EFFECTS OF WEATHER AND HELPERS ON SURVIVAL OF NESTLING RED-COCKADED WOODPECKERS

Non-breeding adult Red-cockaded Woodpeckers (Picoides borealis), terme d helpers, participate in many aspects of the nesting cycle, including feeding nestlings. Typically, groups that include helpers exhibit a h igher nesting success and hedge more young than groups lacking helpers . We studied Red-cockaded Woodpeckers in the Ouachita National Forest in Arkansas in 1991 and 1992. In 1992, at the peak of the woodpecker n estling stage, eight of 10 unexpected deaths of nestlings older than s ix days posthatch occurred during 15 consecutive days of abnormally lo w temperatures (as low as 9 degrees C) and elevated rainfall that redu ced potential adult woodpecker foraging time by 26%. Altogether, durin g the abnormal weather of 1992, eight of nine nestlings survived in gr oups with helpers, whereas only seven of 14 survived in groups lacking helpers. In both years, woodpecker groups with helpers suffered fewer losses and hedged more young per nesting attempt (P = <0.001).