Scatter‐hoarding and cache pilfering of rodents in response to seed abundance

Seed caching and reciprocal cache pilferage play an important role in the coexistence of food‐hoarding animals. Understanding what affects seed caching and how cache pilferage occurs is an important question in seed dispersal ecology. However, tracking seed fate and cache pilferage presents substantial practical difficulties. Siberian chipmunks Tamias sibiricus always remove the entire pericarp when scatter‐hoarding acorns of Mongolian oak Quercus mongolica, whereas wood mice Apodemus peninsulae often store whole acorns in their caches. These differences in behavior provide an opportunity to investigate unilateral cache pilferage of T. sibiricus from A. peninsulae in response to seed abundance. In this study, tagged acorns were released at the peak and end periods of seed rain from Q. mongolica. This allowed us to investigate seed caching and unilateral cache pilferage at different seed abundances. We found that a higher proportion of acorns were cached at lower level of seed abundance (toward the end of seed rain), mainly because T. sibiricus rather than A. peninsulae scatter‐hoarded significantly more acorns at this time. Cache distances decreased with increasing seed abundance, indicating that acorns were cached further away and into smaller caches at lower seed abundance. Unexpectedly, unilateral cache pilferage by T. sibiricus was not significantly influenced by seed abundance—remaining at around 28% during both periods of high and low seed abundance.     

Effects of food value, predation risk, and pilferage on the caching decisions of Dipodomys merriami

Animals that scatter cache their food face a trade-off betweenthe benefits of protecting caches from pilferers and the costsassociated with caching. Placing food into a large number ofwidely spaced caches helps to protect it from pilferage butalso involves costs such as greater exposure to predators. Ipredicted that animals would disperse food into a larger numberof more widely spaced caches when caching (1) a preferred foodversus a less preferred food and (2) under conditions of lowpredation risk versus high predation risk. To test these predictions,I examined the scatter-caching decisions of Merriam's kangaroorats (Dipodomys merriami). D. merriami distributed caches inclumped patterns, regardless of food preference, but they showeda tendency to invest more in a preferred food by distributingcaches more widely. Under the relative safety of the new moon,they did not disperse caches more widely, rather they partitionedthe same amount of food into a larger number of caches thanthey did under the full moon, when predation risk is higher.To examine whether their cache spacing decisions had a significantimpact on the success of cache pilferers, I measured discoveryby pilferers of artificial caches of two food types at differentcaching distances. Results indicate that the cache spacing behaviorof D. merriami functions to protect caches from pilferers, becauseincreased spacing of artificial caches decreased the probabilityof pilferage for both types of food.     

Substrate type affects caching and pilferage of pine seeds by chipmunks

The abiotic environment often influences the ways in which animalsinteract. By affecting the cues associated with buried seeds,the type of substrate used by seed-caching rodents may alterthe relative probabilities of cache pilferage and cache retrieval.We predicted that, after a wildfire, the presence of ash wouldimpair rodents' ability to smell pine seeds on the forest floor.In a laboratory experiment, we compared the foraging success,caching frequency, and cache recovery of chipmunks (six Tamiasamoenus and six T. quadrimaculatus) in ash versus sand substrates.Initial results supported our hypothesis: chipmunks found only2.3% of 108 caches of Jeffrey pine (Pinus jeffreyi) seeds thatwe buried in ash but found 98% of caches in sand. However, chipmunksmade as many or more of their own caches in ash compared withsand (48% for T. amoenus, 73% for T. quadrimaculatus.) Whenforaging for seeds cached in ash by themselves and by otherindividuals, they found significantly higher proportions oftheir own caches (62%) than of caches made by others (25%).However, when foraging in sand, they found high proportionsboth of their own caches and those of others (86 versus 81%).These results suggest that olfaction is less effective in ashthan in sand, that spatial memory enables chipmunks to recovertheir own caches in ash, and that caching in ash may allow animalsto avoid pilferage of stored food. As chipmunks are importantdispersers of seeds, changes in their foraging patterns or competitiveinteractions after fire could significantly affect pine regeneration.     

