ACOUSTIC DIFFERENTIATION OF DRUMMING OF THE RUFOUS-BELLIED WOODPECKER [DENDROCOPOS HYPERYTHRUS SUBRUFINUS (CABANIS & HEINE, 1863)] AND JAPANESE PYGMY WOODPECKER [YUNGIPICUS KIZUKI PERMUTATUS (MEISE, 1934)]
The drumming of the rufous­bellied woodpecker [Dendrocopos hyperythrus subrufinus (Cabanis & Heine, 1863)] and the japanese pygmy woodpecker [Yungipicus kizuki permutatus (Meise, 1934)], even in a place that is inaccessible for visual observation, can be reliably differentiated by the drumming. The most reliable and convenient indicator for use in the field is the interval between fractions in the drumming of the male. The average values of the rufous­bellied woodpecker are 8,191 seconds, and those of the japanese pygmy woodpecker are 2.254 seconds, 3-4 times faster, which is quite real and audible in the field.