Understanding patterns of seed predation in tallgrass prairie restorations is vital because seed additions are often used by managers to increase diversity and promote native species. However, the success of seed additions depends on the extent of seed predation. It is not clear how seed predation varies through time and to what extent it is affected by various commonly used management techniques in grasslands (e.g. spring or fall prescribed burns, mowing). We examined how predation of
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Sorghastrum nutans seeds changed during eight trials between June 2018 and April 2019 in plots that received one of four different plant litter removal treatments (fall mow, fall burn, spring burn, and unaltered control). Granivory varied throughout the year, reaching its peak in the late fall and early winter. However, we found that seed predators consumed significantly fewer seeds when litter was removed following fall burn and fall mow treatment applications. These treatments occurred during times when granivory was otherwise high in areas where litter remained intact (control and spring burn plots). Our findings highlight the importance of management decisions and how they interact with granivory in grassland restorations. Both time of year and litter cover determine seed predation rates; seed predators consume more seeds when seeds are abundant but rely on intact litter cover while foraging. This suggests that if seeds are added during the fall, litter should be removed to minimize the loss of seeds to granivory. Alternatively, seed additions during the spring are likely to experience lower rates of seed predation. -
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Abstract Small mammals are key scatter hoarders in forest ecosystems, acting as both seed predators and dispersers. The outcome of their interactions (i.e., predation vs. dispersal) is determined by a series of decisions made by small mammals, such as the choice of seed, whether the seed is immediately consumed or cached, and where it is cached. These decisions are influenced by a variety of factors, including the intrinsic traits of the seed, the individual personality of the scatter hoarder, and the perceived risk of predation while foraging. Furthermore, these factors may all interact to dictate the fate of the seed, with consequences for forest regeneration. Nevertheless, the ways in which perceived predation risk and personality interact to affect the seed dispersal decisions of scatter hoarders are still poorly understood. To contribute in filling this knowledge gap, we tested the hypotheses that southern red‐backed voles (
Myodes gapperi ), an important scatter hoarder in forest ecosystems, would exhibit personality‐mediated foraging and that predation risk would alter associations between personality and seed dispersal. We conducted a large‐scale field experiment, offering seed trays at stations with altered risk levels and recorded foraging decisions of free‐ranging voles with known personalities. We found that personality and perceived predation risk influenced decisions made by foraging voles. Specifically, docility, and boldness predicted foraging site selection, boldness predicted seed species selection and the number of seeds individuals selected, and the tendency to explore of an individual predicted whether voles would remove or consume seeds. Predation risk, mediated by the amount of cover at a site and by moon illumination, affected which foraging site individuals chose, seed species selection, and the probability of removal versus consumption. We did not find support for an interaction between personality and predation risk in predicting foraging decisions. These findings highlight the importance of scatter hoarder personality and perceived predation risk in affecting foraging decisions, with important consequences for seed dispersal and implications for altered patterns of forest regeneration in areas with different small mammal personality distributions or landscapes of fear. -
null (Ed.)Seed dispersal is important for forest growth, maintenance, and regeneration. Orangutans are large-bodied frugivores with ecological roles as seed predators and seed dispersers. However, little is known about orangutans’ ecological roles and how they relate to orangutans’ patterns of frugivory. We investigated Bornean orangutans’ (Pongo pygmaeus wurmbii) ecological roles at the Cabang Panti Research Station in Gunung Palung National Park, Indonesian Borneo. We collected orangutan feces (n=401) and analyzed them for intact seeds (August 2018 to March 2020). We observed orangutan fruit handling behavior for 306 feeding bouts for 53 fruit genera to measure how often orangutans swallow, spit, or predate seeds. We used Ivlev’s Electivity Index to analyze fruit preference using long-term feeding data and phenology data (2014-2019). Lastly, we combined fruit preference with fruit handling behavior using the seed dispersal effectiveness framework to identify which fruit taxa were most effectively dispersed. Orangutans dispersed seeds in 71.8% of fecal samples with a mean of 27.9 ±4.5 (SD=0.95) seeds (>2mm) per fecal sample. Orangutans predated seeds more often than spitting or swallowing seeds (predating= 42.1% of fruit feeding time; spitting= 21.8%; swallowing= 12.5%; mixed behaviors= 10.6%, not observed=12.0%). Additionally, the top five preferred fruit genera, (Dialium, Sindora, Scaphium, Magnifera, and Spatholobus) were highly predated (0 to 5% of seeds dispersed). We identified Alangium and Tetramerista as the most effectively dispersed genera, orangutans frequently dispersed and preferred these fruits. We found orangutans are frequent seed predators, but this overlaps with their seed dispersal role, and we describe orangutans’ seed dispersal contribution. Funders: NSF (9414388, BCS-1638823, BCS-0936199); National Geographic; USFish/Wildlife (F18AP00898, F15AP00812, F13AP00920, 96200-0-G249, 96200-9-G110); Leakey; Disney Conservation Fund; Wenner-Gren; Nacey-Maggioncalda; Conservation-Food-Health; Orangutan Conservancy; Woodland Park Zoo; Boston University GRAFmore » « less
