<b is alive with the sound of warblers! Take a walk through the Arb this week and enjoy one of the most exciting times of the year for Minnesota birding enthusiasts. Warblers are songbirds of the genus Dendroica, which means “of the tree.” Indeed, high in the tree-tops is where you can expect to see these small, often brightly colored birds. Chances are, it will be hard to get a good look at any of them because they generally move quickly to catch insects. A good eye and a bit of patience will be rewarded by the opportunity to view the spectacular combinations of yellows, oranges, blues, greens and blacks that characterize these birds.
Interestingly, it is common to see multiple species feeding in the same tree. This “sharing” of resources might seem counterintuitive, but in actuality it is evidence that historical competition between warbler populations has caused these populations to evolve into distinct species. Today, each species feeds on a certain resource and competition between species is minimized. For example, the Black-and-white Warbler has an unusually long hind-toe that allows it to ascend tree trunks with the agility of a Nuthatch—this enables it to feed on insects found on tree bark. Both the Magnolia and the Yellow Warbler prefer understory vegetation while the Golden-winged and the Nashville Warbler forage high in the tree-tops. The Dendroica warblers are an excellent example of what evolutionary biologists call an “adaptive radiation”—a single ancestor evolving into many specialized species.
Now is the time to get out and see warblers! Yellow-rumped and Blackburnian Warblers might stray onto campus occasionally, but the majority of these birds are only found in forested areas. These exciting birds will only be in the Arb for several more weeks—all of the Dendroica warblers (except the Yellow Warbler) migrate further north to spend the summer.
If you are interested in learning more about warblers and other birds, join the Arb Naturalists and local birding experts for the Annual Arboretum Bird Count (Tomorrow 5/16, 6am, Arb parking lot near West Gym). All ability levels welcome!