Nest attendants in parakeet auklets

Breeding behaviors in a captive population of parakeet auklets (Cyclorrhynchus psittacula) were observed to determine whether a third bird present at the entrances to nest tunnels was a helper or competitor. Comparisons were made between focal pairs of nesting birds, two with and two without attendants. Pairs with attendants spent more time feeding and more time bathing and had less time with intruders (other than the third bird) at their tunnels. Nest attendants also helped in nest defense and incubation (taking some of the burden off the focal pair). Relatedness is unknown; therefore, kin selection cannot be assessed. Because all nest tunnels were occupied, however, limited breeding resources in the captive environment may make helping an adaptive alternative for mature birds. Zoo Biol 20:271–277, 2001. © 2001 Wiley‐Liss, Inc.