%0 Journal Article
%T Growth effort of Sceloporus scalaris (Sauria: Phrynosomatidae) at La Michil¨ªa Biosphere Reserve, Mexico
%A Alfredo Ortega-Rubio
%A Robert Barbault
%A Gonzalo Halffter
%A Aradit Castellanos
%J Revista de Biolog¨ªa Tropical
%D 1998
%I Universidad de Costa Rica
%X Using Mark-Recapture methods the growth effort of Sceloporus scalaris was studied at La Michil¨¬a Biosphere Reserve, Durango, Mexico. A total of 146 recaptures on 68 individuals were obtained over four years on a 50 000 m 2 transect. To calculate the growth rate of Sceloporus scalaris individuals, we analyzed the data from two sources. The first using the recapture records of the same individuals over different seasons and the second using the records of cohorts during different periods. The growth effort of S. scalaris drastically diminishes as the organism grows. The growth rate of males and females is about equal for individuals from both clutches. In adults, where it is possible to compare among seasons, we measure quicker growth during the spring. The growth pattern of S. scalaris at La Michil¨¬a follows the predictions proposed by the Bertalanffy model. Maximum growth rates are in the younger age classes and these rates decrease as size increases. The growing period of S. scalaris is correlated with the seasons at La Michil¨¬a Biosphere Reserve. Newborn S. scalaris appear when the availability of nourishment is still the most propitious for growth at faster rates. Such adaptations to the environment determine many key population attributes of this species in this zone. The sexual maturity age of S. scalaris is very early at La Michil¨¬a, only 4.5 to 6 months. Undoubtedly, the growth pattern of S. scalaris at La Michil¨¬a Biosphere Reserve can help explain the structure and dynamics of this population. Usando m¨¦todos de Marca-Recaptura estudiamos el esfuerzo de crecimiento de Sceloporus scalaris en la Reserva de la Biosfera de La Michil¨¬a, Durango, M¨¦xico. Se analizaron 146 registros de recaptura sobre 68 individuos en cuatro a os de estudio en un transecto de 50 000 m2. El esfuerzo de crecimiento disminuye drasticamente conforme el individuo crece, es casi igual para los machos y hembras de las dos puestas, y en el caso de los adultos se registr¨® un crecimiento m¨¢s r¨¢pido en primavera. El patr¨®n de crecimiento sigue las predicciones propuestas por el modelo de Bertalanffy. Los reci¨¦n nacidos de S. scalaris eclosionan cuando la disponibilidad de alimento es todav¨¬a la m¡¤s propicia. La madurez sexual de los individuos es muy precoz en La Michil¨ªa: de 4.5 a 6 meses. El patr¨®n de crecimiento de S. scalaris en La Michil¨ªa ayuda a explicar la estructura y din¨¢mica de esta poblaci¨®n.
%K Durango
%K Growth Effort
%K La Michil¨¬a Biosphere Reserve
%K Lizards
%K Mexico
%K Sceloporus scalaris
%U http://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77441998000100013