Hyper-dispersed cache distributions reduce pilferage: a laboratory study

Many animals use hoarding as a long-term strategy to ensure a food supply at times of shortage. We suggest that long-term scatter hoarders, whose caches are vulnerable to potentially high pilferage, should hoard in ways to reduce cache loss. This could be achieved by manipulating the density and dispersal patterns of caches to reduce the foraging efficiency of pilferers. This study explores the effect of distribution patterns on cache loss in the laboratory. We recorded the discovery of food items in different dispersal patterns by two bird species: coal tits Periparus ater (a hoarder) and great tits Parus major (a non-hoarder). Hyper-dispersed distributions reduced foraging efficiency because both species used systematic local search patterns. This study shows that hyper-dispersed distributions would be advantageous to hoarding animals to reduce cache loss.     

Conspecific pilferage but not presence affects Merriam's kangaroo rat cache strategy

We investigated the effects of pilferage on caching behaviorin the Merriam's kangaroo rat by manipulating two factors associatedwith pilferage: the presence of a conspecific, and the opportunityfor pilferage. In one experiment we assessed animals in either"Stealer" or "Victim" roles and measured changes in caching,space use, and behavior after caches were pilfered. Victimsshifted from a majority scatter-hoarding to a majority larder-hoardingstrategy after their caches were pilfered by the Stealer. InExperiment 2, we measured changes after exposure to a conspecificwhen there was no pilferage, with or without prior exposureto pilferage from Experiment 1. Merriam's kangaroo rats werevigilant when a conspecific was present, but did not changecache strategy. Prior exposure did not have any major effecton caching or behavior. Food storage is an economic decisionthat is often made by a solitary forager. Our results suggestthat social competition nonetheless influences such economic decisions, even in a nonsocial forager.     

贮食动物的盗食与反盗食行为策略

食物贮藏是许多动物应对食物短缺、保障其生存和繁衍的一种适应性行为。保护好贮藏食物以供食物短缺期利用,是食物贮藏成功的标志和进化动力。同种或异种动物盗食是贮藏食物损失的重要原因。嗅觉、视觉与空间记忆、随机搜寻等是动物搜寻和盗取食物的重要手段;避免盗食、阻止盗食和容忍盗食是动物反盗食的重要策略。动物通常采用多种行为策略进行盗食和反盗食,分配食物资源,形成相对稳定的种内、种间关系。盗食与反盗食互作及其对贮食行为进化的意义已成为行为生态学的研究热点和前沿之一,针对鸟类和哺乳类动物的研究尤为丰富。本文总结了贮食动物常见的盗食和反盗食行为策略及其相互作用的研究进展,主要内容涉及贮食动物利用嗅觉、视觉与空间记忆、随机搜寻等盗取其他个体食物的盗食策略,以及通过隐藏、转移、保卫、容忍等方式减少被盗食,保护贮藏食物的行为策略。针对现有研究状况,从种间盗食与反盗食及其与物种共存的关系,种间非对称盗食关系及其适应意义,盗食与反盗食最适行为策略及其与贮食动物适合度的关系等方面对今后研究提出了建议。     

Recaching Decisions of Florida Scrub‐Jays are Sensitive to Ecological Conditions

Food caching animals depend on their caches at times of low food availability. Because stored food is susceptible to being stolen or degraded, many species employ cache protection strategies such as ceasing caching in the presence of others or avoiding storing perishable items for long periods. Several species frequently recover their caches and recache, which may reduce pilferage or degradation of cached items. We studied the food handling decisions of Florida scrub‐jays (Aphelocoma coerulescens) after cache recovery to determine the roles that social and ecological environments play in post‐recovery decisions. Instead of reducing recaching in the presence of others, recovering jays flew away from the recovery site, allowing them to eat or recache a recovered item regardless of the social context. Microhabitat type and soil moisture of the recovery sites had a significant influence on whether recoveries were eaten or recached; most items that were recached had been recovered from bare sand sites or sites with low soil moisture. Taken together, our results suggest that food store management of Florida scrub‐jays are unaffected by the social context, but are strongly affected by the habitat conditions that influence the quality of caches.     

Memory for food caches: not just for retrieval

Many animals use hoarding as a long-term strategy to ensurea food supply at times of shortage. Hoarders employ strategiesthat enhance their ability to relocate caches such as rememberingwhere caches are located. Long-term scatterhoarders, whose cacheshave potentially high pilferage rates, should also hoard ina way to reduce potential cache pilferers' ability to find caches.Previous studies have demonstrated that this could be achievedby hyperdispersing caches to reduce the foraging efficiencyof pilferers. This study investigates whether coal tits (Parusater) indeed place their caches away from existing ones. Inour experiment, birds hoarded food in 3 conditions: when cachesfrom a previous storage session were still present, when cachesfrom a previous storage session were not present anymore becausethe bird had retrieved them, and when caches from a previousstorage session had been removed by the experimenter. We showthat coal tits hoard away from existing caches and that theydo not use cues from extant caches to do this. This evidenceis consistent with the use of memory for the locations of previouscaches when deciding where to place new caches. This findinghas important implications for our understanding of the selectivepressures that have shaped spatial memory in food-hoarding birds.     

