We examined the food habits of coyotes (Canis latrans) from the Pico de Orizaba National Park by analyzing 136 scat samples that were collected for 11 months in a 7 km transect. Coyote diet consisted mainly of mammals (48.96%), plants (20.28%), birds (6.76%) and insects (0.68%). Our results indicate that annual coyote diet consisted of 15 prey-species. Their diet is based mainly on the rodent Peromyscus melanotis (25.68%), followed by the tomato plant Lycopersium esculentum (11.48%), and the jack rabbit Lepus callotis (9.46%). In the dry season, P. melanotis was the main prey item (29.16%), followed by L. callotis (8.33%). The most important items in the diet of coyotes in the rainy season were P. melanotis (22.36%) and L. esculentum (14.47%). There was no significant variation in prey consumption between seasons.

<p>The description was made of the karyotype of <em>Peromyscus gratus</em> (Cricetidae) in the municipality of Tecamachalco, Puebla. Performing the technique of bone marrow extraction, in the obtention of chromosome, G bands was used Trypsin and for C bands a Barium Hydroxide solution was employed. <em>P</em>. <em>gratus</em> presents a diploid number of 2n = 48 and a fundamental number of NF = 54, the autosomes correspond to one metacentric, one submetacentric, two subtelocentric and 19 pairs telocentric from large to small. The sex chromosome X was subtelocentric and the Y was submetacentric unlike other populations of the species. The chromosomal banding pattern G was obtained. As for chromosome C banding, it was found that the constitutive heterochromatin was in the centromeric regions of the chromosomes.</p>