Vocalizations Vocalizations performed by Nuttall's woodpecker are considered to be not of any harmonic. Some vocalizations have been described: • Call note: used between mated pairs to communicate their location to each other. • Double call: same function as call note can but also be used as a low threat alarm call. • Rattle call: used to establish territories when feeding • Kweek call: used between sexes mainly by female prior to copulation. Both sexes
drum. Rolls are relatively long, averaging over one second. While feeding, it uses its rigid tail and sturdy feet to stabilize itself on branches. It also accesses the tree sap, particularly from oaks since they provide a plentiful source of nutrients during colder seasons in which insects may become dormant or less active.
Feeding Its strong beak is used to drill into tree trunks and branches to remove branch pieces in order to extract insects. A common behavior is to peel back tree layers to expose ant colonies inhabited within bark. The woodpeckers hammer their beaks into the trees at speeds of 13 to 15 miles per hour (21 to 25 kilometers per hour). This results in 18 to 22 hits on a tree per second, and a total of 12,000 times per day by liberal estimates. In order to survive the deceleration forces of 1200 g with each strike, they have mechanisms and bone structure that creates absorbent forces. Composition wise, their skull consists of a variety of bones that is spaced in a spongelike pattern to absorb shocks. With this, the hyoid bone, which similarly is composed of multiple bones, enters the tongue by way of wrapping around the skulls from the nostrils. This results in the unique ability for the hyoid bone as a protective, seatbelt-like preventive measure for the head that restrains it to absorb stress. Finally, their bill is turned slightly downward in a way that deflects some of the energy, in combination with its elasticity.
Reproduction Pair bonding occurs in late January to March with egg-laying mostly in April and May. When male and female Nuttall Woodpeckers come into contact, they exchange soft wheezing calls which are similar to but less intense than the rattle calls used territorially. Starting in late January both sexes, especially the males, drum on their ranges. Average clutch size has been reported to be around 4.6 eggs. Nuttall's woodpeckers are socially
monogamous and show displays of bi-parental care. New nests are excavated each year by males in the cavities of dead trees such as willow, oak, and alder. These nesting cavities are found from ground level to about 18 meters (60 feet) above ground. The birds aggressively protect their nest sites against predators and coexisting species alike. Clutch sizes range from three to six eggs with the male partner incubating the eggs at night and the female during the day. Incubation period can be up to 14 days. Fledglings are able to leave the nest around 29 days post hatch with parental care continuing for 14 days after that. After fledging level, the adults become inactive and tend to remain in solitary once contact with the juveniles ends. == Additional images ==