Nesting ecology of the Tucuman Amazon (Amazona tucumana) in the cloud forest of Northwestern Argentina

Abstract

In this chapter we use a parrot species that inhabitsthe cloud forests of northwestern Argentina as a model species to elucidateecological aspects related to habitat use, nesting, and breeding biology of abird species. We synthetize the information gathered for the Tucuman Amazon (Amazona tucumana) during 15 years anddiscuss the implications of this information for the conservation of thespecies and the cloud forest. The Tucuman Amazon is a threatened species,with a small geographic range restricted to the narrow strip of montane foreston the eastern slopes of the Andes (i.e., the Southern Yungas) fromsouth-eastern Bolivia to north-western Argentina. In the SouthernYungas the breeding habitat of Tucuman Amazon is the cloud forest found between1,500?2,200 m asl. Most Tucuman Amazon nests occurred in cavitiesof live trees (95%) of six species, and only 5% were in snags. Compared to theavailability of cavities in different tree species, B. salicifolius, J. australis,and C. lilloi were used significantlymore than expected. Average nest tree DBH was 89.9 ± 26.9 cm, cavities werelocated on average at 14.4 ± 3.9 m above the ground. The estimation of thedensity of available suitable cavities for nesting was 4.6 cavities ha-1(95% CI = 3.1?7.0 cavities ha-1). Clutch-size ranged from one tofive eggs (mean 3.6 ± 1.0, n = 86). The number of fledglings per layingfemale was 2.3 ± 0.8 (n = 86) and differed significantly among years.Primary causes of nest-loss were predation (16%) and parental abandonment(12%). The Tucuman Amazon has high rates of nesting success, large clutches anda large number of fledglings per laying female. These results differ fromtrends observed in other bird species that tend to shift to a slowerlife-history strategy with increased elevation. Nesting and spatialrequirements of Tucuman Amazon could limit management actions intended toincrease the density of nesting pairs. A mean distance among suitable cavitiesof at least 150 m could represent the minimum distance to consider in thespacing of active pairs to avoid exclusion by other pairs especially if nestbox provision is necessary. To ensure theconservation of Tucuman Amazon outside protected areas it is necessary thatforest management guidelines promote the retention of large B. salicifolius, C. lilloi and J. australis)that are selected for nesting by Tucuman Amazon and the latter two have also hightimber values.