Breeding behaviors in a captive population of parakeet auklets (Cylorrhynch
us psittacula) were observed to determine whether a third bird present at t
he entrances to nest tunnels was a helper or competitor. Comparisons were m
ade between focal pairs of nesting birds, two with and two without attendan
ts. 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 sel
ection 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. (C) 2001
Wiley-Liss, Inc.