Papers by Ronald Navarrete
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Copeia, 2016
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This report presents the results of the sampling campaign for water quality in the river on Daule... more This report presents the results of the sampling campaign for water quality in the river on Daule, between September 2009 and October 2010. Duale River, runs 245 km from the dam to the bridge Daule Peripa La Aurora north of Guayaquil. It joins with the river Babahoyo, at kilometer 262 to form the Guayas River. It is a river with its flow regulated by Daule Peripa Dam, which is the main contribution (> 100 m3/sec) during the dry season. From this site, in its way, reaching Guayaquil, also receives inputs from diffuse sources and domestic wastewater effluent discharges from seven populations (Pichincha, Balzar, Colimes, Palestine, St. Lucia, and Nobol Daule) settled in the river banks, which together have an urban population of 100,000 inhabitants and lacking, mostly systems for domestic wastewater treatment. Daule river water is used for hydroelectric power, irrigation, all the way to drinking water, navigation, agricultural crops and livestock, and is returned to the river as par...
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Revista ecuatoriana de higiene y medicina tropical
Eristalotabanus violaceus (Krober, 1931) is a blue violaceous horsefly that lives in the bleak pl... more Eristalotabanus violaceus (Krober, 1931) is a blue violaceous horsefly that lives in the bleak plateau and Andean forests of Ecuador. Until 1999, it was known from the scientific literature only for the locality of the holotype, “Pucay, Western Mountain range” and Arrayan at 3600 m altitude on the western slopes of the Ecuadorian Andes. Subsequent collections made since 1985 in 92 localities (21 of the 22 provinces of Ecuador) reveal that E. violaceus occurs above 2 450 m altitude on both the western and eastern slopes of the Ecuadorian Andes. Here it occupies scrublands, forests and Andean subparamo, as well as pine plantations. The geographic distribution and the seasonal activity time in Ecuador are similar to those of several other horseflies species found in these same forests and subparamo/puna areas from Colombia to Bolivia. These species include Dicladocera macula Macquart, D. nigrocaerulea Rondani, D. hirsuta Wilkerson, Dasybasis montiun (Surcouf) 1918 and D. schineri Krobe...
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Check List 05/2014; 10(2):382-385., 2014
Iotabrycon praecox (Characidae: Stevardiinae) has been reported as endemic to the Guayas River dr... more Iotabrycon praecox (Characidae: Stevardiinae) has been reported as endemic to the Guayas River drainage in Western Ecuador since its description in 1973. We collected one specimen of I. praecox in the Santa Rosa River, Santa Rosa drainage, El Oro Province, approximately 144 km south of the Guayas drainage, significantly expanding the known geographic distribution of the species. Given the severe anthropomorphic pressures impacting fishes in Southwestern Ecuador, there is an urgent need to evaluate the present status of I. praecox in the region.
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Sixteen polymorphic, dinucleotide microsatellite loci were developed for Rhoadsia altipinna, a sm... more Sixteen polymorphic, dinucleotide microsatellite loci were developed for Rhoadsia altipinna, a small characid fish from impacted rivers in south western Ecuador. None of the loci were in linkage disequilibrium or deviated significantly from Hardy–Weinberg equilibrium after sequential Bonferroni correction. Variability was relatively high with allelic richness ranging between 2 and 22 alleles per locus (average = 9.125), observed heterozygosity ranging between 0.125 and 0.958 (average = 0.695), and expected heterozygosity ranging between 0.120 and 0.952 (average = 0.736)
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Copeia 2013(2): 312-323, Jul 1, 2013
Little is known about the freshwater fishes of western Ecuador despite serious environmental thre... more Little is known about the freshwater fishes of western Ecuador despite serious environmental threats including the creation of large artificial impoundments. Phenotypic and genetic divergence of populations of a large predatory fish, Hoplias microlepis, is examined in rivers and artificial impoundments of the Guayas River drainage in western Ecuador. Despite the recent formation of the impoundments (~ 20 years prior to the sampling), H. microlepis in these habitats diverged morphologically from river populations. Impoundment fish tended to have larger eyes, longer dorsal and caudal fins, and thinner bodies than river fish. Classification rates for habitat of origin based on morphometric measures were relatively high (71.7-83.3%), and the magnitude of morphological divergence was substantial when contrasted with divergence from H. malabaricus, a congener from eastern Ecuador. Frequencies of mtDNA d-loop haplotypes differed significantly among samples. Genetic divergence between river samples implies that the genetic structure in the drainage predates the formation of the impoundments. The genetic analysis also indicates that the morphological divergence between fish in different habitat types is not likely due to shared ancestry. Genetic diversity tended to be higher in the river samples and the percentage of private alleles was higher in the impoundment populations, which is consistent with rapid population expansion from a limited number of founders in impoundments.
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Check List 01/2012; 8(3):572-574. pp.572-574, 2012
We report the first confirmed evidence of a feral introduced population of Brotogeris versicoloru... more We report the first confirmed evidence of a feral introduced population of Brotogeris versicolorus (Statius Müller, 1776) in Guayaquil city, Ecuador, as part of the World Parrot Count led by City Parrots. A total of 216 individuals were counted, at two places within the city, but no direct evidence of breeding was found. A previously unpublished photograph suggesting nesting activity is also presented, along with brief comments on previous and additional observations and the conservation implications of this recently established feral species.
