Scatter‐hoarding rodents select different caching habitats for seeds with different traits

Abstract

Citation: Wang, B., and R. T. Corlett. 2017. Scatter-hoarding rodents select different caching habitats for seeds with different traits. Ecosphere 8(4):e01774. 10.1002/ecs2.1774Abstract. Seed caching by scatter-hoarding rodents is an important dispersal mechanism for many plant species, and the microhabitat of the caching site influences the quality and effectiveness of this dispersal. Shrub vegetation is a major determinant of microhabitat heterogeneity in the forest understory and influences both rodent activity and foraging behavior, and seed germination and seedling establishment. However, very few studies have investigated how shrubs affect this important mutualistic plant-animal interaction and how this is influenced by seed traits. In this study, we monitored rodent choices of caching microhabitat for 3564 artificial seeds that varied in size, nutrient content, and tannin content. By analyzing 1333 primary caches and 209 secondary caches, we showed that rodents selected different caching microhabitats for seeds with different traits. Larger and more nutritious seeds were cached in shrubs more frequently than in the open, while tannin content had no effects on the probability of seeds being cached in shrubs. Furthermore, shrub cover significantly increased the distance which seeds were transported by rodents. If these caching differences apply to natural seeds and persist through seedling establishment and subsequent growth, they could play an important role in the spatial pattern of forest regeneration.

Land‐use change and the ecological consequences of personality in small mammals

“…Our results also suggest that less anxious mice (i.e., those who show moderate levels of grooming in the open‐field test, indicating the ability to cope with stress) disperse seeds at farther distances than do more anxious mice (grooming behaviours are discussed in Table ). Because previous research suggests relationships between the size/quality of seeds and dispersal distance (Xiao et al ; Cao et al ; Wang & Corlett ), we tested for this effect during our model selection process, but we found no evidence for this. Regardless, these results suggest that the populations of mice in shelterwood forest are less anxious and show better coping than those in reference forest and therefore are dispersing seeds at farther distances than those in reference forest (Table ).…”

“…The location of a cached seed depends on the risk of cache pilferage (Steele et al ) and seed characteristics (Wang & Corlett ). Small mammals can often increase germination probability by transporting seeds to optimal germination sites (Vander Wall ).…”

Deciphering seed dispersal decisions: Size, not tannin content, drives seed fate and survival in a tropical forest

“…). More valuable food items, from the perspective of a seed hoarder, are likely to be buried far away from their source location, escaping high threats from natural enemies concentrated near parent plants (Janzen , Connell , Wang and Corlett ). However, predation of a hoarded seed is only temporally deferred; the ultimate goal of a seed‐caching animal is to consume the hoarded item when alternate food items are scarce (Vander Wall ).…”

“…Large seeds that are easy to digest are highly valued by seed-hoarding animals and are thus preferentially cached over less valued food items (e.g., toxic, small seeds; Wang et al 2013, Shimada et al 2015. More valuable food items, from the perspective of a seed hoarder, are likely to be buried far away from their source location, escaping high threats from natural enemies concentrated near parent plants (Janzen 1970, Connell 1971, Wang and Corlett 2017. However, predation of a hoarded seed is only temporally deferred; the ultimate goal of a seed-caching animal is to consume the hoarded item when alternate food items are scarce (Vander Wall 1990).…”

“…Locally abundant scatter-hoarding rodents have the potential to dramatically affect forest community processes and interactions between seeds and other granivorous animals (Kuprewicz and Garc ıa-Robledo 2010, Vander Wall 2010, Kuprewicz 2015, Wang and Corlett 2017. In fact, tropical reforestation via natural vectors (e.g., terrestrial mammals) is more effective than active restoration in management strategies (Crouzeilles et al 2017).…”