Effect of plant species, fruit density and habitat on post-dispersal fruit and seed removal by spiny pocket mice (Liomys pictus, Heteromyidae) in a tropical dry forest in Mexico

We tested whether quality, habitat, and food patch density affected post-dispersal fruit and seed removal of common plants in a tropical deciduous forest in western Mexico (Chamela, Jalisco). To identify the quality of seed or fruit, caged spiny pocket mice (Liomys pictus) were fed mono-specific diets of sunflower seeds (Helianthus annuus), seeds of Delonix regia, Lonchocarpus eriocarinalis, Caesalpinia coriaria, or fruits of Spondias purpurea. Caged mice gained weight with sunflower seeds, marginally lost weight with D. regia seeds, and significantly lost weight with S. purpurea fruits and L. eriocarinalis and C. coriaria seeds. Fruit and seed removal values in experimental patches were high in sunflower (80%) and D. regia (70%) seeds, and moderate in S. purpurea fruits (50%); L. eriocarinalis (0.1%) and C. coriaria (0%) seeds were not removed. More fruits and seeds were removed from experimental patches in tropical deciduous forest (57%) than from semi-deciduous forest (23%), and from high (43%) and medium density (46%) than from low density (31%) food patches. Similar fruit and seed removal values from experimental patches open either to all removal agents or open only to forest-dwelling rodents, suggest that spiny pocket mice were important removal agents of tested plants. Spiny pocket mice food choices can influence observed non-random patterns in seedling recruitment.