Papers by Irving Bautista
Journal of Experimental Biology, 2004
Flapping flight is the most energetically expensive activity employed by vertebrates averaging 8-... more Flapping flight is the most energetically expensive activity employed by vertebrates averaging 8-15 times basal metabolic rate (BMR; Lasiewiski, 1963;. The energy demands of flight have classically been established in two different ways. First, aerodynamic modelling has been used to evaluate the mechanical power required to maintain an animal in the air. Several different aerodynamic models have been developed that have some common features, and generally all predict that flight mechanical power requirements should follow a U-shaped curve, with the highest demands at both low and high speeds around some 'optimum' where costs are minimised . A second approach has been to measure the metabolic energy costs of flight directly, using several alternative methods. These include flying animals in wind tunnels and measuring stable isotope turnover in free-flying birds using the doubly labelled water method (e.g. . Metabolic power input measured in this manner does not match the mechanical power output Although most birds are accustomed to making short flights, particularly during foraging, the flight patterns during these short periods of activity differ between species. Nectarivorous birds, in particular, often spend time hovering, while non-nectarivorous birds do not. The cost of short flights is likely therefore to differ between nectarivorous and non-nectarivorous birds because of the different energetic contributions of different flight types to the behaviour. The 13 C-labelled bicarbonate technique was used to measure the energy cost of short flights in the nectarivorous Palestine sunbird Nectarinia osea (mean mass 6.17±0.16·g, N=8) and the non-nectarivorous starling Sturnus vulgaris (mean mass 70.11±1.11·g, N=9). The technique was initially calibrated in five individuals for each species at temperatures ranging from 1 to 35°C, by comparing the isotope elimination rate to the metabolic rate measured simultaneously by indirect calorimetry. The cost for short intermittent flight was then measured by encouraging birds to fly between two perches at either end of a narrow corridor (perch distance for sunbirds, 6·m; for starlings, 5·m), and measuring the amount of isotope eliminated during the flight. The isotope elimination rate was interpolated onto the calibration equation to predict flight cost, as a direct calibration could not be performed during flight. Mean energy expenditure during flight was 1.64±0.32·W in sunbirds, while in starlings the flight costs averaged 20.6±0.78·W. Energy cost of flight relative to basal metabolic rate was substantially greater in the starling than the sunbird. Phylogenetic analysis of different modes of flight in these and additional species suggests that differences in flight behaviour may cause these elevated costs in slow flying non-nectarivores such as starlings, compared to birds that are more prone to short intermittent flights like the sunbirds.
El manejo de organismos en cautiverio es un proceso de vital importancia empleado en diversas act... more El manejo de organismos en cautiverio es un proceso de vital importancia empleado en diversas actividades como la disposición de muestras para trabajos de índole científica, así también es importante el reconocimiento de ejemplares para formación educativa o investigación además de permitir al público en general la observación de estos, y así promover acciones de educación ambiental en diversos sectores de la sociedad para desarrollar un mayor conocimiento de ellos en personas que no se desenvuelven en el ámbito herpetológico. Para que esta actividad tenga éxito se deben establecer una serie de acciones que fundamenten una metodología adecuada para llevarla a cabo, entre ellas destacan: la manutención de los ejemplares, las cuestiones y principios de bioseguridad, asimismo, la creación de un microhábitat el cual debe ser semejante al natural, donde ellos puedan realizar la mayoría de sus funciones biológicas y lograr así el bienestar de la especie a mantener en cautiverio, sin caer en los errores de excederse y sobresaturar el paisaje, logrando esto mediante el enriquecimiento el cual debe realizarse frecuentemente o cada vez que el micropaisaje lo requiera.
Se hace una recopilación de los cambios taxonómicos y nomenclaturales que afectan la taxonomía de... more Se hace una recopilación de los cambios taxonómicos y nomenclaturales que afectan la taxonomía de las especies mexicanas de anfibios y reptiles. Asimismo se da una lista de las especies nuevas para la ciencia descritas en los últimos once años y las especies que se citan por primera vez para México. Se registran estos cambios y adiciones hasta diciembre de 2003. Con esta información, se eleva el número de especies de anfibios y reptiles de México de 997 a 1165 desde la publicación de la última lista de especies de herpetozoos para el país.
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Papers by Irving Bautista