What to watch for in November: Yellow-bellied Sapsuckers

Compiled by Jane Tillman, Travis Audubon Volunteer
Feature Photo: Yellow-bellied Sapsucker male by Jeff Osoborne

The Yellow-bellied Sapsucker winters here in central Texas. It’s a migratory woodpecker species that summers in a large swath of North American forests from eastern Alaska across Canada to the northeastern U.S. They winter from the mid-Atlantic states, down and west through Kansas, Oklahoma, into Texas, down through Mexico, with some going as far as Panama. Females outnumber males 3.5 to 1 at the southerly end of their winter range, while closer to the breeding grounds wintering males outnumber females sometimes as much as 10 to 1. In Austin, sapsuckers begin to trickle in during October with more moving through in November. It’s not a cowardly bird as its name might imply but it is sap-loving.

Yellow-bellied Sapsucker by Jane Tillman

See if you can spot one when out enjoying our other woodpecker species. It’s a challenging bird to find as it is quiet, and often sits in one place for some time. What should you look for? Like many of our regular woodpeckers the sapsucker is a study in black, white, and red. Adult birds are about 8-1/2 inches long, so larger than both the Ladder-backed and Downy Woodpeckers, but smaller than the Red-bellied Woodpecker. Like other woodpeckers it hops or hitches up and down trees, supported in an upright position by its tail feathers. Like many woodpeckers its flight is characterized as undulating, since it typically flaps twice, with an upward lift on each flap, then glides when it dips downward. The male has a red crown and red throat outlined in black. It has a medium sized black pointed bill for excavation and drilling. It has a black back with white barring and mottled underparts. The female looks similar but usually has a white throat, and some have a black crown instead of red. The yellow wash on the underparts is variable. The juvenile birds are brownish and dingy looking. By mid-winter they look like the adults. All Yellow-bellied Sapsuckers have a vertical white stripe on the folded wing. They are not very vocal, although will occasionally give a mewing call that sounds catlike.

Yellow-bellied Sapsucker Immature by Jeff Osborne

Why are they called sapsuckers? Their distinctive behavior is to drill small holes in tree bark to lap the sap that flows in with brushy-tipped tongues. Wintering birds in east Texas were observed spending at least 70% of their foraging time drilling square holes in organized rows in tree bark, and then tending the sap wells throughout the season to keep the sap running. One way to find them is to look for evidence of these rows of holes in tree bark and then wait to see if one shows up. However sapsuckers have been observed tending one tree for a couple of hours at a time, so you could be in for a long wait. It’s easiest to spot them when they fly in or fly away.

Verdin at Sap Well by Jane Tillman

Other wildlife are attracted to sap wells, including hummingbirds, kinglets and wintering warblers that sneak in when the sapsucker is absent. Arthropods like insects and spiders are lured to sap too, where some consume it and others become prey. It is thought that the Ruby-throated Hummingbird times its northern migration with the sapsucker’s arrival, as sap can help them through the lean times of a late spring snowfall that covers blooming plants. Hummingbirds also are known to place their nests close to sap wells. On their breeding grounds sapsuckers are known to dip ants in sap before feeding them to their young.

Throughout their range sapsuckers have been recorded making sap wells in about 1000 different perennial woody plants. In Texas popular trees include pecans, oaks and elms. They have been observed making sap wells in mesquites too. For the sap wells, sapsuckers are on the lookout for trees that might already be leaking sap due to wind damage, lightning, disease, or insect infestation, or trees with fungal infections.

Sapsuckers play an important role in the ecosystem of their breeding grounds since they create cavities for nesting and roosting, which are in short supply. When they abandon those cavities, other cavity nesting birds as well as wildlife like flying squirrels move in.

The sapsucker’s diet is not 100% sap. They eat insects, often by probing them from bark. They also occasionally flycatch, flying out from the end of a branch to capture insects. They like fruit too. Sapsuckers may visit backyards offering suet in the winter months. Other woodpeckers are attracted to suet too. Try red pepper suet which squirrels generally avoid. Make sure to keep it fresh and mold-free.

Good places in Austin to look for a Yellow-bellied Sapsucker include the open woods at Commons Ford Metro Park, and the trees at Roy Guerrero. Both of these parks have good numbers of woodpeckers.

Resources: All about Birds, Birds of the World, The Sibley Guide to Birds, and The Crossley ID Guide Eastern Birds