To elaborate the habitat suitability model we removed uncertain locality records, among them 'Bogota' skins. Also, a record from Pamplona (Norte de Santander) in BioMap. The skin apparently was bought and it is not clear from where it came; being the only record in the eastern slope of the Eastern Andes we decided to keep it out for the modelling exercise. Coordinates from the accession 299614 in DatAves from San Lorenzo were moved slightly (centecimals of a degree) to the west to make the locality lay down in a site with an elevation closer to the upper altitudinal limit for this curassow (i.e. 2,000 m).
The habitat suitability model generated in Maxent showed a few areas that are suitable in climatic terms for this species in the high Cauca and Magdalena valleys, the eastern slope of the Eastern Andes, the Catatumbo and even in the far east. These areas are not known to be occupied by this curassow and were excluded from its potential distribution map.
Assuming that the distribution of the species may have filled the complete climatic model generated, its potential distribution today in remnants of forest is about 52,741 km2, which corresponds to a loss of 74 % of its potential original distribution due to deforestation. Correcting the distribution excluding the flood plains of the Caribbean this curassow may remain in about 52,238 km2, being lost already from nearly 72 % of its potential original distribution.
Renjifo et al. (2002) estimated this species has lost 88 % of its habitat and argued its populations have been reduced by 50 % in three generations or 30 years, remaining about 5,000 individuals. Additionally, more recently BirdLife International (2015) have estimated its population in less than 1,000 individuals. Nevertheless, our estimation of the remnant suitable habitat and the 30 localities or more where the species has been reported in the last two decades (Renjifo et al., 2002; BirdLife International, 2015) suggest that there is great uncertainty and no thorough studies to backup the assumption that 50 % of the population has been lost in three generations. Furthermore, since BirdLife population estimation is based solely on data from ProAves Foundation research in serrania de Las Quinchas area, we can assume that possibly the population estimation of Renjifo et al. (2002) is the most conservative and close to reality for the whole possible area this species occupy. However, similarly to other Colombian bird species, this needs further research. This curassow face severe threats from deforestation and hunting and in a lesser degree from other human activities (BirdLife International 2015). Additionally, the lack of knowledge of its ecology throughout its entire potential distribution remains a major challenge to adequately evaluate the conservation status of this species as well as to propose effective conservation plans and actions in the strongholds of this endemic and threatened curassow.
Regularized training gain is 1.524, training AUC is 0.951, unregularized training gain is 2.130.
Algorithm converged after 920 iterations (33 seconds).
The follow settings were used during the run:
28 presence records used for training.
10027 points used to determine the Maxent distribution (background points and presence points).
Environmental layers used (all continuous): bio10co bio11co bio12co bio13co bio14co bio15co bio16co bio17co bio18co bio19co bio1co bio2co bio3co bio4co bio5co bio6co bio7co bio8co bio9co
Regularization values: linear/quadratic/product: 0.288, categorical: 0.250, threshold: 1.720, hinge: 0.500
Feature types used: linear quadratic hinge
'Equal Training Sensitivity and Specificity' and 'Equate Entropy of Thresholded and Original Distributions' thresholds and omission rates:
0.119-0.217-Fractional predicted area
0.107-0.036-Training omission rate