DOI: 10.5061/dryad.c866t1g5m
title: Seed dispersal by carnivores in temperate and tropical dry forests

description: The seed dispersal mechanisms and regeneration of various forest
 ecosystems can benefit from the actions of carnivores via endozoochory.
 This study aims to evaluate the role of carnivores in endozoochory and
 diploendozoochory, as well as their effect on seed viability,
 scarification, and germination in two forest ecosystems: temperate and
 tropical dry forest. We collected carnivore scat in the Protected Natural
 Area of Sierra Fría in Aguascalientes, Mexico, for two years to determine
 the abundance and richness of seeds dispersed by each carnivore species,
 through scat analysis. We assessed seed viability through optical
 densitometry using X-rays, analyzed seed scarification by measuring seed
 coat thickness using a scanning electron microscope, and evaluated seed
 germination in an experiment as the percentage of seeds germinated per
 carnivore disperser, plant species, and forest type. In the temperate
 forest, four plant species (but mainly Arctostaphylos pungens) were
 dispersed by four mammal species. The gray fox dispersed the highest
 average number of seeds per scat (66.8 seeds). Bobcat dispersed seeds
 through diploendozoochory, which was inferred from rabbit (Sylvilagus
 floridanus) hair detected in their scats. The tropical dry forest
 presented higher abundance of seeds and richness of dispersed plant
 species (four species) than in the temperate forest, and the coati
 dispersed the highest number of seeds (8639 seeds). Endozoochory and
 diploendozoochory did not affect viability in thick testas
 seeds in temperate forest and thin testas seeds in
 tropical dry forest. Endozoochory improved the selective germination of
 seeds. Nine plant species were dispersed by endozoochory, but only one
 species (Juniperus sp.) by diploendozoochory. These results suggest that
 carnivores can perform an important ecological function by dispersing a
 great abundance of seeds, scarifying these seeds causing the formation of
 holes and cracks in the testas without affecting viability and promoting
 the selective germination of seeds.
description: The database includes the
 location by UTM coordinates of each of the scats found during the study
 period. Each scat has a code that represents: R = Ringtaill, G = Gray fox,
 C = Coyote, BO = Bobcat, BA = Badger and CO = Coati. We conducted field
 visits in each site once a month throughout the years of 2018 and 2019.
 Within each site, we collected scats located by sight within transects of
 following walking routes through the study area to locate scats by sight.
 Each transect is delimited by a central line of 2 km in length, with two
 parallel lines located at a distance of 20 m on either side of the central
 line. We have established a total of 30 transects in each area on trails
 for the movement of fauna, on dirt roads and among vegetation, i.e., the
 scats were screened over a total area of 2 (temperate, tropical dry
 forest) x 30(replicate transects) x 2000 m (transect length) x 40m
 (transect width/buffer). We collected all the scats found within the
 transect for identification, except for those that were dry and old, with
 a gray coloration, to avoid bias in the data related to the collection of
 old scats and a preference of collection towards specific animals. Thus,
 each transect was sampled twice during the study period. Scats
 corresponding to each mammalian species were identified based on the
 <i>Manual for Tracking the Wild Mammals of
 Mexico.</i>