Large herbivore migration plasticity along environmental gradients in Europe: life‐history traits modulate forage effects

The most common framework under which ungulate migration is studied predicts that it is driven by spatio–temporal variation in plant phenology, yet other hypotheses may explain differences within and between species. To disentangle more complex patterns than those based on single species/ single populations, we quantified migration variability using two sympatric ungulate species differing in their foraging strategy, mating system and physiological constraints due to body size. We related observed variation to a set of hypotheses. We used GPS‐collar data from 537 individuals in 10 roe Capreolus capreolus and 12 red deer Cervus elaphus populations spanning environmental gradients across Europe to assess variation in migration propensity, distance and timing. Using time‐to‐event models, we explored how the probability of migration varied in relation to sex, landscape (e.g. topography, forest cover) and temporally‐varying environmental factors (e.g. plant green‐up, snow cover). Migration propensity varied across study areas. Red deer were, on average, three times more migratory than roe deer (56% versus 18%). This relationship was mainly driven by red deer males which were twice as migratory as females (82% versus 38%). The probability of roe deer migration was similar between sexes. Roe deer (both sexes) migrated earliest in spring. While territorial male roe deer migrated last in autumn, male and female red deer migrated around the same time in autumn, likely due to their polygynous mating system. Plant productivity determined the onset of spring migration in both species, but if plant productivity on winter ranges was sufficiently high, roe deer were less likely to leave. In autumn, migration coincided with reduced plant productivity for both species. This relationship was stronger for red deer. Our results confirm that ungulate migration is influenced by plant phenology, but in a novel way, that these effects appear to be modulated by species‐specific traits, especially mating strategies.     

Low-Cost Global Positioning System Harness for Pampas Deer

ABSTRACT Global Positioning System (GPS) collars have proven to be an efficient tool for studying wildlife. However, this technique generally requires great investment in material, which notwithstanding its possible cost-effectiveness, is still beyond the means of most of the scientific community in developing countries. We developed and applied a low-cost GPS harness system placed on pampas deer (Ozotoceros bezoarticus) in the Central Pantanal of Brazil and compared costs of our technique to other commonly manufactured GPS collar systems. Of the 19 GPS harness attached to deer, 8 failed to obtain data series. For the remaining 11 animals, we stored 31,596 locations at 5-minute and 10-minute fix interval schedules (<120 days of continuous monitoring). Monitoring period of each animal lasted from 4.5 days to 17.4 days. Location error tested with a stationary GPS receiver was >3.7 m for 95% of locations. Rate of fixes acquired on the programmed schedule after correcting for errors was 98.5%. Compared to the 4 most used GPS radiocollar manufacturers, cost per fix of the GPS harness we developed was >50% of the cost per fix of the cheapest available product, although our modified device was heavier than all available products for medium-sized deer. Our approach was cost-effective to generate reliable information about activity patterns of pampas deer and may represent an alternative technique, especially for researchers in underdeveloped countries.     

Landscape Utilisation,Animal Behaviour and Hendra Virus Risk

Hendra virus causes sporadic fatal disease in horses and humans in eastern Australia. Pteropid bats (flying-foxes) are the natural host of the virus. The mode of flying-fox to horse transmission remains unclear, but oro-nasal contact with flying-fox urine, faeces or saliva is the most plausible. We used GPS data logger technology to explore the landscape utilisation of black flying-foxes and horses to gain new insight into equine exposure risk. Flying-fox foraging was repetitious, with individuals returning night after night to the same location. There was a preference for fragmented arboreal landscape and non-native plant species, resulting in increased flying-fox activity around rural infrastructure. Our preliminary equine data logger study identified significant variation between diurnal and nocturnal grazing behaviour that, combined with the observed flying-fox foraging behaviour, could contribute to Hendra virus exposure risk. While we found no significant risk-exposing difference in individual horse movement behaviour in this study, the prospect warrants further investigation, as does the broader role of animal behaviour and landscape utilisation on the transmission dynamics of Hendra virus.     

