronata) by April Raver
“Just a bunch of butterbutts!” When I first began birding several years ago, I took a trip up to Jasper Pulaski to see the Sandhill Cranes in the fall. As I walked down the path through the trees towards the viewing platform, a flock of birds caught my eyes in the treetops above. I watched joyfully through my binoculars as they flitted among the branches chasing insects. A fellow birder passed me on the path and asked what I was watching, and I excitedly exclaimed “a flock of warblers!’ I had heard of these amazing little birds – but never spotted one with my own eyes – and here was a whole flock of them! The other birder put her camera up to her eye and zoomed in to have a look. “Just a bunch of butterbutts!” she sighed and walked on down the path towards her car.
“Butterbutts? What were butterbutts?” I wondered to myself. It didn’t take long for me to learn that the birds I had seen that day were Yellow-rumped Warblers (Setophaga coronate) or butterbutts as they are affectionally known in the birding world.
Year-round, Yellow-rumped Warblers have a distinguishable patch of yellow on the top of their rump which is where they get the name butterbutt. During Spring mating season, both sexes are vibrant colors of gray, black, and white with bits of yellow on their sides, face and rump, but during the winter these colors fade to a paler brown with just a bit of yellow on their sides along with the yellow rump. These cheerful warblers are about the size of a Chickadee and are fairly large for a Warbler.
Yellow-rumped Warblers are one of the most common species of warblers that can be seen in Indiana. They are different than other warblers in that they can withstand the colder weather of winter and can be spotted in our state year-round. What makes them different than other warblers? Their digestive systems are uniquely suited to digest great numbers of fruits – particularly bayberry and wax myrtle. You may also find them feasting on poison ivy or oak berries, juniper berries, Virginia creeper, and dogwood. They may visit feeders and eat sunflower seeds or suet. During the summer, when insects are abundant you will find them eating caterpillars, larvae, beetles, ants, aphids, crane flies, gnats, and spiders. Keep your eyes open for them in abundance during early Spring and late Fall, but you may also spot them during the Winter with a splash of bright yellow on a dreary winter day.
Two distinct subspecies make up the species of Yellow-rumped Warbler. The subspecies we see in Indiana is known as the Myrtle Warbler. These can be seen in the eastern U.S. and in Canada’s boreal forest. The other subspecies is known as Audubon’s Warbler and can be found in the mountainous West. The best way to tell which subspecies of Yellow-rumped Warbler you are seeing is by looking at their throat. Myrtle subspecies have a white throat whereas Audubon’s subspecies have a yellow throat. There are places, like in the Canadian Rockies, where the two subspecies’ breeding ranges intertwine, and a mixed form occurs.
During the Spring, Yellow-rumped Warblers build nests in conifer forests of spruce, pine, or cedar. The female builds the nest with twigs, bark and weeds and then lines the nest with hair and feathers. The female will lay a clutch of four to five eggs and incubate them for twelve to thirteen days. Both parents will feed the newly hatched chicks for just ten to twelve days before they are able to fledge the nest. The male will continue to feed the chicks after they have fledged. Most Yellow-rumped Warblers have two broods per year.
With an estimated breeding population of 130 million Yellow-rumped Warblers according to Partners in Flight, your chances of seeing one are pretty good! So, grab your binoculars and head out this Spring to the nearest forest and scan the branches for a flash of yellow and see if you can find your own butterbutt!