Introducción: Una manifestación de los impactos ambientales provocados por la urbanización es la ... more Introducción: Una manifestación de los impactos ambientales provocados por la urbanización es la contaminación acústica, relacionada con la presencia de niveles sonoros no deseados provocados por actividades humanas. Estos afectan a la vida silvestre con incomodidad, estrés y otros efectos dañinos, e incluso pueden incluir daño físico. Objetivo: Analizar el ruido presente en áreas verdes periurbanas y urbanas adyacentes a la microcuenca del río Bermúdez, en Heredia, Costa Rica. Métodos: Instalamos equipos de grabación automatizados Audiomoth en seis sitios de muestreo a lo largo de la microcuenca. Se establecieron tres sitios de estudio en el área periurbana y tres en el área urbana. Los dispositivos se programaron para registrar 1 minuto cada 10 minutos durante 24 horas durante 6 días continuos, dos veces por sitio. El índice de ruido (SPL1) se utilizó para evaluar los sonidos grabados a través de medidas de presión sonora. Resultados: Los niveles de ruido promedio en el área urban...
Memorias del I Congreso Internacional de Ciencias Exactas y Naturales de la Universidad Nacional, Costa Rica, 2019, 2019
Los ecosistemas urbanos poseen gran variedad de agentes contaminantes como el ruido que afectan l... more Los ecosistemas urbanos poseen gran variedad de agentes contaminantes como el ruido que afectan la comunicación de las especies. Existen pocos estudios al respecto en zonas urbanas de Costa Rica y nuestro objetivo fue caracterizar el ruido ambiental y la riqueza de aves de la microcuenca del río Bermúdez. Se establecieron ocho transectos donde se registraron la riqueza de aves y el ruido ambiental mediante puntos de conteo a lo largo de la microcuenca. Registramos 171 especies pertenecientes a 41 familias. Se encontraron diferencias significativas en la cantidad de especies por sitio en la zona periurbana (136 especies) y urbana (108 especies). El ruido presentó valores más bajos en la zona periubana (45.4 dB) respecto a la urbana (59.4 dB). El ruido ambiental podría tener efectos negativos sobre las aves y es necesario establecer medidas de mitigación respecto al ruido que beneficie la conservación de los ecosistemas urbanos y ribereños.
Introducción: Una manifestaciónde los impactos ambientales provocados por la urbanización es la c... more Introducción: Una manifestaciónde los impactos ambientales provocados por la urbanización es la contaminación acústica, relacionada con la presencia de niveles sonoros no deseados provocados por actividades humanas. Estos afectan a la vida silvestre con incomodidad, estrésy otros efectos dañinos,e incluso pueden incluir daño físico. Objetivo: Analizar el ruido presente en áreas verdes periurbanas y urbanas adyacentes a la microcuenca del río Bermúdez, en Heredia, Costa Rica. Métodos:Instalamos equipos de grabación automatizados Audiomothen seis sitios de muestreo a lo largo de la microcuenca. Se establecieron tres sitios de estudio en el área periurbana y tres en el área urbana. Los dispositivos se programaron para registrar 1 minuto cada 10 minutos durante 24 horas durante 6 días continuos, dos veces por sitio. El índice de ruido (SPL1) se utilizó para evaluar los sonidos grabados a través de medidas de presión sonora. Resultados:Los niveles de ruido promedio en el área urbana fuer...
