Reproduction in Blue-throated Macaws: factors limiting the recovery of a critically threatened parrot under intense management

BERKUNSKY, IGOR; DANIELE, GONZALO; KACOLIRIS, FEDERICO PABLO; DIAZ LUQUE, JOSÉ ANTONIO; ARAMBURÚ, ROSANA M; GILARDI, JAMES D.

Congreso; 26th International Ornithological Congress; 2014

The Blue-throated Macaw Ara glaucogularis is an endemic Bolivian macaw, and one of the two critically endangered macaw species that still lives in the wild. Until now, the only available biological information of Blue-throated Macaw came from studies related to distribution, range, habitat use and population size estimations. Here, we analyse reproductive parameters in an intensively managed wild population of Blue throated Macaws. During the 2007-2012 period we identified 64 individuals in the study area, of which at least 32 were active breeding birds. Egg-laying season was different for north and south sub-populations. Average clutch size was 2.53 and the incubation period lasted 25 days. Partial losses during incubation were low: two cracked eggs were removed by parents before hatching date. Average clutch size at hatching was 2.10 and hatching success was 72%. In successful nests, the survival of nestlings was 100 %, average clutch size 2.00 and the nestling period lasted 85 days. Between 2007 and 2012, a total of 26 nestlings of Blue-throated Macaw successfully fledged. Given that the average total clutch was 2.5 eggs per nesting attempt, and the average of 0.89 fledglings per nesting attempt, each pair is losing on average 65% of its initial reproductive investment at each nesting attempt. Fifty-seven per cent of 30 monitored nests failed. Most failures occurred during the incubation stage. All monitored breeding pairs showed a high nest site fidelity reusing hardwood-tree cavities and nest boxes. Our research provides the first data on the breeding biology of this critically endangered species. We hope our findings will aid conservation efforts by refining current actions and prompting new approaches towards the conservation and recovery of the Blue-throated Macaw.