Predators in natural fragments: foraging ecology of wolves in British Columbia's central and north coast archipelago

Aim Predator–prey dynamics in fragmented areas may be influenced by spatial features of the landscape. Although little is known about these processes, an increasingly fragmented planet underscores the urgency to predict its consequences. Accordingly, our aim was to examine foraging behaviour of an apex mammalian predator, the wolf (Canis lupus), in an archipelago environment. Location Mainland and adjacent archipelago of British Columbia, Canada; a largely pristine and naturally fragmented landscape with islands of variable size and isolation. Methods We sampled 30 mainland watersheds and 29 islands for wolf faeces in summers 2000 and 2001 and identified prey remains. We examined broad geographical patterns and detailed biogeographical variables (area and isolation metrics) as they relate to prey consumed. For island data, we used Akaike Information Criteria to guide generalized linear regression model selection to predict probability of black‐tailed deer (main prey; Odocoileus hemionus) in faeces. Results Black‐tailed deer was the most common item in occurrence per faeces (63%) and occurrence per item (53%) indices, representing about 63% of mammalian biomass. Wolves consumed more deer on islands near the mainland (65% occurrence per item) than on the mainland (39%) and outer islands (45%), where other ungulates (mainland only) and small mammals replaced deer. On islands, the probability of detecting deer was influenced primarily by island distance to mainland (not by area or inter‐landmass distance), suggesting limited recolonization by deer from source populations as a causal mechanism. Main conclusions Although sampling was limited in time, consistent patterns among islands suggest that population dynamics in isolated fragments are less stable and can result in depletion of prey. This may have important implications in understanding predator–prey communities in isolation, debate regarding wolf–deer systems and logging in temperate rain forests, and reserve design.     

Genotyping faeces links individuals to their diet

The detection of individual variation in foraging behaviour within wild mammal populations requires large sample sizes and relies on the multifold re-sampling of individuals. However, limits for observational studies are posed by the rarity and nocturnal or otherwise elusive habits of many mammals. We propose that the detection of foraging variation within populations of mammals may be facilitated if conventional diet analysis from faeces is combined with DNA-based individual identification methods using "genetic fingerprinting" from faeces. We applied our approach to a coyote ( Canis latrans ) population, and showed how individuals may vary from one another in their diet profiles. Two main groups of coyotes were distinguished on the basis of their relative use of small mammals and "other vertebrates" as primary food sources, and these two groups were further subdivided on the basis of their relative use of "other vertebrates" and fruit as secondary food sources. We show that, unless a faecal sampling scheme is used that maximizes the number of different individuals included in a survey, individual foraging variation that is left unaccounted for may result in downwardly biased faecal diet diversity estimates. Our approach allows the re-sampling of individuals over time and space, and thus may be generally useful for the testing of optimal foraging theory hypotheses in mammals and also has conservation applications.     

Fine scale biologging of an inshore marine animal

We compared the results of two biologging techniques used to study the foraging behaviour of a colony of small inshore predators, little penguins (Eudyptula minor). The first technique involved the use of satellite transmitters and diving loggers deployed on separate individuals, which has been the conventional method of tracking the movements and behaviour of this species for > 10 years. The second technique combined a diving logger and a global positioning system (GPS) logger deployed on the same individual, which is similar to the biologging methods presently being developed and used for many other species. We then considered the value of each technique as a conservation tool operating at the small scale (foraging area < 5000 ha and duration < 1 day).We found that the separately deployed satellite transmitters significantly underestimated the penguins' foraging area size. However, the size of the foraging area and other foraging parameters, such as total distance travelled, were influenced by the degree of GPS location sub-sampling. Furthermore, only the combined diving and GPS loggers could confidently describe the diving behaviour of the penguins in relation to the sea floor and identify that they were using small areas of conservation interest (shipping channel) inside their foraging area.Hence, the method employed to assess habitat use at fine scales can influence conservation measures that rely upon the data collected. We suggest that researchers fast-track their adoption of high resolution multi-loggers for increased data confidence when tracking animals at a fine scale, but also consider the potential effect of sampling rate on the calculation of parameters of interest.     

Does foraging mode mould morphology in lacertid lizards?

Evolutionary changes in foraging style are often believed to require concurrent changes in a complex suite of morphological, physiological, behavioural and life-history traits. In lizards, species from families with a predominantly sit-and-wait foraging style tend to be more stocky and robust, with larger heads and mouths than species belonging to actively foraging families. Here, we test whether morphology and foraging behaviour show similar patterns of association within the family Lacertidae. We also examine the association of bite force abilities with morphology and foraging behaviour. Lacertid lizards exhibit considerable interspecific variation in foraging indices, and we found some evidence for a covariation between foraging style and body shape. However, the observed relationships are not always in line with the predictions. Also, the significance of the relationships varies with the evolutionary model used. Our results challenge the idea that foraging style is evolutionarily conservative and invariably associated with particular morphologies. It appears that the flexibility of foraging mode and its morphological correlates varies among lizard taxa.     