The frequency and intensity of hurricanes are likely to increase in the Caribbean due to climate ... more The frequency and intensity of hurricanes are likely to increase in the Caribbean due to climate change, potentially threatening the long-term conservation of biodiversity in vulnerable island ecosystems. The effects of hurricanes were assessed for the understory forest birds of Cozumel Island during the first and second year after two consecutive hurricanes (Emily and Wilma) struck the island in July and October of 2005. Post-hurricanes values were compared to pre-hurricanes values for summer and winter bird assemblages. A total of 2,504 individuals of 45 species (29 resident and 16 migrants) were captured using mist nets. Strong negative effects of the hurricanes were detected during the first winter season, that is, 3 months following the second hurricane, with significantly lower mean values per site for the number of individuals, the number of species, and the percentages of migratory individuals and species. During the second winter (16 months after the hurricanes), parameter values of the bird assemblages were similar to pre-hurricane values. Response variables showed no effects of hurricanes in the case of summer bird assemblages (either 8 or 21 months after the hurricanes). Yet, when we carried out ordinations of the samples, taking into consideration the bird species and their relative abundances, we found that in both winter and summer seasons, bird assemblages for the three sampling periods (pre-hurricanes, first year and second year after the hurricanes) could be clearly distinguished. Management strategies for hurricane-prone areas are recommended, in particular for diverse insular ecosystems highly threatened by the synergistic effects of natural and anthropogenic disturbances.
En los ecosistemas costeros, las geofonías forman parte fundamental del entorno acústico y el imp... more En los ecosistemas costeros, las geofonías forman parte fundamental del entorno acústico y el impacto del oleaje sobre su geomorfología es un ejemplo de ello. Se colocó una grabadora Audiomoth en cuatro sitios de Punta Morales, Puntarenas, Costa Rica, del 22 de noviembre al 18 de diciembre, 2020. Se programaron para registrar 60 segundos cada 10 minutos durante 24 horas con el objetivo de caracterizar el paisaje acústico asociado al ciclo de mareas de la localidad. De las grabaciones obtenidas, se analizaron: el Índice de Diferencia Normalizada del Paisaje Sonoro (NDSI), las Tecnofonías, la Entropía Acústica (TE) y el Nivel de Presión Sonora (SPL). Estos valores se contrastaron entre sitios mediante un análisis de medias recortadas unidireccionales; se realizó una correlación entre el SPL y el nivel de marea en cada lugar y, por último, se compararon los valores en un mismo punto de muestreo entre pleamar y bajamar. Se encontraron diferencias en todas las comparaciones realizadas; a...
Memorias del I Congreso Internacional de Ciencias Exactas y Naturales de la Universidad Nacional, Costa Rica,, 2019
communication of species. There are few studies on this subject in urban areas of Costa Rica and ... more communication of species. There are few studies on this subject in urban areas of Costa Rica and our objective was to characterize the environmental noise and bird richness of the microbasin of the Bermudez River. Eight transects were established where bird richness and environmental noise were recorded through counting points along the microbasin. We recorded 171 species belonging to 41 families. Significant differences were found in the number of species per site in periurban (136 species) and urban (108 species) areas. Noise was lower in the periurban zone (45.4 dB) than in the urban zone (59.4 dB). Environmental noise could have negative effects on birds, and it is necessary to establish noise mitigation measures that benefit the conservation of urban and riparian ecosystems.
The frequency and intensity of hurricanes are likely to increase in the Caribbean due to climate ... more The frequency and intensity of hurricanes are likely to increase in the Caribbean due to climate change, potentially threatening the long-term conservation of biodiversity in vulnerable island ecosystems. The effects of hurricanes were assessed for the understory forest birds of Cozumel Island during the first and second year after two consecutive hurricanes (Emily and Wilma) struck the island in July and October of 2005. Post-hurricanes values were compared to pre-hurricanes values for summer and winter bird assemblages. A total of 2,504 individuals of 45 species (29 resident and 16 migrants) were captured using mist nets. Strong negative effects of the hurricanes were detected during the first winter season, that is, 3 months following the second hurricane, with significantly lower mean values per site for the number of individuals, the number of species, and the percentages of migratory individuals and species. During the second winter (16 months after the hurricanes), parameter ...
