Abstract

Bali mynahs are the only species endemic to the island of Bali in Indonesia. They are critically endangered, and for all practical purposes, already extinct in the wild. Much more still needs to be understood about these unique birds and how they behave in captivity if successful reintroduction is ever going to be feasible. Throughout the month of June 2002, nineteen to twenty hours of observation were completed for each of three pairs of Bali mynahs, two at the Begawan Giri Estate, and one at the Bali Bird Park in Bali. Observations were also completed for the 21 birds in Begawan Giri's flight cage. The Bali Barat National Park breeding and release facilities were also visited, and observations were made, including some of 5 recently released birds. Differences were found in the amounts of time birds spent in their nest-boxes and the amounts of time they spent proximate to one another, possibly attributed to the pair's history and whether or not they were nesting at the time. High numbers of proximity scans (52.8%) in the flight cage and the relatively high occurrence of proximity scans for released birds (18.9%), as well as general observations of the groups lend support to the social and flocking tendencies of the birds that they are not often allowed in captivity. Differences were also found in the frequencies of self-maintenance and allogrooming behaviors between males and females among the paired birds. Females exhibited significantly more of both behaviors. There was no correlation, however, between the frequencies of these behaviors and the birds observed that exhibited feather loss. More general observations and information regarding the bird populations at Begawan Giri and the TNBB have lead to speculation that the feather loss condition may have to do with how the birds are reared, and possibly whether or not they have spent time in a flock as juveniles.