Of the four nuthatch species living in the United States, the most common are the Red-breasted Nuthatch, seen left here, and the White-breasted Nuthatch, on the right. The nuthatch's insistent call matches its aggressiveness. As it works its way down a tree trunk, the nuthatch can spot-and eat-all the tasty morsels missed by the rest of the birds working their way up the tree.More info and transcript at BirdNote.org. Want more BirdNote? Subscribe to our weekly newsletter. Sign up for BirdNote+ to get ad-free listening and other perks. BirdNote is a nonprofit. Your tax-deductible gift makes these shows possible.