The frequency and intensity of hurricanes are likely to increase in the Caribbean due to climate ... more The frequency and intensity of hurricanes are likely to increase in the Caribbean due to climate change, potentially threatening the long-term conservation of biodiversity in vulnerable island ecosystems. The effects of hurricanes were assessed for the understory forest birds of Cozumel Island during the first and second year after two consecutive hurricanes (Emily and Wilma) struck the island in July and October of 2005. Post-hurricanes values were compared to pre-hurricanes values for summer and winter bird assemblages. A total of 2,504 individuals of 45 species (29 resident and 16 migrants) were captured using mist nets. Strong negative effects of the hurricanes were detected during the first winter season, that is, 3 months following the second hurricane, with significantly lower mean values per site for the number of individuals, the number of species, and the percentages of migratory individuals and species. During the second winter (16 months after the hurricanes), parameter values of the bird assemblages were similar to pre-hurricane values. Response variables showed no effects of hurricanes in the case of summer bird assemblages (either 8 or 21 months after the hurricanes). Yet, when we carried out ordinations of the samples, taking into consideration the bird species and their relative abundances, we found that in both winter and summer seasons, bird assemblages for the three sampling periods (pre-hurricanes, first year and second year after the hurricanes) could be clearly distinguished. Management strategies for hurricane-prone areas are recommended, in particular for diverse insular ecosystems highly threatened by the synergistic effects of natural and anthropogenic disturbances.
The microphone is the main component of the recording equipment used in bioacoustics. There is cu... more The microphone is the main component of the recording equipment used in bioacoustics. There is currently a wide range of microphones in the market; choosing the right one is a difficult task, if the specifications are unknown, and rarely described. This study describes and compares acoustic features of the main commercial microphones as well as a couple of homemade devices. We determined and compared the microphones fidelity to a scale of frequencies ranging between 100 Hz and 20,000 Hz, and two bird sample vocalizations, with a range from 300 Hz to 10,000 Hz. This experiment was conducted at the Gamboa research station of the Smithsonian Institute in Panama in September of 2012. The professional microphones had the highest correlation values; nonetheless, the homemade microphones also had high values and a close-to-professional fidelity. The study allowed us to determine that, in order to choose an adequate microphone for a specific research objective, it is essential to know the acoustic features. Furthermore, we concluded that homemade microphones are a viable option, which offers acceptable fidelity and can reduce the production costs in more than 50 percent
Introducción: Una manifestación de los impactos ambientales provocados por la urbanización es la ... more Introducción: Una manifestación de los impactos ambientales provocados por la urbanización es la contaminación acústica, relacionada con la presencia de niveles sonoros no deseados provocados por actividades humanas. Estos afectan a la vida silvestre con incomodidad, estrés y otros efectos dañinos, e incluso pueden incluir daño físico. Objetivo: Analizar el ruido presente en áreas verdes periurbanas y urbanas adyacentes a la microcuenca del río Bermúdez, en Heredia, Costa Rica. Métodos: Instalamos equipos de grabación automatizados Audiomoth en seis sitios de muestreo a lo largo de la microcuenca. Se establecieron tres sitios de estudio en el área periurbana y tres en el área urbana. Los dispositivos se programaron para registrar 1 minuto cada 10 minutos durante 24 horas durante 6 días continuos, dos veces por sitio. El índice de ruido (SPL1) se utilizó para evaluar los sonidos grabados a través de medidas de presión sonora. Resultados: Los niveles de ruido promedio en el área urban...
Memorias del I Congreso Internacional de Ciencias Exactas y Naturales de la Universidad Nacional, Costa Rica, 2019, 2019
Los ecosistemas urbanos poseen gran variedad de agentes contaminantes como el ruido que afectan l... more Los ecosistemas urbanos poseen gran variedad de agentes contaminantes como el ruido que afectan la comunicación de las especies. Existen pocos estudios al respecto en zonas urbanas de Costa Rica y nuestro objetivo fue caracterizar el ruido ambiental y la riqueza de aves de la microcuenca del río Bermúdez. Se establecieron ocho transectos donde se registraron la riqueza de aves y el ruido ambiental mediante puntos de conteo a lo largo de la microcuenca. Registramos 171 especies pertenecientes a 41 familias. Se encontraron diferencias significativas en la cantidad de especies por sitio en la zona periurbana (136 especies) y urbana (108 especies). El ruido presentó valores más bajos en la zona periubana (45.4 dB) respecto a la urbana (59.4 dB). El ruido ambiental podría tener efectos negativos sobre las aves y es necesario establecer medidas de mitigación respecto al ruido que beneficie la conservación de los ecosistemas urbanos y ribereños.