Seed caching and cache pilferage by three rodent species in a temperate forest in the Xiaoxinganling Mountains

Although differences in food-hoarding tactics both reflect a behavioral response to cache pilferage among rodent species and may help explain their coexistence, differentiation in cache pilfering abilities among sympatric rodents with different hoarding strategies is seldom addressed. We carried out semi-natural enclosure experiments to investigate seed hoarding tactics among three sympatric rodent species (Tamias sibiricus, Apodemus peninsulae and Clethrionomys rufocanus) and the relationship of their pilfering abilities at the inter- and intraspecific levels. Our results showed that T. sibiricus exhibited a relatively stronger pilfering ability than A. peninsulae and C. rufocanus, as indicated by its higher recovery rate of artificial caches. Meanwhile A. peninsulae showed a medium pilfering ability and C. rufocanus displayed the lowest ability. We also noted that both cache size and cache depth significantly affected cache recovery in all three species. T. sibiricus scatter-hoarded more seeds than it larder-hoarded, A. peninsulae larder-hoarded more than scatter-hoarded, and C. rufocanus acted as a pure larder-hoarder. In T. sibiricus, individuals with lower pilfering abilities tended to scatter hoard seeds, indicating an intraspecific variation in hoarding propensity. Collectively, these results indicated that sympatric rodent species seem to deploy different food hoarding tactics that allow their coexistence in the temperate forests, suggesting a strong connection between hoarding strategy and pilfering ability.     

基于贮食行为的鸟类社会认知研究进展

贮食是动物应对环境变化和不可预测性而进化出的有效生存对策,认知则是当前鸟类学研究的热点问题之一。目前鸟类贮食行为中的认知研究多集中在空间认知,而社会认知研究相对滞后。对于贮食物种而言,储藏食物被盗现象非常普遍,为了避免被盗食,贮食者不仅要有发达的空间认知能力去记忆贮食地点,同时还需要极强的社会认知能力处理与盗食者的关系,可见社会认知在鸟类的贮食行为中扮演着重要角色。本文将从鸟类贮食的社会关系认知以及社会地位认知两个方面,对鸟类贮食行为中的社会认知研究进行综述,以期为后续鸟类社会认知研究提供借鉴和参考。     

The effects of cache loss on choice of cache sites in black-capped chickadees

Food-storing birds lose a great deal of their stored food toother animals. We examined whether blackcapped chickadees (Parusairicapillus) modify their choice of cache sites using informationthat predicts cache loss. In experiment 1, birds learned toavoid caching at spatial locations where cache loss had previouslyoccurred, but they did not avoid caching near local color cuesthat predicted cache loss. Birds did not modify their generaluse of space in the aviary. Birds also learned to reduce searchingfor caches where spatial location predicted cache loss. Experiment2 confirmed the birds’ ability to discriminate among thespatial locations and the local color cues used in experiment1. In experiment 3, learning a food-rewarded approach to potentialcache sites occurred without any change in the choice of sitesfor caching. We discuss how chickadees selectively associatethe choice of cache site with its consequences, even over delaysof several hours between caching and cache recovery.     

Cachers, scavengers, and thieves: a novel mechanism for desert rodent coexistence

A biologically explicit simulation model of resource competition between two species of seed-eating heteromyid rodent indicates that stable coexistence is possible on a homogeneous resource if harvested food is stored and consumers steal each other's caches. Here we explore the coexistence mechanisms involved by analyzing how consumer phenotypes and presence of a noncaching consumer affect the competitive outcome. Without cache exchange, the winning consumer is better at harvesting seeds and produces more offspring per gram of stored food. With cache exchange, coexistence is promoted by interspecific trade-offs between harvest ability, metabolic efficiency, and ability to pilfer defended caches of heterospecifics or scavenge undefended caches of dead conspecifics or heterospecifics. Cache exchange via pilferage can equalize competitor fitnesses but has little stabilizing effect and leads to stable coexistence only in the presence of a noncaching consumer. In contrast, scavenging is both equalizing and stabilizing and promotes coexistence without a third consumer. Because body size affects a heteromyid rodent's metabolic rate, seed harvest rate, caching strategy, and ability to steal caches, interspecific differences in body size should produce the trade-offs necessary for coexistence. The observation that coexisting heteromyids differ in body size therefore indicates that cache exchange may promote diversity in heteromyid communities.     

