Effects of early rearing experience on adult behavior and nesting in captive Hawaiian crows (Corvus hawaiiensis)

Abstract

AbstractBehavioral data were collected during the breeding season on eight pairs of Hawaiian crows (Corvus hawaiiensis) housed at two facilities on different islands. All data were collected from videocamera time‐lapse recordings of the nesting platforms. Behaviors included frequency of nest cup manipulation, percent of time spent on nest, allopreening, play, and stereotypy. The number of breeding pairs increased from four in 1996 to six in 1997, to seven in 1998, and to eight in 1999. Five of the older birds (three males and two females) were solitary‐reared for most if not all of their first year, while the remaining 12 birds were all socially reared. Significant differences were found between isolate‐ and socially‐reared birds, with isolate‐reared birds having higher rates of solo play (P = 0.0041) and stereotypies (P = 0.0090). Pairs that were comprised of at least one isolate‐reared bird engaged in significantly less allopreening (P = <0.0001) than pairs in which both birds were socially reared. From 1996 to 1999, 87 eggs were laid, with a mean of 1.88 ± 0.24 SEM eggs per clutch. Only three females produced clutches every year, and they were responsible for 85.1% of the eggs laid. Although not significant, the mean number of clutches produced per pair decreased from 2.50 ± 0.65 in 1996 to 0.87 ± 0.99 in 1999. Age of females does not appear to be a critical factor in the decrease in clutch production. New pairing combinations are under way in an effort to improve propagation in this highly endangered species. Zoo Biol 21:59–75, 2002. © 2002 Wiley‐Liss, Inc.