Introducción: Una manifestaciónde los impactos ambientales provocados por la urbanización es la c... more Introducción: Una manifestaciónde los impactos ambientales provocados por la urbanización es la contaminación acústica, relacionada con la presencia de niveles sonoros no deseados provocados por actividades humanas. Estos afectan a la vida silvestre con incomodidad, estrésy otros efectos dañinos,e incluso pueden incluir daño físico. Objetivo: Analizar el ruido presente en áreas verdes periurbanas y urbanas adyacentes a la microcuenca del río Bermúdez, en Heredia, Costa Rica. Métodos:Instalamos equipos de grabación automatizados Audiomothen seis sitios de muestreo a lo largo de la microcuenca. Se establecieron tres sitios de estudio en el área periurbana y tres en el área urbana. Los dispositivos se programaron para registrar 1 minuto cada 10 minutos durante 24 horas durante 6 días continuos, dos veces por sitio. El índice de ruido (SPL1) se utilizó para evaluar los sonidos grabados a través de medidas de presión sonora. Resultados:Los niveles de ruido promedio en el área urbana fuer...
The frequency and intensity of hurricanes are likely to increase in the Caribbean due to climate ... more The frequency and intensity of hurricanes are likely to increase in the Caribbean due to climate change, potentially threatening the long-term conservation of biodiversity in vulnerable island ecosystems. The effects of hurricanes were assessed for the understory forest birds of Cozumel Island during the first and second year after two consecutive hurricanes (Emily and Wilma) struck the island in July and October of 2005. Post-hurricanes values were compared to pre-hurricanes values for summer and winter bird assemblages. A total of 2,504 individuals of 45 species (29 resident and 16 migrants) were captured using mist nets. Strong negative effects of the hurricanes were detected during the first winter season, that is, 3 months following the second hurricane, with significantly lower mean values per site for the number of individuals, the number of species, and the percentages of migratory individuals and species. During the second winter (16 months after the hurricanes), parameter values of the bird assemblages were similar to pre-hurricane values. Response variables showed no effects of hurricanes in the case of summer bird assemblages (either 8 or 21 months after the hurricanes). Yet, when we carried out ordinations of the samples, taking into consideration the bird species and their relative abundances, we found that in both winter and summer seasons, bird assemblages for the three sampling periods (pre-hurricanes, first year and second year after the hurricanes) could be clearly distinguished. Management strategies for hurricane-prone areas are recommended, in particular for diverse insular ecosystems highly threatened by the synergistic effects of natural and anthropogenic disturbances.
En los ecosistemas costeros, las geofonías forman parte fundamental del entorno acústico y el imp... more En los ecosistemas costeros, las geofonías forman parte fundamental del entorno acústico y el impacto del oleaje sobre su geomorfología es un ejemplo de ello. Se colocó una grabadora Audiomoth en cuatro sitios de Punta Morales, Puntarenas, Costa Rica, del 22 de noviembre al 18 de diciembre, 2020. Se programaron para registrar 60 segundos cada 10 minutos durante 24 horas con el objetivo de caracterizar el paisaje acústico asociado al ciclo de mareas de la localidad. De las grabaciones obtenidas, se analizaron: el Índice de Diferencia Normalizada del Paisaje Sonoro (NDSI), las Tecnofonías, la Entropía Acústica (TE) y el Nivel de Presión Sonora (SPL). Estos valores se contrastaron entre sitios mediante un análisis de medias recortadas unidireccionales; se realizó una correlación entre el SPL y el nivel de marea en cada lugar y, por último, se compararon los valores en un mismo punto de muestreo entre pleamar y bajamar. Se encontraron diferencias en todas las comparaciones realizadas; a...
