A morphological comparison of jaguars and pumas in southern Mexico

Abstract

Jaguars (Panthera onca) and pumas (Puma concolor) are sympatric throughout the entire range of the jaguar. Pumas are smaller in areas where they are sympatric with jaguars and their body size is larger outside the distribution range of jaguars. This pattern has been explained as an effect that natural selection has promoted through character displacement to partially avoid competition. We examined and compared the body and craniodental measurements of sympatric jaguars and pumas from a tropical rainforest in southern Mexico. Data on body sizes were obtained from jaguars and pumas captured with foot snares. We implemented a principal component analysis (PCA) to evaluate variability in sizes between species and sexes and to characterize groups of individuals according to these morphological variables. Finally, we compared morphological variables using analyses of variance (ANOVAs) and pairwise comparisons using the Bonferroni adjustment. Body size and mass of female jaguars were similar to male pumas in southern Mexico. But, canines and mouth breadth were larger in female jaguars than in male pumas. In general, male jaguars were larger than male pumas and female jaguars were larger than female pumas, throughout the distribution of the jaguar. However, female jaguars and male pumas may have similar body mass and size in much of their sympatric distribution. Our results suggest that character displacement between jaguars and pumas might be expressed not only by their body size, but also by their skull size, the length and robustness of canines, and the mouth breadth, and these morphological differences allow for resource partitioning and the coexistence of these two species that have very similar ecological requirements.Jaguares (Panthera onca) y pumas (Puma concolor) son simpátricos a lo largo de toda la distribución del jaguar. Los pumas son de menor tamaño en las áreas de simpatría con el jaguar y su tamaño incrementa en las áreas en donde los jaguares no están presentes. Este patrón se ha explicado como un resultado de la selección natural promovido a través del desplazamiento de caracteres para evitar la competencia, al menos parcialmente. En este estudio, examinamos y comparamos las medidas del cuerpo y cránio-dentales de jaguares y pumas de un bosque lluvioso tropical del sur de México. La información del tamaño corporal fue obtenida de jaguares y pumas capturados con trampas de lazo en el sureste de México. Se realizó un análisis de componentes principales para medir la variabilidad en el tamaño entre especies y sexos y para caracterizar grupos de individuos de acuerdo a estas variables morfológicas. Finalmente, se compararon las variables morfológicas usando un análisis de varianza y pruebas de comparación de pares utilizando el ajuste de Bonferroni. Nuestros resultados indican que el tamaño del cuerpo y el peso son similares entre las hembras de jaguar y los pumas machos. Sin embargo, el largo y robustez de los caninos y la amplitud de la boca son más grandes en las hembras de jaguar que en los pumas macho...

Unraveling Genome- and Immunome-wide Genetic Diversity in Jaguars (Panthera onca): Implications for Targeted Conservation

“…The jaguar ( Panthera onca ) stands out as one of the most remarkable and distinctive members of Panthera and is America’s largest feline predator 1 . Unusual for its genus, the jaguar is very muscular for its size and possesses the strongest bite of all extant felids 2 .…”