Helping Behavior within Sapsuckers (Sphyrapicusspp.)

Abstract

I documented interspecific and intraspecific helping behavior (more than two adults feeding young at a nest) within sapsuckers of the genus Sphyrapicus. Of 120 nests, 97 belonged to Red-breasted (Sphyrapicus ruber), Red-naped (Sphyrapicus nuchalis), or hybrid (Red-breasted × Red-naped) sapsuckers, and 23 to Williamson's Sapsuckers (Sphyrapicus thyroideus). Interspecific helping behavior was observed at two nests (1 with a Red-breasted × Red-naped and hybrid female, 1 with Red-breasted × Red-breasted and Williamson's male) and intraspecific helping behavior (Red-breasted male) was observed at one nest. Given the rarity of helping behavior observed in these species a functional advantage is unlikely; individuals that helped might simply have been responding to a feeding stimulus.