Strong temporal consistency in the individual foraging behaviour of Imperial Shags Phalacrocorax atriceps

Individual consistency in foraging behaviour can generate behavioural variability within populations and may, ultimately, lead to species diversification. However, individual‐based long‐term behavioural studies are particularly scarce in seabird species. Between 2008 and 2011, breeding Imperial Shags Phalacrocorax atriceps at the Punta León colony, Argentina, were tracked with GPS devices to evaluate behavioural consistency during their foraging trips. Within a breeding season, individuals were highly consistent in the maximum distances they reached from the shore and the colony, as well as in the time invested in flight and diving across consecutive days during early chick rearing. In addition, each individual had its specific foraging area distinct from the foraging area of other individuals. Comparing between early and late chick rearing in the same season, individuals were consistent, to a lesser degree, in the maximum distance they reached from the colony and the shore, increasing in consistency later on in the season. Within the season, females were more consistent than males in the maximum distance they moved from the colony and the shore, the sexes segregated in their foraging areas and individual females were segregated from one another. Twenty‐eight individuals tracked in different breeding seasons were marginally consistent in their trip durations and maximum distance reached from shore across seasons. Among seasons, foraging locations differed between sexes and among individual females. Individuals from this colony exhibited consistency over time in several aspects of foraging behaviour, which may be due to a combination of individual characteristics such as learning abilities, breeding experience or health, as well as targeted prey type and stability of the environment at this location.     

贺兰山马鹿冬季食性分析

2003年11月-2004年2月在宁夏贺兰山国家级自然保护区和内蒙古贺兰山国家级自然保护区,利用粪便显微组织学分析技术结合野外啃食调查对马鹿阿拉善亚种(Cervus elaphus alxaicus)冬季食性进行了研究.从7个沟系中一共收集了219堆马鹿粪便中捡拾粪粒,组成14个复合样本进行分析,其结果表明,灰榆(27.37%)、山杨(11.75%)、蒙古扁桃(9.83%)、金露梅(8.12%)、锦鸡儿(6.52%)等植物的当年枝和落叶以及禾本科草本植物(7.51%)是马鹿冬季主要食物,其中灰榆为大宗食物,针叶树种(杜松、油松、青海云杉)和其他草本植物所占比例均较小.马鹿对灰榆、山杨、蒙占扁桃、金露梅、锦鸡儿和杜松有正选择性;而对禾本科草本植物、油松和青海云杉有负选择性.马鹿对它们选择性的强弱顺序为:山杨＞杜松＞锦鸡儿＞蒙古扁桃＞金露梅＞灰榆＞禾本科草本植物＞油松＞青海云杉.马鹿取食乔木36.8%、灌木44.7%、禾本科草本植物8.0%和非禾本科草本植物10.5%,这4类植物的利用性与可利用性存在极显著差异,乔木和灌木的利用性高于可利用性;禾本科草本植物和非禾本科草本植物的利用性低于可利用性,说明马鹿的食物以木本植物镲为主,草本植物为辅.Spearman相关分析得出马鹿对食物的选择性与水分、灰分、粗蛋白、粗脂肪、粗纤维和无氮浸出物之间无明显的相关关系.被啃食植物中粗蛋白含量较高,蛋白质不是越冬马鹿的限制因子,而能量可能是影响冬季马鹿采食较为关键的因子.马鹿冬季采食策略主要是以最小的能量消耗获取最大的能量收益.     