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The uptdated Tabanidae’s list of the Ecuador was made being based to thebibliographical reference... more The uptdated Tabanidae’s list of the Ecuador was made being based to thebibliographical reference and the Jaime Buestán’s collection of tabanids, this collection has 8898 specimens. In this article 263 species arementioned, grouped in 29 Genera, 5 Tribes and 3 Subfamilies. By eachspecies when it is possible is provided with infomation of the places, height,number of specimens, dates of capture and collector. The markedspecies with asterisk (*) they are alone reported for the Ecuador andwith a cross (+) the new registries.
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Eristalotabanus violaceus (Krober, 1931) is a blue violaceous horsefly that lives in the treeless... more Eristalotabanus violaceus (Krober, 1931) is a blue violaceous horsefly that lives in the treeless plateau and Andean forests of Ecuador. Until 1999, it was known from the scientific literature only from the locality of the holotype, “Pucay, Western Mountain range” and Arrayan at 3600 m altitude on the western slopes of the Ecuadorian Andes. Subsequent collections made since 1985 in 92 localities (21 of the 22 provinces of Ecuador) reveal that E. violaceus occurs above 2450 m altitude on both the western and eastern slopes of the Ecuadorian Andes. Here it occupies scrublands, forests and Andean subparamo, as well as pine plantations.
The geographic distribution and the seasonal activity time in Ecuador are similar to those of several other horsefly species found in these same forests and subparamo/puna areas from Colombia to Bolivia. These species include Dicladocera macula Macquart, D. nigrocaerulea Rondani, D. hirsuta Wilkerson, Dasybasis montiun (Surcouf), D. schineri Krober, Spilotabanus multiguttatus Krober and several species of the genus Scione Walker.
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Conservation Biology, Jan 1, 2010
Informally gathered species lists are a potential source of data for conservation biology, but mo... more Informally gathered species lists are a potential source of data for conservation biology, but most remain unused because of questions of reliability and statistical issues. We applied two alternative analytical methods (contingency tests and occupancy modeling) to a 35-year data set (1973-2007) to test hypotheses about local bird extinction. We compiled data from bird lists collected by expert amateurs and professional scientists in a 2-km(2) fragment of lowland tropical forest in coastal Ecuador.
We tested the effects of the following on local extinction: trophic level, sociality, foraging specialization, light tolerance, geographical range area, and biogeographic source. First we assessed extinction on the basis of the number of years in which a species was not detected on the site and used contingency tests with each factor to compare the frequency of expected and observed extinction events among different species categories. Then we defined four multiyear periods that reflected different stages of deforestation and isolation of the study site and used occupancy modeling to test extinction hypotheses singly and in combination. Both types of analyses supported the biogeographic source hypothesis and the species-range hypothesis as causes of extinction; however, occupancy modeling indicated the model incorporating all factors except foraging specialization best fit the data.
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TESIS by Ronald Navarrete
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Documentos de difusión by Ronald Navarrete
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Papers by Ronald Navarrete
The geographic distribution and the seasonal activity time in Ecuador are similar to those of several other horsefly species found in these same forests and subparamo/puna areas from Colombia to Bolivia. These species include Dicladocera macula Macquart, D. nigrocaerulea Rondani, D. hirsuta Wilkerson, Dasybasis montiun (Surcouf), D. schineri Krober, Spilotabanus multiguttatus Krober and several species of the genus Scione Walker.
We tested the effects of the following on local extinction: trophic level, sociality, foraging specialization, light tolerance, geographical range area, and biogeographic source. First we assessed extinction on the basis of the number of years in which a species was not detected on the site and used contingency tests with each factor to compare the frequency of expected and observed extinction events among different species categories. Then we defined four multiyear periods that reflected different stages of deforestation and isolation of the study site and used occupancy modeling to test extinction hypotheses singly and in combination. Both types of analyses supported the biogeographic source hypothesis and the species-range hypothesis as causes of extinction; however, occupancy modeling indicated the model incorporating all factors except foraging specialization best fit the data.
TESIS by Ronald Navarrete
Documentos de difusión by Ronald Navarrete
The geographic distribution and the seasonal activity time in Ecuador are similar to those of several other horsefly species found in these same forests and subparamo/puna areas from Colombia to Bolivia. These species include Dicladocera macula Macquart, D. nigrocaerulea Rondani, D. hirsuta Wilkerson, Dasybasis montiun (Surcouf), D. schineri Krober, Spilotabanus multiguttatus Krober and several species of the genus Scione Walker.
We tested the effects of the following on local extinction: trophic level, sociality, foraging specialization, light tolerance, geographical range area, and biogeographic source. First we assessed extinction on the basis of the number of years in which a species was not detected on the site and used contingency tests with each factor to compare the frequency of expected and observed extinction events among different species categories. Then we defined four multiyear periods that reflected different stages of deforestation and isolation of the study site and used occupancy modeling to test extinction hypotheses singly and in combination. Both types of analyses supported the biogeographic source hypothesis and the species-range hypothesis as causes of extinction; however, occupancy modeling indicated the model incorporating all factors except foraging specialization best fit the data.