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

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.Fil: Rivera, Luis Osvaldo. Universidad Nacional de Jujuy. Instituto de Ecorregiones Andinas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Ecorregiones Andinas; ArgentinaFil: Politi, Natalia. Universidad Nacional de Jujuy. Instituto de Ecorregiones Andinas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Ecorregiones Andinas; Argentin

Morphology and genetics reveal an intriguing pattern of differentiation at a very small geographic scale in a bird species, the forest thrush Turdus lherminieri.

12 pagesInternational audienceMobile organisms are expected to show population differentiation only over fairly large geographical distances. However, there is growing evidence of discrepancy between dispersal potential and realized gene flow. Here we report an intriguing pattern of differentiation at a very small spatial scale in the forest thrush (Turdus lherminieri), a bird species endemic to the Lesser Antilles. Analysis of 331 individuals from 17 sampling sites distributed over three islands revealed a clear morphological and genetic differentiation between these islands isolated by 40-50 km. More surprisingly, we found that the phenotypic divergence between the two geographic zones of the island of Guadeloupe was associated with a very strong genetic differentiation (Fst from 0.073-0.153), making this pattern a remarkable case in birds given the very small spatial scale considered. Molecular data (mitochondrial control region sequences and microsatellite genotypes) suggest that this strong differentiation could have occurred in situ, although alternative hypotheses cannot be fully discarded. This study suggests that the ongoing habitat fragmentation, especially in tropical forests, may have a deeper impact than previously thought on avian populations