Chlorostilbon olivaresi

NOTES

To elaborate our model we removed uncertain localities such as 'Bogota skins', those localities with no coordinates and all records with coordinates laying down in sites with estimated elevations above 600 m.

The habitat suitability model generated in Maxent showed areas suitable in climatic terms for this species in most of the central and west Amazonia, the central and west Orinoco region and in a few zones west of the Andes. These areas are not known to be occupied by the species and were excluded from the potential distribution map of this hummingbird. Areas between within the range 300-700 m and predicted as suitable were kept in our map, including some areas north and south from serrania de Chiribiquete, which hold these preconditions.

Assuming that the distribution of the species may have filled the complete climatic model generated, its distribution today in remnants of forest is about 4,367 km2, which corresponds to a loss of 19 % of its potential original distribution due to deforestation.

BirdLife International (2017) has catalogued this hummingbird as of Least Concern (LC) since it is believed it does not approach to the thresholds to be considered Vulnerable (VU) under the range size, population trend or population size criterion. However, this evaluation has a series of pitfalls that must be considered. According to our maps the species has a extent of occurrence of 5,415 km2, which is well below the 20,000 km2 threshold for Vulnerable. Additionally, the forests part of its range although possibly not threatened at present time, it is known some areas nearby have been logged for ilicit crops in the past. On the other hand, the species is believed to be very local and although its population has not been quantified it is assumed it does not approach to the thresholds to be Vulnerable (VU), which is below 10,000 mature individuals (BirdLife International 2017). This is extremely uncertain, assuming a regular occupancy of the extent of occurrence estimated here and if the population is 10,000 individuals the average density will be around 2.3 Individuals/km2, giving that we know the species is common in some sectors of Chiribiquete, maybe this estimation of density may be somehow optimistic anyway in those areas. Until further studies are conducted to know better its general ecology, and given that its very local range makes it highly vulnerable in biological terms, as a precaution this hummingbird must be reclassified at least as Near Threatened (NT).

MODEL METADATA

Regularized training gain is 0.755, training AUC is 0.930, unregularized training gain is 1.276.

Algorithm converged after 140 iterations (1 seconds).

The follow settings were used during the run:

6 presence records used for training.

10006 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: 1.000, categorical: 0.560, threshold: 1.940, hinge: 0.500

Feature types used: linear

responsecurves: true

jackknife: true

maximumiterations: 2000

'Equal Training Sensitivity and Specificity' and 'Equate Entropy of Thresholded and Original Distributions' thresholds and omission rates:

ETSS-EETOD-Description

47.449-6.432-Cumulative threshold

0.538-0.173-Logistic threshold

0.135-0.470-Fractional predicted area

0.167-0.000-Training omission rate