Memorias del I Congreso Internacional de Ciencias Exactas y Naturales de la Universidad Nacional, Costa Rica,, 2019
communication of species. There are few studies on this subject in urban areas of Costa Rica and ... more communication of species. There are few studies on this subject in urban areas of Costa Rica and our objective was to characterize the environmental noise and bird richness of the microbasin of the Bermudez River. Eight transects were established where bird richness and environmental noise were recorded through counting points along the microbasin. We recorded 171 species belonging to 41 families. Significant differences were found in the number of species per site in periurban (136 species) and urban (108 species) areas. Noise was lower in the periurban zone (45.4 dB) than in the urban zone (59.4 dB). Environmental noise could have negative effects on birds, and it is necessary to establish noise mitigation measures that benefit the conservation of urban and riparian ecosystems.
The frequency and intensity of hurricanes are likely to increase in the Caribbean due to climate ... more The frequency and intensity of hurricanes are likely to increase in the Caribbean due to climate change, potentially threatening the long-term conservation of biodiversity in vulnerable island ecosystems. The effects of hurricanes were assessed for the understory forest birds of Cozumel Island during the first and second year after two consecutive hurricanes (Emily and Wilma) struck the island in July and October of 2005. Post-hurricanes values were compared to pre-hurricanes values for summer and winter bird assemblages. A total of 2,504 individuals of 45 species (29 resident and 16 migrants) were captured using mist nets. Strong negative effects of the hurricanes were detected during the first winter season, that is, 3 months following the second hurricane, with significantly lower mean values per site for the number of individuals, the number of species, and the percentages of migratory individuals and species. During the second winter (16 months after the hurricanes), parameter ...
The frequency and intensity of hurricanes are likely to increase in the Caribbean due to climate ... more The frequency and intensity of hurricanes are likely to increase in the Caribbean due to climate change, potentially threatening the long-term conservation of biodiversity in vulnerable island ecosystems. The effects of hurricanes were assessed for the understory forest birds of Cozumel Island during the first and second year after two consecutive hurricanes (Emily and Wilma) struck the island in July and October of 2005. Post-hurricanes values were compared to pre-hurricanes values for summer and winter bird assemblages. A total of 2,504 individuals of 45 species (29 resident and 16 migrants) were captured using mist nets. Strong negative effects of the hurricanes were detected during the first winter season, that is, 3 months following the second hurricane, with significantly lower mean values per site for the number of individuals, the number of species, and the percentages of migratory individuals and species. During the second winter (16 months after the hurricanes), parameter values of the bird assemblages were similar to pre-hurricane values. Response variables showed no effects of hurricanes in the case of summer bird assemblages (either 8 or 21 months after the hurricanes). Yet, when we carried out ordinations of the samples, taking into consideration the bird species and their relative abundances, we found that in both winter and summer seasons, bird assemblages for the three sampling periods (pre-hurricanes, first year and second year after the hurricanes) could be clearly distinguished. Management strategies for hurricane-prone areas are recommended, in particular for diverse insular ecosystems highly threatened by the synergistic effects of natural and anthropogenic disturbances.
The microphone is the main component of the recording equipment used in bioacoustics. There is cu... more The microphone is the main component of the recording equipment used in bioacoustics. There is currently a wide range of microphones in the market; choosing the right one is a difficult task, if the specifications are unknown, and rarely described. This study describes and compares acoustic features of the main commercial microphones as well as a couple of homemade devices. We determined and compared the microphones fidelity to a scale of frequencies ranging between 100 Hz and 20,000 Hz, and two bird sample vocalizations, with a range from 300 Hz to 10,000 Hz. This experiment was conducted at the Gamboa research station of the Smithsonian Institute in Panama in September of 2012. The professional microphones had the highest correlation values; nonetheless, the homemade microphones also had high values and a close-to-professional fidelity. The study allowed us to determine that, in order to choose an adequate microphone for a specific research objective, it is essential to know the acoustic features. Furthermore, we concluded that homemade microphones are a viable option, which offers acceptable fidelity and can reduce the production costs in more than 50 percent
Uploads
Papers by Héctor Perdomo