Evidence of Social Influences on Cache‐Making by Grey Squirrels (Sciurus carolinensis)

Many studies have found that scatter‐hoarding animals change their behaviour when storing food in the presence of conspecifics to minimize the likelihood that their caches will be pilfered; they refrain from caching, move away from conspecifics or choose visually obscured sites. This study reports the first evidence that the presence of conspecifics continues to influence the caching behaviour of a scatter‐hoarding mammal, the grey squirrel, after a suitable cache site has been selected and the hoarder is filling and covering its cache. Wild grey squirrels were filmed when storing preferred and less preferred nuts and when they were alone or with conspecifics present. In line with previous findings, squirrels spent longer travelling from the nut patch and were more vigilant when conspecifics were present. However, squirrels also spent longer disguising their caches and were more likely to stop digging and become vigilant when conspecifics were present than when they were alone. In particular, they were most likely to curtail their digging when storing their preferred nuts in the presence of conspecifics. The results indicate that caching squirrels remain sensitive to the presence of conspecifics until the cache is complete and that they respond flexibly to conspecifics according to the type of food they are storing.     

Management of fat reserves and food caches in tufted titmice (Parus bicolor) in relation to unpredictable food supply

In the temperate zone, permanent-resident birds and mammalsthat do not hibernate must survive harsh winter conditions oflow ambient temperature, long nights, and reduced food levels.To understand the energy management strategy of food-hoardingbirds, it has been hypothesized that such birds respond to increasedstarvation risk by increasing the number of their hoards ratherthan by increasing their fat reserves and that they cache earlyin the day and retrieve their caches later to achieve fat reservesnecessary to survive the night We tested these hypotheses byobserving the responses in captivity of a caching bird, thetufted titmouse (Parus bicolor), to the combined influencesof reduced predictability of food and naturally occurring ambienttemperature and photoperiod. When the food supply was unpredictable,birds significantly increased both internal fat reserves atdusk and external food caches. Initially leaner birds tendedto increase their fat reserves to a greater extent and initiallyfatter birds tended to cache more food and to fly significantlyless. Half the birds also increased their dawn and mean dailybody mass. All birds tended to forage, gain body mass, and cachefood at significantly lower rates in the morning and at significantlyhigher rates in the evening. Cache retrieval showed the oppositetrend, with birds retrieving most of their caches in the morning.Our results do not support the hypothesis that caching birdsincrease caching rate but not body mass under an unpredictablefood regime. Instead fat reserves and food caches are both importantcomplementary sources of energy in food-hoarding birds. Energymanagement by wintering birds occurs in response to a numberof biotic and abiotic factors acting simultaneously; thus futuremodels must incorporate independent variables in addition tothe state of the food supply and time of day     

A reevaluation of the logic of pilferage effects, predation risk, and environmental variability on avian energy regulation: the critical role of time budgets

We studied the effect of pilferage rates, variation in foodencounter rate, and predation risk on cache and fat-storageregulation using dynamic programming. Previous predictionsthat small birds facing increased pilferage rates should cacheless and store more body fat are not generally supported. Instead,cache investment (caching rate or percent of food cached) is predicted to be unimodal, peaking at intermediate pilferagerates. This pattern is determined, in part, by pilferage-inducedchanges in time budgets: at low pilferage rates, a marginalincrease in pilferage rates can be offset by an increase incache investment. However, increased caching increases time allocated to both caching and foraging. The increased foragingis caused by the energetic costs of caching and by the lossof energy from the cache. Increased time spent caching andforaging in turn decreases time spent resting under low predationrisk. Above some threshold pilferage rate, the marginal valueof resting exceeds the marginal value of caching, and cacheinvestment declines with further increasing pilferage rates.These patterns hold for three levels of variation in food encounterrate: time-invariant, between-day, and within-day variation;they also hold across different mean rates of food encounter.We show that previous predictions concerning decreased energy-storagelevels with increased food abundance are not supported when there is between-day variation in mean food encounter ratesand food abundance increases only on "good" days. Finally,predation risk affects the predictions described above in twoways. First, these trends assume that the birds can rest ina predator-free refuge. If the refuge is not available, birdsare predicted to cache less at higher pilferage rates irrespectiveof the absolute level of pilferage. With the refuge in place,levels of predation risk affect the skew in the pilferage-rate/cachingfunction. As a result, the relative effect of predation riskon caching intensity varies with pilfer rate. At very low pilferrates, lowered predation risk causes more caching, but loweredpredation risk under high pilferage rates can lower caching intensity, contrary to previous predictions. Surprisingly, predationrisk has an appreciable effect on body mass only when the birdis predicted to cease caching (i.e., at the highest pilferrates); otherwise a change of two orders of magnitude in theprobability of encountering predators has little effect on body mass. Our results suggest that the tradeoffs associatedwith the joint regulation of internal energy stores and externallycached stores are more complicated than previous literaturewould indicate. Our results also show that we have underestimatedthe role that time budgets play in patterns of energy regulation.     