Inter‐colony foraging area segregation quantified in small colonies of Adélie Penguins

Theoretical models on the movement of colonial animals predict that neighbouring colonies may segregate their foraging areas, and many seabird studies have reported the presence of such segregations. However, these studies have often lacked the appropriate null model to test the effect of neighbouring colonies on foraging areas, especially in small colonies or in short‐ranging species. Here, we examined the foraging areas of Adélie Penguins Pygoscelis adeliae from two neighbouring (2 km apart) colonies by using bird‐borne GPS loggers. The field study was conducted at Hukuro Cove colony (104 pairs) and Mizukuguri Cove colony (338 pairs) in Lützow‐Holm Bay, East Antarctica. We obtained GPS tracks for 504 foraging trips from 48 chick‐rearing Adélie Penguins and quantified the degree of overlap in the foraging areas between two colonies. We also produced simulated movement tracks by using correlated random‐walks assuming no inter‐colony competition and quantified the degree of overlap in the simulated foraging areas. Finally, we compared the results from real GPS tracks with those from simulated tracks to examine the effect of neighbouring colonies on Adélie Penguin movement. The results indicate that the degree of overlap was significantly smaller in real tracks than in simulated tracks. In real tracks, the foraging area of the smaller Hukuro Cove colony extended to the other side of the larger Mizukuguri Cove colony, unlike in simulated tracks. Consequently, we suggest that Adélie Penguins from two neighbouring colonies segregated their foraging areas and that the larger colony appeared to affect the foraging area of the smaller colony.     

Testing Global Positioning System Telemetry to Study Wolf Predation on Deer Fawns

ABSTRACT We conducted a pilot study to test the usefulness of Global Positioning System (GPS) collars for investigating wolf (Canis lupus) predation on white-tailed deer (Odocoileus virginianus) fawns. Using GPS collars with short location-attempt intervals on 5 wolves and 5 deer during summers 2002–2004 in northeastern Minnesota, USA, demonstrated how this approach could provide new insights into wolf hunting behavior of fawns. For example, a wolf traveled ≥1.5–3.0 km and spent 20–22 hours in the immediate vicinity of known fawn kill sites and ≥0.7 km and 8.3 hours at scavenging sites. Wolf travel paths indicated that wolves intentionally traveled into deer summer ranges, traveled ≥0.7–4.2 km in such ranges, and spent <1–22 hours per visit. Each pair of 3 GPS-collared wolf pack members were located together for ≤6% of potential locations. From GPS collar data, we estimated that each deer summer range in a pack territory containing 5 wolves ≥1 year old and hunting individually would be visited by a wolf on average every 3–5 days. This approach holds great potential for investigating summer hunting behavior of wolves in areas where direct observation is impractical or impossible.     

Individual differences in searching behaviour and spatial foraging consistency in a central place marine predator

Consistent intra‐population variability in foraging behaviour is found among a wide range of taxa. Such foraging specialisations are common among marine vertebrates, yet it is not clear how individuals repeatedly locate prey or foraging sites at ocean‐wide scales. Using GPS and time‐depth loggers we studied the fine‐scale foraging behaviour of central‐place northern gannets Morus bassanus at two large colonies. First, we estimated the degree of consistency in individual foraging routes and sites across repeated trips. Second, we tested for individual differences in searching behaviour in response to environmental covariates using reaction norms, estimated from mixed effect models. Adult gannets tracked over multiple foraging trips showed repeatable between‐individual differences in terminal points and departure angles of foraging trips, but low repeatability in trip duration and trip length. Importantly, individual birds showed highly repeatable dive locations, with consistently different environmental conditions (such as copepod abundance), suggesting a high degree of foraging site specialisation. Gannets also showed between‐individual differences in searching behaviour along environmental gradients, such that individuals intensified searching under different conditions. Together these results suggest that widespread individual foraging consistency may represent specialisation and be linked with individual responses to environmental conditions. Such divergent searching behaviour could provide a mechanism by which consistent foraging behaviour arises and is maintained among animals that forage across large spatial scales.     

Habitat�Cperformance relationships: finding the right metric at a given spatial scale

The field of habitat ecology has been muddled by imprecise terminology regarding what constitutes habitat, and how importance is measured through use, selection, avoidance and other bio-statistical terminology. Added to the confusion is the idea that habitat is scale-specific. Despite these conceptual difficulties, ecologists have made advances in understanding ‘how habitats are important to animals’, and data from animal-borne global positioning system (GPS) units have the potential to help this clarification. Here, we propose a new conceptual framework to connect habitats with measures of animal performance itself—towards assessing habitat–performance relationship (HPR). Long-term studies will be needed to estimate consequences of habitat selection for animal performance. GPS data from wildlife can provide new approaches for studying useful correlates of performance that we review. Recent examples include merging traditional resource selection studies with information about resources used at different critical life-history events (e.g. nesting, calving, migration), uncovering habitats that facilitate movement or foraging and, ultimately, comparing resources used through different life-history strategies with those resulting in death. By integrating data from GPS receivers with other animal-borne technologies and combining those data with additional life-history information, we believe understanding the drivers of HPRs will inform animal ecology and improve conservation.     

