Hasil (
Bahasa Indonesia) 1:
[Salinan]Disalin!
The population of great hornbills living in U.S. zoos is rapidly aging, andcaptive reproduction efforts have not met a self-sustaining population goal (only 19chicks have hatched in the last 10 years). A number of case reports have beenpublished in the last 20 years describing successful breeding seasons at differentinstitutions [Choy, 1978; de Ruiter, 1998; Golding and Williams, 1986; Bohmke,1987]. However, no one captive breeding program has been consistently successful,and to date no critical variable that increases the chances of hatching a chick hasbeen identified. In 1996 and again in 1998, the American Zoo and AquariumAssociation (AZA) proposed that the hornbill be the subject of a concerted captivebreeding effort, and directed zoos to develop artificial nest sites, record life historydata (which is difficult to obtain in the field), and increase support for fieldconservation through exhibition and publication. To date, these projects havehad very little success. In the 1999–2000 breeding season, a pair of birds at the SanDiego Wild Animal Park (SDWAP) hatched and reared the only chick in the UnitedStates.While the nesting behavior of the great hornbill has been well documentedelsewhere [Kannan and James, 1997], little is known about their reproductivephysiology. This study compares the testosterone, estradiol, and corticosterone levelsin the pairs of birds that successfully and unsuccessfully reproduced in the 1999–2000season. The aim of this study was to determine what constituted a baseline
reproductive hormone profile for great hornbills (Buceros bicornis), and to determine
how the profiles of nonreproducing pairs compared to that of the only pair in the
United States that hatched a chick in the 1999–2000 mating season. This information
may ultimately be used to increase the success of captive breeding programs by
pairing great hornbills with individuals whose hormone profiles indicate they might
successfully reproduce.
136 Crofoot et al.
MATERIALS AND METHODS
Animals and Collection Procedures
Fecal samples were collected from seven pairs of great hornbills (Buceros
bicornis) housed at four different U.S zoos: three at SDWAP, two at Zoo New
England (ZNE) in Boston, one at the Denver Zoo, and one at the Kansas City Zoo
(KCZ) (Table 1). Collections were made on an opportunistic basis over a period of
3–4 months (December 1999 to April 2000), with an average of 24 samples per bird.
The sample collection was discontinued once the female was sealed in her nest, to
minimize disturbance of the female. All fecal samples were placed in plastic cups,
immediately frozen, and stored at –201C until analysis.
Sedang diterjemahkan, harap tunggu..