A dynamic model of short-term energy management in small food-caching and non-caching birds

The survival of small birds in winter is critically dependenton the birds' ability to accumulate and maintain safe levelsof energy reserves. In some species, food caching facilitatesenergy regulation by providing an energy source complementaryto body fat. We present a dynamic optimization model of short-term,diurnal energy management for both food-caching and non-caching birds in which only short-day, winter conditions are considered.We assumed that birds can either rest, forage and eat, forageand cache, or retrieve existing caches (the two latter optionsare available only to caching birds). The model predicted thatwhen there is variability in foraging success (here modeledstrictly as within-day variability), both caching and non-caching birds should increase their fat reserves almost linearly inthe morning slowing down toward late afternoon, a result consistentwith field data but different than the result of a previousdynamic program. Non-cachers were predicted to carry higherfat levels than cachers especially when the variability inforaging success is high. Probability of death for non-caching birds was predicted to be higher than that for cachers, especiallyat higher levels of variability in foraging success. Amongcaching birds, an increase in number of caches and fat reserveswas also predicted if: (1) mean foraging success was decreased,(2) variability in foraging success was increased, and (3)energy expenditure at night was increased over our baselineconditions. Under the conditions simulated in our model, birdswere predicted to cache only if cache half-life (i.e., timeinterval over which 50% of the caches are forgotten or lostto pilferage) exceeded 2.5 days, indicating that low pilferagerate and long memory favor more caching. Finally, we showedthat such daily patterns of energy management do not necessarilyrequire relaxing assumptions about mass-dependent predationrisk.     

Seasonal variation in the effect of cache pilferage on cache and body mass regulation in Carolina chickadees: what are the trade-offs?

Current dynamic optimization models predict that animals shouldrespond to cache pilferage by decreasing the probability ofcaching food and by increasing internal fat storage to compensatefor a reduction in cache size. We tested these predictions underlaboratory conditions with variable food access (four 15-minintervals/day). Carolina chickadees (Poecile carolinensis) weresubjected to two environments: under pilferage conditions, one-quarterof their cached seeds were stolen every 0.5 h, and under no-pilferageconditions, seeds were left in place. Half the birds startedwith pilferage conditions and were then switched to the no-pilferagecondition; the other half started with no pilferage and werethen switched to pilferage conditions. The experiment was conductedover the course of a year to test for seasonal variation inthe response to seed pilferage. The birds responded to seedpilferage by taking more seeds from a feeder, suggesting thatthey monitored cache availability. Alternatively, the birdsmay have taken additional seeds from the feeder in responseto increased hunger caused by a loss of cached food. Contraryto our prediction, birds cached a higher percentage of seedsfrom the feeder when cached seeds were pilfered than when cacheswere left in place. Treatment order also affected caching behaviorfor all but the summer birds: chickadees initially subjectedto pilferage stored a higher proportion of seeds than thoseinitially subjected to no pilferage. Caching percentages inthe summer were unaffected by cache pilferage. Caching rates(number cached/day) also followed the same trends: rates werehigher when seeds were pilfered than when seeds were not pilfered,and there was a treatment-order effect for all but the summerbirds. Variation in body mass also failed to match predictedtrends. All birds exhibited a monotonic increase in mass asthe experiments proceeded, irrespective of treatment order.Controlling for this monotonic increase in mass, an analysisof residual variation in body mass indicated that birds gainedless weight when seeds were pilfered than when seeds were leftin place. Finally, birds tested in the fall and spring wereheavier than those tested in the summer. These results failto support the relationship between cache maintenance and bodymass regulation predicted by current models of energy regulation.We discuss the applicability of three hypotheses for the observedtrends.     

