A Partnership That Works Sapsuckers and Hummingbirds The tiny holes drilled by this Yellow-bellied Sapsucker are an important source of sweet fluid for Ruby-throated Hummingbirds in early spring People aren't the only ones who love sweet syrup! Yellow-bellied Sapsuckers time their migration to returns north right when sap is running. These special woodpeckers tap little holes in a circle around the trunk or higher limb, and come back over and over again to lap up the sap with their brushy tongues and also to pick up insects that are drawn to the sweet liquid. Eventually the trees make "scabs," closing off the holes, and then the sapsuckers make another ring of holes right above or below the first ring. They would probably choose maple syrup if healthy maple trees didn't have such hard wood. So sapsuckers tap their sap in softer trees, especially aspens. Many other birds love sap, but without those woodpecker beaks they can't get it themselves. And those same birds also love the insects that collect at running sap. So sapsucker holes are an important food source for many species, including warblers, kinglets, and phoebes. And the first Ruby-throated Hummingbirds to return north in the spring, usually when weather is still cool or cold, are often very dependent on sapsucker holes for their food until a lot of flowers are blooming. Like the rest of us, hummers "get by with a little help from their friends." The Sapsucker Connection Sapsuckers winter in the southern U.S. states, and are one of the first migrants to appear in northern states and provinces in early spring--right when sap is running strong. They migrate a good two or three weeks before hummingbirds do. They often rest for a week or two here and there between their winter and summer homes, making temporary feeding stations along the way. Sapsuckers spend much of their time drilling holes, usually going back and forth working on two or three different tree branches at a time. One migrating sapsucker drilled 286 tiny holes in a pine tree in 9 1/2 hours one April day, providing a bounty of food for itself--and for other birds. While sapsuckers are guarding and feeding at one set of holes, a host of other birds may visit their other sets of holes. At least 35 species of birds including hummingbirds, warblers, kinglets, and phoebes are attracted to sapsucker borings for sap and insects. Sapsuckers only drill holes during the spring and summer, while sap is running. As sap dwindles, the sapsuckers turn to flying insects, ants, fruits, and nuts for food. Ruby-throated Hummingbirds have been seen actually following sapsuckers as these woodpeckers visit their sap trees. Do you think this may help the hummingbirds learn the location of these trees? As long ago as 1891, a scientist named Frank Bolles noticed that hummingbirds visit sapsucker holes more than any other birds. He saw them come to these holes throughout the summer, but especially in early spring. Experts who have analyzed sap say it is remarkably like flower nectar. Both contain sucrose and traces of amino acids. So sap is a perfect substitute for nectar in areas where few nectar-rich flowers are blooming and where sapsuckers live. When two species associate closely with one another, benefiting at least one without harming either, the relationship is called symbiosis. Hummingbirds get an obvious food benefit from sapsuckers, but sapsuckers may also get help from the hummers. Hummers Return the Favor In northern Wisconsin one May, ornithologist Laura Erickson spent many hours studying some sapsucker trees. The woodpecker had drilled circles of holes in three different aspen branches for feeding. While the sapsucker fed or rested on one branch, Laura watched other birds--Ruby-crowned Kinglets, Cape May Warblers, Yellow-rumped Warblers and Eastern Phoebes--come to the holes in the other two branches. Most of the time, two or three birds gorged themselves at each feeding spot. But whenever a hummingbird visited, it pugnaciously chased away any birds that happened to be there--except the sapsucker. While hummingbirds eat a lot of food compared to their body weight, they don't eat much compared to warblers and phoebes. Therefore, hummingbirds may be helping sapsuckers by defending the sapsucker's hole borings from other larger, hungrier species. It may be a partnership that works both ways! Try This! Using binoculars, look very carefully at the top branch tips of different kinds of trees. Do you see any with tiny insects swarming at the newly running sap? Can you find any birds up there? This Season Teachers Kids Orientation Registration Search Copyright 1997-2008 Journey North. All Rights Reserved. Questions or comments? Contact us.