Individual differences in reproductive costs examined using multi-state methods

1.?Trade-offs among life-history traits are common because individuals have to partition limited resources between multiple traits. Reproductive costs are generally assumed to be high, resulting in reduced survival and fecundity in the following year. However, it is common to find positive rather than negative correlations between life-history traits. 2.?Here, we use a data set from the individual-based study of red deer on the Isle of Rum to examine how these costs vary between individuals and at different ages, using multi-state mark-recapture methodology. 3.?Females that had reproduced frequently in the past incurred lower costs of reproduction in terms of survival in the following year and were more likely to reproduce in two consecutive years. Older individuals and those that had not reproduced frequently exhibited higher costs. 4.?These results highlight the importance of considering heterogeneity and individual quality when examining trade-offs and demonstrate the effectiveness of using detailed long-term data sets to explore life-history strategies using multi-state mark-recapture models.     

Foraging of lynxes in a managed boreal-alpine environment

Foraging of Eurasian lynxes Lynx lynx was studied with telemetry and snow tracking in central Norway. In all habitats and at all seasons, medium-sized ungulates (roe deer Capreolus capreolus , reindeer Rangifer tarandus and domestic sheep Ovis aries) dominated the diet (81% of ingested biomass estimated from faeces). Mountain hares Lepus timidus and galliform birds comprised the remainder of the diet (15% and 3%, respectively). Lynxes with different life history status did not differ in prey choice, but adult males utilised carcasses of ungulate prey considerably less (16% of the edible parts) than did females with offspring (80%) and subadults (58%.). Forest habitats in lowlands and adjacent to cultivated fields were the most favourable foraging habitats (indexed as the prey encounter rate per km lynx track) primarily owing to the presence of roe deer. Two family groups tracked in winter killed 0.2 ungulate per day. The importance of agricultural land as a foraging habitat and the dominance of livestock in the diet in remoter areas indicate that the lynx has responded to agriculture and reindeer husbandry during the past century by switching from smaff game to ungulates.     

Feedback effects of chronic browsing on life-history traits of a large herbivore

1. Increasing ungulate populations are affecting vegetation negatively in many areas, but few studies have assessed the long-term effects of overbrowsing on individual life-history traits of ungulates. 2. Using an insular population of white-tailed deer (Odocoileus virginianus Zimmermann; Anticosti, Québec, Canada) introduced in 1896, and whose density has remained high since the first evidence of severe browsing in the 1930s, we investigated potential feedbacks of long-term and heavy browsing on deer life-history traits. 3. We assessed whether chronic browsing contributed to a decline of the quality of deer diet in early autumn during the last 25 years, and evaluated the impacts of reduced diet quality on deer body condition and reproduction. 4. Rumen nitrogen content declined 22% between two time periods, 1977-79 and 2002-04, indicating a reduction in diet quality. 5. After accounting for the effects of year within the time period, age and date of harvest in autumn, peak body mass of both sexes declined between the two time periods. At the end of November, males were on average 12% heavier and adult does 6% heavier in 1977-79 than in 2002-04. Hind foot length did not vary between time periods. 6. The probability of conception increased 15% between the two time periods, but litter size at ovulation declined 7%, resulting in a similar total number of ovulations in 2002-04 and in 1977-79. 7. Our results suggest that following a decline in diet quality, white-tailed deer females modified their life-history strategies to maintain reproduction at the expense of growth. 8. Deer appear to tolerate drastic reductions in diet quality by modifying their life history traits, such as body mass and reproduction, before a reduction in density is observed. Such modifications may contribute to maintain high population density of large herbivores following population irruption.     