Integrating ecology,psychology and neurobiology within a food-hoarding paradigm

Many animals regularly hoard food for future use, which appears to be an important adaptation to a seasonally and/or unpredictably changing environment. This food-hoarding paradigm is an excellent example of a natural system that has broadly influenced both theoretical and empirical work in the field of biology. The food-hoarding paradigm has played a major role in the conceptual framework of numerous fields from ecology (e.g. plant–animal interactions) and evolution (e.g. the coevolution of caching, spatial memory and the hippocampus) to psychology (e.g. memory and cognition) and neurobiology (e.g. neurogenesis and the neurobiology of learning and memory). Many food-hoarding animals retrieve caches by using spatial memory. This memory-based behavioural system has the inherent advantage of being tractable for study in both the field and laboratory and has been shaped by natural selection, which produces variation with strong fitness consequences in a variety of taxa. Thus, food hoarding is an excellent model for a highly integrative approach to understanding numerous questions across a variety of disciplines. Recently, there has been a surge of interest in the complexity of animal cognition such as future planning and episodic-like-memory as well as in the relationship between memory, the environment and the brain. In addition, new breakthroughs in neurobiology have enhanced our ability to address the mechanisms underlying these behaviours. Consequently, the field is necessarily becoming more integrative by assessing behavioural questions in the context of natural ecological systems and by addressing mechanisms through neurobiology and psychology, but, importantly, within an evolutionary and ecological framework. In this issue, we aim to bring together a series of papers providing a modern synthesis of ecology, psychology, physiology and neurobiology and identifying new directions and developments in the use of food-hoarding animals as a model system.     

Bolus recovery by gray jays: an experimental analysis

Gray jays (Perisoreus canadensis) typically store food boli in various sites on conifers. In a laboratory setting we determined whether gray jays recover stored boli by means of olfaction, trial-and-error search or spatial memory. Using an artificial tree with 52 possible caching sites, caching and/or recovery trials were performed with five captive gray jays for the following experiments: (1) no extra visual cues on tree; (2) extra visual cues (pine foliage) attached to tree; (3) pungent-smelling food hidden by observer; (4) one bird allowed to cache food but caches recovered by a second bird; (5) one bird allowed to observe another bird cache food and later permitted to recover those caches. Results supported the memory hypothesis, but cache site preferences were apparent for individual birds. To control for this, an additional experiment (6), in which cache site access was limited by the investigators, was conducted with two new birds. These results also indicated that gray jays use spatial memory to recover stored boli.     

Dispersal by rodent caching increases seed survival in multiple ways in canopy‐fire ecosystems

Seed‐caching rodents have long been seen as important actors in dispersal ecology. Here, we focus on the interactions with plants in a fire‐disturbance community, specifically Arctostaphylos species (Ericaceae) in California chaparral. Although mutualistic relationships between caching rodents and plants are well studied, little is known how this type of relationship functions in a disturbance‐driven system, and more specifically to systems shaped by fire disturbance. By burying seeds in the soil, rodents inadvertently improve the probability of seed surviving high temperatures produced by fire. We test two aspects of vertical dispersal, depth of seed and multiple seeds in caches as two important dimensions of rodent‐caching behavior. We used a laboratory experimental approach to test seed survival under different heating conditions and seed bank structures. Creating a synthetic soil seed bank and synthetic fire/heating in the laboratory allowed us to have control over surface heating, depth of seed in the soil, and seed cache size. We compared the viability of Arctostaphylos viscida seeds from different treatment groups determined by these factors and found that, as expected, seeds slightly deeper in the soil had substantial increased chances of survival during a heating event. A key result was that some seeds within a cache in shallow soil could survive fire even at a depth with a killing heat pulse compared to isolated seeds; temperature measurements indicated lower temperatures immediately below caches compared to the same depth in adjacent soil. These results suggest seed caching by rodents increases seed survival during fire events in two ways, that caches disrupt heat flow or that caches are buried below the heat pulse kill zone. The context of natural disturbance drives the significance of this mutualism and further expands theory regarding mutualisms into the domain of disturbance‐driven systems.