RESUMO
Resumen El Cortarrama peruano Phytotoma raimondii es una especie amenazada de rango restringido y endémico a la costa norte del Perú. Como un herbívoro especializado, solo se encuentra en sitios con una diversidad adecuada de flora xerofítica. A pesar de reconocerse que la especie está bajo amenaza por la degradación y pérdida de su hábitat, se ha hecho poco o nada para medir estos cambios. Este estudio cataloga la diversidad florística y la degradación de sitios en los alrededores del pueblo de Lobitos, al norte de Talara, con el fin de cuantificar la pérdida del hábitat de esta especie. El trabajo de campo se realizó entre noviembre de 2019 y enero de 2020. Todas las plantas grandes (con un diámetro ≥ 5 cm cerca del suelo) y todos los tocones de Prosopis pallida (Algarrobo) deforestados se georreferenciaron en una parcela de 10 ha en el sitio principal de Cerro Blanco, c. 2 km al sur del pueblo de Lobitos. Para cada planta se anotó su altura, ancho y salud general. También se midió el diámetro de los tocones de P. pallida. Además, dos parcelas comparativas más pequeñas (0.3 ha y 0.75 ha) fueron monitoreadas c. 2.5 km al norte del pueblo de Lobitos. Los resultados indican una degradación alarmante y acelerada de este tipo de hábitat debido a la deforestación y la muerte masiva (dieback) de P. pallida; una especie clave en este hábitat e importante fuente de alimento para el Cortarrama. La pérdida de P. pallida parece afectar la estabilidad de los sitios, con otras especies importantes, por ejemplo, Lycium boerhaviifolium (Palo Negro) muriendo después de la tala. Sin una acción correctiva urgente, el hábitat del Cortarrama peruano continuará siendo cada vez más escaso y fragmentado.
Abstract The threatened Peruvian Plantcutter Phytotoma raimondii is a restricted-range species, endemic to the north coast of Peru. As a specialist herbivore, it is only found at sites with an adequate diversity of xerophytic flora. Although it is recognized that the species is under threat from habitat degradation and loss, little or no attempt has been made to measure these changes. This study catalogues the floral diversity and degradation of sites near Lobitos town, north of Talara, to determine the loss of this species´ habitat. Fieldwork was conducted between November 2019 and January 2020. All larger plants (with a diameter ≥ 5 cm near ground level) and all deforested Prosopis pallida (Algarrobo) stumps were georeferenced over a 10 ha plot at the main site of Cerro Blanco, c. 2 km south of Lobitos. The height, width and general health of each bush were noted, and the diameter of P. pallida stumps measured. Additionally, two smaller comparative plots, (0.3 and 0.75 ha) were surveyed c. 2.5 km to the north of Lobitos. Results point to an alarming and accelerated rate of degradation of this habitat type due to the deforestation and dieback of P. pallida: a key species in this habitat and important food source for the Plantcutter. Removal of P. pallida appears to affect the stability of sites, with other important species, e.g. Lycium boerhaviifolium (Palo Negro) dying off after logging. Without urgent remedial action, the Peruvian Plantcutter´s habitat will continue to become ever scarcer and more fragmented.
RESUMO
Crotalus durissus are found from Mexico to northern Argentina in a highly disjunct distribution. According to some studies, this species is prone to occupy areas disturbed by human activities and floods comprise a plausible method of dispersal as inferred for some North American rattlesnakes. Based on the literature, it seems plausible that Crotalus durissus expanded their natural distribution in Brazil due to floods, but only in a few municipalities in Rio de Janeiro State. Data entries of Butantan Institute, in São Paulo, Brazil, from 1998 to 2012 show a declining tendency of snakes brought by donors. In addition, research shows no evidence of Crotalus durissus being an expanding species in the Brazilian territory.(AU)
Assuntos
Animais , Crotalus , Conservação dos Recursos Naturais , Distribuição AnimalRESUMO
Crotalus durissus are found from Mexico to northern Argentina in a highly disjunct distribution. According to some studies, this species is prone to occupy areas disturbed by human activities and floods comprise a plausible method of dispersal as inferred for some North American rattlesnakes. Based on the literature, it seems plausible that Crotalus durissus expanded their natural distribution in Brazil due to floods, but only in a few municipalities in Rio de Janeiro State. Data entries of Butantan Institute, in São Paulo, Brazil, from 1998 to 2012 show a declining tendency of snakes brought by donors. In addition, research shows no evidence of Crotalus durissus being an expanding species in the Brazilian territory.