Ranging behaviour and excursions of female roe deer during the rut

Anecdotal evidence has suggested that, during the rutting period, female roe deer may undertake short excursions, outside of their normal home range, possibly to mate with a reproductive partner. To address this question, we analysed the ranging behaviour of 27 female roe deer Capreolus capreolus, equipped with GPS collars, inhabiting a fragmented landscape in France. We compared female movements during the rutting period with a non-rutting period over two summers using a recently published approach. Search intensity and home range size were significantly greater during the rutting period. The difference in home range size between the two periods was significantly greater in 2006 compared to 2005 and in open compared to closed habitat. We were not able to identify any influence of body mass on the difference in ranging behaviour between the two periods. Visual analysis of movement trajectories for 11 females revealed that 5 (45%) performed an excursion for a duration of a few hours to several days. We speculatively suggest that female rut excursions provide an opportunity for active mate choice in roe deer, where males are territorial, although we cannot rule out the alternative explanation that these movements are a means to avoid male harassment.     

Selectivity of harvesting differs between local and foreign roe deer hunters: trophy stalkers have the first shot at the right place

Harvesting represents a major source of mortality in many deer populations. The extent to which harvesting is selective for specific traits is important in order to understand contemporary evolutionary processes. In addition, since such data are frequently used in life-history studies, it is important to know the pattern of selectivity as a source of bias. Recently, it was demonstrated that different hunting methods were selected for different weights in red deer (Cervus elaphus), but little insight was offered into why this occurs. In this study, we show that foreign trophy stalkers select for larger antlers when hunting roe deer (Capreolus capreolus) than local hunters, but that close to half of the difference in selectivity was due to foreigners hunting earlier in the season and in locations with larger males. The relationship between antler size and age was nevertheless fairly similar based on whether deer was shot by foreign or local hunters.     

A Long-Term Assessment of the Variability in Winter Use of Dense Conifer Cover by Female White-Tailed Deer

Backgound

Long-term studies allow capture of a wide breadth of environmental variability and a broader context within which to maximize our understanding of relationships to specific aspects of wildlife behavior. The goal of our study was to improve our understanding of the biological value of dense conifer cover to deer on winter range relative to snow depth and ambient temperature.

Methodology/Principal Findings

We examined variation among deer in their use of dense conifer cover during a 12-year study period as potentially influenced by winter severity and cover availability. Female deer were fitted with a mixture of very high frequency (VHF, n = 267) and Global Positioning System (GPS, n = 24) collars for monitoring use of specific cover types at the population and individual levels, respectively. We developed habitat composites for four study sites. We fit multinomial response models to VHF (daytime) data to describe population-level use patterns as a function of snow depth, ambient temperature, and cover availability. To develop alternative hypotheses regarding expected spatio-temporal patterns in the use of dense conifer cover, we considered two sets of competing sub-hypotheses. The first set addressed whether or not dense conifer cover was limiting on the four study sites. The second set considered four alternative sub-hypotheses regarding the potential influence of snow depth and ambient temperature on space use patterns. Deer use of dense conifer cover increased the most with increasing snow depth and most abruptly on the two sites where it was most available, suggestive of an energy conservation strategy. Deer use of dense cover decreased the most with decreasing temperatures on the sites where it was most available. At all four sites deer made greater daytime use (55 to >80% probability of use) of open vegetation types at the lowest daily minimum temperatures indicating the importance of thermal benefits afforded from increased exposure to solar radiation. Date-time plots of GPS data (24 hr) allowed us to explore individual diurnal and seasonal patterns of habitat use relative to changes in snow depth. There was significant among-animal variability in their propensity to be found in three density classes of conifer cover and other open types, but little difference between diurnal and nocturnal patterns of habitat use.

Conclusions/Significance

Consistent with our findings reported elsewhere that snow depth has a greater impact on deer survival than ambient temperature, herein our population-level results highlight the importance of dense conifer cover as snow shelter rather than thermal cover. Collectively, our findings suggest that maximizing availability of dense conifer cover in an energetically beneficial arrangement with quality feeding sites should be a prominent component of habitat management for deer.     

Correlation between Olfactory Responses, Dispersal Tendencies, and Life-history Traits of the Predatory Mite Neoseiulus Womersleyi (Acari: Phytoseiidae) of Eight Local Populations

To investigate the relationship between foraging behavior and life-history traits of the predatory mite Neoseiulus womersleyi, the olfactory responses, dispersal ratios from a prey patch, predation rates, fecundity, and developmental times in eight local populations of N. womersleyi were investigated. Significant differences among local populations were found in all these traits except fecundity. None of the life-history traits correlated with foraging behavior. A significant positive correlation was found only between the olfactory response and the dispersal ratio. These results suggested that predatory mites with low olfactory responses would stay in a prey patch longer than predatory mites with high olfactory responses.