Chlorostilbon stenurus

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 below 568 m and above 2,800 m. Also seven records in BioMap from Atlantico, Antioquia, Cauca and Amazonas, which represent corrupted information in the database were deleted previous to modelling.

The habitat suitability model generated in Maxent showed extensive areas suitable in climatic terms for this species in the Carribean region, the Eastern Andes and even the extreme southern Amazon region. Within the altitudinal range of this species, areas off from the northern end of the Eastern Andes are not known to be occupied by the species and were deleted from our final potential distribution map. There is a record from 'Puente Negro' (La Guajira) that is of particular interest since it is a study skin placed in Colegio San Jose, and if correct extends the known range of the species some 215 km to the north. This needs further revision and confirmation.

Assuming that the distribution of the species may have filled the complete climatic model generated, its distribution today in remnants of forest is about 9,631 km², which corresponds to a loss of 60 % 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. It has estimated its extent of occurrence in 138,000 km², most of it in Venezuela. According to our maps the species has a extent of occurrence of 24,410 km² in Colombia, which is very close to the 20,000 km² threshold for Vulnerable. Additionally, differently to what is believed in the evaluation of this species the forests part of its range in the Eastern Andes are severely fragmented and forest part of its range in the country continue being threatened by deforestation and fragmentation. The species is poorly known in Colombia (McMullan and Donegan 2014) and its population has not been quantified (BirdLife International 2017). Until further studies are conducted to understand its dependance on large intact forest tracts and know better its general ecology, and given that potentially has lost a major part of its forested range, as a precaution this hummingbird must be reclassified at least as Near Threatened (NT) at country level.

MODEL METADATA

Regularized training gain is 1.663, training AUC is 0.962, unregularized training gain is 2.244.

Algorithm converged after 100 iterations (0 seconds).

The follow settings were used during the run:

8 presence records used for training.

10008 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: 0.530, threshold: 1.920, 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

15.044-8.652-Cumulative threshold

0.238-0.098-Logistic threshold

0.125-0.189-Fractional predicted area

0.125-0.000-Training omission rate