This PhD Project is underway in the Conservation Biology Department, supervised by Dr. José L. Tella. We started working together in March 2014 in an investigation of the deterministic and stochastic effects that may be acting upon the dynamics of the remaining population of the endangered Lear’s Macaw, an endemic species from the Caatinga (Brazilian tropical dry forest), using a multidisciplinary approach with molecular tools, ecological modeling, stable isotope analysis and indices of breeding success.
The entire population of the Lear’s Macaw is estimated at ca. 1200 birds, of which only 20% are breeders concentrated in two localities.
This current population may be the outcome of a recent demographic increase from only approximately two hundred birds, estimated before the 2000s. Nesting and roosting sites are restricted to sandstone cliffs walls and the Licuri Palm fruit is supposedly their main food item.
Our central hypothesis is that, if the population does not expand geographically, their continuous increase could result in the saturation of the environmental resources and generate negative density dependent effects. In this context, we aim to answer the following questions: Do breeding sites and food availability constrain the breeding success and the distribution of the Lear’s Macaw population? Is the genetic diversity of the current population constrained as a result of a genetic bottleneck? Is there sexual bias in the current population affecting the recruitment? Can the viability of the population be affect by any of these processes?