Seed dynamics of an endemic palm in a Northwestern Mexican tropical dry forest: implications for population spatial structure
Leonel Lopez-Toledo
1,2
, Yazmin Portillo-Cruz
3
, María T. Pulido
3
, Bryan A. Endress
2
1
Instituto de Investigaciones sobre los Recursos Naturales-Universidad Michoacana de
San Nicolás de Hidalgo. C.P. 58337, Morelia, Michoacán, México.
2
Division of Applied Plant Ecology, Institute for Conservation Research, San Diego Zoo
Global, 15600 San Pasqual Valley Road, Escondido, California 92027, U.S.A.
3 Centro de Investigaciones Biológicas, Universidad Autónoma del Estado de Hidalgo.
Carretera Pachuca, Hidalgo, México.
Supplementary material. Camera trap to identify seed removers/predators of Brahea aculeata .
Methods
We supplemented this study with a camera-trap monitoring. The main goal was to identify seed removers/predators of B. aculeata and their activity, which help us to understand our results. We used four camera traps for the 107 days period of the experiment. We randomly selected the site and topographic position to establish the cameras. We left the cameras for 15 days and then changed them to another Topographic position and site. We used digital trail cameras Hyperfire-Reconyx HC600, with infrared motion sensors to detect the movement of any warm-bodied animal passing in front of them. The motion detector has adjustable sensitivity and is able to detect even small rodents or birds at 8–10 m. Cameras were programmed to take pictures every 30 seconds, for the next 3 min after it was first triggered with a 5 min delayed period. Reviewing each picture we were able to identify what animal was predating the seeds (those biting and eating the seeds in situ ), removing (those carrying the seeds in their mouth-cheeks) or just passing in front of the camera without touching the seeds.
Results
Images from camera traps suggest that rodents may have conducted most of this removal,

as images caught numerous rodents removing grouped seeds within the span of several minutes. Eighty five percent of the images taken by the camera traps corresponded to three morphospecies of mice and one species of opossum ( Marmosa cannescens ), while the rest (15%) correspond to other vertebrates, which seemed only passing by and not removing/predating seeds. Cameras caught mice (75% of the pictures) and opossums
(10% of the pictures) biting and/or carrying seeds in their mouth or cheeks, which indicate these taxa are the main removers/predators for B. acuelata . With the images from cameras we were also able to show that for grouped seeds, predators prefer to disperse rather than predate the seeds in situ in a single event. Cameras also showed that the Brahea aculeata seed dispersers/predators are mainly nocturnal as all images of removers/predators were taken at night.
Pictures show mice predating in situ a single seed

Picture showing grouped seeds being removed and not eaten in situ

Second of three different morphospecies of mice
Third morphospecies of mice removing seeds of Brahea aculeata

Marmosa cannescens